Chapter 487. Cardiac Tumors

Primary cardiac tumors are rare at any age. About 90% are benign, and 10% are malignant, most of them sarcomas. These tumors are found mainly in the heart, but can occur in the pericardium or the great arteries. Secondary cardiac involvement from malignant tumors of adjacent organs (lung, thymus) or from kidney (Wilms tumor) or liver, or even remote organs, are also seen. The main types of tumors and age groups at which they occur are shown in eTable 487.1.

Most primary tumors have no specific symptoms. They present with pericardial involvement (pain, effusion, tamponade); features of obstruction to blood flow (congestive heart failure, syncope, murmurs, chest pain); conduction defects; arrhythmias (including sudden death); or peripheral embolization. Right-sided tumors may present with pulmonary embolism. Occasionally, tumors are found incidentally during cardiac imaging done for some other reason, including in fetuses.

Diagnosis of suspected tumors is usually by an imaging technique, usually transthoracic echocardiography. It can be supplemented by transesophageal echocardiography, magnetic resonance imaging, and cardiac catheterization and angiography. It is important to remember that an intracardiac mass might be a thrombus or a cyst, rather than a cellular tumor.

Rhabdomyomas are the most common tumors. They are single or multiple, in the ventricles or ventricular septum, and distinguishable from the surrounding compressed myocardium. They usually cause death in children under 5 years of age by obstructing blood flow, but often they regress. They may also cause arrhythmias or heart block. About half of them are associated with the syndrome of tuberous sclerosis, and about half the patients with tuberous sclerosis have cardiac rhabdomyomas. Surgery can be done for isolated tumors.

Fibromas are usually solitary and in the ventricular walls; they are hamartomas. They may cause obstruction but more often cause heart block or ventricular arrhythmias. Surgical excision has been successful.

Papillary fibroelastomas occur predominantly on valves, especially on the left side, and have the typical appearance of papillomas, with long fronds coming from a central stalk, resembling a sea anemone. They frequently embolize.

Myxomas are benign, usually pedunculated tumors that usually arise from the atrial septum near the foramen ovale; occasionally, they attach elsewhere in the atria or the ventricles. They are more common in the left than the right atrium and can even be biatrial. Atrial myxomas may simulate mitral or tricuspid valve disease because they often prolapse into the valve ring to produce obstruction or regurgitation; chest pain, dyspnea, or syncope may result. They frequently embolize to systemic or pulmonary arteries or obstruct pulmonary veins. They may be associated with fever, weight loss, myalgia, anorexia, Raynaud syndrome, as well as increases in sedimentation rate, γ-globulins, and serum antihyaluronidase titers. These systemic symptoms result from release of cytokines, especially interleukin-6, and often lead to misdiagnosis of collagen vascular disease or infective endocarditis. The diagnosis may be suspected clinically, especially if the mitral or tricuspid murmurs change from time to time or with differences of position. Surgical removal is usually successful, except that recurrences often occur in the familial types. About 5% of myxomas are familial or associated with cutaneous or endocrine syndromes. The Carney complex is an autosomal dominant mutation associated with alterations of the PRKAR1A gene on chromosome 17 in some patients. The syndrome includes skin pigmentation (lentigenes, blue nevi), myxoma, primary pigmented nodular adrenocortical disease, Sertoli cell tumors, and acromegaly

Teratomas are rare and usually occur in infants. They arise at the base of the heart or within the pericardium and may cause obstruction or arrhythmias. Surgical excision is possible.

Hemangiomas are usually in the atrial walls and may cure themselves by thrombosis and fibrosis.

Atrioventricular nodal tumors are vascular lesions of the atrioventricular node. Most of the patients have complete heart block, and some present with sudden death. Because the tumors are small and confined to the AV node, they are easily missed at routine autopsy.

The rare primary malignant tumors are usually sarcomas. They are often anaplastic, invasive melanomas and spread beyond the heart. Cure by surgery or chemotherapy is rare. Kaposi sarcoma, now seen more often because of its association with AIDS, is more often epicardial than myocardial and usually does not affect cardiac function.

Secondary metastatic malignant tumors can occur with non-Hodgkin lymphoma, neuroblastoma, Wilms tumor, melanomas, and a variety of sarcomas. They may produce obstruction, usually right-sided.1-28