CARDIAC TUMORS



CARDIAC TUMORS | |

|Metastatic Neoplasms |

|The most common tumor of the heart is a metastatic tumor; tumor metastases to the heart occur in about 5% of patients dying|

|of cancer. Although any malignancy can secondarily involve the heart, certain tumors have a higher predilection to spread |

|to the heart. In descending order these tumors are carcinoma of the lung, lymphoma, breast cancer, leukemia, melanoma, |

|carcinomas of the liver, and colon. |

|Primary Neoplasms |

|Primary cardiac tumors are uncommon; in addition, most primary cardiac tumors are also (thankfully) benign. The five most |

|common have no malignant potential and account for 80% to 90% of all primary heart tumors. In descending order of frequency|

|(adults) the primary cardiac tumors are: myxomas, fibromas, lipomas, papillary fibroelastomas, rhabdomyomas, and |

|angiosarcomas (this last one is malignant). Only the myxomas and rhabdomyomas will receive any significant attention here. |

|Myxomas |

|Myxomas are the most common primary tumor of the adult heart (Fig. 11-28). Roughly 90% are located in the atria, with the |

|left atrium accounting for 80% of those. |

|Clinical Features |

|The major clinical manifestations are due to valvular "ball-valve" obstruction, embolization, or a syndrome of |

|constitutional symptoms, such as fever and malaise. Constitutional symptoms are probably due to the elaboration of |

|interleukin-6, a major mediator of the acute-phase response. Echocardiography is the diagnostic modality of choice, and |

|surgical resection is almost uniformly curative. |

|Rhabdomyomas : |

|Rhabdomyomas are the most frequent primary tumor of the heart in infants and children; they are frequently discovered |

|because of an obstruction of a valvular orifice or cardiac chamber. Cardiac rhabdomyomas occur with high frequency in |

|patients with tuberous sclerosis . Rhabdomyomas are probably better classified as hamartomas or malformations rather than |

|true neoplasms; recent work suggests that these lesions may be caused by defective apoptosis during developmental |

|remodeling. |

|Other Primary Cardiac Tumors |

|Lipomas are localized, poorly encapsulated masses of adipose tissue, which can be asymptomatic, can create ball-valve |

|obstructions (as with myxomas), or can produce arrhythmias. Lipomas are typically located in the left ventricle, right |

|atrium, or atrial septum.Papillary fibroelastomas are curious, usually incidental, lesions that can sometimes embolize. |

|They are generally located on valves, forming hairlike projections that grossly resemble sea anemones. Histologically there|

|is myxoid connective tissue containing abundant mucopolysaccharide matrix and laminated elastic fibers, all surrounded by |

|endothelium. While these masses are called neoplasms, it is possible that at least some fibroelastomas represent organized |

|thrombi.Cardiac angiosarcomas and other sarcomas are not clinically or morphologically distinctive from their counterparts |

|in other locations and therefore need no further comments. |

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