Pathology 10 AM - Angelfire



Pathology 10 AM Scribes: Kellie & Patti

Dr. Jeffrey Oliver January 10, 2001

Head & Neck Pathology, Continued

Upper respiratory Tract Infections

• Infectious Rhinitis - the common cold

➢ usually caused by rhinoviruses (majority), coronaviruses and adenoviruses

➢ patient presents with low-grade fever and a runny nose

• Allergic Rhinitis

➢ clinically very similar to infectious rhinitis, except no fever

➢ an IgE-mediated hypersensitivity reaction

➢ patient presents with runny nose and sneezing

➢ should see eosinophils on a nasal smear

➢ 20% of population suffers from allergic rhinitis

• Nasal polyps

➢ If you suffer from either type of rhinitis for any length of time, you can develop nasal polyps.

➢ You get edema of the nasal stroma, which causes outpouchings of the mucosa.

➢ The polyps may get as large as 3-4 cm, and they can cause problems by obstructing the sinus orifices.

➢ Histologically, you see edematous stroma, usually containing eosinophils and other inflammatory cells (Fig 17-6, p.762 in Robbins and pictures 5.7-5.8, p.94 in Curran).

• Sinusitis

➢ Colds, allergic rhinitis, obstructions due to nasal polyps, and some believe deviated septums can all contribute to sinusitis. The vast majority of cases of sinusutis are due to complications of rhinitis.

➢ Occasionally you can get an infection in the maxillary sinus that is due to a tooth infection that erupts up through the base of the sinus.

➢ You get sinusitis because of impaired drainage of the orifices, and it is usually caused by components of the nasal or oral flora. The most common organisms are Haemophilus influenzae and Streptococcus pneumoniae.

➢ A trapping of pus within the sinuses is termed an empyema, the same term used when there is pus within the pleural cavity.

• Rhinocerebral Mucormycosis

➢ a severe fungal infection caused by fungi in the class Zygomycetes (Mucor is the most common cause.)

➢ seen almost always in diabetics, especially when they are in DKA (diabetic ketoacidosis)

➢ The infection is called rhino-cerebral because it invades from the nose up into the brain and causes life-threatening infections, like brain stem infarcts.

➢ Slide shown of a lady with a serious head and neck infection (the whole right side of her face was very swollen), but you can't diagnose mucormycosis just by appearance.

➢ Slide of tissue with a special fungal stain showing black fungal hyphae and many inflammatory cells

➢ Treatment of choice is surgical excision.

• Pharyngitis and Tonsillitis

➢ The most common cause is the Group A beta-hemolytic streptococci or Streptococcus pyogenes. There are also common viral causes that are often overlooked, such as EBV.

➢ Not every case of pharyngitis or tonsillitis is treatable with antibiotics.

➢ It is important to rule out group A strep as the cause because of the possible complications of rheumatic fever and glomerulonephritis.

➢ These can be chronic infections and lead to rather massive lymphoid hyperplasia; sometime the tonsils will almost occlude the posterior pharynx - that is called follicular tonsillitis.

➢ Slides shown of pharyngitis and acute tonsillitis with pus on the tonsils.

➢ Today we do rapid strep testing. If the test is positive, the patient has strep throat and you do not need to do a culture. If the rapid test is negative, then do a throat culture, as the sensitivity is not great on the rapid test.

➢ Slide of beta hemolytic strep on blood agar

➢ Slide of gram stain showing gram-positive cocci in chains.

➢ You don't want to miss a group A strep infection.

• Laryngitis

➢ Slide of a larynx, showing acute laryngoepiglottitis. The airway is almost swollen shut, and this is an acute medical emergency. It is not very common, usually seen in children. 90% of the cases are caused by H. influenzae.

EAR

• Otitis Media

➢ Slide shown of a bulging eardrum. This is a horrible case of otitis media, with a lot of pressure behind the tympanic membrane. Redness is not diagnostic because the child crying can cause it.

➢ Mainly occurs in kids as they have the shortest Eustachian tubes. Most kids have an average of 5-6 cases of otitis media during their first year of life.

➢ Complications

▪ Cholesteatoma - a kind of a reactive scarring process in the middle ear. There is deposition of cholesterol in the middle ear, creating fibrotic nodules with cholesterol, which may interfere with the actions of the ossicles. Slide showing cholesterol clefts with inflammation, fibrosis and scarring.

▪ Mastoiditis - a more serious complication where the infection spreads into the mastoid air cells. The worst-case scenario is when it spreads to the meninges and causes meningitis or brain abscesses. These are rare, but be aware that they can occur.

• Labyrinthitis

➢ Inner ear infections, which usually present with vertigo

➢ These are almost always viral infections so all you can do is give steroids to help calm the inflammation.

NASAL TUMORS

• Dr. Oliver showed a horrible picture of a ?woman? with a huge growth and black things all over what was left of her face. This is called a lethal midline granuloma. It is not a good thing to have. This is a clinical term as there are several histological entities that can give you a similar picture. It is basically a rapidly growing mass in the midline of the face. The majority of these cases are due to a lymphoma called angiocentric lymphoma. It’s a really bizarre tumor, which rapidly progresses and used to be fatal, but now that we know they are lymphomas, they respond to chemotherapy pretty well. Hopefully you will never see a patient like this.

• Benign Nasal Tumors

➢ Nasopharyngeal angiofibroma

▪ Gross slide - a tan rubbery mass, with quite a few large blood vessels.

▪ Histologically, you see fibrotic stroma with lots and lots of blood vessels.

▪ It is benign tumor, but it has a tendency to bleed a lot during surgery.

▪ The tumor may occur in other places, but characteristic in the nose.

➢ Inverted papilloma

▪ Slide shown (Fig 17-7, p.764 in Robbins and 5.10, p.95 in Curran) - instead of growing out like an exophytic mass, the tumor grows inward.

▪ It may occur in other places, but again it is characteristic in the nose.

▪ It is benign in that it practically never metastasizes, but it is very aggressive locally. These need to be taken out and have a high recurrence rate.

▪ They are believed to be caused by HPV – “Not our friend!”

➢ Solitary or Isolated plasmacytoma

▪ Slide of tumor in woman's mouth. Histology shows sheets of plasma cells, which looks identical to a malignant plasma cell tumor (similar to 5.21, p.98 in Curran).

▪ When it is a localized proliferation like this it is benign, but you always have to worry about multiple myeloma, which is a malignant tumor of plasma cells usually in the bone marrow or bones. When there is a solitary plasmacytoma in the nose, it is usually benign and almost never progresses to myeloma.

• Malignant Nasal Tumors:

➢ Olfactory neuroblastoma or esthesioneuroblastoma

▪ He showed a slide with sheets of small blue cells. Pathologists have a differential diagnosis for the “small blue cell tumors’; it includes neuroblastoma, lymphoma, rhabdomyocytoma, Ewing's sarcoma, and peripheral neural ectodermal tumor, which all look pretty much the same.

▪ When you have a small blue cell tumor arising from the superior aspect of the nose it is called an olfactory neuroblastoma.

▪ These are very aggressive, very malignant tumors. They tend to metastasize widely early.

▪ They arise from neuroendocrine cells that are in the olfactory mucosa in the superior aspect of the nose.

▪ Another slide showing rosettes of cells called Homer-Wright Rosettes. If this tumor arose from the adrenal gland it would be called a neuroblastoma. If it arose from the cerebellum it would be called a medulloblastoma.

➢ Nasopharyngeal carcinoma

▪ This tumor is firmly established as being caused by EBV—“another thing that is not your friend!”

▪ The interesting thing is its geographic and age distributions. Here in the US this tumor is very rare. It is the most common malignant tumor of childhood in North Africa. In Southern China it is the most common malignant tumor in adults.

▪ Histologically, it is basically a squamous cell carcinoma with 3 different forms.

- The first one is a keratinizng squamous cell carcinoma.

- The second form is a non-keratinizing squamous cell carcinoma, which is a little trickier to diagnose because it doesn't have keratin pearls. You have to look for the intracellular bridges discussed in the last lecture.

- The third form is undifferentiated carcinoma. Slide shown (Fig 17-8, p.764 in Robbins and 5.19, p.98 in Curran) – the characteristic feature is the many lymphocytes intimately associated with the tumor. The lymphocytes are not really part of the tumor, just a reactive process.

□ This was formerly called a lymphoepithelioma, but this name sounds benign; you may see this term but nasopharyngeal undifferentiated carcinoma is a better name for it.

□ These usually are really bad news as they grow silently until they kill you, they are usually unresectable, and they present with wide metastases. Standard treatment is radiation, and the 3-year survival is around 50-70%. Usually doctors measure tumors in terms of 5-year survival, so this is probably somewhat lower than that at five years. This is a very aggressive tumor.

□ Slide of a tumor that invaded the brain – large mass around the optic chiasm, but the smaller tumor on the pons is probably what killed the person.

NECK

• There a couple of different types of cysts found in the neck:

➢ Branchial cleft cysts

▪ They were thought to be embryologic remnants of the branchial pouches or branchial arches. Now they think that these cysts may be remnants from little salivary gland inclusions that are in lymph nodes in the neck. Dr. Oliver doesn't know which is true.

▪ Slide (similar to 5.1-5.2, p.92 in Curran) - you see a cystic space with a simple lining, but in the wall behind the epithelium there is a lot of lymphoid tissue.

▪ These almost always occur on the anterolateral sides of the neck, so you will see them near the edges of the sternocleidomastoid.

➢ Thyroglossal duct cyst

▪ This cyst looks somewhat similar to the one above, but it is always in the midline. Remember from embryology that when the thyroid is developing, it starts from the base of the tongue at the foramen cecum and works its way down to where it lies in the anterior neck. Along the way you can get little portions of that tract that remain patent and these portions can become thyroglossal duct cysts.

▪ The epithelium surrounding the cyst depends on the location of the cyst. Close to the tongue, you will normally see a stratified squamous epithelium, and the further down you go the more likely you are to see a more glandular columnar type epithelium.

▪ Slide shown (6.10, p.107 in Curran) - in the wall of the cyst you will often see a few thyroid follicles. This characteristic plus the cyst being in the midline of the neck gives away the diagnosis.

▪ These are pretty stubborn and hard to get rid of; if you do not do a complete excision they will reoccur. The surgeon usually excises the mid-portion of the hyoid bone because the tract goes right through there.

▪ Why worry about these things since they are not malignant? They have a tendency to become infected and can cause bad head and neck infections. That is why we like to get rid of both of these kinds of cysts.

• Tumors of the neck:

➢ Paraganglioma or Carotid Body Tumor - this is a tumor that is not that common, but most commonly found in the neck

▪ Slide (Fig 17-11, p.768 in Robbins) – see little collections of neuroendocrine cells, usually associated with the paraganglia of the sympathetic chains or the parasympathetic system.

▪ One of the most common places for them is right at the bifurcation of the common carotid artery. There is a little paraganglion there called the carotid body, which serves as an oxygen and CO2 sensor. Those cells can give rise to this type of tumor. When they do it's called a carotid body tumor or a carotid body paraganglioma. It is also sometimes called a chemodectoma. These tumors are very vascular, so they bleed very easily.

▪ Histologically, they look like encapsulated benign tumors, but they are not always benign. The tumor cells are in little balls or clusters called Zellballen with a rich vascular network. There are capillaries running between all the cell balls. The tumor cells themselves usually look quite benign; they have very uniform nuclei and very few mitoses. But sometimes they are malignant—you cannot tell by looking. Bottom line – it looks and sounds like something benign, and it usually is but not always.

SALIVARY GLANDS

• Sialadenitis - inflammation and swelling of the parotid gland

➢ Mumps was the most common cause of parotitis. He showed a slide of a little girl with bilateral swelling of her parotid glands.

➢ You can also get bacterial sialadenitis that is usually due to obstruction of the ducts with stones.

• Sialolithiasis - stone in the salivary duct. This can be caused by impaction of food at the orifice, a scarring injury, or chronic dehydration. A person with sialolithiasis is at risk for severe bacterial sialadenitis. He showed a slide of a submandibular gland with a stone in it.

• Tumors of the salivary glands – a variety of tumors “loved by pathologists because these tumors are weird and we are weird people.” Most adenocarcinomas from one place are very similar to an adenocarcinoma from anyplace else, but salivary gland tumors are very characteristic.

➢ In general salivary gland tumors are not very common, and the majority of them occur in the parotid glands (70-80%). About 10% occur in the submandibular glands, and the remainder occur in the sublingual and minor salivary glands. Don't forget that salivary glands are not just in the mouth, but minor ones are found in the ear canal and also down the bronchial tree. He has seen salivary gland tumors arising down in the lung.

➢ Another important thing is that the larger the gland the less likely that the tumors will be malignant. Most tumors in the parotid gland are benign. A tumor arising from a minor salivary gland is more likely to be malignant.

➢ All but one of the salivary tumors (Warthin tumor) are more common in females than males.

➢ Pleomorphic adenoma

▪ This is the most common salivary tumor. It is also called a mixed tumor because both the glandular and stromal parts of the gland are believed to be neoplastic. It is called pleomorphic because histologically these tumors can look very different from each other depending on how much of the epithelial component and how much of the stromal component they have.

▪ These usually occur in the parotid gland but can occur in other glands, too. They look very well circumscribed at least grossly. They are benign, but often there are tiny microscopic fingers extending beyond the visible edge of the tumor. Since it looks so well circumcised it is real tempting for the surgeon to just pull it out and be done with it; but microscopic fingers will be left behind, and the tumor will reoccur about 25% of the time. The best surgery for this is a partial parotidectomy so that plenty of normal tissue around the tumor is removed, which reduces the risk of reoccurrence.

▪ They usually present as a painless, slow-growing mass.

▪ Histo slide (Fig 17-13, p.770 in Robbins) showing the glandular epithelial component and the stromal or mesenchymal component. There is often a lot of mucin in the stroma, so it is called a mixoid stroma – very characteristic. These tumors may also produce a little bit of cartilage and rarely even bone.

▪ In the gross picture (similar to Fig 17-12, p. 770 in Robbins), the glistening shiny appearance is probably due to some cartilage production in there.

▪ These tumors are generally benign, but once in a while if neglected and not removed, a carcinoma may arise, which is called carcinoma ex pleomorphic adenoma, or carcinoma ex mixed tumor. When that happens it is a pretty aggressive tumor with a 5-year survival rate of about 50%. This is rare.

➢ Warthin's tumor

▪ This is the only salivary tumor more common in men. It is the second most common salivary tumor behind the pleomorphic adenoma.

▪ It is also known as the papillary cystadenoma lymphomatosum. It occurs almost exclusively in the parotid gland. It is also the most likely to be multifocal (10%) or bilateral (10%).

▪ For some reason smokers have a much greater risk of this tumor than non-smokers do, which may explain why it is more common in males. Historically men were bigger smokers.

▪ The histology is really strange. Slide (Fig 17-14, p. 771 in Robbins) – it is kind of papillary, with little fingers of tumor sticking out. There are two-layers of cells lining the cysts; these cells are very dark pink (eosinophilic), which is called oncocytic change. The oncocytic change or dark staining is due to packing of the cells with abnormal mitochondria. You see a double layer of oncocytic columnar cells and a lot of lymphocytes underneath the epithelial tissue.

▪ These are benign tumors that do not metastasize, but they have been described in cervical lymph nodes. Those are not metastases; sometimes these tumors just arise in cervical lymph nodes.

➢ Mucoepidermoid carcinoma

▪ 60-70% of these occur in the parotid, the rest in smaller salivary glands. Overall this is the most common malignant salivary tumor. It is not as common as the pleomorphic adenoma or the Warthin's tumor, but those are benign.

▪ Histologically (Fig 17-15, p. 772 in Robbins), you see epithelial cells that are basically squamous cells, mucous secreting cells and intermediate hybrids. These are divided into low, intermediate, or high grades depending on how “ugly” they look. The low-grade ones are barely malignant - they are locally aggressive but rarely metastasize, with a 5-year survival rate of 90%. The high grade mucoepidermoid carcinomas are much more aggressive; they have a very high local recurrence rate, and about 30% of them metastasize, lowering the 5 year survival rate to 50%. The intermediate grades are somewhere in between.

➢ Adenoid cystic carcinoma

▪ This tumor is rarely found in the parotid glands. It loves the minor salivary glands and is the most common tumor of minor salivary glands overall.

▪ Slide of gross tumor on the side of the tongue. They are usually fairly small, but very locally invasive and aggressive.

▪ Histo slide (Fig 17-16, p.773 in Robbins) – they have weird shaped islands of glandular or epithelial cells, and some of the tumors have lumens. The cribiform pattern is common – this looks like a solid sheet of cells with holes punched in it. In the little holes, there is often a thick material that is thought to be extra basement membrane material.

▪ Another feature of the adenoid cystic carcinomas is that they almost always demonstrate perineural invasion. Some people say with out perineural invasion the diagnosis is in doubt. This makes them quite painful.

▪ Theses tumors are very insidious. They do not kill you right away; they are slow growing, but extremely stubborn and hard to get rid of. Eventually, nearly everybody dies from them. 50% of them will metastasize widely over 5, 10,or 15 years. The 5-year survival rate may be 80-90%, but the 10 and 20 year survival rates are extremely low.

➢ Acinic cell carcinoma

▪ This tumor is less common than any of those discussed already.

▪ It is usually a small discrete tumor in the parotid gland.

▪ Histologically, they look like relatively normal serous glandular cells that you would expect to see in the parotid, but the architecture is all screwed up – there are just sheets of cells. You can’t see ducts associated with them or discrete acini - just sheets of serous cells.

▪ This is a pretty indolent tumor. The 5-year survival rate is about 90%, and the 20-year survival rate is about 60%. It is not nearly as deadly as the mucoepidermoid or the adenoid cystic carcinomas.

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