Neoplastic Diseases of the Heart

Primary cardiac tumors are rare and constitute only a small fraction of all tumors that involve the heart or pericardium. Metastases from malignant tumors elsewhere are more frequent. Tumors involving the heart are bronchogenic carcinoma, carcinoma of the breast, malignant melanoma, the lymphomas, renal cell carcinoma, and, in patients with AIDS, Kaposi's sarcoma. These are often clinically silent but may lead to pericardial tamponade, arrhythmias and conduction disturbances, heart failure, and peripheral emboli. The diagnosis is often made by echocardiography, but MRI and CT scanning are also helpful. Electrocardiography may reveal regional Q waves. The prognosis is dismal; effective treatment is not available.

The commonest primary tumors of the heart are atrial myxomas. These tend to occur in middle age, more often in women than in men. They usually originate in the intraventricular septum, with over 80% growing into the left atrium. Myxomas are benign tumors but can embolize systemically.

Patients with myxoma can present with a picture of a systemic illness, obstruction of blood flow through the heart, or signs of peripheral embolization. The characteristic picture includes fever, malaise, weight loss, leukocytosis, elevated sedimentation rate, and emboli (peripheral or pulmonary, depending on the location of the tumor). This picture is often confused with infective endocarditis, lymphoma, other cancers, or autoimmune diseases. In other cases, the tumor may grow to considerable size and produce symptoms by obstructing mitral flow. Episodic pulmonary edema (classically occurring when an upright posture is assumed) and signs of low output may result. Physical examination may reveal a diastolic sound related to motion of the tumor ("tumor plop") or a diastolic murmur similar to that of mitral stenosis. Right-sided myxomas may cause symptoms of right-sided failure. The diagnosis is established by echocardiography or by pathologic study of embolic material. MRI is also useful. Contrast angiography is usually not necessary. Surgical excision is usually curative.

Other primary cardiac tumors include rhabdomyomas, fibrous histiocytomas, hemangiomas, and a variety of unusual sarcomas. The diagnosis may be supported by an abnormal cardiac contour on x-ray. Echocardiography is usually helpful but may miss tumors infiltrating the ventricular wall. It is likely that MRI will be useful as well.

Roberts WC: Primary and secondary neoplasms of the heart. Am J Cardiol 1997;80:671.