Microsoft



Name of Journal: World Journal of RadiologyESPS Manuscript NO: 30316Manuscript Type: Original ArticleBasic StudyCystic lesions of peripheral nerves: Are we missing the diagnosis of the intraneural ganglion cyst?Panwar J et al. Intraneural ganglion cyst of peripheral nervesJyoti Panwar, Anil Mathew, Binu P ThomasJyoti Panwar, Department of Radiology, Christian Medical College, Vellore 632004, IndiaJyoti Panwar, Joint Department of Medical Imaging, University Health Network, University of Toronto, Toronto, M5G 2N2, Ontario, CanadaAnil Mathew, Binu P Thomas, Department of Hand Surgery and Leprosy Reconstructive Surgery, Christian Medical College, Vellore 632004, IndiaAuthor contributions: Panwar J and Mathew A participated in the conception, acquisition, analysis, interpretation of the data and drafted the initial manuscript; Panwar J was the guarantor and designed the study; Thomas BP revised the article critically for important intellectual content; Language revision and final approval of the version of the article was done by Mathew A and Thomas BP.Institutional review board statement: The study was reviewed and approved by the Institutional review board, Christian Medical College, Vellore, rmed consent statement: Not applicable given the retrospective design of our study.Conflict-of-interest statement: There are no conflicts of interest to report.Data sharing statement: No additional data are available.Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: source: Invited manuscriptCorrespondence to: Jyoti Panwar, MD, FRCR, Musculoskeletal Radiology Fellow, Joint Department of Medical Imaging, University Health Network, University of Toronto, 585 University Avenue, Toronto, M5G 2N2, Ontario, Canada. drjyoticmch@Telephone: +1-416-3403372Received: September 26, 2016Peer-review started: September 28, 2016First decision: October 20, 2016Revised: January 17, 2017Accepted: March 16, 2017Article in press: Published online: AbstractAIMTo highlight the salient magnetic resonance imaging (MRI) features of the intraneural ganglion cyst (INGC) of various peripheral nerves for their precise diagnosis and to differentiate them from other intra and extra-neural cystic lesions.METHODSA retrospective analysis of the magnetic resonance (MR) images of a cohort of 245 patients presenting with nerve palsy involving different peripheral nerves was done. MR images were analyzed for the presence of a nerve lesion, and if found, it was further characterized as solid or cystic. The serial axial, coronal and sagittal MR images of the lesions diagnosed as INGC were studied for their pattern and the anatomical extent along the course of the affected nerve and its branches. Its relation to identifiable anatomical landmarks, intra-articular communication and presence of denervation changes in the muscles supplied by involved nerve was also studied.RESULTSA total of 45 cystic lesions in the intra or extraneural locations of the nerves were identified from the 245 MR scans done for patients presenting with nerve palsy. Out of these 45 cystic lesions, 13 were diagnosed to have INGC of a peripheral nerve on MRI. The other cystic lesions included extraneural ganglion cyst, paralabral cyst impinging upon the suprascapular nerve, cystic schwannoma and nerve abscesses related to Hansen’s disease involving various peripheral nerves. Thirteen lesions of INGC were identified in 12 patients. Seven of these affected the common peroneal nerve with one patient having a bilateral involvement. Two lesions each were noted in the tibial and suprascapular nerves, and one each in the obturator and proximal sciatic nerve. An intra-articular connection along the articular branch was demonstrated in 12 out of 13 lesions. Varying stages of denervation atrophy of the supplied muscles of the affected nerves were seen in 7 cases. Out of these 13 lesions in 12 patients, 6 underwent surgery.CONCLUSIONINGC is an important cause of reversible mono-neuropathy if diagnosed early and surgically treated. Its classic MRI pattern differentiates it from other lesions of the peripheral nerve and aid in its therapeutic planning. In each case, the joint connection has to be identified preoperatively, and the same should be excised during surgery to prevent further cyst recurrence.Key words: Ganglion cyst; Intra-neural; Magnetic resonance imaging; Peripheral nerves; Extra-neural? The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.Core tip: This is a retrospective study to emphasize the characteristic magnetic resonance imaging (MRI) features of the intraneural ganglion cyst (INGC) of the peripheral nerves. The radiologist should recognize the classic MRI pattern of the INGC, its joint connection and imaging anatomy of the involved nerve. This would be helpful to surgeons and will aid complete removal of the cyst, prevention of recurrence and improved patient outcomes. Both the radiologists and surgeons should also be able to differentiate this entity from a neurogenic lesion and extra-neural ganglion cyst which can also have joint connection. Panwar J, Mathew A, Thomas BP. Cystic lesions of peripheral nerves: Are we missing the diagnosis of the intraneural ganglion cyst? World J Radiol 2017; In pressINTRODUCTIONPatients presenting with thickened peripheral nerves and nerve palsy are often diagnosed as Hansen’s disease (HD) in endemic areas when other diagnostic tests come back inconclusive[1-4]. These patients may be thus treated with long term empirical multi-drug therapy (MDT) for the same ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"p4q3dobi","properties":{"unsorted":true,"formattedCitation":"[2]","plainCitation":"[2]"},"citationItems":[{"id":105,"uris":[""],"uri":[""],"itemData":{"id":105,"type":"article-journal","title":"Global leprosy situation, 2005","container-title":"Relevé ?pidémiologique Hebdomadaire / Section D'hygiène Du Secrétariat De La Société Des Nations = Weekly Epidemiological Record / Health Section of the Secretariat of the League of Nations","page":"289-295","volume":"80","issue":"34","source":"PubMed","ISSN":"0049-8114","note":"PMID: 16149384","journalAbbreviation":"Wkly. Epidemiol. Rec.","language":"eng, fre","author":[{"literal":"World Health Organization"}],"issued":{"date-parts":[["2005",8,26]]},"PMID":"16149384"}}],"schema":""} [3-6]. An intraneural ganglion cyst (INGC) is a non-neoplastic mucinous cyst within the epineurium of a nerve and commences from an adjoining joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"h6QtEyXL","properties":{"unsorted":true,"formattedCitation":"{\\rtf [3\\uc0\\u8211{}5]}","plainCitation":"[3–5]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":123,"uris":[""],"uri":[""],"itemData":{"id":123,"type":"article-journal","title":"Peroneal intraneural ganglia. Part I. Techniques for successful diagnosis and treatment","container-title":"Neurosurgical Focus","page":"E16","volume":"22","issue":"6","source":"PubMed","abstract":"The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.","ISSN":"1092-0684","note":"PMID: 17613207","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Rock","given":"Michael G."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2007"]]},"PMID":"17613207"}}],"schema":""} [7–13]. These cysts are filled with a mucinous material which is walled off by a fibrous layer ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"h6QtEyXL","properties":{"unsorted":true,"formattedCitation":"{\\rtf [3\\uc0\\u8211{}5]}","plainCitation":"[3–5]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":123,"uris":[""],"uri":[""],"itemData":{"id":123,"type":"article-journal","title":"Peroneal intraneural ganglia. Part I. Techniques for successful diagnosis and treatment","container-title":"Neurosurgical Focus","page":"E16","volume":"22","issue":"6","source":"PubMed","abstract":"The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.","ISSN":"1092-0684","note":"PMID: 17613207","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Rock","given":"Michael G."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2007"]]},"PMID":"17613207"}}],"schema":""} [7–9]. As these cysts expand within the epineurium, they displace and compress the adjacent nerve fascicles leading to pain, paresthesia, tingling and muscle paralysis in the distribution of the involved nerve ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"BJFxpyfP","properties":{"formattedCitation":"[3]","plainCitation":"[3]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}}],"schema":""} [14,15]. It may follow trivial trauma to the joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"jQtxkeO9","properties":{"formattedCitation":"[3]","plainCitation":"[3]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}}],"schema":""} [7]. The clinical evaluation of an involved nerve will show thickening if superficial and a variable degree of sensory-motor disturbance along its distribution ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"Dxed5608","properties":{"formattedCitation":"[6]","plainCitation":"[6]"},"citationItems":[{"id":129,"uris":[""],"uri":[""],"itemData":{"id":129,"type":"article-journal","title":"Intraneural ganglion cyst of the peroneal nerve in a four-year-old girl: a case report","container-title":"Journal of Pediatric Orthopedics","page":"944-946","volume":"27","issue":"8","source":"PubMed","abstract":"Intraneural ganglion cysts of the peroneal nerve are rare, usually occurring in adult men with a typical presentation of knee or proximal leg pain preceding motor weakness and/or sensory disturbances in the peroneal nervous distribution. A history of knee trauma and a palpable mass of the lateral knee in the region of the peroneal nerve are common. We present the unusual case of an intraneural ganglion cyst of the peroneal nerve in a 4-year-old girl. Although extremely rare in the pediatric population, the condition should be considered in the differential diagnosis of children presenting with new-onset foot deformities, foot drop, or clinical examinations consistent with a peroneal nerve lesion. Surgical treatment consisting of ganglion decompression with exploration and ligation of the articular branch of the peroneal nerve may result in improved functional recovery in the pediatric population compared with the adult population. Greater access to magnetic resonance imaging may allow diagnosis of cases that were not previously identified.","DOI":"10.1097/BPO.0b013e3181558c05","ISSN":"0271-6798","note":"PMID: 18209620","shortTitle":"Intraneural ganglion cyst of the peroneal nerve in a four-year-old girl","journalAbbreviation":"J Pediatr Orthop","language":"eng","author":[{"family":"Johnston","given":"Joshua A."},{"family":"Lyne","given":"Dennis E."}],"issued":{"date-parts":[["2007",12]]},"PMID":"18209620"}}],"schema":""} [13-15]. This presentation of variable motor palsy and sensory symptoms of acute onset may mimic other conditions like lumbosacral disc disease, pelvic or shoulder pathologies and may delay early detection ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"2BdlWbOI","properties":{"formattedCitation":"[7]","plainCitation":"[7]"},"citationItems":[{"id":131,"uris":[""],"uri":[""],"itemData":{"id":131,"type":"article-journal","title":"Pure peroneal intraneural ganglion cyst ascending along the sciatic nerve","container-title":"Turkish Neurosurgery","page":"254-258","volume":"21","issue":"2","source":"PubMed","abstract":"Peroneal nerve entrapment is most commonly seen in the popliteal fossa. It is rarely caused by a ganglion. Intraneural ganglia, although uncommon and seldom cause serious complications, are well recognized and most commonly affect the common peroneal (lateral popliteal) nerve. Ganglionic cysts developing in the sheath of a peripheral nerve or joint capsule may cause compression neuropathy. The differential diagnosis should involve L5 root lesions, posttraumatic intraneural hemorrhage, nerve compression near the tendinous arch located at the fibular insertion of the peroneal longus muscle and nerve-sheath tumors. We present a unique case of a pure intraneural ganglion of the common peroneal nerve ascending along the sciatic nerve. This case underscores the importance of consideration of an intraneural ganglion cyst with sciatic nerve involvement.","DOI":"10.5137/1019-5149.JTN.2660-09.1","ISSN":"1019-5149","note":"PMID: 21534214","journalAbbreviation":"Turk Neurosurg","language":"eng","author":[{"family":"Tehli","given":"Ozkan"},{"family":"Celikmez","given":"Ramazan Cengiz"},{"family":"Birgili","given":"Baris"},{"family":"Solmaz","given":"Ilker"},{"family":"Celik","given":"Ertugrul"}],"issued":{"date-parts":[["2011"]]},"PMID":"21534214"}}],"schema":""} [14,16]. The diagnosis of INGC can be confirmed by imaging techniques like magnetic resonance imaging (MRI) and high resolution ultrasonography (HRUS) ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"05dof7gw","properties":{"formattedCitation":"{\\rtf [7\\uc0\\u8211{}9]}","plainCitation":"[7–9]"},"citationItems":[{"id":131,"uris":[""],"uri":[""],"itemData":{"id":131,"type":"article-journal","title":"Pure peroneal intraneural ganglion cyst ascending along the sciatic nerve","container-title":"Turkish Neurosurgery","page":"254-258","volume":"21","issue":"2","source":"PubMed","abstract":"Peroneal nerve entrapment is most commonly seen in the popliteal fossa. It is rarely caused by a ganglion. Intraneural ganglia, although uncommon and seldom cause serious complications, are well recognized and most commonly affect the common peroneal (lateral popliteal) nerve. Ganglionic cysts developing in the sheath of a peripheral nerve or joint capsule may cause compression neuropathy. The differential diagnosis should involve L5 root lesions, posttraumatic intraneural hemorrhage, nerve compression near the tendinous arch located at the fibular insertion of the peroneal longus muscle and nerve-sheath tumors. We present a unique case of a pure intraneural ganglion of the common peroneal nerve ascending along the sciatic nerve. This case underscores the importance of consideration of an intraneural ganglion cyst with sciatic nerve involvement.","DOI":"10.5137/1019-5149.JTN.2660-09.1","ISSN":"1019-5149","note":"PMID: 21534214","journalAbbreviation":"Turk Neurosurg","language":"eng","author":[{"family":"Tehli","given":"Ozkan"},{"family":"Celikmez","given":"Ramazan Cengiz"},{"family":"Birgili","given":"Baris"},{"family":"Solmaz","given":"Ilker"},{"family":"Celik","given":"Ertugrul"}],"issued":{"date-parts":[["2011"]]},"PMID":"21534214"}},{"id":137,"uris":[""],"uri":[""],"itemData":{"id":137,"type":"article-journal","title":"Ultrasound diagnosis of an intraneural ganglion cyst of the peroneal nerve. Case report","container-title":"Journal of Neurosurgery","page":"538-540","volume":"76","issue":"3","source":"PubMed","abstract":"The authors present the case of an intraneural ganglion cyst of the peroneal nerve. The cyst was diagnosed by means of ultrasound, which also gave an exact definition of its size and location, confirmed at operation. Some controversial aspects of these lesions are discussed.","DOI":"10.3171/jns.1992.76.3.0538","ISSN":"0022-3085","note":"PMID: 1310730","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Leijten","given":"F. S."},{"family":"Arts","given":"W. F."},{"family":"Puylaert","given":"J. B."}],"issued":{"date-parts":[["1992",3]]},"PMID":"1310730"}},{"id":141,"uris":[""],"uri":[""],"itemData":{"id":141,"type":"article-journal","title":"The MRI appearance of cystic lesions around the knee","container-title":"Skeletal Radiology","page":"187-209","volume":"33","issue":"4","source":"PubMed","abstract":"This review presents a comprehensive illustrated overview of the wide variety of cystic lesions around the knee. The aetiology, clinical presentation, MRI appearances and differential diagnosis are discussed. Bursae include those related to the patella as well as pes anserine, tibial collateral ligament, semimembranosus-tibial collateral ligament, iliotibial and fibular collateral ligament-biceps femoris. The anatomical extension, imaging features and clinical significance of meniscal cysts are illustrated. Review of ganglia includes intra-articular, extra-articular, intraosseous and periosteal ganglia, highlighting imaging findings and differential diagnoses. The relationship between proximal tibiofibular joint cysts and intraneural peroneal nerve ganglia is discussed. Intraosseous cystic lesions, including insertional and degenerative cysts, as well as lesions mimicking cysts of the knee are described and illustrated. Knowledge of the location, characteristic appearance and distinguishing features of cystic masses around the knee as well as potential imaging pitfalls such as normal anatomical recesses and atypical cyst contents on MR imaging aids in allowing a specific diagnosis to be made. This will prevent unnecessary additional investigations and determine whether intra-articular surgery or conservative management is appropriate.","DOI":"10.1007/s00256-003-0741-y","ISSN":"0364-2348","note":"PMID: 14991250","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"McCarthy","given":"Catherine L."},{"family":"McNally","given":"Eugene G."}],"issued":{"date-parts":[["2004",4]]},"PMID":"14991250"}}],"schema":""} [14–19]. The nerve paralysis is usually reversible if the nerve is surgically decompressed early. Its articular connection should be identified and disconnected during surgery to prevent recurrence ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"I3IK6bIS","properties":{"formattedCitation":"{\\rtf [7\\uc0\\u8211{}10]}","plainCitation":"[7–10]"},"citationItems":[{"id":131,"uris":[""],"uri":[""],"itemData":{"id":131,"type":"article-journal","title":"Pure peroneal intraneural ganglion cyst ascending along the sciatic nerve","container-title":"Turkish Neurosurgery","page":"254-258","volume":"21","issue":"2","source":"PubMed","abstract":"Peroneal nerve entrapment is most commonly seen in the popliteal fossa. It is rarely caused by a ganglion. Intraneural ganglia, although uncommon and seldom cause serious complications, are well recognized and most commonly affect the common peroneal (lateral popliteal) nerve. Ganglionic cysts developing in the sheath of a peripheral nerve or joint capsule may cause compression neuropathy. The differential diagnosis should involve L5 root lesions, posttraumatic intraneural hemorrhage, nerve compression near the tendinous arch located at the fibular insertion of the peroneal longus muscle and nerve-sheath tumors. We present a unique case of a pure intraneural ganglion of the common peroneal nerve ascending along the sciatic nerve. This case underscores the importance of consideration of an intraneural ganglion cyst with sciatic nerve involvement.","DOI":"10.5137/1019-5149.JTN.2660-09.1","ISSN":"1019-5149","note":"PMID: 21534214","journalAbbreviation":"Turk Neurosurg","language":"eng","author":[{"family":"Tehli","given":"Ozkan"},{"family":"Celikmez","given":"Ramazan Cengiz"},{"family":"Birgili","given":"Baris"},{"family":"Solmaz","given":"Ilker"},{"family":"Celik","given":"Ertugrul"}],"issued":{"date-parts":[["2011"]]},"PMID":"21534214"}},{"id":137,"uris":[""],"uri":[""],"itemData":{"id":137,"type":"article-journal","title":"Ultrasound diagnosis of an intraneural ganglion cyst of the peroneal nerve. Case report","container-title":"Journal of Neurosurgery","page":"538-540","volume":"76","issue":"3","source":"PubMed","abstract":"The authors present the case of an intraneural ganglion cyst of the peroneal nerve. The cyst was diagnosed by means of ultrasound, which also gave an exact definition of its size and location, confirmed at operation. Some controversial aspects of these lesions are discussed.","DOI":"10.3171/jns.1992.76.3.0538","ISSN":"0022-3085","note":"PMID: 1310730","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Leijten","given":"F. S."},{"family":"Arts","given":"W. F."},{"family":"Puylaert","given":"J. B."}],"issued":{"date-parts":[["1992",3]]},"PMID":"1310730"}},{"id":141,"uris":[""],"uri":[""],"itemData":{"id":141,"type":"article-journal","title":"The MRI appearance of cystic lesions around the knee","container-title":"Skeletal Radiology","page":"187-209","volume":"33","issue":"4","source":"PubMed","abstract":"This review presents a comprehensive illustrated overview of the wide variety of cystic lesions around the knee. The aetiology, clinical presentation, MRI appearances and differential diagnosis are discussed. Bursae include those related to the patella as well as pes anserine, tibial collateral ligament, semimembranosus-tibial collateral ligament, iliotibial and fibular collateral ligament-biceps femoris. The anatomical extension, imaging features and clinical significance of meniscal cysts are illustrated. Review of ganglia includes intra-articular, extra-articular, intraosseous and periosteal ganglia, highlighting imaging findings and differential diagnoses. The relationship between proximal tibiofibular joint cysts and intraneural peroneal nerve ganglia is discussed. Intraosseous cystic lesions, including insertional and degenerative cysts, as well as lesions mimicking cysts of the knee are described and illustrated. Knowledge of the location, characteristic appearance and distinguishing features of cystic masses around the knee as well as potential imaging pitfalls such as normal anatomical recesses and atypical cyst contents on MR imaging aids in allowing a specific diagnosis to be made. This will prevent unnecessary additional investigations and determine whether intra-articular surgery or conservative management is appropriate.","DOI":"10.1007/s00256-003-0741-y","ISSN":"0364-2348","note":"PMID: 14991250","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"McCarthy","given":"Catherine L."},{"family":"McNally","given":"Eugene G."}],"issued":{"date-parts":[["2004",4]]},"PMID":"14991250"}},{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}}],"schema":""} [14,15,20].MATERIALS AND METHODSThis study was approved by the institutional review board, and consent from all patients was waived. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Patient selectionAll MR images of the patients presenting with peripheral nerve palsy from July 2005 to December 2015 were selected from our radiology database. A computer search was also performed for the term “ganglion cyst” of proximal tibiofibular (PTF) joint, “paralabral cyst”, “intraneural ganglion cyst”, ganglion cyst of knee, shoulder, elbow and hip joints in the radiology information system (RIS) database. From this cohort of images, all nerves with solid and cystic lesions were first identified. Among the cystic lesions thus identified the images showing elongated cystic lesions of the peripheral nerve along its course and those that fulfilled one or more of the inclusion criteria for INGC (Table 1) were selected. Thirteen such lesions were identified and their MR images, available clinical details, follow-up information and histopathology were reviewed by a musculoskeletal radiologist.Image acquisitionImages were obtained with by a variety of MRI scanners, including 0.5-T units (n = 1; NT Intera, Philips Healthcare, Netherland), 1.5-T units (n = 2; Magnetom Avanto, Siemens Healthcare, Erlangen, Germany), and 3-T units (n = 6; Intera Achieva, Philips Healthcare, Best, Netherland). The imaging protocol and parameters also varied from case to case. The images were acquired in all three orthogonal planes including axial, coronal and sagittal in all patients. Fast spin echo (FSE) T2-weighted axial, coronal and sagittal images with or without fat suppression and T1-weighted axial images were done in all patients scanned in the 0.5-T and 1.5-T MR scanner. Proton density (PD) fat suppressed axial, coronal and sagittal images along with T1-weighted axial images were available for all cases done in the 3-T MR scanner.Image analysisThe MR images of all cystic lesions were reviewed by a musculoskeletal radiologist on a General Electric? (GE) picture archiving and communication system (PACS) workstation. The images were evaluated, specifically looking for the presence of the following features: (1) the presence of T2/fat suppressed (T2 or proton density) hyperintense cystic lesion, along the nerve or its branches; (2) the exact anatomical site, intra or extra-neural location; (3) any communication to the adjacent joint along an articular branch; (4) the morphology of the cyst in terms of shape and pattern; and (5) denervation changes of the affected muscle compartment was also assessed.RESULTSClinical findingsThe mean age of the patients was 38.2 years (range 9-67 years). There were ten males and two females in this series. Pain along the distribution of the involved nerve and weakness of muscles supplied by the same were the most common presenting symptoms and was present in all 12 patients. One lesion was asymptomatic. The same was discovered incidentally on the contralateral side during routine imaging. Four cases of INGCs involving the common peroneal nerve (CPN) were primarily diagnosed as cystic schwannoma and one suprascapular and obturator nerves lesion were labeled as a paralabral and obturator foramen ganglion cysts respectively. However, no labral tear was seen on MR imaging in either case. Of the 13 lesions, 6 cysts were excised or decompressed by surgery. The articular connection was excised during surgery in 4 out of 5 patients with CPN (PTF joint connection) and in one patient with suprascapular nerve (AC joint connection) involvement. The other cystic lesions included: 9 cases of extraneural ganglion cyst (ENGC) of PTF joint in close relation with CPN, one ENGC of radio-humeral (elbow) joint impinging upon the deep branch of radial nerve, 6 cases of paralabral cyst impinging upon the suprascapular nerve, 8 cases of cystic schwannoma and 8 cases of nerve abscesses related to HD involving various peripheral nerves. Table 2 summarizes the clinical details of patients with cystic lesions related to and of the nerve.MRI findingsINGSs: An elongated multi-lobulated cystic lesion, oriented longitudinally along the course of the nerve was seen in all 13 INGC lesions. An extension of the cyst along the articular branch with intra-articular communication was demonstrated in 12 of these lesions (Figures 1 and 2). Out of the 13 lesions, 7 involved the peroneal nerve with one patient having bilateral lesions of which one side was asymptomatic. The Tibial (Figures 3-5) and suprascapular nerves (Figure 6) was involved in 2 patients each. One case each of the obturator (Figures 7, 8) and proximal sciatic nerves (Figures 9 and 10) were also identified. A variable extension of cysts along the branches of the parent nerve is also seen in 12 cases (Figures 1-5, 8 and 11). Varying stages of denervation of the supplied muscles are seen in 7 cases (Figures 3-5, 8 and 11). Six patients underwent surgical intervention and the diagnosis was histo-pathologically confirmed in them. The intraoperative images of one of these patients are shown in Figure 12. In one tibial nerve INGC, in addition to PTF joint connection, a second posterior knee joint connection was also noted (Figure 4). In four cases with CPN involvement, the INGC could also be seen extending distally for a variable length along the deep (Figures 2) and superficial peroneal (Figure 11) nerve branches. The obturator nerve cyst also extended along it’s anterior branch (Figure 8) the tibial nerve lesions extended along the branch to the popliteus and tibialis posterior muscles (Figure 3-5). Table 3 summarizes the MRI findings of INGC of the peripheral nerves in this series.Other cystic lesionsENGC: These are most commonly seen around the PTF joint in close relation with CPN and its branches. Its characteristic MR features are described in Figure 13 and its differentiation from INGC on imaging is illustrated in Figure 14 and summarized in Table 4. Cystic schwannoma: Schwannomas are the most common peripheral nerve sheath tumors ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"blarseDW","properties":{"formattedCitation":"[11]","plainCitation":"[11]"},"citationItems":[{"id":145,"uris":[""],"uri":[""],"itemData":{"id":145,"type":"article-journal","title":"[Multiple schwannoma of the sciatic nerve. Apropos of a case]","container-title":"Revue De Chirurgie Orthopédique Et Réparatrice De L'appareil Moteur","page":"632-635","volume":"85","issue":"6","source":"PubMed","abstract":"A case of multiple neurilemmoma at the sciatic nerve is presented. A 79 years old male reported as initial symptom the appearance of a mass at the popliteal fossa without any neurological impairment. The MRI showed numerous tumors along the that were no previously detected. The tumor was easy to remove without affecting the nerve. No neurologic alteration occurred at the postoperative period which confirms the good prognosis of this tumor.","ISSN":"0035-1040","note":"PMID: 10575727","journalAbbreviation":"Rev Chir Orthop Reparatrice Appar Mot","language":"fre","author":[{"family":"Martinez Algarra","given":"J. C."},{"family":"Gastaldi Rodrigo","given":"P."},{"family":"Palomares Talens","given":"E."}],"issued":{"date-parts":[["1999",10]]},"PMID":"10575727"}}],"schema":""} [21], mostly solid or heterogeneous solid tumors. However, cystic schwannomas of the peripheral nerve are uncommon ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"rngqGbK8","properties":{"formattedCitation":"[12]","plainCitation":"[12]"},"citationItems":[{"id":149,"uris":[""],"uri":[""],"itemData":{"id":149,"type":"article-journal","title":"Totally cystic schwannoma of the lumbar spine","container-title":"Orthopedics","page":"e679-682","volume":"36","issue":"5","source":"PubMed","abstract":"A schwannoma is a benign tumor arising from a schwann cell and occurs mainly in the nerve sheath in the intradural extramedullary region. Schwannomas have been well described as occurring in the lumbar spine, but total cystic degeneration of schwannomas is rarely reported. The authors describe the clinical and radiographic evaluations and treatment of a rare case of an intraextradural totally cystic schwannoma on the lumbar spine.Two patients reported a history of 6 to 12 months of pain accompanied by weakness in the lower extremities. On examination, 1 patient had bilateral lower-extremity muscle strength graded at 4/5, and magnetic resonance imaging revealed a cystic schwannoma (1.5 × 2.0 cm in the sagittal dimension) at L2-L3. The other patient had a right lower-extremity muscle strength graded at 3/5, and magnetic resonance imaging revealed a cystic schwannoma (2.0 × 3.0 cm in the sagittal dimension) at L4-L5. The patients underwent operative treatment, and the tumors were completely removed, as were the filum terminale adhered to the tumor. Pedicle screws were used to maintain stability of the lumbar spine. Gross examination of the tumors showed yellowish-white soft contents. Histologic examination confirmed that they were benign totally cystic schwannomas. Postoperatively, the patients' neurologic symptoms completely resolved.Cystic schwannomas can be diagnosed using preoperative magnetic resonance imaging. The filum terminale cut off the tumor walls did not cause the clinical symptoms in the 2 patients.","DOI":"10.3928/01477447-20130426-36","ISSN":"1938-2367","note":"PMID: 23672923","journalAbbreviation":"Orthopedics","language":"eng","author":[{"family":"Wu","given":"Desheng"},{"family":"Ba","given":"Zhaoyu"},{"family":"Huang","given":"Yufeng"},{"family":"Zhao","given":"Weidong"},{"family":"Shen","given":"Bin"},{"family":"Kan","given":"Heng"}],"issued":{"date-parts":[["2013",5]]},"PMID":"23672923"}}],"schema":""} [22,23] and may mimic other extra or intraneural cystic lesions. MR features of cystic schwannoma of CPN are illustrated in Figure 15.Paralabral cyst: Paralabral cysts of the shoulder joint are commonly seen in the middle age men and cause impingement of the suprascapular nerve. They are commonly located at the posterosuperior glenoid region, secondary to a labral tear. They can extend into the spinoglenoid notch and can cause compression of the suprascapular nerve (Figure 16).Nerve abscess related to HD: Granulomatous nerve lesions of HD may show central breakdown and abscess formation. These are relatively uncommon and are seen in the tuberculoid form of the leprosy (Figure 17).DISCUSSIONINGC is often referred to as a rare non-neoplastic mucinous cyst located within the epineurium of peripheral nerves and is closely related to an adjoining joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1ttCtB1Z","properties":{"formattedCitation":"{\\rtf [7\\uc0\\u8211{}11,20,24,25]}","plainCitation":"[7–11,20,24,25]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":121,"uris":[""],"uri":[""],"itemData":{"id":121,"type":"article-journal","title":"Ganglion cyst involvement of peripheral nerves","container-title":"Journal of Neurosurgery","page":"403-408","volume":"87","issue":"3","source":"PubMed","abstract":"Despite their benign histological appearance and the current literature composed primarily of case reports with favorable outcomes, ganglion cysts involving peripheral nerves (GCPNs) can cause permanent neurological deficits. The authors present a 27-year Louisiana State University Medical Center (LSUMC) experience with the surgical management of GCPNs. From 1968 to 1995, 27 patients were surgically treated for 27 cysts that involved nerves at nine locations. Cysts of the peroneal nerve were the most common, comprising 52% of the cases. Motor deficit, pain, and sensory changes were present in 83%, 78%, and 48% of cases, respectively. A history of acute trauma was noted in 22%. The mean follow-up duration in these cases was 61 months. Motor recovery was good in only 58% of cases and was related to the severity of the preoperative motor deficit. Pain resolved or was significantly improved in 89% of cases. Five patients underwent nine procedures before referral to LSUMC for treatment of recurrence of their ganglion cysts. None of these patients suffered recurrence after undergoing surgery at LSUMC. However, four additional patients (17%) experienced a total of six recurrences after undergoing their initial procedure. The mean time to recurrence for the patient group as a whole was 16 months. On the basis of their experience, the authors conclude that GCPNs can behave in an aggressive fashion. Patients should be counseled preoperatively about the potential for limited motor recovery and a significant chance for recurrence.","DOI":"10.3171/jns.1997.87.3.0403","ISSN":"0022-3085","note":"PMID: 9285606","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Harbaugh","given":"K. S."},{"family":"Tiel","given":"R. L."},{"family":"Kline","given":"D. G."}],"issued":{"date-parts":[["1997",9]]},"PMID":"9285606"}},{"id":123,"uris":[""],"uri":[""],"itemData":{"id":123,"type":"article-journal","title":"Peroneal intraneural ganglia. Part I. Techniques for successful diagnosis and treatment","container-title":"Neurosurgical Focus","page":"E16","volume":"22","issue":"6","source":"PubMed","abstract":"The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.","ISSN":"1092-0684","note":"PMID: 17613207","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Rock","given":"Michael G."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2007"]]},"PMID":"17613207"}},{"id":125,"uris":[""],"uri":[""],"itemData":{"id":125,"type":"article-journal","title":"Ganglia of the nerve. Presentation of two unusual cases, a review of the literature, and a discussion of pathogenesis","container-title":"Clinical Orthopaedics and Related Research","page":"135-144","issue":"113","source":"PubMed","abstract":"Two cases of intraneural ganglia are reported: the first reported involvement of the sciatic nerve and the first reported involvement of the tibial nerve in the tarsal tunnel. Both were successfully treated by excision with sparing the neural elements leading to neurological recovery. A review of the literature fails to reveal any consensus that lesions arise from normal synovial cavities. Incision, evacuation, and complete excision under magnification sparing neural elements gives satisfactory results. Excision of the nerve is not indicated. Pathologic examination suggests that the lesion arises by multicentric metaplasia of connective tissue elements of the nerve rather than by invasion.","ISSN":"0009-921X","note":"PMID: 172271","journalAbbreviation":"Clin. Orthop. Relat. Res.","language":"eng","author":[{"family":"Jacobs","given":"R. R."},{"family":"Maxwell","given":"J. A."},{"family":"Kepes","given":"J."}],"issued":{"date-parts":[["1975",12]]},"PMID":"172271"}},{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}},{"id":151,"uris":[""],"uri":[""],"itemData":{"id":151,"type":"article-journal","title":"Patterns of intraneural ganglion cyst descent","container-title":"Clinical Anatomy (New York, N.Y.)","page":"233-245","volume":"21","issue":"3","source":"PubMed","abstract":"On the basis of the principles of the unifying articular theory, predictable patterns of proximal ascent have been described for fibular (peroneal) and tibial intraneural ganglion cysts in the knee region. The mechanism underlying distal descent into the terminal branches of the fibular and tibial nerves has not been previously elucidated. The purpose of this study was to demonstrate if and when cyst descent distal to the articular branch-joint connection occurs in intraneural ganglion cysts to understand directionality of intraneural cyst propagation. In Part I, the clinical records and MRIs of 20 consecutive patients treated at our institution for intraneural ganglion cysts (18 fibular and two tibial) arising from the superior tibiofibular joint were retrospectively analyzed. These patients underwent cyst decompression and disconnection of the articular branch. Five of these patients developed symptomatic cyst recurrence after cyst decompression without articular branch disconnection which was done elsewhere prior to our intervention. In Part II, five additional patients with intraneural ganglion cysts (three fibular and two tibial) treated at other institutions without disconnection of the articular branch were compared. These patients in Parts I and II demonstrated ascent of intraneural cyst to differing degrees (12 had evidence of sciatic nerve cross-over). In addition, all of these patients demonstrated previously unrecognized MRI evidence of intraneural cyst extending distally below the level of the articular branch to the joint of origin: cyst within the proximal most portions of the deep fibular and superficial fibular branches in fibular intraneural ganglion cysts and descending tibial branches in tibial intraneural ganglion cysts. The patients in Part I had complete resolution of their cysts at follow-up MRI examination 1 year postoperatively. The patients in Part II had intraneural recurrences postoperatively within the articular branch, the parent nerve, and the terminal branches, although in three cases they were subclinical. The authors demonstrate that cyst descent distal to the take-off of the articular branch to the joint of origin occurs regularly in patients with fibular and tibial intraneural ganglion cysts. The authors believe that parent terminal branch descent follows ascent up the articular branch from an affected joint of origin. This mechanism for bidirectional flow explains cyst within terminal branches of the fibular and tibial nerves and is dependent on pressure fluxes and resistances. This new pattern is consistent with principles previously described in a unified (articular) theory, is generalizable to other intraneural ganglion cysts arising from joints, and has important implications for pathogenesis and treatment of these intraneural cysts.","DOI":"10.1002/ca.20614","ISSN":"1098-2353","note":"PMID: 18330922","journalAbbreviation":"Clin Anat","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Carmichael","given":"Stephen W."},{"family":"Wang","given":"Huan"},{"family":"Parisi","given":"Thomas J."},{"family":"Skinner","given":"John A."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",4]]},"PMID":"18330922"}},{"id":153,"uris":[""],"uri":[""],"itemData":{"id":153,"type":"article-journal","title":"Intraneural ganglion of the common peroneal nerve in a 4-year-old boy","container-title":"Journal of Child Neurology","page":"213-215","volume":"10","issue":"3","source":"PubMed","abstract":"The case history of a 4-year-old boy with an intraneural ganglion of the common peroneal nerve is presented. These lesions are rare, more commonly affect males, and typically present with a painful foot-drop. A mass is often palpable adjacent to the neck of the fibula. Our patient has made a good recovery after surgery.","ISSN":"0883-0738","note":"PMID: 7642891","journalAbbreviation":"J. Child Neurol.","language":"eng","author":[{"family":"Nicholson","given":"T. R."},{"family":"Cohen","given":"R. C."},{"family":"Grattan-Smith","given":"P. J."}],"issued":{"date-parts":[["1995",5]]},"PMID":"7642891"}}],"schema":""} [7–11,20,24,25]. These lesions commonly affect the peroneal nerve at the knee but can involve the other peripheral nerves ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"t7cea3b6j","properties":{"formattedCitation":"[7,26,27]","plainCitation":"[7,26,27]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":209,"uris":[""],"uri":[""],"itemData":{"id":209,"type":"article-journal","title":"Intraneural Ganglion Cyst of the Peripheral Nerve: Two Cases Report","container-title":"The Journal of the Korean Bone and Joint Tumor Society","page":"83","volume":"19","issue":"2","source":"CrossRef","DOI":"10.5292/jkbjts.2013.19.2.83","ISSN":"1226-4962, 2233-9841","shortTitle":"Intraneural Ganglion Cyst of the Peripheral Nerve","language":"ko","author":[{"family":"Kim","given":"Tai-Seung"},{"family":"Jo","given":"Young-Hoon"},{"family":"Paik","given":"Seung-Sam"},{"family":"Kim","given":"Sung-Jae"}],"issued":{"date-parts":[["2013"]]}}},{"id":155,"uris":[""],"uri":[""],"itemData":{"id":155,"type":"article-journal","title":"Intraneural ganglion in superficial radial nerve mimics de quervain tenosynovitis","container-title":"Journal of Wrist Surgery","page":"262-264","volume":"3","issue":"4","source":"PubMed","abstract":"Background?Intraneural ganglions in peripheral nerves of the upper extremity are extremely rare and poorly understood. Case Description?We report a patient with symptoms consistent with de Quervain tenosynovitis who was found to have an intraneural ganglion in the superficial radial nerve. The ganglion did not communicate with the wrist joint. We removed the intraneural ganglion, and the patient's symptoms resolved. At her 6-month postoperative follow-up, she remained asymptomatic.\nLITERATURE REVIEW: There is only one case report of intraneural ganglion in the superficial radial nerve. In that case, the patient had symptoms consistent with nerve irritation, including radiating pain and paresthesias. In contrast to that previous report, the patient in the current case had only localized pain, no paresthesias, and a physical exam consistent with de Quervain tenosynovitis. Clinical Relevance?This case demonstrates that an intraneural ganglion cyst can mimic the symptoms of de Quervain tenosynovitis without the more usual presentation of painful paresthesias.","DOI":"10.1055/s-0034-1384746","ISSN":"2163-3916","note":"PMID: 25364639\nPMCID: PMC4208964","journalAbbreviation":"J Wrist Surg","language":"eng","author":[{"family":"Haller","given":"Justin M."},{"family":"Potter","given":"Michael Q."},{"family":"Sinclair","given":"Micah"},{"family":"Hutchinson","given":"Douglas T."}],"issued":{"date-parts":[["2014",11]]},"PMID":"25364639","PMCID":"PMC4208964"}}],"schema":""} [7,26,27] as shown in this series. They usually present with mild symptoms and remain undiagnosed initially ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"220vkrjvau","properties":{"formattedCitation":"[27]","plainCitation":"[27]"},"citationItems":[{"id":155,"uris":[""],"uri":[""],"itemData":{"id":155,"type":"article-journal","title":"Intraneural ganglion in superficial radial nerve mimics de quervain tenosynovitis","container-title":"Journal of Wrist Surgery","page":"262-264","volume":"3","issue":"4","source":"PubMed","abstract":"Background?Intraneural ganglions in peripheral nerves of the upper extremity are extremely rare and poorly understood. Case Description?We report a patient with symptoms consistent with de Quervain tenosynovitis who was found to have an intraneural ganglion in the superficial radial nerve. The ganglion did not communicate with the wrist joint. We removed the intraneural ganglion, and the patient's symptoms resolved. At her 6-month postoperative follow-up, she remained asymptomatic.\nLITERATURE REVIEW: There is only one case report of intraneural ganglion in the superficial radial nerve. In that case, the patient had symptoms consistent with nerve irritation, including radiating pain and paresthesias. In contrast to that previous report, the patient in the current case had only localized pain, no paresthesias, and a physical exam consistent with de Quervain tenosynovitis. Clinical Relevance?This case demonstrates that an intraneural ganglion cyst can mimic the symptoms of de Quervain tenosynovitis without the more usual presentation of painful paresthesias.","DOI":"10.1055/s-0034-1384746","ISSN":"2163-3916","note":"PMID: 25364639\nPMCID: PMC4208964","journalAbbreviation":"J Wrist Surg","language":"eng","author":[{"family":"Haller","given":"Justin M."},{"family":"Potter","given":"Michael Q."},{"family":"Sinclair","given":"Micah"},{"family":"Hutchinson","given":"Douglas T."}],"issued":{"date-parts":[["2014",11]]},"PMID":"25364639","PMCID":"PMC4208964"}}],"schema":""} [27]. MRI plays an important role in diagnosing this condition and can reliably demonstrate the presence and the pattern of the cystic lesion and the exact level of communication of the cyst to the adjacent joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1jbhi7m8dl","properties":{"formattedCitation":"[8,20,28,29]","plainCitation":"[8,20,28,29]"},"citationItems":[{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}},{"id":157,"uris":[""],"uri":[""],"itemData":{"id":157,"type":"article-journal","title":"Proximal sciatic nerve intraneural ganglion cyst","container-title":"Case Reports in Medicine","page":"810973","volume":"2009","source":"PubMed","abstract":"Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009.","DOI":"10.1155/2009/810973","ISSN":"1687-9635","note":"PMID: 20069041\nPMCID: PMC2797755","journalAbbreviation":"Case Rep Med","language":"eng","author":[{"family":"Swartz","given":"Karin R."},{"family":"Wilson","given":"Dianne"},{"family":"Boland","given":"Michael"},{"family":"Fee","given":"Dominic B."}],"issued":{"date-parts":[["2009"]]},"PMID":"20069041","PMCID":"PMC2797755"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}}],"schema":""} [8,20,28,29]. This typical imaging pattern and the appearance of this lesion with a consistent anatomic site within the nerves and its communication with the adjoining joints, distinguish the intraneural cyst from the other neurogenic or extra neural cystic lesions ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"6zsqlyqs","properties":{"formattedCitation":"[8,28,29]","plainCitation":"[8,28,29]"},"citationItems":[{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":157,"uris":[""],"uri":[""],"itemData":{"id":157,"type":"article-journal","title":"Proximal sciatic nerve intraneural ganglion cyst","container-title":"Case Reports in Medicine","page":"810973","volume":"2009","source":"PubMed","abstract":"Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009.","DOI":"10.1155/2009/810973","ISSN":"1687-9635","note":"PMID: 20069041\nPMCID: PMC2797755","journalAbbreviation":"Case Rep Med","language":"eng","author":[{"family":"Swartz","given":"Karin R."},{"family":"Wilson","given":"Dianne"},{"family":"Boland","given":"Michael"},{"family":"Fee","given":"Dominic B."}],"issued":{"date-parts":[["2009"]]},"PMID":"20069041","PMCID":"PMC2797755"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}}],"schema":""} [8,28,29]. Recognition of its articular connection on MR further helps in complete removal of the cyst, thus avoiding cyst recurrences ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"fUMI9Bhw","properties":{"formattedCitation":"[20,29]","plainCitation":"[20,29]"},"citationItems":[{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}}],"schema":""} [20,29].The exact pathogenesis of INGC is still not known. There are numerous hypotheses for its pathogenesis ranging from recurrent trauma, intra-neural hemorrhage, mucoid degeneration, de novo formation from haemartomatous cell rests ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"2fhnbesan8","properties":{"formattedCitation":"{\\rtf [7,11,30\\uc0\\u8211{}32]}","plainCitation":"[7,11,30–32]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":125,"uris":[""],"uri":[""],"itemData":{"id":125,"type":"article-journal","title":"Ganglia of the nerve. Presentation of two unusual cases, a review of the literature, and a discussion of pathogenesis","container-title":"Clinical Orthopaedics and Related Research","page":"135-144","issue":"113","source":"PubMed","abstract":"Two cases of intraneural ganglia are reported: the first reported involvement of the sciatic nerve and the first reported involvement of the tibial nerve in the tarsal tunnel. Both were successfully treated by excision with sparing the neural elements leading to neurological recovery. A review of the literature fails to reveal any consensus that lesions arise from normal synovial cavities. Incision, evacuation, and complete excision under magnification sparing neural elements gives satisfactory results. Excision of the nerve is not indicated. Pathologic examination suggests that the lesion arises by multicentric metaplasia of connective tissue elements of the nerve rather than by invasion.","ISSN":"0009-921X","note":"PMID: 172271","journalAbbreviation":"Clin. Orthop. Relat. Res.","language":"eng","author":[{"family":"Jacobs","given":"R. R."},{"family":"Maxwell","given":"J. A."},{"family":"Kepes","given":"J."}],"issued":{"date-parts":[["1975",12]]},"PMID":"172271"}},{"id":161,"uris":[""],"uri":[""],"itemData":{"id":161,"type":"article-journal","title":"Cross-over: a generalizable phenomenon necessary for secondary intraneural ganglion cyst formation","container-title":"Clinical Anatomy (New York, N.Y.)","page":"111-118","volume":"21","issue":"2","source":"PubMed","abstract":"The appearances of intraneural ganglion cysts are being elucidated. We previously introduced the cross-over phenomenon to explain how a fibular (peroneal) or tibial intraneural ganglion cyst arising from the superior tibiofibular joint could give rise to multiple cysts: cyst fluid ascending up the primarily affected nerve could reach the level of the sciatic nerve, fill its common epineurial sheath and spread circumferentially (cross over), at which time pressure fluxes could result in further ascent up the sciatic or descent down the same parent nerve or the opposite, previously unaffected fibular or tibial nerves. In this study, we hypothesized that cross-over could occur in other nerves, potentially leading to the formation of more than one intraneural ganglion cyst in such situations. We analyzed the literature and identified a single case that we could review where proximal extension of an intraneural ganglion cyst involving a nerve at a different site could theoretically undergo cross-over in another major nerve large enough for available magnetic resonance images to resolve this finding. A case of a suprascapular intraneural ganglion cyst previously reported by our group that arose from the glenohumeral joint and extended to the neck was reanalyzed for the presence or absence of cross-over. An injection of dye into the outer epineurium of the suprascapular nerve in a fresh cadaveric specimen was performed to test for cross-over experimentally. Retrospective review of this case of suprascapular intraneural ganglion cyst demonstrated evidence to support previously unrecognized cross-over at the level of the upper trunk, with predominant ascent up the C5 and the C6 nerve roots and subtle descent down the anterior and posterior divisions of the upper trunk as well as the proximal portion of the suprascapular nerve. This appearance gave rise to multiple interconnected intraneural ganglion cysts arising from a single distant connection to the glenohumeral joint. The injection study also demonstrated the cross-over phenomenon and produced a similar pattern as the cyst dissection. This article illustrates that cross-over can occur in another nerve (apart from the prototype fibular nerve). Furthermore, understanding the more complex anatomic nature of the upper trunk cross-over model provides insight into important mechanistic information regarding the bidirectional propagation patterns and formation of primary and secondary intraneural ganglion cysts not afforded by the previously described sciatic nerve cross-over model.","DOI":"10.1002/ca.20590","ISSN":"1098-2353","note":"PMID: 18220283","shortTitle":"Cross-over","journalAbbreviation":"Clin Anat","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Wang","given":"Huan"},{"family":"Kliot","given":"Michel"},{"family":"Carmichael","given":"Stephen W."}],"issued":{"date-parts":[["2008",3]]},"PMID":"18220283"}},{"id":163,"uris":[""],"uri":[""],"itemData":{"id":163,"type":"article-journal","title":"Intraneural ganglion cysts: a case of sciatic nerve involvement","container-title":"British Journal of Plastic Surgery","page":"183-186","volume":"56","issue":"2","source":"PubMed","abstract":"The pathogenesis of intraneural ganglion cysts is unknown. Some authors have established a connection between the cysts and the joint, while others have failed to find this communication. Most intraneural ganglion cysts occur in the proximity of a joint. We present the case of a 53-year-old Caucasian male with an intraneural cyst of the sciatic nerve located high above its bifurcation and without a connection to the joint. The lesion was microsurgically removed in toto. There was no recurrence of the cyst at follow-up 9 months postoperatively; complete resolution of the clinical symptoms occurred within 8 months of surgery. This case shows that ganglion cysts can occur in locations far from a joint, supporting the extra-articular embryonic synovial remnant theory of their genesis.","ISSN":"0007-1226","note":"PMID: 12791372","shortTitle":"Intraneural ganglion cysts","journalAbbreviation":"Br J Plast Surg","language":"eng","author":[{"family":"Krishnan","given":"Kartik G."},{"family":"Schackert","given":"Gabriele"}],"issued":{"date-parts":[["2003",3]]},"PMID":"12791372"}},{"id":165,"uris":[""],"uri":[""],"itemData":{"id":165,"type":"article-journal","title":"Case report: intraneural ganglion cyst of the ulnar nerve at the wrist","container-title":"Hand (New York, N.Y.)","page":"317-320","volume":"6","issue":"3","source":"PubMed","abstract":"We report a case of a 69-year-old male who presented with pain, weakness, and clumsiness of his right hand. Initial evaluation suggested possible neoplastic process affecting his cervical spine, which was fortunately ruled out by bone biopsy. Subsequent electrodiagnostic studies and magnetic resonance imaging confirmed a lesion of the deep ulnar motor branch. Exploration of Guyon's canal was performed, and an intraneural ganglion involving the deep motor branch of the ulnar nerve was found and excised. Despite more than 14?months of symptomatic duration, the patient made a near-complete recovery with virtually no functional limitations. This provides supporting evidence for a functional benefit of intraneural ganglion excision and nerve decompression even in cases of chronic muscle atrophy.","DOI":"10.1007/s11552-011-9329-5","ISSN":"1558-9455","note":"PMID: 22942857\nPMCID: PMC3153631","shortTitle":"Case report","journalAbbreviation":"Hand (N Y)","language":"eng","author":[{"family":"Colbert","given":"Stephen H."},{"family":"Le","given":"Mychi H."}],"issued":{"date-parts":[["2011",9]]},"PMID":"22942857","PMCID":"PMC3153631"}}],"schema":""} [7,11,30–32] and the more recent “unified articular theory ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"140bsc814m","properties":{"formattedCitation":"[20,29,33,34]","plainCitation":"[20,29,33,34]"},"citationItems":[{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}},{"id":167,"uris":[""],"uri":[""],"itemData":{"id":167,"type":"article-journal","title":"Dynamic phases of peroneal and tibial intraneural ganglia formation: a new dimension added to the unifying articular theory","container-title":"Journal of Neurosurgery","page":"296-307","volume":"107","issue":"2","source":"PubMed","abstract":"OBJECT: The pathogenesis of intraneural ganglia has been a controversial issue for longer than a century. Recently the authors identified a stereotypical pattern of occurrence of peroneal and tibial intraneural ganglia, and based on an understanding of their pathogenesis provided a unifying articular explanation. Atypical features, which occasionally are observed, have offered an opportunity to verify further and expand on the authors' proposed theory.\nMETHODS: Three unusual cases are presented to exemplify the dynamic features of peroneal and tibial intraneural ganglia formation.\nRESULTS: Two patients with a predominant deep peroneal nerve deficit shared essential anatomical findings common to peroneal intraneural ganglia: namely, 1) joint connections to the anterior portion of the superior tibiofibular joint, and 2) dissection of the cyst along the articular branch of the peroneal nerve and proximally. Magnetic resonance (MR) images obtained in these patients demonstrated some unusual findings, including the presence of a cyst within the tibial and sural nerves in the popliteal fossa region, and spontaneous regression of the cysts, which was observed on serial images obtained weeks apart. The authors identified a clinical outlier, a case that could not be understood within the context of their previously reported theory of intraneural ganglion cyst formation. Described 32 years ago, this patient had a tibial neuropathy and was found at surgery to have tibial, peroneal, and sciatic intraneural cysts without a joint connection. The authors' hypothesis about this case, based on their unified theory, was twofold: 1) the lesion was a primary tibial intraneural ganglion with proximal extension followed by sciatic cross-over and distal descent; and 2) a joint connection to the posterior aspect of the superior tibiofibular joint with a remnant cyst within the articular branch would be present, a finding that would help explain the formation of different cysts by a single mechanism. The authors proved their hypothesis by careful inspection of a recently obtained postoperative MR image.\nCONCLUSIONS: These three cases together with data obtained from a retrospective review of the authors' clinical material and findings reported in the literature provide firm evidence for mechanisms underlying intraneural ganglia formation. Thus, expansion of the authors' unified articular theory permits understanding and elucidation of unusual presentations of intraneural cysts. Whereas an articular connection and fluid following the path of least resistance was pivotal, the authors now incorporate dynamic aspects of cyst formation due to pressure fluxes. These basic principles explain patterns of ascent, cross-over, and descent down terminal nerve branches based on articular connections, paths of diminished resistance to fluid flow within recognized anatomical compartments, and the effects of fluctuating pressure gradients.","DOI":"10.3171/JNS-07/08/0296","ISSN":"0022-3085","note":"PMID: 17695383","shortTitle":"Dynamic phases of peroneal and tibial intraneural ganglia formation","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Wolanskyj","given":"Alexandra P."},{"family":"Desy","given":"Nicholas M."},{"family":"Wang","given":"Huan"},{"family":"Benarroch","given":"Eduardo E."},{"family":"Skinner","given":"John A."},{"family":"Rock","given":"Michael G."},{"family":"Scheithauer","given":"Bernd W."}],"issued":{"date-parts":[["2007",8]]},"PMID":"17695383"}},{"id":169,"uris":[""],"uri":[""],"itemData":{"id":169,"type":"article-journal","title":"Intraneural ganglia: a clinical problem deserving a mechanistic explanation and model","container-title":"Neurosurgical Focus","page":"E11","volume":"26","issue":"2","source":"PubMed","abstract":"Intraneural ganglion cysts have been considered a curiosity for 2 centuries. Based on a unifying articular (synovial) theory, recent evidence has provided a logical explanation for their formation and propagation. The fundamental principle is that of a joint origin and a capsular defect through which synovial fluid escapes following the articular branch, typically into the parent nerve. A stereotypical, reproducible appearance has been characterized that suggests a shared pathogenesis. In the present report the authors will provide a mechanistic explanation that can then be mathematically tested using a preliminary model created by finite element analysis.","DOI":"10.3171/FOC.2009.26.2.E11","ISSN":"1092-0684","note":"PMID: 19435441","shortTitle":"Intraneural ganglia","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Elangovan","given":"Shreehari"},{"family":"Odegard","given":"Gregory M."},{"family":"Morrow","given":"Duane A."},{"family":"Wang","given":"Huan"},{"family":"Hébert-Blouin","given":"Marie-No?lle"},{"family":"Spinner","given":"Robert J."}],"issued":{"date-parts":[["2009",2]]},"PMID":"19435441"}}],"schema":""} [20,29,33,34]. According to the latter, the INGC originates from an adjoining joint and dissects along the articular branch into the parent nerve. The cyst dissects along the path of least resistance, namely the perineural tissue of the nerve[11,30,31]. The diagnostic work-up includes clinical examination, electrophysiological studies and imaging. The ganglion cyst usually presents with pain, motor weakness and paraesthesia along the distribution of involved nerve ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"2cgov8e104","properties":{"formattedCitation":"[7,13,35]","plainCitation":"[7,13,35]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":129,"uris":[""],"uri":[""],"itemData":{"id":129,"type":"article-journal","title":"Intraneural ganglion cyst of the peroneal nerve in a four-year-old girl: a case report","container-title":"Journal of Pediatric Orthopedics","page":"944-946","volume":"27","issue":"8","source":"PubMed","abstract":"Intraneural ganglion cysts of the peroneal nerve are rare, usually occurring in adult men with a typical presentation of knee or proximal leg pain preceding motor weakness and/or sensory disturbances in the peroneal nervous distribution. A history of knee trauma and a palpable mass of the lateral knee in the region of the peroneal nerve are common. We present the unusual case of an intraneural ganglion cyst of the peroneal nerve in a 4-year-old girl. Although extremely rare in the pediatric population, the condition should be considered in the differential diagnosis of children presenting with new-onset foot deformities, foot drop, or clinical examinations consistent with a peroneal nerve lesion. Surgical treatment consisting of ganglion decompression with exploration and ligation of the articular branch of the peroneal nerve may result in improved functional recovery in the pediatric population compared with the adult population. Greater access to magnetic resonance imaging may allow diagnosis of cases that were not previously identified.","DOI":"10.1097/BPO.0b013e3181558c05","ISSN":"0271-6798","note":"PMID: 18209620","shortTitle":"Intraneural ganglion cyst of the peroneal nerve in a four-year-old girl","journalAbbreviation":"J Pediatr Orthop","language":"eng","author":[{"family":"Johnston","given":"Joshua A."},{"family":"Lyne","given":"Dennis E."}],"issued":{"date-parts":[["2007",12]]},"PMID":"18209620"}},{"id":171,"uris":[""],"uri":[""],"itemData":{"id":171,"type":"article-journal","title":"Compression neuropathy of the peroneal nerve secondary to a ganglion cyst","container-title":"The Canadian Journal of Plastic Surgery = Journal Canadien De Chirurgie Plastique","page":"181-183","volume":"16","issue":"3","source":"PubMed","abstract":"Peripheral neuropathies caused by ganglion cysts are rare, particularly in the lower extremities. The case of a 45-year-old man with a two-month history of foot drop and swelling in the region of the right fibular head is presented. Physical examination and electromyogram studies verified a peroneal nerve palsy. Magnetic resonance imaging revealed a lobulated, multilocular, cystic-appearing mass extending around the fibular neck. Surgical decompression of the nerve with removal of the mass and careful articular branch ligation was performed. Surgical pathology reports confirmed the diagnosis of a ganglion cyst. The patient regained full function within four months of the decompression. Pertinent findings on physical examination are discussed, as well as electromyogram and magnetic resonance imaging results. If symptoms persist, early surgical decompression (between the third and fourth months) is recommended.","ISSN":"1195-2199","note":"PMID: 19721802\nPMCID: PMC2691018","journalAbbreviation":"Can J Plast Surg","language":"eng","author":[{"family":"Greer-Bayramoglu","given":"Rebecca J."},{"family":"Nimigan","given":"André S."},{"family":"Gan","given":"Bing Siang"}],"issued":{"date-parts":[["2008"]]},"PMID":"19721802","PMCID":"PMC2691018"}}],"schema":""} [13-15,35]. Electrophysiological studies including electromyography and nerve conduction studies may indicate muscle denervation and conduction latency, respectively ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"bm1h0s7at","properties":{"formattedCitation":"{\\rtf [35\\uc0\\u8211{}38]}","plainCitation":"[35–38]"},"citationItems":[{"id":171,"uris":[""],"uri":[""],"itemData":{"id":171,"type":"article-journal","title":"Compression neuropathy of the peroneal nerve secondary to a ganglion cyst","container-title":"The Canadian Journal of Plastic Surgery = Journal Canadien De Chirurgie Plastique","page":"181-183","volume":"16","issue":"3","source":"PubMed","abstract":"Peripheral neuropathies caused by ganglion cysts are rare, particularly in the lower extremities. The case of a 45-year-old man with a two-month history of foot drop and swelling in the region of the right fibular head is presented. Physical examination and electromyogram studies verified a peroneal nerve palsy. Magnetic resonance imaging revealed a lobulated, multilocular, cystic-appearing mass extending around the fibular neck. Surgical decompression of the nerve with removal of the mass and careful articular branch ligation was performed. Surgical pathology reports confirmed the diagnosis of a ganglion cyst. The patient regained full function within four months of the decompression. Pertinent findings on physical examination are discussed, as well as electromyogram and magnetic resonance imaging results. If symptoms persist, early surgical decompression (between the third and fourth months) is recommended.","ISSN":"1195-2199","note":"PMID: 19721802\nPMCID: PMC2691018","journalAbbreviation":"Can J Plast Surg","language":"eng","author":[{"family":"Greer-Bayramoglu","given":"Rebecca J."},{"family":"Nimigan","given":"André S."},{"family":"Gan","given":"Bing Siang"}],"issued":{"date-parts":[["2008"]]},"PMID":"19721802","PMCID":"PMC2691018"}},{"id":173,"uris":[""],"uri":[""],"itemData":{"id":173,"type":"article-journal","title":"Sequential tibial and peroneal intraneural ganglia arising from the superior tibiofibular joint","container-title":"Skeletal Radiology","page":"79-84","volume":"37","issue":"1","source":"PubMed","abstract":"We present a patient who developed a peroneal intraneural ganglion and an adventitial cyst following the incomplete treatment of a tibial intraneural ganglion. These separate cysts all originated from the superior tibiofibular joint and dissected along their respective articular branches. A logical mechanistic explanation for these coexisting cysts is provided, which highlights the shared pathogenesis--its joint-related nature--rather than a multifocal de novo process. These observations would not only be consistent with, but would extend previous evidence in support of, the unifying articular (synovial) theory.","DOI":"10.1007/s00256-007-0400-9","ISSN":"0364-2348","note":"PMID: 17968541","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",1]]},"PMID":"17968541"}},{"id":210,"uris":[""],"uri":[""],"itemData":{"id":210,"type":"webpage","title":"Common Peroneal Nerve Palsy Secondary to a Proximal Tibiofibular Joint “Ganglion Cyst”—A Case Report and Review of Literature","URL":"","author":[{"family":"Kukreja","given":"Mohit M"},{"family":"Telang","given":"Vidyadhar G"}],"accessed":{"date-parts":[["2016",6,19]]}}},{"id":175,"uris":[""],"uri":[""],"itemData":{"id":175,"type":"article-journal","title":"Direct and indirect MRI findings in ganglion cysts of the common peroneal nerve","container-title":"Clinical Radiology","page":"168-169","volume":"50","issue":"3","source":"PubMed","abstract":"MRI findings in three cases of ganglion cyst of the common peroneal nerve are presented. In each case the cyst was imaged as an oval structure in transverse section section adjacent to the fibular neck. The cyst extended in a tubular fashion over several slices with an inferior extension towards the superior tibiofibular joint. Signal intensity was intermediate on T1- and high on T2-weighted images. In addition, increased signal on both T1- and T2-weighted images was noted throughout the peroneal compartment and was associated with clinical and EMG evidence of denervation. This has not been previously described but may be an important indirect sign which, when seen, should prompt a careful search in the region of the fibular neck for an underlying ganglion cyst of the common peroneal nerve.","ISSN":"0009-9260","note":"PMID: 7889707","journalAbbreviation":"Clin Radiol","language":"eng","author":[{"family":"Coakley","given":"F. V."},{"family":"Finlay","given":"D. B."},{"family":"Harper","given":"W. M."},{"family":"Allen","given":"M. J."}],"issued":{"date-parts":[["1995",3]]},"PMID":"7889707"}}],"schema":""} [35-38]. MRI is the imaging of choice for the nerve and its surrounding soft tissues ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"gefqciqqv","properties":{"formattedCitation":"{\\rtf [37,39\\uc0\\u8211{}41]}","plainCitation":"[37,39–41]"},"citationItems":[{"id":210,"uris":[""],"uri":[""],"itemData":{"id":210,"type":"webpage","title":"Common Peroneal Nerve Palsy Secondary to a Proximal Tibiofibular Joint “Ganglion Cyst”—A Case Report and Review of Literature","URL":"","author":[{"family":"Kukreja","given":"Mohit M"},{"family":"Telang","given":"Vidyadhar G"}],"accessed":{"date-parts":[["2016",6,19]]}}},{"id":177,"uris":[""],"uri":[""],"itemData":{"id":177,"type":"article-journal","title":"The use of MR arthrography to document an occult joint communication in a recurrent peroneal intraneural ganglion","container-title":"Skeletal Radiology","page":"172-179","volume":"35","issue":"3","source":"PubMed","abstract":"The pathogenesis of intraneural ganglia remains controversial. Only half of the reported cases of the most common type, the peroneal nerve at the fibular neck, have been found to have pedicles connecting the cysts to neighboring joints detected with preoperative imaging or intraoperatively. We believe that all intraneural ganglia arise from joints, and that radiologists and surgeons need to look closely preoperatively and intraoperatively for connections. Not identifying these connections with imaging and surgical exploration has led not only to skepticism about an articular origin of the cyst, but also to a high recurrence rate after surgery. We present a patient who had two recurrences of a peroneal intraneural ganglion in whom a joint connection was not detected on previous MRIs and operations. Reinterpretation of the original films and high-resolution MRI demonstrated an \"occult\" joint connection to the superior tibiofibular joint. MR arthrography performed after exercise and 1 h delay, however, clearly showed the connection and communication. The joint connection was then confirmed at surgery through an articular branch. Postoperatively the patient regained nearly normal neurologic function, and follow-up MRI showed no cyst recurrence. MR arthrography with delayed imaging should be considered in cases of intraneural ganglia when a joint connection is not obvious on MRI.","DOI":"10.1007/s00256-005-0036-6","ISSN":"0364-2348","note":"PMID: 16333654","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Rock","given":"Michael G."}],"issued":{"date-parts":[["2006",3]]},"PMID":"16333654"}},{"id":179,"uris":[""],"uri":[""],"itemData":{"id":179,"type":"article-journal","title":"Recurrent intraneural ganglion cyst of the tibial nerve. Case report","container-title":"Journal of Neurosurgery","page":"334-337","volume":"92","issue":"2","source":"PubMed","abstract":"Different theories have evolved to explain the pathogenesis and the cell of origin of intraneural ganglion cysts. Reportedly only three cases of intraneural ganglion of the tibial nerve have been located within the popliteal fossa, and all of these were thought to arise within the nerve. The authors report a case of a recurrent tibial intraneural ganglion in which a connection to the proximal tibiofibular joint was demonstrated on magnetic resonance (MR) images and at surgery. Surgical ligation of the articular branch and evacuation of the cyst led to symptomatic relief, and an MR image obtained 1 year after surgery documented no recurrence. This case reinforces the fact that surgeons need to consider and search for an articular connection in all cases of intraneural ganglia, especially in those that have recurred.","DOI":"10.3171/jns.2000.92.2.0334","ISSN":"0022-3085","note":"PMID: 10659022","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"R. J."},{"family":"Atkinson","given":"J. L."},{"family":"Harper","given":"C. M."},{"family":"Wenger","given":"D. E."}],"issued":{"date-parts":[["2000",2]]},"PMID":"10659022"}},{"id":181,"uris":[""],"uri":[""],"itemData":{"id":181,"type":"article-journal","title":"MRI of peroneal nerve entrapment due to a ganglion cyst","container-title":"Magnetic Resonance Imaging","page":"307-309","volume":"5","issue":"4","source":"PubMed","abstract":"Ganglion cysts are relatively common entities, but impingement upon the peripheral nerves is rare. We describe a case in which peroneal nerve palsy was caused by a ganglion cyst demonstrated by MRI.","ISSN":"0730-725X","note":"PMID: 3657403","journalAbbreviation":"Magn Reson Imaging","language":"eng","author":[{"family":"Leon","given":"J."},{"family":"Marano","given":"G."}],"issued":{"date-parts":[["1987"]]},"PMID":"3657403"}}],"schema":""} [37,39–41]. It helps in defining the lesion along the course of the nerve. On MR, these cysts are small in size and demonstrate the typical, tubular beaded configuration oriented longitudinally along the course of the involved nerve and its branches ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1lf1jbsgr7","properties":{"formattedCitation":"[8,9,19,38,40]","plainCitation":"[8,9,19,38,40]"},"citationItems":[{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":121,"uris":[""],"uri":[""],"itemData":{"id":121,"type":"article-journal","title":"Ganglion cyst involvement of peripheral nerves","container-title":"Journal of Neurosurgery","page":"403-408","volume":"87","issue":"3","source":"PubMed","abstract":"Despite their benign histological appearance and the current literature composed primarily of case reports with favorable outcomes, ganglion cysts involving peripheral nerves (GCPNs) can cause permanent neurological deficits. The authors present a 27-year Louisiana State University Medical Center (LSUMC) experience with the surgical management of GCPNs. From 1968 to 1995, 27 patients were surgically treated for 27 cysts that involved nerves at nine locations. Cysts of the peroneal nerve were the most common, comprising 52% of the cases. Motor deficit, pain, and sensory changes were present in 83%, 78%, and 48% of cases, respectively. A history of acute trauma was noted in 22%. The mean follow-up duration in these cases was 61 months. Motor recovery was good in only 58% of cases and was related to the severity of the preoperative motor deficit. Pain resolved or was significantly improved in 89% of cases. Five patients underwent nine procedures before referral to LSUMC for treatment of recurrence of their ganglion cysts. None of these patients suffered recurrence after undergoing surgery at LSUMC. However, four additional patients (17%) experienced a total of six recurrences after undergoing their initial procedure. The mean time to recurrence for the patient group as a whole was 16 months. On the basis of their experience, the authors conclude that GCPNs can behave in an aggressive fashion. Patients should be counseled preoperatively about the potential for limited motor recovery and a significant chance for recurrence.","DOI":"10.3171/jns.1997.87.3.0403","ISSN":"0022-3085","note":"PMID: 9285606","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Harbaugh","given":"K. S."},{"family":"Tiel","given":"R. L."},{"family":"Kline","given":"D. G."}],"issued":{"date-parts":[["1997",9]]},"PMID":"9285606"}},{"id":141,"uris":[""],"uri":[""],"itemData":{"id":141,"type":"article-journal","title":"The MRI appearance of cystic lesions around the knee","container-title":"Skeletal Radiology","page":"187-209","volume":"33","issue":"4","source":"PubMed","abstract":"This review presents a comprehensive illustrated overview of the wide variety of cystic lesions around the knee. The aetiology, clinical presentation, MRI appearances and differential diagnosis are discussed. Bursae include those related to the patella as well as pes anserine, tibial collateral ligament, semimembranosus-tibial collateral ligament, iliotibial and fibular collateral ligament-biceps femoris. The anatomical extension, imaging features and clinical significance of meniscal cysts are illustrated. Review of ganglia includes intra-articular, extra-articular, intraosseous and periosteal ganglia, highlighting imaging findings and differential diagnoses. The relationship between proximal tibiofibular joint cysts and intraneural peroneal nerve ganglia is discussed. Intraosseous cystic lesions, including insertional and degenerative cysts, as well as lesions mimicking cysts of the knee are described and illustrated. Knowledge of the location, characteristic appearance and distinguishing features of cystic masses around the knee as well as potential imaging pitfalls such as normal anatomical recesses and atypical cyst contents on MR imaging aids in allowing a specific diagnosis to be made. This will prevent unnecessary additional investigations and determine whether intra-articular surgery or conservative management is appropriate.","DOI":"10.1007/s00256-003-0741-y","ISSN":"0364-2348","note":"PMID: 14991250","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"McCarthy","given":"Catherine L."},{"family":"McNally","given":"Eugene G."}],"issued":{"date-parts":[["2004",4]]},"PMID":"14991250"}},{"id":175,"uris":[""],"uri":[""],"itemData":{"id":175,"type":"article-journal","title":"Direct and indirect MRI findings in ganglion cysts of the common peroneal nerve","container-title":"Clinical Radiology","page":"168-169","volume":"50","issue":"3","source":"PubMed","abstract":"MRI findings in three cases of ganglion cyst of the common peroneal nerve are presented. In each case the cyst was imaged as an oval structure in transverse section section adjacent to the fibular neck. The cyst extended in a tubular fashion over several slices with an inferior extension towards the superior tibiofibular joint. Signal intensity was intermediate on T1- and high on T2-weighted images. In addition, increased signal on both T1- and T2-weighted images was noted throughout the peroneal compartment and was associated with clinical and EMG evidence of denervation. This has not been previously described but may be an important indirect sign which, when seen, should prompt a careful search in the region of the fibular neck for an underlying ganglion cyst of the common peroneal nerve.","ISSN":"0009-9260","note":"PMID: 7889707","journalAbbreviation":"Clin Radiol","language":"eng","author":[{"family":"Coakley","given":"F. V."},{"family":"Finlay","given":"D. B."},{"family":"Harper","given":"W. M."},{"family":"Allen","given":"M. J."}],"issued":{"date-parts":[["1995",3]]},"PMID":"7889707"}},{"id":179,"uris":[""],"uri":[""],"itemData":{"id":179,"type":"article-journal","title":"Recurrent intraneural ganglion cyst of the tibial nerve. Case report","container-title":"Journal of Neurosurgery","page":"334-337","volume":"92","issue":"2","source":"PubMed","abstract":"Different theories have evolved to explain the pathogenesis and the cell of origin of intraneural ganglion cysts. Reportedly only three cases of intraneural ganglion of the tibial nerve have been located within the popliteal fossa, and all of these were thought to arise within the nerve. The authors report a case of a recurrent tibial intraneural ganglion in which a connection to the proximal tibiofibular joint was demonstrated on magnetic resonance (MR) images and at surgery. Surgical ligation of the articular branch and evacuation of the cyst led to symptomatic relief, and an MR image obtained 1 year after surgery documented no recurrence. This case reinforces the fact that surgeons need to consider and search for an articular connection in all cases of intraneural ganglia, especially in those that have recurred.","DOI":"10.3171/jns.2000.92.2.0334","ISSN":"0022-3085","note":"PMID: 10659022","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"R. J."},{"family":"Atkinson","given":"J. L."},{"family":"Harper","given":"C. M."},{"family":"Wenger","given":"D. E."}],"issued":{"date-parts":[["2000",2]]},"PMID":"10659022"}}],"schema":""} [8,9,19,38,40]. They appear as low signal on T1-weighted and high signal on T2-weighted images ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"7q9jvb1qu","properties":{"formattedCitation":"[42,43]","plainCitation":"[42,43]"},"citationItems":[{"id":183,"uris":[""],"uri":[""],"itemData":{"id":183,"type":"article-journal","title":"Recurrent ganglion cyst of the peroneal nerve: radiological and operative observations. Case report","container-title":"Journal of Neurosurgery","page":"280-283","volume":"84","issue":"2","source":"PubMed","abstract":"This 34-year-old man presented with right leg pain and foot drop of 1-month duration. The preoperative diagnosis of a 10-cm-long ganglion cyst of the peroneal nerve was achieved using ultrasonography (US), computerized tomography and, particularly magnetic resonance (MR) imaging. Surgical exploration disclosed a lobulated cystic mass filled with gelatinous material, which intermingled with the nerve substance of the deep peroneal nerve. The lesion was completely resected, with the sacrifice of some electrically nonfunctioning fascicles. No connection with the knee joint was found. A good postoperative recovery of motor function was obtained. However, routine postoperative MR imaging disclosed a recurrent ganglion cyst that was slightly less extensive than the original. A careful radiological examination of the knee joint was performed, including arthrography. A communication of the cyst with the tibiofibular joint was clearly demonstrated and was meticulously closed at reoperation. The patient's postoperative course was uneventful, and a third MR image, obtained 5 months after reoperation, showed no sign of cyst recurrence. The patient remained free of symptoms 11 months postoperatively. This case illustrates the value of US and MR in diagnostic imaging. The diagnostic efficacy of US and MR imaging in identifying and characterizing a ganglion cyst is described. Close contact between a ganglion cyst and the tibiofibular joint should raise the possibility of an existing cyst-joint communication and lead to an aggressive radiological workup and/or a surgical search for such a communication.","DOI":"10.3171/jns.1996.84.2.0280","ISSN":"0022-3085","note":"PMID: 8592235","shortTitle":"Recurrent ganglion cyst of the peroneal nerve","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Dubuisson","given":"A. S."},{"family":"Stevenaert","given":"A."}],"issued":{"date-parts":[["1996",2]]},"PMID":"8592235"}},{"id":185,"uris":[""],"uri":[""],"itemData":{"id":185,"type":"article-journal","title":"MRI detection of cysts of the knee causing common peroneal neuropathy","container-title":"Neurology","page":"1829-1831","volume":"65","issue":"11","source":"PubMed","abstract":"In 10 consecutive patients with footdrop due to common peroneal neuropathy without an obvious cause, MRI of the knee showed pathology at the fibular head in 6, including 5 patients with clinically unsuspected cysts of the tibiofibular joint. All 6 of the patients improved with surgery.","DOI":"10.1212/01.wnl.0000187098.42938.b6","ISSN":"1526-632X","note":"PMID: 16344535","journalAbbreviation":"Neurology","language":"eng","author":[{"family":"Iverson","given":"Donald J."}],"issued":{"date-parts":[["2005",12,13]]},"PMID":"16344535"}}],"schema":""} [42,43]. The joint connection and the extension of the cyst along the articular branch of nerve when present, can be well demonstrated ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"27rqm2ukvb","properties":{"formattedCitation":"[20,29,30,36,38,39]","plainCitation":"[20,29,30,36,38,39]"},"citationItems":[{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}},{"id":161,"uris":[""],"uri":[""],"itemData":{"id":161,"type":"article-journal","title":"Cross-over: a generalizable phenomenon necessary for secondary intraneural ganglion cyst formation","container-title":"Clinical Anatomy (New York, N.Y.)","page":"111-118","volume":"21","issue":"2","source":"PubMed","abstract":"The appearances of intraneural ganglion cysts are being elucidated. We previously introduced the cross-over phenomenon to explain how a fibular (peroneal) or tibial intraneural ganglion cyst arising from the superior tibiofibular joint could give rise to multiple cysts: cyst fluid ascending up the primarily affected nerve could reach the level of the sciatic nerve, fill its common epineurial sheath and spread circumferentially (cross over), at which time pressure fluxes could result in further ascent up the sciatic or descent down the same parent nerve or the opposite, previously unaffected fibular or tibial nerves. In this study, we hypothesized that cross-over could occur in other nerves, potentially leading to the formation of more than one intraneural ganglion cyst in such situations. We analyzed the literature and identified a single case that we could review where proximal extension of an intraneural ganglion cyst involving a nerve at a different site could theoretically undergo cross-over in another major nerve large enough for available magnetic resonance images to resolve this finding. A case of a suprascapular intraneural ganglion cyst previously reported by our group that arose from the glenohumeral joint and extended to the neck was reanalyzed for the presence or absence of cross-over. An injection of dye into the outer epineurium of the suprascapular nerve in a fresh cadaveric specimen was performed to test for cross-over experimentally. Retrospective review of this case of suprascapular intraneural ganglion cyst demonstrated evidence to support previously unrecognized cross-over at the level of the upper trunk, with predominant ascent up the C5 and the C6 nerve roots and subtle descent down the anterior and posterior divisions of the upper trunk as well as the proximal portion of the suprascapular nerve. This appearance gave rise to multiple interconnected intraneural ganglion cysts arising from a single distant connection to the glenohumeral joint. The injection study also demonstrated the cross-over phenomenon and produced a similar pattern as the cyst dissection. This article illustrates that cross-over can occur in another nerve (apart from the prototype fibular nerve). Furthermore, understanding the more complex anatomic nature of the upper trunk cross-over model provides insight into important mechanistic information regarding the bidirectional propagation patterns and formation of primary and secondary intraneural ganglion cysts not afforded by the previously described sciatic nerve cross-over model.","DOI":"10.1002/ca.20590","ISSN":"1098-2353","note":"PMID: 18220283","shortTitle":"Cross-over","journalAbbreviation":"Clin Anat","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Wang","given":"Huan"},{"family":"Kliot","given":"Michel"},{"family":"Carmichael","given":"Stephen W."}],"issued":{"date-parts":[["2008",3]]},"PMID":"18220283"}},{"id":173,"uris":[""],"uri":[""],"itemData":{"id":173,"type":"article-journal","title":"Sequential tibial and peroneal intraneural ganglia arising from the superior tibiofibular joint","container-title":"Skeletal Radiology","page":"79-84","volume":"37","issue":"1","source":"PubMed","abstract":"We present a patient who developed a peroneal intraneural ganglion and an adventitial cyst following the incomplete treatment of a tibial intraneural ganglion. These separate cysts all originated from the superior tibiofibular joint and dissected along their respective articular branches. A logical mechanistic explanation for these coexisting cysts is provided, which highlights the shared pathogenesis--its joint-related nature--rather than a multifocal de novo process. These observations would not only be consistent with, but would extend previous evidence in support of, the unifying articular (synovial) theory.","DOI":"10.1007/s00256-007-0400-9","ISSN":"0364-2348","note":"PMID: 17968541","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",1]]},"PMID":"17968541"}},{"id":175,"uris":[""],"uri":[""],"itemData":{"id":175,"type":"article-journal","title":"Direct and indirect MRI findings in ganglion cysts of the common peroneal nerve","container-title":"Clinical Radiology","page":"168-169","volume":"50","issue":"3","source":"PubMed","abstract":"MRI findings in three cases of ganglion cyst of the common peroneal nerve are presented. In each case the cyst was imaged as an oval structure in transverse section section adjacent to the fibular neck. The cyst extended in a tubular fashion over several slices with an inferior extension towards the superior tibiofibular joint. Signal intensity was intermediate on T1- and high on T2-weighted images. In addition, increased signal on both T1- and T2-weighted images was noted throughout the peroneal compartment and was associated with clinical and EMG evidence of denervation. This has not been previously described but may be an important indirect sign which, when seen, should prompt a careful search in the region of the fibular neck for an underlying ganglion cyst of the common peroneal nerve.","ISSN":"0009-9260","note":"PMID: 7889707","journalAbbreviation":"Clin Radiol","language":"eng","author":[{"family":"Coakley","given":"F. V."},{"family":"Finlay","given":"D. B."},{"family":"Harper","given":"W. M."},{"family":"Allen","given":"M. J."}],"issued":{"date-parts":[["1995",3]]},"PMID":"7889707"}},{"id":177,"uris":[""],"uri":[""],"itemData":{"id":177,"type":"article-journal","title":"The use of MR arthrography to document an occult joint communication in a recurrent peroneal intraneural ganglion","container-title":"Skeletal Radiology","page":"172-179","volume":"35","issue":"3","source":"PubMed","abstract":"The pathogenesis of intraneural ganglia remains controversial. Only half of the reported cases of the most common type, the peroneal nerve at the fibular neck, have been found to have pedicles connecting the cysts to neighboring joints detected with preoperative imaging or intraoperatively. We believe that all intraneural ganglia arise from joints, and that radiologists and surgeons need to look closely preoperatively and intraoperatively for connections. Not identifying these connections with imaging and surgical exploration has led not only to skepticism about an articular origin of the cyst, but also to a high recurrence rate after surgery. We present a patient who had two recurrences of a peroneal intraneural ganglion in whom a joint connection was not detected on previous MRIs and operations. Reinterpretation of the original films and high-resolution MRI demonstrated an \"occult\" joint connection to the superior tibiofibular joint. MR arthrography performed after exercise and 1 h delay, however, clearly showed the connection and communication. The joint connection was then confirmed at surgery through an articular branch. Postoperatively the patient regained nearly normal neurologic function, and follow-up MRI showed no cyst recurrence. MR arthrography with delayed imaging should be considered in cases of intraneural ganglia when a joint connection is not obvious on MRI.","DOI":"10.1007/s00256-005-0036-6","ISSN":"0364-2348","note":"PMID: 16333654","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Rock","given":"Michael G."}],"issued":{"date-parts":[["2006",3]]},"PMID":"16333654"}}],"schema":""} [20,29,30,36,38,39]. Further denervation muscle edema as T2 hyperintensity and muscle atrophy as T1 hyperintensity can be seen ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"r0ttvtbg","properties":{"formattedCitation":"[8,10,38]","plainCitation":"[8,10,38]"},"citationItems":[{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":123,"uris":[""],"uri":[""],"itemData":{"id":123,"type":"article-journal","title":"Peroneal intraneural ganglia. Part I. Techniques for successful diagnosis and treatment","container-title":"Neurosurgical Focus","page":"E16","volume":"22","issue":"6","source":"PubMed","abstract":"The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.","ISSN":"1092-0684","note":"PMID: 17613207","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Rock","given":"Michael G."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2007"]]},"PMID":"17613207"}},{"id":175,"uris":[""],"uri":[""],"itemData":{"id":175,"type":"article-journal","title":"Direct and indirect MRI findings in ganglion cysts of the common peroneal nerve","container-title":"Clinical Radiology","page":"168-169","volume":"50","issue":"3","source":"PubMed","abstract":"MRI findings in three cases of ganglion cyst of the common peroneal nerve are presented. In each case the cyst was imaged as an oval structure in transverse section section adjacent to the fibular neck. The cyst extended in a tubular fashion over several slices with an inferior extension towards the superior tibiofibular joint. Signal intensity was intermediate on T1- and high on T2-weighted images. In addition, increased signal on both T1- and T2-weighted images was noted throughout the peroneal compartment and was associated with clinical and EMG evidence of denervation. This has not been previously described but may be an important indirect sign which, when seen, should prompt a careful search in the region of the fibular neck for an underlying ganglion cyst of the common peroneal nerve.","ISSN":"0009-9260","note":"PMID: 7889707","journalAbbreviation":"Clin Radiol","language":"eng","author":[{"family":"Coakley","given":"F. V."},{"family":"Finlay","given":"D. B."},{"family":"Harper","given":"W. M."},{"family":"Allen","given":"M. J."}],"issued":{"date-parts":[["1995",3]]},"PMID":"7889707"}}],"schema":""} [8,10,38]. In the peroneal intraneural cyst, the PTF joint connection and a cyst along the descending and ascending limb of articular branch of CPN can be seen in all the three orthogonal planes ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"vK3F0FUa","properties":{"formattedCitation":"[20,24,29,38,39]","plainCitation":"[20,24,29,38,39]"},"citationItems":[{"id":143,"uris":[""],"uri":[""],"itemData":{"id":143,"type":"article-journal","title":"Peroneal intraneural ganglia: the importance of the articular branch. Clinical series","container-title":"Journal of Neurosurgery","page":"319-329","volume":"99","issue":"2","source":"PubMed","abstract":"OBJECT: The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis.\nMETHODS: Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint.\nCONCLUSIONS: The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.","DOI":"10.3171/jns.2003.99.2.0319","ISSN":"0022-3085","note":"PMID: 12924707","shortTitle":"Peroneal intraneural ganglia","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Atkinson","given":"John L. D."},{"family":"Scheithauer","given":"Bernd W."},{"family":"Rock","given":"Michael G."},{"family":"Birch","given":"Rolfe"},{"family":"Kim","given":"Thomas A."},{"family":"Kliot","given":"Michel"},{"family":"Kline","given":"David G."},{"family":"Tiel","given":"Robert L."}],"issued":{"date-parts":[["2003",8]]},"PMID":"12924707"}},{"id":151,"uris":[""],"uri":[""],"itemData":{"id":151,"type":"article-journal","title":"Patterns of intraneural ganglion cyst descent","container-title":"Clinical Anatomy (New York, N.Y.)","page":"233-245","volume":"21","issue":"3","source":"PubMed","abstract":"On the basis of the principles of the unifying articular theory, predictable patterns of proximal ascent have been described for fibular (peroneal) and tibial intraneural ganglion cysts in the knee region. The mechanism underlying distal descent into the terminal branches of the fibular and tibial nerves has not been previously elucidated. The purpose of this study was to demonstrate if and when cyst descent distal to the articular branch-joint connection occurs in intraneural ganglion cysts to understand directionality of intraneural cyst propagation. In Part I, the clinical records and MRIs of 20 consecutive patients treated at our institution for intraneural ganglion cysts (18 fibular and two tibial) arising from the superior tibiofibular joint were retrospectively analyzed. These patients underwent cyst decompression and disconnection of the articular branch. Five of these patients developed symptomatic cyst recurrence after cyst decompression without articular branch disconnection which was done elsewhere prior to our intervention. In Part II, five additional patients with intraneural ganglion cysts (three fibular and two tibial) treated at other institutions without disconnection of the articular branch were compared. These patients in Parts I and II demonstrated ascent of intraneural cyst to differing degrees (12 had evidence of sciatic nerve cross-over). In addition, all of these patients demonstrated previously unrecognized MRI evidence of intraneural cyst extending distally below the level of the articular branch to the joint of origin: cyst within the proximal most portions of the deep fibular and superficial fibular branches in fibular intraneural ganglion cysts and descending tibial branches in tibial intraneural ganglion cysts. The patients in Part I had complete resolution of their cysts at follow-up MRI examination 1 year postoperatively. The patients in Part II had intraneural recurrences postoperatively within the articular branch, the parent nerve, and the terminal branches, although in three cases they were subclinical. The authors demonstrate that cyst descent distal to the take-off of the articular branch to the joint of origin occurs regularly in patients with fibular and tibial intraneural ganglion cysts. The authors believe that parent terminal branch descent follows ascent up the articular branch from an affected joint of origin. This mechanism for bidirectional flow explains cyst within terminal branches of the fibular and tibial nerves and is dependent on pressure fluxes and resistances. This new pattern is consistent with principles previously described in a unified (articular) theory, is generalizable to other intraneural ganglion cysts arising from joints, and has important implications for pathogenesis and treatment of these intraneural cysts.","DOI":"10.1002/ca.20614","ISSN":"1098-2353","note":"PMID: 18330922","journalAbbreviation":"Clin Anat","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Carmichael","given":"Stephen W."},{"family":"Wang","given":"Huan"},{"family":"Parisi","given":"Thomas J."},{"family":"Skinner","given":"John A."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",4]]},"PMID":"18330922"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}},{"id":175,"uris":[""],"uri":[""],"itemData":{"id":175,"type":"article-journal","title":"Direct and indirect MRI findings in ganglion cysts of the common peroneal nerve","container-title":"Clinical Radiology","page":"168-169","volume":"50","issue":"3","source":"PubMed","abstract":"MRI findings in three cases of ganglion cyst of the common peroneal nerve are presented. In each case the cyst was imaged as an oval structure in transverse section section adjacent to the fibular neck. The cyst extended in a tubular fashion over several slices with an inferior extension towards the superior tibiofibular joint. Signal intensity was intermediate on T1- and high on T2-weighted images. In addition, increased signal on both T1- and T2-weighted images was noted throughout the peroneal compartment and was associated with clinical and EMG evidence of denervation. This has not been previously described but may be an important indirect sign which, when seen, should prompt a careful search in the region of the fibular neck for an underlying ganglion cyst of the common peroneal nerve.","ISSN":"0009-9260","note":"PMID: 7889707","journalAbbreviation":"Clin Radiol","language":"eng","author":[{"family":"Coakley","given":"F. V."},{"family":"Finlay","given":"D. B."},{"family":"Harper","given":"W. M."},{"family":"Allen","given":"M. J."}],"issued":{"date-parts":[["1995",3]]},"PMID":"7889707"}},{"id":177,"uris":[""],"uri":[""],"itemData":{"id":177,"type":"article-journal","title":"The use of MR arthrography to document an occult joint communication in a recurrent peroneal intraneural ganglion","container-title":"Skeletal Radiology","page":"172-179","volume":"35","issue":"3","source":"PubMed","abstract":"The pathogenesis of intraneural ganglia remains controversial. Only half of the reported cases of the most common type, the peroneal nerve at the fibular neck, have been found to have pedicles connecting the cysts to neighboring joints detected with preoperative imaging or intraoperatively. We believe that all intraneural ganglia arise from joints, and that radiologists and surgeons need to look closely preoperatively and intraoperatively for connections. Not identifying these connections with imaging and surgical exploration has led not only to skepticism about an articular origin of the cyst, but also to a high recurrence rate after surgery. We present a patient who had two recurrences of a peroneal intraneural ganglion in whom a joint connection was not detected on previous MRIs and operations. Reinterpretation of the original films and high-resolution MRI demonstrated an \"occult\" joint connection to the superior tibiofibular joint. MR arthrography performed after exercise and 1 h delay, however, clearly showed the connection and communication. The joint connection was then confirmed at surgery through an articular branch. Postoperatively the patient regained nearly normal neurologic function, and follow-up MRI showed no cyst recurrence. MR arthrography with delayed imaging should be considered in cases of intraneural ganglia when a joint connection is not obvious on MRI.","DOI":"10.1007/s00256-005-0036-6","ISSN":"0364-2348","note":"PMID: 16333654","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Rock","given":"Michael G."}],"issued":{"date-parts":[["2006",3]]},"PMID":"16333654"}}],"schema":""} [20,24,29,38,39]. As described by Spinner et al ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1bqkgfu772","properties":{"formattedCitation":"[24,29,31]","plainCitation":"[24,29,31]"},"citationItems":[{"id":151,"uris":[""],"uri":[""],"itemData":{"id":151,"type":"article-journal","title":"Patterns of intraneural ganglion cyst descent","container-title":"Clinical Anatomy (New York, N.Y.)","page":"233-245","volume":"21","issue":"3","source":"PubMed","abstract":"On the basis of the principles of the unifying articular theory, predictable patterns of proximal ascent have been described for fibular (peroneal) and tibial intraneural ganglion cysts in the knee region. The mechanism underlying distal descent into the terminal branches of the fibular and tibial nerves has not been previously elucidated. The purpose of this study was to demonstrate if and when cyst descent distal to the articular branch-joint connection occurs in intraneural ganglion cysts to understand directionality of intraneural cyst propagation. In Part I, the clinical records and MRIs of 20 consecutive patients treated at our institution for intraneural ganglion cysts (18 fibular and two tibial) arising from the superior tibiofibular joint were retrospectively analyzed. These patients underwent cyst decompression and disconnection of the articular branch. Five of these patients developed symptomatic cyst recurrence after cyst decompression without articular branch disconnection which was done elsewhere prior to our intervention. In Part II, five additional patients with intraneural ganglion cysts (three fibular and two tibial) treated at other institutions without disconnection of the articular branch were compared. These patients in Parts I and II demonstrated ascent of intraneural cyst to differing degrees (12 had evidence of sciatic nerve cross-over). In addition, all of these patients demonstrated previously unrecognized MRI evidence of intraneural cyst extending distally below the level of the articular branch to the joint of origin: cyst within the proximal most portions of the deep fibular and superficial fibular branches in fibular intraneural ganglion cysts and descending tibial branches in tibial intraneural ganglion cysts. The patients in Part I had complete resolution of their cysts at follow-up MRI examination 1 year postoperatively. The patients in Part II had intraneural recurrences postoperatively within the articular branch, the parent nerve, and the terminal branches, although in three cases they were subclinical. The authors demonstrate that cyst descent distal to the take-off of the articular branch to the joint of origin occurs regularly in patients with fibular and tibial intraneural ganglion cysts. The authors believe that parent terminal branch descent follows ascent up the articular branch from an affected joint of origin. This mechanism for bidirectional flow explains cyst within terminal branches of the fibular and tibial nerves and is dependent on pressure fluxes and resistances. This new pattern is consistent with principles previously described in a unified (articular) theory, is generalizable to other intraneural ganglion cysts arising from joints, and has important implications for pathogenesis and treatment of these intraneural cysts.","DOI":"10.1002/ca.20614","ISSN":"1098-2353","note":"PMID: 18330922","journalAbbreviation":"Clin Anat","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Carmichael","given":"Stephen W."},{"family":"Wang","given":"Huan"},{"family":"Parisi","given":"Thomas J."},{"family":"Skinner","given":"John A."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",4]]},"PMID":"18330922"}},{"id":159,"uris":[""],"uri":[""],"itemData":{"id":159,"type":"article-journal","title":"The clock face guide to peroneal intraneural ganglia: critical \"times\" and sites for accurate diagnosis","container-title":"Skeletal Radiology","page":"1091-1099","volume":"37","issue":"12","source":"PubMed","abstract":"OBJECTIVE: The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia.\nDESIGN: This study is designed as a retrospective clinical study.\nMATERIALS AND METHODS: MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning.\nCONCLUSIONS: By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.","DOI":"10.1007/s00256-008-0545-1","ISSN":"0364-2348","note":"PMID: 18641980","shortTitle":"The clock face guide to peroneal intraneural ganglia","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Luthra","given":"Gauri"},{"family":"Desy","given":"Nicholas M."},{"family":"Anderson","given":"Meredith L."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",12]]},"PMID":"18641980"}},{"id":163,"uris":[""],"uri":[""],"itemData":{"id":163,"type":"article-journal","title":"Intraneural ganglion cysts: a case of sciatic nerve involvement","container-title":"British Journal of Plastic Surgery","page":"183-186","volume":"56","issue":"2","source":"PubMed","abstract":"The pathogenesis of intraneural ganglion cysts is unknown. Some authors have established a connection between the cysts and the joint, while others have failed to find this communication. Most intraneural ganglion cysts occur in the proximity of a joint. We present the case of a 53-year-old Caucasian male with an intraneural cyst of the sciatic nerve located high above its bifurcation and without a connection to the joint. The lesion was microsurgically removed in toto. There was no recurrence of the cyst at follow-up 9 months postoperatively; complete resolution of the clinical symptoms occurred within 8 months of surgery. This case shows that ganglion cysts can occur in locations far from a joint, supporting the extra-articular embryonic synovial remnant theory of their genesis.","ISSN":"0007-1226","note":"PMID: 12791372","shortTitle":"Intraneural ganglion cysts","journalAbbreviation":"Br J Plast Surg","language":"eng","author":[{"family":"Krishnan","given":"Kartik G."},{"family":"Schackert","given":"Gabriele"}],"issued":{"date-parts":[["2003",3]]},"PMID":"12791372"}}],"schema":""} [24,29,31] in 2008, on serial axial sections, the joint connection is interpreted as the “tail sign” (Figures 1-5, 14) and the extension of the cyst in the ascending limb of the articular branch as the “transverse limb sign” (Figures 1, 2, 14). An eccentric cyst within the outer epineurium of the CPN is interpreted as the “signet ring sign” (Figures 3-5, 14). In all our seven CPN lesions, we found that they had evidence of joint connection; presence of cysts along the articular branch; variable proximal ascent of the intra-neural cyst along the CPN and distal descent along its branches. On coronal images this extension of the cyst along the descending and ascending portions of the articular branch is interpreted as “u-sign” (Figures 1, 2, 11). In the lower extremity, less commonly, they can involve the lumbosacral plexus, sciatic, obturator and tibial nerves ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"211hhitbss","properties":{"formattedCitation":"[9,12,28,32,44]","plainCitation":"[9,12,28,32,44]"},"citationItems":[{"id":121,"uris":[""],"uri":[""],"itemData":{"id":121,"type":"article-journal","title":"Ganglion cyst involvement of peripheral nerves","container-title":"Journal of Neurosurgery","page":"403-408","volume":"87","issue":"3","source":"PubMed","abstract":"Despite their benign histological appearance and the current literature composed primarily of case reports with favorable outcomes, ganglion cysts involving peripheral nerves (GCPNs) can cause permanent neurological deficits. The authors present a 27-year Louisiana State University Medical Center (LSUMC) experience with the surgical management of GCPNs. From 1968 to 1995, 27 patients were surgically treated for 27 cysts that involved nerves at nine locations. Cysts of the peroneal nerve were the most common, comprising 52% of the cases. Motor deficit, pain, and sensory changes were present in 83%, 78%, and 48% of cases, respectively. A history of acute trauma was noted in 22%. The mean follow-up duration in these cases was 61 months. Motor recovery was good in only 58% of cases and was related to the severity of the preoperative motor deficit. Pain resolved or was significantly improved in 89% of cases. Five patients underwent nine procedures before referral to LSUMC for treatment of recurrence of their ganglion cysts. None of these patients suffered recurrence after undergoing surgery at LSUMC. However, four additional patients (17%) experienced a total of six recurrences after undergoing their initial procedure. The mean time to recurrence for the patient group as a whole was 16 months. On the basis of their experience, the authors conclude that GCPNs can behave in an aggressive fashion. Patients should be counseled preoperatively about the potential for limited motor recovery and a significant chance for recurrence.","DOI":"10.3171/jns.1997.87.3.0403","ISSN":"0022-3085","note":"PMID: 9285606","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Harbaugh","given":"K. S."},{"family":"Tiel","given":"R. L."},{"family":"Kline","given":"D. G."}],"issued":{"date-parts":[["1997",9]]},"PMID":"9285606"}},{"id":127,"uris":[""],"uri":[""],"itemData":{"id":127,"type":"article-journal","title":"Intraneural ganglion cyst of the tibial nerve","container-title":"Acta Neurochirurgica","page":"885-889; discussion 889-890","volume":"148","issue":"8","source":"PubMed","abstract":"Intraneural ganglion cyst of the tibial nerve is very rare. To date, only 5 cases of this entity in the popliteal fossa have been reported. We report a new case and review the previously reported cases. A 40-year-old man experienced a mild vague pain in the medial half of his right foot for 3 years. Magnetic resonance imaging scan demonstrated a soft-tissue mass along the right tibial nerve. At surgery, an intraneural ganglion cyst was evacuated. After 12 months, the patient was pain-free with no signs of recurrence. Trauma might be a contributing factor to the development of intraneural ganglion cysts. Application of microsurgical techniques is encouraged.","DOI":"10.1007/s00701-006-0803-8","ISSN":"0001-6268","note":"PMID: 16775659","journalAbbreviation":"Acta Neurochir (Wien)","language":"eng","author":[{"family":"Adn","given":"M."},{"family":"Hamlat","given":"A."},{"family":"Morandi","given":"X."},{"family":"Guegan","given":"Y."}],"issued":{"date-parts":[["2006",8]]},"PMID":"16775659"}},{"id":157,"uris":[""],"uri":[""],"itemData":{"id":157,"type":"article-journal","title":"Proximal sciatic nerve intraneural ganglion cyst","container-title":"Case Reports in Medicine","page":"810973","volume":"2009","source":"PubMed","abstract":"Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009.","DOI":"10.1155/2009/810973","ISSN":"1687-9635","note":"PMID: 20069041\nPMCID: PMC2797755","journalAbbreviation":"Case Rep Med","language":"eng","author":[{"family":"Swartz","given":"Karin R."},{"family":"Wilson","given":"Dianne"},{"family":"Boland","given":"Michael"},{"family":"Fee","given":"Dominic B."}],"issued":{"date-parts":[["2009"]]},"PMID":"20069041","PMCID":"PMC2797755"}},{"id":165,"uris":[""],"uri":[""],"itemData":{"id":165,"type":"article-journal","title":"Case report: intraneural ganglion cyst of the ulnar nerve at the wrist","container-title":"Hand (New York, N.Y.)","page":"317-320","volume":"6","issue":"3","source":"PubMed","abstract":"We report a case of a 69-year-old male who presented with pain, weakness, and clumsiness of his right hand. Initial evaluation suggested possible neoplastic process affecting his cervical spine, which was fortunately ruled out by bone biopsy. Subsequent electrodiagnostic studies and magnetic resonance imaging confirmed a lesion of the deep ulnar motor branch. Exploration of Guyon's canal was performed, and an intraneural ganglion involving the deep motor branch of the ulnar nerve was found and excised. Despite more than 14?months of symptomatic duration, the patient made a near-complete recovery with virtually no functional limitations. This provides supporting evidence for a functional benefit of intraneural ganglion excision and nerve decompression even in cases of chronic muscle atrophy.","DOI":"10.1007/s11552-011-9329-5","ISSN":"1558-9455","note":"PMID: 22942857\nPMCID: PMC3153631","shortTitle":"Case report","journalAbbreviation":"Hand (N Y)","language":"eng","author":[{"family":"Colbert","given":"Stephen H."},{"family":"Le","given":"Mychi H."}],"issued":{"date-parts":[["2011",9]]},"PMID":"22942857","PMCID":"PMC3153631"}},{"id":187,"uris":[""],"uri":[""],"itemData":{"id":187,"type":"article-journal","title":"Intraneural ganglia in the hip and pelvic region. Clinical article","container-title":"Journal of Neurosurgery","page":"317-325","volume":"111","issue":"2","source":"PubMed","abstract":"OBJECT: The authors describe their experience in a series of cases of intraneural ganglia within the hip and pelvic regions, and explain the mechanism of formation and propagation of this pathological entity.\nMETHODS: Five patients with 6 intraneural ganglia are presented. Four patients presented with symptomatic intraneural ganglia in the buttock and pelvis affecting the sciatic and lumbosacral plexus elements. An asymptomatic cyst affecting the opposite sciatic nerve was found on MR imaging in 1 patient. The fifth patient, previously reported on by another group, had an obturator intraneural ganglion that the authors reinterpreted.\nRESULTS: All 5 intraneural ganglia affecting the sciatic and lumbosacral plexus elements were found to have a joint connection to the posteromedial aspect of the hip joint; the obturator intraneural cyst had a joint connection to the anteromedial aspect of the hip joint. In all cases, initial review of the MR images led to their misinterpretation.\nCONCLUSIONS: To the authors' knowledge, these are the first cases of intraneural ganglia demonstrated to have a connection to the hip joint. This finding at a rare site provides further evidence for the unifying articular (synovial) theory for the formation of intraneural ganglia and reveals a shared mechanism for their propagation. Furthermore, understanding the pathogenesis of these lesions provides insight into their successful treatment and their recurrence.","DOI":"10.3171/2009.2.JNS081720","ISSN":"0022-3085","note":"PMID: 19374493","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Hébert-Blouin","given":"Marie-No?lle"},{"family":"Trousdale","given":"Robert T."},{"family":"Midha","given":"Rajiv"},{"family":"Russell","given":"Stephen M."},{"family":"Yamauchi","given":"Tatsuya"},{"family":"Sasaki","given":"Syouzou"},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2009",8]]},"PMID":"19374493"}}],"schema":""} [9,12,28,,44]. The sciatic nerve can be involved in its proximal or distal portion. We have seen in our case, the presence of intra-neural sciatic ganglion cyst at the sacral notch, with characteristic tubular connection to the posteromedial hip joint on MR. There were no obvious degenerative changes in the joint, labral tears or other structural problems on both the conventional MR and radiographs in the case reported herein. However, intra-articular contrast was not given and hence, the common underlying pathology of labral tear or capsular rent with intra-neural extension from a paralabral or para-articular cyst cannot be completely excluded. In Spinner’s series of INGC around the hip and pelvic region ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"2nlno7cms2","properties":{"formattedCitation":"[44]","plainCitation":"[44]"},"citationItems":[{"id":187,"uris":[""],"uri":[""],"itemData":{"id":187,"type":"article-journal","title":"Intraneural ganglia in the hip and pelvic region. Clinical article","container-title":"Journal of Neurosurgery","page":"317-325","volume":"111","issue":"2","source":"PubMed","abstract":"OBJECT: The authors describe their experience in a series of cases of intraneural ganglia within the hip and pelvic regions, and explain the mechanism of formation and propagation of this pathological entity.\nMETHODS: Five patients with 6 intraneural ganglia are presented. Four patients presented with symptomatic intraneural ganglia in the buttock and pelvis affecting the sciatic and lumbosacral plexus elements. An asymptomatic cyst affecting the opposite sciatic nerve was found on MR imaging in 1 patient. The fifth patient, previously reported on by another group, had an obturator intraneural ganglion that the authors reinterpreted.\nRESULTS: All 5 intraneural ganglia affecting the sciatic and lumbosacral plexus elements were found to have a joint connection to the posteromedial aspect of the hip joint; the obturator intraneural cyst had a joint connection to the anteromedial aspect of the hip joint. In all cases, initial review of the MR images led to their misinterpretation.\nCONCLUSIONS: To the authors' knowledge, these are the first cases of intraneural ganglia demonstrated to have a connection to the hip joint. This finding at a rare site provides further evidence for the unifying articular (synovial) theory for the formation of intraneural ganglia and reveals a shared mechanism for their propagation. Furthermore, understanding the pathogenesis of these lesions provides insight into their successful treatment and their recurrence.","DOI":"10.3171/2009.2.JNS081720","ISSN":"0022-3085","note":"PMID: 19374493","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Hébert-Blouin","given":"Marie-No?lle"},{"family":"Trousdale","given":"Robert T."},{"family":"Midha","given":"Rajiv"},{"family":"Russell","given":"Stephen M."},{"family":"Yamauchi","given":"Tatsuya"},{"family":"Sasaki","given":"Syouzou"},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2009",8]]},"PMID":"19374493"}}],"schema":""} [44], four out of five cases showed a cyst at the sciatic notch with an articular communication with the ipsilateral hip joint and further extension of the same into the sciatic nerve. Likewise, the obturator INGC also has a known joint connection with the anteromedial hip joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1ekkllgj2s","properties":{"formattedCitation":"[44,45]","plainCitation":"[44,45]"},"citationItems":[{"id":187,"uris":[""],"uri":[""],"itemData":{"id":187,"type":"article-journal","title":"Intraneural ganglia in the hip and pelvic region. Clinical article","container-title":"Journal of Neurosurgery","page":"317-325","volume":"111","issue":"2","source":"PubMed","abstract":"OBJECT: The authors describe their experience in a series of cases of intraneural ganglia within the hip and pelvic regions, and explain the mechanism of formation and propagation of this pathological entity.\nMETHODS: Five patients with 6 intraneural ganglia are presented. Four patients presented with symptomatic intraneural ganglia in the buttock and pelvis affecting the sciatic and lumbosacral plexus elements. An asymptomatic cyst affecting the opposite sciatic nerve was found on MR imaging in 1 patient. The fifth patient, previously reported on by another group, had an obturator intraneural ganglion that the authors reinterpreted.\nRESULTS: All 5 intraneural ganglia affecting the sciatic and lumbosacral plexus elements were found to have a joint connection to the posteromedial aspect of the hip joint; the obturator intraneural cyst had a joint connection to the anteromedial aspect of the hip joint. In all cases, initial review of the MR images led to their misinterpretation.\nCONCLUSIONS: To the authors' knowledge, these are the first cases of intraneural ganglia demonstrated to have a connection to the hip joint. This finding at a rare site provides further evidence for the unifying articular (synovial) theory for the formation of intraneural ganglia and reveals a shared mechanism for their propagation. Furthermore, understanding the pathogenesis of these lesions provides insight into their successful treatment and their recurrence.","DOI":"10.3171/2009.2.JNS081720","ISSN":"0022-3085","note":"PMID: 19374493","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Hébert-Blouin","given":"Marie-No?lle"},{"family":"Trousdale","given":"Robert T."},{"family":"Midha","given":"Rajiv"},{"family":"Russell","given":"Stephen M."},{"family":"Yamauchi","given":"Tatsuya"},{"family":"Sasaki","given":"Syouzou"},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2009",8]]},"PMID":"19374493"}},{"id":189,"uris":[""],"uri":[""],"itemData":{"id":189,"type":"article-journal","title":"Intraneural ganglion cysts of obturator nerve causing obturator neuropathy","container-title":"Acta Neurologica Belgica","page":"229-230","volume":"112","issue":"2","source":"PubMed","DOI":"10.1007/s13760-012-0041-1","ISSN":"2240-2993","note":"PMID: 22426671","journalAbbreviation":"Acta Neurol Belg","language":"eng","author":[{"family":"Sureka","given":"Jyoti"},{"family":"Panwar","given":"Sanuj"},{"family":"Mullapudi","given":"Indira"}],"issued":{"date-parts":[["2012",6]]},"PMID":"22426671"}}],"schema":""} [44,45] as seen in our case. The propagation of the cyst along the articular branch and further dissection of the cyst along the parent nerve and its anterior and posterior branches has been described ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"2bgavcrf8s","properties":{"formattedCitation":"[45]","plainCitation":"[45]"},"citationItems":[{"id":189,"uris":[""],"uri":[""],"itemData":{"id":189,"type":"article-journal","title":"Intraneural ganglion cysts of obturator nerve causing obturator neuropathy","container-title":"Acta Neurologica Belgica","page":"229-230","volume":"112","issue":"2","source":"PubMed","DOI":"10.1007/s13760-012-0041-1","ISSN":"2240-2993","note":"PMID: 22426671","journalAbbreviation":"Acta Neurol Belg","language":"eng","author":[{"family":"Sureka","given":"Jyoti"},{"family":"Panwar","given":"Sanuj"},{"family":"Mullapudi","given":"Indira"}],"issued":{"date-parts":[["2012",6]]},"PMID":"22426671"}}],"schema":""} [45] and is demonstrated in the current case. Variable atrophy and denervation hyperintensity of ipsilateral adductor brevis and magnus muscles was also seen in our case.Various case reports have described the involvement of tibial nerve in the popliteal fossa by the INGC ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"rq3jkobev","properties":{"formattedCitation":"[7,12,36,40,46,47]","plainCitation":"[7,12,36,40,46,47]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":127,"uris":[""],"uri":[""],"itemData":{"id":127,"type":"article-journal","title":"Intraneural ganglion cyst of the tibial nerve","container-title":"Acta Neurochirurgica","page":"885-889; discussion 889-890","volume":"148","issue":"8","source":"PubMed","abstract":"Intraneural ganglion cyst of the tibial nerve is very rare. To date, only 5 cases of this entity in the popliteal fossa have been reported. We report a new case and review the previously reported cases. A 40-year-old man experienced a mild vague pain in the medial half of his right foot for 3 years. Magnetic resonance imaging scan demonstrated a soft-tissue mass along the right tibial nerve. At surgery, an intraneural ganglion cyst was evacuated. After 12 months, the patient was pain-free with no signs of recurrence. Trauma might be a contributing factor to the development of intraneural ganglion cysts. Application of microsurgical techniques is encouraged.","DOI":"10.1007/s00701-006-0803-8","ISSN":"0001-6268","note":"PMID: 16775659","journalAbbreviation":"Acta Neurochir (Wien)","language":"eng","author":[{"family":"Adn","given":"M."},{"family":"Hamlat","given":"A."},{"family":"Morandi","given":"X."},{"family":"Guegan","given":"Y."}],"issued":{"date-parts":[["2006",8]]},"PMID":"16775659"}},{"id":173,"uris":[""],"uri":[""],"itemData":{"id":173,"type":"article-journal","title":"Sequential tibial and peroneal intraneural ganglia arising from the superior tibiofibular joint","container-title":"Skeletal Radiology","page":"79-84","volume":"37","issue":"1","source":"PubMed","abstract":"We present a patient who developed a peroneal intraneural ganglion and an adventitial cyst following the incomplete treatment of a tibial intraneural ganglion. These separate cysts all originated from the superior tibiofibular joint and dissected along their respective articular branches. A logical mechanistic explanation for these coexisting cysts is provided, which highlights the shared pathogenesis--its joint-related nature--rather than a multifocal de novo process. These observations would not only be consistent with, but would extend previous evidence in support of, the unifying articular (synovial) theory.","DOI":"10.1007/s00256-007-0400-9","ISSN":"0364-2348","note":"PMID: 17968541","journalAbbreviation":"Skeletal Radiol.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2008",1]]},"PMID":"17968541"}},{"id":179,"uris":[""],"uri":[""],"itemData":{"id":179,"type":"article-journal","title":"Recurrent intraneural ganglion cyst of the tibial nerve. Case report","container-title":"Journal of Neurosurgery","page":"334-337","volume":"92","issue":"2","source":"PubMed","abstract":"Different theories have evolved to explain the pathogenesis and the cell of origin of intraneural ganglion cysts. Reportedly only three cases of intraneural ganglion of the tibial nerve have been located within the popliteal fossa, and all of these were thought to arise within the nerve. The authors report a case of a recurrent tibial intraneural ganglion in which a connection to the proximal tibiofibular joint was demonstrated on magnetic resonance (MR) images and at surgery. Surgical ligation of the articular branch and evacuation of the cyst led to symptomatic relief, and an MR image obtained 1 year after surgery documented no recurrence. This case reinforces the fact that surgeons need to consider and search for an articular connection in all cases of intraneural ganglia, especially in those that have recurred.","DOI":"10.3171/jns.2000.92.2.0334","ISSN":"0022-3085","note":"PMID: 10659022","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"R. J."},{"family":"Atkinson","given":"J. L."},{"family":"Harper","given":"C. M."},{"family":"Wenger","given":"D. E."}],"issued":{"date-parts":[["2000",2]]},"PMID":"10659022"}},{"id":191,"uris":[""],"uri":[""],"itemData":{"id":191,"type":"article-journal","title":"Peroneal and tibial intraneural ganglion cysts in the knee region: a technical note","container-title":"Neurosurgery","page":"ons71-78; discussion ons78","volume":"67","issue":"3 Suppl Operative","source":"PubMed","abstract":"BACKGROUND: Recent research has resulted in an improved understanding of the pathogenesis and treatment of intraneural ganglia, particularly with respect to the most common form, the peroneal nerve at the fibular neck region.\nOBJECTIVE: To outline the mechanism for the development and propagation of intraneural ganglia located in the knee region, along with their treatment, as well as highlight how shared principles can be exploited for successful treatment of the more commonly occurring peroneal intraneural ganglia.\nMETHODS: A surgical approach has been developed for peroneal intraneural cysts based on the pathogenesis. The treatment of the less common tibial intraneural cysts is designed along the same principles.\nRESULTS: A strategy consisting of (1) disarticulation (resection) of the superior tibiofibular joint (ie, the source), (2) disconnection of the articular branch connection (ie, the conduit), and (3) decompression (rather than resection) of the cyst has improved outcomes and eliminated intraneural recurrences in peroneal intraneural cysts. These same principles and techniques can be applied to the rarer tibial intraneural ganglia derived from the same joint. The mechanism of development and propagation for intraneural cysts in the knee region as well as a surgical technique and its rational are described and illustrated.\nCONCLUSION: Understanding the joint-related basis of intraneural cysts leads to simple targeted surgery that addresses the joint, its articular branch, and the cyst. The success of the shared surgical strategy for both peroneal and tibial intraneural ganglia confirms the principles of the unifying articular theory.","DOI":"10.1227/01.NEU.0000374683.91933.0E","ISSN":"1524-4040","note":"PMID: 20679946","shortTitle":"Peroneal and tibial intraneural ganglion cysts in the knee region","journalAbbreviation":"Neurosurgery","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Hébert-Blouin","given":"Marie-No?lle"},{"family":"Amrami","given":"Kimberly K."},{"family":"Rock","given":"Michael G."}],"issued":{"date-parts":[["2010",9]]},"PMID":"20679946"}},{"id":193,"uris":[""],"uri":[""],"itemData":{"id":193,"type":"article-journal","title":"Tibial intraneural ganglia at the ankle and knee: incorporating the unified (articular) theory in adults and children","container-title":"Journal of Neurosurgery","page":"236-239","volume":"114","issue":"1","source":"PubMed","abstract":"OBJECT: The etiology of intraneural ganglia has been debated for centuries, and only recently a unifying theory has been proposed. The incidence of tibial nerve intraneural ganglia is restricted to the occasional case report, and there are no reported cases of these lesions in children. While evidence of the unifying theory for intraneural ganglia of the common peroneal nerve is strong, there are only a few reports describing the application of the theory in the tibial nerve. In this report the authors examine tibial nerve intraneural ganglia at the ankle and knee in an adult and a child, respectively, and describe the clinical utility of incorporating the unifying (articular) theory in the management of tibial intraneural ganglia in adults and children.\nMETHODS: Cases of tibial intraneural ganglion cysts were examined clinically, radiologically, operatively, and histologically to demonstrate the application of the unified (articular) theory for the development of these cysts in adults and children.\nRESULTS: Two patients with intraneural ganglion cysts of the tibial nerve were identified: an adult with an intraneural ganglion cyst of the tibial nerve at the tarsal tunnel and a child with an intraneural ganglion cyst of the tibial nerve at the knee. In each case, preoperative MR imaging demonstrated the intraneural cyst and its connection to the adjacent joint via the articular branch to the subtalar joint and superior tibiofibular joint. At surgery the articular branch was identified and resected, thus disconnecting the tibial nerve intraneural cyst from the joint of origin.\nCONCLUSIONS: These cases detail the important features of intraneural ganglion cysts of the tibial nerve and document the clinical utility of incorporating the unifying (articular) theory for the surgical management of tibial intraneural ganglia in adults and children.","DOI":"10.3171/2010.3.JNS10427","ISSN":"1933-0693","note":"PMID: 20415523","shortTitle":"Tibial intraneural ganglia at the ankle and knee","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Davis","given":"Gavin A."},{"family":"Cox","given":"Ian H."}],"issued":{"date-parts":[["2011",1]]},"PMID":"20415523"}}],"schema":""} [7,12,36,40,46,47]. These tibial INGCs are the posterior counterpart of the peroneal INGCs and demonstrate an intraneural cyst and its connection to the adjacent joint via the articular branch to the PTF joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1lck2vdv8s","properties":{"formattedCitation":"[40,47]","plainCitation":"[40,47]"},"citationItems":[{"id":179,"uris":[""],"uri":[""],"itemData":{"id":179,"type":"article-journal","title":"Recurrent intraneural ganglion cyst of the tibial nerve. Case report","container-title":"Journal of Neurosurgery","page":"334-337","volume":"92","issue":"2","source":"PubMed","abstract":"Different theories have evolved to explain the pathogenesis and the cell of origin of intraneural ganglion cysts. Reportedly only three cases of intraneural ganglion of the tibial nerve have been located within the popliteal fossa, and all of these were thought to arise within the nerve. The authors report a case of a recurrent tibial intraneural ganglion in which a connection to the proximal tibiofibular joint was demonstrated on magnetic resonance (MR) images and at surgery. Surgical ligation of the articular branch and evacuation of the cyst led to symptomatic relief, and an MR image obtained 1 year after surgery documented no recurrence. This case reinforces the fact that surgeons need to consider and search for an articular connection in all cases of intraneural ganglia, especially in those that have recurred.","DOI":"10.3171/jns.2000.92.2.0334","ISSN":"0022-3085","note":"PMID: 10659022","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"R. J."},{"family":"Atkinson","given":"J. L."},{"family":"Harper","given":"C. M."},{"family":"Wenger","given":"D. E."}],"issued":{"date-parts":[["2000",2]]},"PMID":"10659022"}},{"id":193,"uris":[""],"uri":[""],"itemData":{"id":193,"type":"article-journal","title":"Tibial intraneural ganglia at the ankle and knee: incorporating the unified (articular) theory in adults and children","container-title":"Journal of Neurosurgery","page":"236-239","volume":"114","issue":"1","source":"PubMed","abstract":"OBJECT: The etiology of intraneural ganglia has been debated for centuries, and only recently a unifying theory has been proposed. The incidence of tibial nerve intraneural ganglia is restricted to the occasional case report, and there are no reported cases of these lesions in children. While evidence of the unifying theory for intraneural ganglia of the common peroneal nerve is strong, there are only a few reports describing the application of the theory in the tibial nerve. In this report the authors examine tibial nerve intraneural ganglia at the ankle and knee in an adult and a child, respectively, and describe the clinical utility of incorporating the unifying (articular) theory in the management of tibial intraneural ganglia in adults and children.\nMETHODS: Cases of tibial intraneural ganglion cysts were examined clinically, radiologically, operatively, and histologically to demonstrate the application of the unified (articular) theory for the development of these cysts in adults and children.\nRESULTS: Two patients with intraneural ganglion cysts of the tibial nerve were identified: an adult with an intraneural ganglion cyst of the tibial nerve at the tarsal tunnel and a child with an intraneural ganglion cyst of the tibial nerve at the knee. In each case, preoperative MR imaging demonstrated the intraneural cyst and its connection to the adjacent joint via the articular branch to the subtalar joint and superior tibiofibular joint. At surgery the articular branch was identified and resected, thus disconnecting the tibial nerve intraneural cyst from the joint of origin.\nCONCLUSIONS: These cases detail the important features of intraneural ganglion cysts of the tibial nerve and document the clinical utility of incorporating the unifying (articular) theory for the surgical management of tibial intraneural ganglia in adults and children.","DOI":"10.3171/2010.3.JNS10427","ISSN":"1933-0693","note":"PMID: 20415523","shortTitle":"Tibial intraneural ganglia at the ankle and knee","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Davis","given":"Gavin A."},{"family":"Cox","given":"Ian H."}],"issued":{"date-parts":[["2011",1]]},"PMID":"20415523"}}],"schema":""} [40,47,48]. In one of our cases there was evidence of dual communication of the tibial intraneural cyst to both the knee and PTF joint through its corresponding articular branches (Figures 3-5) and further extension of cyst into the popliteus and tibialis posterior nerve branches (Figures 3-5). Denervation edema was noted in both popliteus and tibialis posterior muscles (Figures 3-5).In the upper extremity, less commonly, they can involve the suprascapular, ulnar or median nerves ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"n24n0ak8q","properties":{"formattedCitation":"[8,48]","plainCitation":"[8,48]"},"citationItems":[{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":195,"uris":[""],"uri":[""],"itemData":{"id":195,"type":"article-journal","title":"Adherence of intraneural ganglia of the upper extremity to the principles of the unifying articular (synovial) theory","container-title":"Neurosurgical Focus","page":"E10","volume":"26","issue":"2","source":"PubMed","abstract":"OBJECT: Intraneural ganglia are nonneoplastic mucinous cysts contained within the epineurium of peripheral nerves. Their pathogenesis has been controversial. Historically, the majority of authors have favored de novo formation (degenerative theory). Because of their rarity, intraneural ganglia affecting the upper limb have been misunderstood. This study was designed to critically analyze the literature and to test the hypothesis that intraneural ganglia of the upper limb act analogously to those in the lower limb, being derived from an articular source (synovial theory).\nMETHODS: Two patients with digital intraneural cysts were included in the study. An extensive literature review of intraneural ganglia of the upper limb was undertaken to provide the historical basis for the study.\nRESULTS: In both cases, the digital intraneural ganglia were demonstrated to have joint connections; the one patient in whom an articular branch was not appreciated initially had evidence on postoperative MR images of persistence of intraneural cyst after simple decompression was performed. Eighty-six cases of intraneural lesions were identified in varied locations of the upper limb: the most common sites were the ulnar nerve at the elbow and wrist, occurring 38 and 22 times, respectively. Joint connections were present in only 20% of the cases published by other groups.\nCONCLUSIONS: The authors believe that the fundamental principles of the unifying articular (synovial) theory (that is, articular branch connections, cyst fluid following a path of least resistance, and the role of pressure fluxes) previously described to explain intraneural ganglia in the lower limb apply to those cases in the upper limb. In their opinion, the joint connection is often not identified because of the cysts' rarity, radiologists' and surgeons' inexperience, and the difficulty visualizing and demonstrating it because of the small size of the cysts. Furthermore, they believe that recurrence (subclinical or clinical) is not only underreported but also predictable after simple decompression that fails to address the articular branch. In contrast, intraneural recurrence can be eliminated with disconnection of the articular branch.","DOI":"10.3171/FOC.2009.26.2.E10","ISSN":"1092-0684","note":"PMID: 19435440","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Wang","given":"Huan"},{"family":"Terrill","given":"Robert Q."},{"family":"Tanaka","given":"Shota"},{"family":"Amrami","given":"Kimberly K."},{"family":"Spinner","given":"Robert J."}],"issued":{"date-parts":[["2009",2]]},"PMID":"19435440"}}],"schema":""} [8,49]. INGC is a common cause of suprascapular nerve impingement at the suprascapular and more commonly at the spino-glenoid notch originating from gleno-humeral joint and often associated with tears of the glenoid labrum ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"ck0cpk3sb","properties":{"formattedCitation":"[49,50]","plainCitation":"[49,50]"},"citationItems":[{"id":197,"uris":[""],"uri":[""],"itemData":{"id":197,"type":"article-journal","title":"Suprascapular nerve neuropathy secondary to spinoglenoid notch ganglion cyst: case reports and review of literature","container-title":"Annals of the Academy of Medicine, Singapore","page":"1032-1035","volume":"36","issue":"12","source":"PubMed","abstract":"INTRODUCTION: Suprascapular nerve neuropathy secondary to ganglion cyst impingement has increasingly been found to be a cause of shoulder pain.\nCLINICAL PICTURE: We present 2 patients who complained of dull, poorly localised shoulder pain, which worsened with overhead activities. Magnetic resonance imaging showed ganglion cysts in the spinoglenoid notch.\nTREATMENT: Both patients failed conservative management with physiotherapy and underwent shoulder arthroscopy. One patient underwent arthroscopic decompression of the cyst and the other had open excision of the cyst.\nOUTCOME: Both patients experienced resolution of symptoms within 6 months of surgery.\nCONCLUSION: With appropriate treatment, suprascapular nerve neuropathy secondary to ganglion cyst impingement is a treatable condition with potentially good results.","ISSN":"0304-4602","note":"PMID: 18185886","shortTitle":"Suprascapular nerve neuropathy secondary to spinoglenoid notch ganglion cyst","journalAbbreviation":"Ann. Acad. Med. Singap.","language":"eng","author":[{"family":"Lee","given":"Bernard C. S."},{"family":"Yegappan","given":"Muthukaruppan"},{"family":"Thiagarajan","given":"Palaniappan"}],"issued":{"date-parts":[["2007",12]]},"PMID":"18185886"}},{"id":199,"uris":[""],"uri":[""],"itemData":{"id":199,"type":"article-journal","title":"Bilateral suprascapular nerve entrapment by glenoid labral cysts associated with rotator cuff damage and posterior instability in an amateur weightlifter","container-title":"The Journal of Sports Medicine and Physical Fitness","page":"64-67","volume":"50","issue":"1","source":"PubMed","abstract":"Suprascapular nerve entrapment is a common condition in athletes. The entrapment is most frequently due to a \"glenoid labral cyst\" produced by joint fluid extrusion in consequence of labral degenerative changes. The bilaterality of the entrapment and the association with rotator cuff pathology are a rare evidence. We present the case of a 38-year-old amateur weightlifter with an history of left shoulder chronic posterior pain and progressive external rotation weakness, and with an acute right shoulder pain and weakness. Magnetic resonance imaging showed a bilateral glenoid labral cyst in association with partial tear of the supraspinatus tendon, atrophy of the infraspinatus muscle and type 2 SLAP lesion at the left shoulder and subacromial impingement syndrome (due to acromio-clavicular osteophyte), mild atrophy of the infraspinatus muscle and type 1-2 SLAP lesion at the right side.","ISSN":"0022-4707","note":"PMID: 20308974","journalAbbreviation":"J Sports Med Phys Fitness","language":"eng","author":[{"family":"Limbucci","given":"N."},{"family":"Rossi","given":"F."},{"family":"Salvati","given":"F."},{"family":"Pistoia","given":"L. M."},{"family":"Barile","given":"A."},{"family":"Masciocchi","given":"C."}],"issued":{"date-parts":[["2010",3]]},"PMID":"20308974"}}],"schema":""} [50,51]. It may also arise from the acromioclavicular (AC) joint as articular branch of the suprascapular nerve innervate the AC joint ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"1fbd5m0rij","properties":{"formattedCitation":"[51]","plainCitation":"[51]"},"citationItems":[{"id":201,"uris":[""],"uri":[""],"itemData":{"id":201,"type":"article-journal","title":"The suprascapular nerve and its articular branch to the acromioclavicular joint: an anatomic study","container-title":"Journal of Shoulder and Elbow Surgery / American Shoulder and Elbow Surgeons ... [et Al.]","page":"e13-17","volume":"20","issue":"2","source":"PubMed","abstract":"HYPOTHESIS: The suprascapular nerve and its articular branch innervate the acromioclavicular (AC) joint. Documenting the detailed anatomy of this innervation in the AC joint, including the pertinent surgical and anatomic relationships of the suprascapular nerve and its branches to the AC joint, will aid in the prevention of injury and the reduction of risk of denervation during shoulder surgery.\nMATERIALS AND METHODS: Twelve shoulders from 6 embalmed human cadavers were bilaterally dissected to study the course of the suprascapular nerve and its motor and sensory branches.\nRESULTS: The sensory branch runs superiorly to the supraspinatus muscle towards the AC joint. The average distance from the supraglenoid tubercle to the nerve at the coracoid base was 15 mm. The average distance from the coracoclavicular ligaments to the nerve at the coracoid base was 6 mm. The average distance from the spinoglenoid notch to the sensory branch at the suprascapular notch was 22 mm. The average length of the sensory branch was 30 mm. In half of the specimen shoulders, the suprascapular artery accompanied the nerve at the suprascapular notch under the transverse scapular ligament.\nDISCUSSION: The innervation of the AC joint by the suprascapular nerve has been described, along with pertinent distances to anatomic landmarks. The sensory branch of the suprascapular nerve, which passed through the scapular notch inferior to the transverse scapular ligament, was found in 100% of the study specimens.\nCONCLUSION: The sensory branch of the suprascapular nerve runs superiorly to the supraspinatus muscle towards the AC joint. The detailed information can be used to help decrease the risk of nerve injury during shoulder surgery and to aid in effectively diagnosing and treating AC joint-related disorders.","DOI":"10.1016/j.jse.2010.09.004","ISSN":"1532-6500","note":"PMID: 21194975","shortTitle":"The suprascapular nerve and its articular branch to the acromioclavicular joint","journalAbbreviation":"J Shoulder Elbow Surg","language":"eng","author":[{"family":"Ebraheim","given":"Nabil A."},{"family":"Whitehead","given":"Jennifer L."},{"family":"Alla","given":"Sreenivasa R."},{"family":"Moral","given":"Muhammad Z."},{"family":"Castillo","given":"Sharmaine"},{"family":"McCollough","given":"Andre L."},{"family":"Yeasting","given":"Richard A."},{"family":"Liu","given":"Jiayong"}],"issued":{"date-parts":[["2011",3]]},"PMID":"21194975"}}],"schema":""} [52]. They track along the articular branch into the parent nerve and can be associated with a labral tear or capsular rent ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"6FONtplI","properties":{"formattedCitation":"[52]","plainCitation":"[52]"},"citationItems":[{"id":203,"uris":[""],"uri":[""],"itemData":{"id":203,"type":"article-journal","title":"Suprascapular intraneural ganglia and glenohumeral joint connections","container-title":"Journal of Neurosurgery","page":"551-557","volume":"104","issue":"4","source":"PubMed","abstract":"OBJECT: Unlike the more commonly noted paralabral cysts (extraneural ganglia), which are well known to result in suprascapular nerve compression, only four cases of suprascapular intraneural ganglia have been reported. Because of their rarity, the pathogenesis of suprascapular intraneural ganglia has been poorly understood and a pathoanatomical explanation has not been provided. In view of the growing literature demonstrating strong associations between paralabral cysts and labral (capsular) pathology, joint connections, and joint communications, the authors retrospectively reviewed the magnetic resonance (MR) imaging studies and postoperative results in the two featured patients to test a hypothesis that suprascapular intraneural ganglia would have analogous findings.\nMETHODS: Two patients who presented with suprascapular neuropathy were found to have intraneural ganglia. Connections to the glenohumeral joint could be established in both patients through posterior labrocapsular complex tears. In neither patient was the joint connection identified preoperatively or intraoperatively, and cyst decompression was performed by itself without attention to the labral tear. The suprascapular intraneural ganglia extended from the glenohumeral joint as far proximally as the level of the nerves' origin from the upper trunk in the supraclavicular fossa. Although both patients experienced symptomatic improvement after surgery, neurological recovery was incomplete. In both cases, postoperative MR images revealed cyst persistence. In addition, previously unrecognized superior labral anteroposterior (SLAP) Type II lesions (tears of the superior labrum extending anteroposterior and involving the biceps anchor at the labrum without actual extension into the tendon) were visualized. In one patient with a persistent cyst, an MR arthrogram was obtained and demonstrated a communication between the joint and the cyst.\nCONCLUSIONS: The findings in these two patients support the synovial theory for intraneural ganglia. Based on their experience with intraneural ganglia at other sites, the authors believe that suprascapular intraneural ganglia arise from the glenohumeral joint, egress through a superior (posterior) labral tear, and dissect within the epineurium along an articular branch into the main nerve, following the path of least resistance. Furthermore, these two cases of intraneural ganglia with SLAP lesions are directly analogous to the many cases of paralabral cysts associated with these types of labral tears. By better understanding the origin of this unusual type of ganglia and drawing analogies to the more common extraneural cysts, surgical strategies can be formulated to address the underlying pathoanatomy, improve operative outcomes, and prevent recurrences.","DOI":"10.3171/jns.2006.104.4.551","ISSN":"0022-3085","note":"PMID: 16619659","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Kliot","given":"Michel"},{"family":"Johnston","given":"Shawn P."},{"family":"Casa?as","given":"Joaquim"}],"issued":{"date-parts":[["2006",4]]},"PMID":"16619659"}}],"schema":""} [53]. However, in one of our cases, the joint connection could not be demonstrated. In the other case there was an AC joint connection (Figure 6). In contrast to this extra neural paralabral cyst where the nerve is seen separately from the cyst with a preserved fat plane in between, an INGC affecting the suprascapular nerve evolves within the epineurium of the nerve as seen in other peripheral nerve INGCs ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"tAcbrfuF","properties":{"formattedCitation":"{\\rtf [52\\uc0\\u8211{}54]}","plainCitation":"[52–54]"},"citationItems":[{"id":203,"uris":[""],"uri":[""],"itemData":{"id":203,"type":"article-journal","title":"Suprascapular intraneural ganglia and glenohumeral joint connections","container-title":"Journal of Neurosurgery","page":"551-557","volume":"104","issue":"4","source":"PubMed","abstract":"OBJECT: Unlike the more commonly noted paralabral cysts (extraneural ganglia), which are well known to result in suprascapular nerve compression, only four cases of suprascapular intraneural ganglia have been reported. Because of their rarity, the pathogenesis of suprascapular intraneural ganglia has been poorly understood and a pathoanatomical explanation has not been provided. In view of the growing literature demonstrating strong associations between paralabral cysts and labral (capsular) pathology, joint connections, and joint communications, the authors retrospectively reviewed the magnetic resonance (MR) imaging studies and postoperative results in the two featured patients to test a hypothesis that suprascapular intraneural ganglia would have analogous findings.\nMETHODS: Two patients who presented with suprascapular neuropathy were found to have intraneural ganglia. Connections to the glenohumeral joint could be established in both patients through posterior labrocapsular complex tears. In neither patient was the joint connection identified preoperatively or intraoperatively, and cyst decompression was performed by itself without attention to the labral tear. The suprascapular intraneural ganglia extended from the glenohumeral joint as far proximally as the level of the nerves' origin from the upper trunk in the supraclavicular fossa. Although both patients experienced symptomatic improvement after surgery, neurological recovery was incomplete. In both cases, postoperative MR images revealed cyst persistence. In addition, previously unrecognized superior labral anteroposterior (SLAP) Type II lesions (tears of the superior labrum extending anteroposterior and involving the biceps anchor at the labrum without actual extension into the tendon) were visualized. In one patient with a persistent cyst, an MR arthrogram was obtained and demonstrated a communication between the joint and the cyst.\nCONCLUSIONS: The findings in these two patients support the synovial theory for intraneural ganglia. Based on their experience with intraneural ganglia at other sites, the authors believe that suprascapular intraneural ganglia arise from the glenohumeral joint, egress through a superior (posterior) labral tear, and dissect within the epineurium along an articular branch into the main nerve, following the path of least resistance. Furthermore, these two cases of intraneural ganglia with SLAP lesions are directly analogous to the many cases of paralabral cysts associated with these types of labral tears. By better understanding the origin of this unusual type of ganglia and drawing analogies to the more common extraneural cysts, surgical strategies can be formulated to address the underlying pathoanatomy, improve operative outcomes, and prevent recurrences.","DOI":"10.3171/jns.2006.104.4.551","ISSN":"0022-3085","note":"PMID: 16619659","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."},{"family":"Kliot","given":"Michel"},{"family":"Johnston","given":"Shawn P."},{"family":"Casa?as","given":"Joaquim"}],"issued":{"date-parts":[["2006",4]]},"PMID":"16619659"}},{"id":215,"uris":[""],"uri":[""],"itemData":{"id":215,"type":"article-journal","title":"Intraneural ganglion of the suprascapular nerve: Case report","container-title":"The Journal of Hand Surgery","page":"1698-1699","volume":"31","issue":"10","source":"PubMed","DOI":"10.1016/j.jhsa.2006.09.015","ISSN":"0363-5023","note":"PMID: 17145396","shortTitle":"Intraneural ganglion of the suprascapular nerve","journalAbbreviation":"J Hand Surg Am","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2006",12]]},"PMID":"17145396"}},{"id":205,"uris":[""],"uri":[""],"itemData":{"id":205,"type":"article-journal","title":"Intraneural ganglion of the suprascapular nerve: case report","container-title":"The Journal of Hand Surgery","page":"40-44","volume":"31","issue":"1","source":"PubMed","abstract":"We present a case of multicystic ganglion of the suprascapular nerve in an 18-year-old man. Pain and shoulder weakness were present and examination showed weakness and atrophy of the supraspinatus and infraspinatus muscles. Electromyography showed severe denervation of the infraspinatus and supraspinatus muscles. At surgery a multicystic lesion of the suprascapular nerve extending approximately 5.7 cm from its origin was resected and reconstructed by sural nerve grafting.\nTYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level V.","DOI":"10.1016/j.jhsa.2005.08.010","ISSN":"0363-5023","note":"PMID: 16443102","shortTitle":"Intraneural ganglion of the suprascapular nerve","journalAbbreviation":"J Hand Surg Am","language":"eng","author":[{"family":"Sanger","given":"James"},{"family":"Cortes","given":"Wilberto"},{"family":"Yan","given":"Ji-Geng"}],"issued":{"date-parts":[["2006",1]]},"PMID":"16443102"}}],"schema":""} [53–55].In our series of 245 cases of peripheral nerve palsy for which imaging was done, 45 cases of cystic lesions were identified. Of these 45 cystic lesions, more than a fourth (13 cases), were diagnosed to be INGC retrospectively. Although the exact incidence of INGC is not known, in our series it was the commonest cause for the cystic nerve lesions. The fact that these lesions are reported as rare ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"eTnxjnHa","properties":{"formattedCitation":"{\\rtf [7\\uc0\\u8211{}11]}","plainCitation":"[7–11]"},"citationItems":[{"id":115,"uris":[""],"uri":[""],"itemData":{"id":115,"type":"article-journal","title":"A rare case of intraneural ganglion cyst involving the tibial nerve","container-title":"Proceedings (Baylor University. Medical Center)","page":"132-135","volume":"25","issue":"2","source":"PubMed","abstract":"Cystic lesions around the knee are a relatively common occurrence. Several types of cysts have been reported, including synovial, bursal, and ganglion. Ganglion cysts are not lined by synovial cells. Their location is highly variable, with occurrences described in the fat pads near the tibia or femur, muscles, nerves, and arteries. Intraneural ganglia are rare nonneoplastic cysts caused by the accumulation of thick mucinous fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule. These cysts can cause compression of the adjacent nerve fascicles, resulting in pain, paresthesias, weakness, muscle denervation, and atrophy. They are most commonly manifested by local and radiating pain, but sensory and motor deficits have also been described. Involvement of the tibial nerve is exceptionally rare, with <15 reported cases in the literature. We present a case of intraneural tibial ganglion cyst in a young woman. We also discuss the imaging features, differential considerations, proposed pathogenesis and anatomic origin, and treatment of this rare entity.","ISSN":"1525-3252","note":"PMID: 22481843\nPMCID: PMC3310510","journalAbbreviation":"Proc (Bayl Univ Med Cent)","language":"eng","author":[{"family":"Patel","given":"Purvak"},{"family":"Schucany","given":"William G."}],"issued":{"date-parts":[["2012",4]]},"PMID":"22481843","PMCID":"PMC3310510"}},{"id":119,"uris":[""],"uri":[""],"itemData":{"id":119,"type":"article-journal","title":"Peripheral nerve intraneural ganglion cyst: MR findings in three cases","container-title":"Journal of Computer Assisted Tomography","page":"629-632","volume":"22","issue":"4","source":"PubMed","abstract":"We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.","ISSN":"0363-8715","note":"PMID: 9676458","shortTitle":"Peripheral nerve intraneural ganglion cyst","journalAbbreviation":"J Comput Assist Tomogr","language":"eng","author":[{"family":"Uetani","given":"M."},{"family":"Hashmi","given":"R."},{"family":"Hayashi","given":"K."},{"family":"Nagatani","given":"Y."},{"family":"Narabayashi","given":"Y."},{"family":"Imamura","given":"K."}],"issued":{"date-parts":[["1998",8]]},"PMID":"9676458"}},{"id":121,"uris":[""],"uri":[""],"itemData":{"id":121,"type":"article-journal","title":"Ganglion cyst involvement of peripheral nerves","container-title":"Journal of Neurosurgery","page":"403-408","volume":"87","issue":"3","source":"PubMed","abstract":"Despite their benign histological appearance and the current literature composed primarily of case reports with favorable outcomes, ganglion cysts involving peripheral nerves (GCPNs) can cause permanent neurological deficits. The authors present a 27-year Louisiana State University Medical Center (LSUMC) experience with the surgical management of GCPNs. From 1968 to 1995, 27 patients were surgically treated for 27 cysts that involved nerves at nine locations. Cysts of the peroneal nerve were the most common, comprising 52% of the cases. Motor deficit, pain, and sensory changes were present in 83%, 78%, and 48% of cases, respectively. A history of acute trauma was noted in 22%. The mean follow-up duration in these cases was 61 months. Motor recovery was good in only 58% of cases and was related to the severity of the preoperative motor deficit. Pain resolved or was significantly improved in 89% of cases. Five patients underwent nine procedures before referral to LSUMC for treatment of recurrence of their ganglion cysts. None of these patients suffered recurrence after undergoing surgery at LSUMC. However, four additional patients (17%) experienced a total of six recurrences after undergoing their initial procedure. The mean time to recurrence for the patient group as a whole was 16 months. On the basis of their experience, the authors conclude that GCPNs can behave in an aggressive fashion. Patients should be counseled preoperatively about the potential for limited motor recovery and a significant chance for recurrence.","DOI":"10.3171/jns.1997.87.3.0403","ISSN":"0022-3085","note":"PMID: 9285606","journalAbbreviation":"J. Neurosurg.","language":"eng","author":[{"family":"Harbaugh","given":"K. S."},{"family":"Tiel","given":"R. L."},{"family":"Kline","given":"D. G."}],"issued":{"date-parts":[["1997",9]]},"PMID":"9285606"}},{"id":123,"uris":[""],"uri":[""],"itemData":{"id":123,"type":"article-journal","title":"Peroneal intraneural ganglia. Part I. Techniques for successful diagnosis and treatment","container-title":"Neurosurgical Focus","page":"E16","volume":"22","issue":"6","source":"PubMed","abstract":"The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.","ISSN":"1092-0684","note":"PMID: 17613207","journalAbbreviation":"Neurosurg Focus","language":"eng","author":[{"family":"Spinner","given":"Robert J."},{"family":"Desy","given":"Nicholas M."},{"family":"Rock","given":"Michael G."},{"family":"Amrami","given":"Kimberly K."}],"issued":{"date-parts":[["2007"]]},"PMID":"17613207"}},{"id":125,"uris":[""],"uri":[""],"itemData":{"id":125,"type":"article-journal","title":"Ganglia of the nerve. Presentation of two unusual cases, a review of the literature, and a discussion of pathogenesis","container-title":"Clinical Orthopaedics and Related Research","page":"135-144","issue":"113","source":"PubMed","abstract":"Two cases of intraneural ganglia are reported: the first reported involvement of the sciatic nerve and the first reported involvement of the tibial nerve in the tarsal tunnel. Both were successfully treated by excision with sparing the neural elements leading to neurological recovery. A review of the literature fails to reveal any consensus that lesions arise from normal synovial cavities. Incision, evacuation, and complete excision under magnification sparing neural elements gives satisfactory results. Excision of the nerve is not indicated. Pathologic examination suggests that the lesion arises by multicentric metaplasia of connective tissue elements of the nerve rather than by invasion.","ISSN":"0009-921X","note":"PMID: 172271","journalAbbreviation":"Clin. Orthop. Relat. Res.","language":"eng","author":[{"family":"Jacobs","given":"R. R."},{"family":"Maxwell","given":"J. A."},{"family":"Kepes","given":"J."}],"issued":{"date-parts":[["1975",12]]},"PMID":"172271"}}],"schema":""} [7–11] may be incorrect since they are often underdiagnosed as shown in our series. The primary radiological diagnosis of INGC in our series was correct in only 60 percent of the cases, i.e., the last 7 cases in this series. Lack of knowledge of this pathological entity and absence of this entity in standard radiological textbooks were probable reasons for its under-diagnosis among the early cases in this series. INGC as an entity was little known before the 90s even in western literature, being reported as rare case reports or case series prior to that ADDIN ZOTERO_ITEM CSL_CITATION {"citationID":"5b8oXNMy","properties":{"formattedCitation":"[14,55,56]","plainCitation":"[14,55,56]"},"citationItems":[{"id":131,"uris":[""],"uri":[""],"itemData":{"id":131,"type":"article-journal","title":"Pure peroneal intraneural ganglion cyst ascending along the sciatic nerve","container-title":"Turkish Neurosurgery","page":"254-258","volume":"21","issue":"2","source":"PubMed","abstract":"Peroneal nerve entrapment is most commonly seen in the popliteal fossa. It is rarely caused by a ganglion. Intraneural ganglia, although uncommon and seldom cause serious complications, are well recognized and most commonly affect the common peroneal (lateral popliteal) nerve. Ganglionic cysts developing in the sheath of a peripheral nerve or joint capsule may cause compression neuropathy. The differential diagnosis should involve L5 root lesions, posttraumatic intraneural hemorrhage, nerve compression near the tendinous arch located at the fibular insertion of the peroneal longus muscle and nerve-sheath tumors. We present a unique case of a pure intraneural ganglion of the common peroneal nerve ascending along the sciatic nerve. This case underscores the importance of consideration of an intraneural ganglion cyst with sciatic nerve involvement.","DOI":"10.5137/1019-5149.JTN.2660-09.1","ISSN":"1019-5149","note":"PMID: 21534214","journalAbbreviation":"Turk Neurosurg","language":"eng","author":[{"family":"Tehli","given":"Ozkan"},{"family":"Celikmez","given":"Ramazan Cengiz"},{"family":"Birgili","given":"Baris"},{"family":"Solmaz","given":"Ilker"},{"family":"Celik","given":"Ertugrul"}],"issued":{"date-parts":[["2011"]]},"PMID":"21534214"}},{"id":207,"uris":[""],"uri":[""],"itemData":{"id":207,"type":"article-journal","title":"Intraneural ganglion of the lateral popliteal nerve","container-title":"The Journal of Bone and Joint Surgery. British Volume","page":"784-790","volume":"43-B","source":"PubMed","ISSN":"0301-620X","note":"PMID: 14038186","journalAbbreviation":"J Bone Joint Surg Br","language":"eng","author":[{"family":"Parkes","given":"A."}],"issued":{"date-parts":[["1961",11]]},"PMID":"14038186"}},{"id":223,"uris":[""],"uri":[""],"itemData":{"id":223,"type":"article-journal","title":"US and MR imaging of peroneal intrneural ganglia: Emphasis on the articular branch","container-title":"Skeletal Radiology","page":"588","volume":"34","issue":"9","source":"ProQuest","abstract":"PURPOSE:\nTo describe US and MR imaging findings in patients\nwith peroneal intraneural ganglia.\n588\nMATERIALS and METHODS: Seventeen consecutive patients\nwith a palpable mass in the fibular neck area and foot-drop sug-\ngesting dysfunction of the common peroneal nerve were prospec-\ntively evaluated with high-resolution (12-5MHz and 17-5MHz)\nUS and 1.5T MR imaging. All patients had abnormal nerve con-\nduction studies\nRESULTS:\nIn all but one patients, US and MR imaging identified\nganglia of variable size and shape in proximity to the superior ti-\nbiofibular joint. Based on their relationship with the peroneal\nnerve, US and MR imaging divided these cysts in extraneural gan-\nglia (\nn=\n9/16), which developed outside the nerve, and intraneural\nganglia (\nn=\n7/16), developing within the nerve. Intraneural ganglia\nhad a stereotypical appearance. US found the bulk of the ganglion\non the anterolateral aspect of the superior tibiofibular joint, located\nremotely from the position of the peroneal nerve. The ganglion\nwas invariably associated with a dilated articular branch of this\nnerve. This branch appeared as a long tubular process coursing\nalong the posterolateral aspect of the fibula to join the bulk of the\nganglion with the nerve. In all cases, it was markedly enlarged and\nassumed a cystic appearance without detectable fascicles. More\nproximally, the fascicles of the deep and common peroneal nerve\nwere displaced eccentrically by the cyst growing within the epi-\nneurium. In three nonoperated cases, the overall size of the gangli-\non and the entity of the nerve deficit varied with time with fluctu-\nating phases of worsening and recovery of symptoms: one of them\ncompletely regressed at 6-months follow-up.\nCONCLUSIONS:\nUS and MR imaging are promising for evaluating\npatients with peroneal neuropathy caused by superior tibiofibular\njoint ganglia. By providing unique information on the intraneural lo-\ncation of the cyst and the status of the involved nerve, US and MR\nimaging have potential for major impact on treatment planning","DOI":"","ISSN":"0364-2348","language":"English","author":[{"family":"Bacigalupo","given":"L E"},{"family":"Damasio","given":"M B"},{"family":"Zuccarino","given":"F"},{"family":"Succio","given":"G"},{"family":"Silversti","given":"E"},{"family":"Bianchi","given":"S"},{"family":"Martinoli","given":"C"}],"issued":{"date-parts":[["2005",9]]}}}],"schema":""} [14,56,57]. The others cystic lesions in this series varied from cystic schwannoma, extra-neural ganglion cysts, paralabral cysts and nerve abscesses. All of these cystic lesions were correctly diagnosed primarily except two ENGCs which were mistaken as cystic schwannoma. This article endeavors to describe different INGCs at varying anatomical locations, to emphasize the fact that it is the single largest cause of surgically treatable mono-neuropathy due to a cystic nerve lesion. These lesions have a classic configuration, anatomical location within the nerve and extensions along its branches. Most have defined communications to the nearby joint and the innervated muscles show signs of denervation. Identification of the articular branch and disconnecting it is important to prevent recurrence. The youngest patient in this series had surgery, 7 mo after the onset of nerve palsy due to the late presentation at the hospital. The cysts were decompressed and the articular branch disconnected during the surgery. The innervated muscles showed MRC grade 4 recovery about one year after surgery, in spite of the late intervention. In conclusion, over the past years, INGC has been increasingly recognized as a radio-pathologic entity. It is a cause of peripheral neuropathy that can be treated by surgery, but is often under-diagnosed. This research looked at a historic cohort of patients that were imaged for mono-neuropathy and within that the subsets of patients with cystic lesions were looked at, in greater detail. We were certainly missing the diagnosis of the INGC until recently. The surgical treatment of a cystic schwannoma is enucleation as opposed to the INGC where the nerve is decompressed and the articular branch is excised. This study re- emphasizes that any elongated cystic lesion along the course of a peripheral nerve and in the vicinity of a joint should be considered as an INGC unless proved otherwise. This will ensure that both the radiologist and the surgeon would diligently search for the articular (branch) connection and hence prevent a misdiagnosis and a possible recurrence. COMMENTSBackgroundintraneural ganglion cysts (INGCs) of peripheral nerves occur within the epineurium and related to the adjoining joint are relatively uncommon entity. They generally formed when joint fluid track in the epineural sheath of the articular branch of the nerve and further along the path of least resistance. They commonly present with sensory-motor symptoms along the distribution of the involved nerve. If these are identified and treated early, symptoms are reversible. The articular branch disconnection of the cyst will avoid the recurrence of the cyst. In this study, we evaluated 13 such cases involving the different peripheral nerves. Research frontiersMagnetic resonance imaging (MRI) is the most important modality to diagnose this condition. It also allows differentiating it from other intra or juxtra-neural lesions like neurogenic tumors and the extra-neural ganglion cyst. Though it has been described as a rare disease in literature, the results of this study showed that it is the single largest cause of surgically treatable mono-neuropathy caused by a cystic nerve lesion.Innovations and breakthroughsIn this study, the classic MRI pattern of the INGC was a useful tool in diagnosing this condition and to differentiate it from other intra or extraneural cystic lesions. These results agree with prior literature. However, in this study, 40% of cases representing the initial cases in this series were misdiagnosed preoperatively and were mistaken for neurogenic tumor. This emphasizes the diagnostic knowledge of this condition. An early diagnosis and surgical intervention will improve patient outcomes.ApplicationsIn the order of differential diagnosis of cystic nerve lesions arising in the vicinity of a joint, the INGC comes first. This research re-emphasizes that the knowledge of the classic MRI pattern is paramount in diagnosing the INGC. An early surgical intervention will cause significant reversal of neurologic symptoms.TerminologyINGC: Intraneural ganglion cyst, cyst occurring within the epineurium of nerve; ENGC: Extraneural ganglion cyst, cyst adjacent to nerve but outside the epineural sheath; CPN: Common peroneal nerve, a nerve in the lower leg that provides sensation and motor function to parts of the lower leg.Peer-reviewThis review article has well described the use and dose optimisation of computed tomography in patients with cystic. It is well-organized and useful for clinical practice, especially for western radiology society.REFERENCES1?van Brakel WH, Nicholls PG, Das L, Barkataki P, Suneetha SK, Jadhav RS, Maddali P, Lockwood DN, Wilder-Smith E, Desikan KV. The INFIR Cohort Study: investigating prediction, detection and pathogenesis of neuropathy and reactions in leprosy. 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US and MR imaging of peroneal intraneural ganglia: Emphasis on the articular branch. Skeletal Radiol 2005; 34: 588 [DOI: 10.1007/s00256-005-0959-y.P- Reviewer: Ju CI, Reddy CG, Squires JH S- Editor: Song XX L- Editor: E- Editor:Figure 1 A shows a diagrammatic representation of the intraneural ganglion cyst associated with the proximal tibiofibular joint in the coronal plane; B-D are serial, coronal, T2-weighted, fast spin echo images of the knee show the origin of the lobulated tubular cyst from the proximal tibiofibular joint also called the “tail sign” demonstrated by the black arrows. The further extension along the descending limb (yellow arrows) of the articular branch represents the “vertical limb sign”. The ascending limb of the articular branch (red arrows) demonstrates the “transverse limb sign” which continues to the CPN (blue arrows). Extension of the cyst into the two limbs of the articular branch and further ascent into the parent nerve represents the “u-sign”. T: Tibia; F: Fibula; CPN: Common peroneal nerve.Figure 2 A shows a diagrammatic representation of the intraneural ganglion cyst associated with the proximal tibiofibular joint in the sagittal plane; B-E serial, sagittal, T2-weighted, fast spin echo images of the knee show the origin of the lobulated tubular cyst from the proximal tibiofibular joint represents the “tail sign” (black arrows). The further extension along the descending limb (yellow arrows) represents the “vertical limb sign” and ascending limb (red arrows) of the articular branch demonstrates the “transverse limb sign”; which continues to the CPN (blue arrows). The cyst also extends along the deep peroneal nerve (open arrows) in image E. T: Tibia; F: Fibula; CPN: Common peroneal nerve.Figure 3 Images A-H show serial, proton density-weighted fat suppressed sagittal sections of the knee demonstrate the longitudinally oriented cystic lesion in the tibial nerve (red arrows) with extension along the articular branch to proximal tibiofibular joint (yellow arrows), branch to popliteus (blue arrows) and tibialis posterior muscles (white arrows). Note the denervation edema in the popliteus muscle (star). T: Tibia; Fi: Fibula; Fe: Femur.Figure 4 Images A-H show serial, proton density -weighted fat suppressed coronal sections of the knee demonstrate the longitudinal extent of intraneural cyst in the tibial nerve (red arrows), with propagation of cyst along the articular branches that communicate with the posterior aspect of knee joint (pink arrows, dashed line and circle) and to the postero-inferior part of proximal tibiofibular joint (yellow arrows). This represents a dual joint connection (knee and proximal tibiofibular) from the same intraneural ganglion cyst. The cyst also extends along the branch to the popliteus (blue arrows) and tibialis posterior muscles (white arrows). Note the denervation edema in the popliteus (blue star) and tibialis posterior (red star) muscles. Superiorly, the cyst extends up to the bifurcation of the sciatic nerve in the distal third of the thigh.Figure 5 Images A-C show serial, proton density-weighted fat suppressed axial images of the knee demonstrate the eccentric cyst (red arrows) within the epineurium of tibial nerve displacing the nerve fascicles (yellow arrows) which represents the “signet ring sign” (A). The joint connection (pink arrows) is well appreciated where the cyst arises from the posterior aspect of the PTF joint. This represents the “tail sign” (B). The cyst (yellow arrows) extends along the posterior surface of the popliteus muscle into the branch to popliteus muscle. Denervation edema is seen in the popliteus (blue star) and tibialis posterior (red star) muscles. T: Tibia; F: Fibula; Fe: Femur; PTF: Proximal tibiofibular.Figure 6 Images A-L show serial T2-weighted fat suppressed axial sections of the right shoulder, outlines the longitudinally oriented cyst (stars) along the course of the suprascapular nerve. The cyst extends from the level of the acromioclavicular joint (B) to the posterior aspect of glenohumeral joint (L). A narrow joint connection extends along the expected course of the articular branch of the suprascapular nerve to the acromioclavicular joint (yellow arrows). Further descend of the intraneural cyst through the posterior triangle into the suprascapular and spinoglenoid notches are demonstrated by red, blue and pink arrows respectively. No obvious labral or capsular tear or degeneration of joint is noted on magnetic resonance imaging. Figure 7 Images A, B show serial, T2-weighted fat suppressed coronal sections of the pelvis that demonstrates the longitudinally oriented intraneural cyst in the right obturator nerve (black arrows). The extension along the articular branch to the anteromedial aspect of right hip joint (white arrows) is also seen. Note the normal left obturator nerve (ON, yellow arrows). Reprinted with permission from Acta Neurologica Belgica.Figure 8 Image A, B show serial, T2-weighted fat suppressed axial images of the pelvis that demonstrates the further inferior extension of the cyst along the anterior branch of the obturator nerve (black arrow). Note the denervation atrophy of adductor brevis (AB) and magnus (AM) muscles. Reprinted with permission from Acta Neurologica Belgica.Figure 9 Image A-D show serial, T2-weighted, FSE axial sections of the left hip joint highlighting a cyst (star) at the level of the left sciatic notch. An extension along the expected course of the articular branch of the sciatic nerve (white arrows) communicating with the posteromedial aspect of the ipsilateral hip joint (open arrows) is also seen.Figure 10 Images A-D show serial, T2- weighted fat suppressed coronal sections of the pelvis, demonstrate a cyst (black arrows) at the level of the left sciatic notch. The cyst extends along the articular branch of the sciatic nerve (white arrows) and communicates with the posteromedial aspect of the ipsilateral hip joint (D). No obvious labral or capsular tear or degeneration of joint is noted.Figure 11 Images A-C show serial, coronal, proton density fat suppressed sections of the knee and proximal leg. The entire extent of the cyst within the articular branch (white dashes) to the PTF joint extending to the CPN (yellow dashes) at the posterolateral fibular neck is seen, demonstrating the “u-sign” (A). The cyst extends into the proximal portion of the superficial peroneal nerve (pink dashes) for a length of approximately 5 cm (B). Denervation hyperintensity of the muscles?(stars) of anterior and peroneal compartments of the leg is also seen. T: Tibial; F: Fibula; PTF: Proximal tibiofibular; CPN: Common peroneal nerve.ABFigure 12 The intraoperative images of one of these patients. A: Surgical exposure and decompression of the CPN in a 9-year-old girl presenting with foot drop. The intraoperative picture shows a thickened CPN (thick block arrow); the sural communicating branch of the CPN (thick hollow arrow); the articular branch of the CPN (thin block arrow) and the arthrotomy of the PTF joint and a mucinous cyst within it (thin hollow arrow); B: Close up of the CPN, being decompressed with multiple stab incisions with mucin (hollow arrow) within the substance of the nerve. The superficial peroneal branch of the nerve (block arrow) appeared unaffected which correlated clinically. PTF: Proximal tibiofibular; CPN: Common peroneal nerve.Figure 13 Images A-F show serial, T2-weighted fat suppressed axial sections of the proximal leg and demonstrate a large multilobulated globular extra-neural ganglion cyst (block arrows). The ENGC is antero-lateral to the proximal fibula and indenting the peroneus longus muscle anteriorly (A-C). The CPN (open arrows) lies posterior to the cyst but is seen separate from it. The tail of the cyst (arrows in D-F) extends superiorly and communicates with the superior aspect of the PTF joint. PTF: Proximal tibiofibular; CPN: Common peroneal nerve; ENGC: Extraneural ganglion cyst.Figure 14 Axial, T2-weighted fat suppressed images A-H of the proximal leg show the left clock face model to differentiate intraneural ganglion cyst from extraneural ganglion cyst. A-C represent INGC where images A, B (at the upper-mid fibular head level) depict the joint connection of the cyst at the 10 o’clock (white arrows) which signifies the “tail sign”. The cyst (red arrows) within the outer epineurium of the CPN (yellow arrow), between the 4 and 5 o’clock position represents the “signet ring sign”. Image C, (at the level of fibular neck) shows the extension of the cyst along the ascending limb of the articular branch (dotted white line) depicting the “transverse limb sign”. It crosses the anterior surface of fibula from the PTF joint and progresses clockwise from 12-3 o’clock position around the fibular head. On the other hand, images D-H, depicting ENGC show a more superiorly located joint connection (white arrow) in between 12-2 o’clock position in images D, E. It lies anterolateral to the fibula (dotted white line) and never crosses it as seen in images F, G. The cyst (star) is more globular and lying in the intermuscular plane as seen in the image H. INGC: Intraneural ganglion cyst; CPN: Common peroneal nerve; ENGC: Extraneural ganglion cyst.Figure 15 Serial, coronal, (images A-C), and axial, (images D-E), proton density fat suppressed sections show a well-defined oval cystic lesion at the posterolateral aspect of upper fibula along the expected course of common peroneal nerve which does not communicate within the proximal tibiofibular joint. Mild denervation edema is seen in the anterior compartment muscles (star). This is a case of cystic schwannoma involving the CPN. T: Tibia; F: Fibula; Fe: Femur; CPN: Common peroneal nerve.Figure 16 Proton density fat suppressed, serial axial (A, B); coronal (C) and T1-weighted, axial (D) show a well-defined lobulated slightly elongated cystic lesion (black stars) at the spinoglenoid notch compressing upon the suprascapular nerve (white arrow), which is seen separately from the cyst with preserved fat plane. There is a tail like communication (yellow arrow) of the cyst with the posterior labrum. This suggests labral tear with paralabral cyst formation. Denervation edema and mild volume loss in the infraspinatus muscle (white stars) is seen. Figure 17 T2-weighted fat suppressed, serial sagittal (A, B); T1-weighted, sagittal (C); T2-weighted fat suppressed, axial (D) and proton density-weighted, axial (E) show an elongated tubular cystic lesion (stars) along the posterior tibial nerve at the lower leg, ankle and foot. The lesion is seen within the substance of the nerve and has a central cystic component (stars) and a peripheral thin wall consistent with an abscess (D, E). This is a case of Hansen’s disease with posterior tibial nerve abscess.Table 1 Inclusion criteria for intraneural ganglion cystMultilocular elongated hyperintense cystic mass on T2 weighted imagingDistributed along the course of a peripheral nerve and its branchesExtension along the articular branch to the adjacent jointDenervation changes of the muscles supplied by involved nerveTable 2 Epidemiological data of patients diagnosed with cystic lesions related to the nervePatient dataIntraneural ganglion cystExtraneural ganglion cystPara-labral cystCystic schwannomaNerve abscessTotal number of lesions1310688Mean age (yr) SD38.214.6630.516.42323.9442.610.7928.212.84Common symptomsPain along distribution of nerve, motor weaknessPain and swellingPain and weakness of external rotatorsParasthesia, pain along distribution of nerveParasthesia and weaknessMale:female ratio 10:26:46:05:38:0Nerves involvedCPN 7Tibial 2Suprascapular 2Prox. Sciatic 1Obturator 1Near CPN 9Radial 1 Near SSN 6CPN 3Median 2Sciatic 1Tibial 1Radial 1Ulnar 51CPN 21Median 31Radial 31Number who underwent surgery6/1310/106/68/83/8Correct diagnosis on MRI7/138/106/68/88/81Combined involvement of multiple nerves. MRI: Magnetic resonance imaging.Table 3 Summery of magnetic resonance imaging findings of intraneural ganglion cyst of peripheral nervesSNInvolved Nerve ExtensionLabral or Capsular TearJoint abnormalityMuscle denervationAnatomical extent along the parent nerveBranchesIntra-articular extension1.Rt CPNUpto sciatic bifurcationRecurrent articular Anterior aspect of PTF jointNegative-Muscles of anterolateral compartment of leg2.Lt CPNUpto posterolateral fibular headRecurrent articular, deep peronealAnterior aspect of PTF jointNegative--3.Rt CPNUpto sciatic bifurcationRecurrent articular, superficial and deep peronealAnterior aspect of PTF jointNegative-Muscles of anterolateral compartment of leg4.Lt CPNUpto posterolateral fibular headRecurrent articular, deep peronealAnterior aspect of PTF jointNegative--5.Lt CPNUpto posterolateral fibular headRecurrent articular, deep peronealAnterior aspect of PTF jointNegative-Muscles of anterolateral compartment of leg6.Rt CPNUpto posterolateral fibular headRecurrent articularAnterior aspect of PTF jointNegative-Muscles of anterolateral compartment of leg 7.Rt CPNUpto neck of fibulaRecurrent articularAnterior aspect of PTFNegative-8.Rt obturator Along the lateral pelvic wall to pelvic brimAnterior divisionAnteromedial aspect of hip jointNegative-Adductor brevis and magnus9.Rt suprascapularSuprascapular to spinoglenoid notch--Negative-Supra and infraspinatus10.Lt proximal sciatic At sciatic notchArticular Posteromedial aspect of hip jointNegative--11.Rt tibial Upto tibial nerveArticular, branch to popliteus musclePosterior aspect of PTF jointNegative--12.Lt tibialUpto sciatic bifurcationArticular, branch to popliteus muscle, branch to tibialis posterior musclePosterior aspect of PTF and knee jointsNegative-Popliteus and tibialis posterior 13.Rt suprascapularFrom the level of AC joint to below the spinoglenoid notchArticular branch to AC jointAC jointNegative--PTF: Proximal tibiofibular. Table 4 Magnetic resonance features differentiating intraneural ganglion cyst from extraneural ganglion cystIntraneural ganglion cystExtraneural ganglion cystCyst sizeSmallLargeCyst shapeTubular beaded configurationGlobular Cyst pattern and locationIt is along the course of the nerve and its branches with no fat plane between the cyst and the nerveIt does not follow the course of the nerve; the nerve is seen separately from the cyst with an intervening preserved fat plane; usually located in between the fibula and peroneus longus muscle, with or without an intramuscular extension PTF joint connection Is present and the tail lies anteromedial to proximal fibula between 10-12 o’clock position on axial MR imagesIs present but located more superiorly and anterolateral to the proximal fibula at 12–2 o’clock position on axial MR imagesRelation with fibulaThe extension of the cyst along the articular branch appears to cross the fibula from medial to lateral (“Transverse limb sign”)The cyst never crosses the fibula and always lies anterior, anterolateral or lateral to the fibula (Absent “Transverse limb sign”)Muscle denervationCommonUncommonMR: Magnetic resonance. ................
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