Primary cardiac tumors are extremely rare, with a prevalence of less than 0.3% in most pathologic series. Myxoma is the most common primary tumor of the heart and is usually benign.
These tumors are frequently isolated lesions, arising most often in the left atrium in the region of the fossa ovalis. Less commonly , myxomas may be detected in the right atrium, in the right or left ventricle, or in multiple sites within the heart. A familial pattern of myxomas can occur and is transmitted in an autosomal dominant manner.
In these patients, multiple cardiac myxomas may be present in association with a constellation of extracardiac abnormalities, including pigmented nevi cutaneous myxomas, breast fibroadenomas, and pituitary and adrenal gland disease. In addition, patients with familial myxoma may have recurrence of the tumor or tumors after surgical excision. Whether sporadic or familial, less than 10% of myxomas are malignant. Symptoms associated with myxoma are usually related to embolization of tumor fragments and obstruction of the mitral valve. In addition, patients may present with a constellation of nonspecific symptoms and laboratory abnormalities, including fever, malaise, weight loss, anemia, and elevated erythrocyte sedimentation rate. The diagnosis is usually made by echocardiography, with the transesophageal approach being the most sensitive method for detecting small left atrial tumors. Given the propensity for embolization, most myxomas are surgically removed when diagnosed. Because tumors may recur, follow-up echocardiograms should be performe.
Other less common benign tumors include papillary fibroelastomas, fibromas, and rhabdomyomas. Fibroelastomas are pedunculated tumors with frondlike attachments that usually arise from the surface of the mitral and aortic valve leaflets. These tumors do not result in valve dysfunction but may be a source of systemic em bolization. Fibromas most often arise within the interventricular septum and may be associated with arrhythmias or conduction disturbances.