Skin biopsy or Woods light examination of these lesions establishes the diagnosis. There is no association of cardiac rhabdomyoma with any genetic or familial disorders with the exception of tuberous sclerosis. The differential diagnosis of fetal cardiac tumors includes, in order of descending frequency, rhabdomyoma, teratoma, fibroma, myxoma and hemangioma. Sonographically, these tumors appear as single or multiple, homogeneous, echogenic masses within the myocardium. Teratomas may appear as complex masses, typically involve the pericardium and are usually associated with pericardial effusions.
Fibromas tend to be discrete single lesions usually found in the left ventricular wall.
Myxomas are very rare lesions, usually involving the left atrium, and appear similar to rhabdomyomas. The prognosis depends on the number, size and location of the tumors as well as the presence or absence of associated anomalies. Intracavitary growth of the tumors may cause disruption of intracardiac blood flow leading to congestive heart failure and hydrops. Cardiac dysrhythmias, caused by compression of the conducting system, are also frequently identified. Rhabdomyomas grow slowly in utero but tend to regress spontaneously after birth 14 .