Ninety percent of these tumors are benign 13 . In our case, the fibroma appeared as a very echogenic mass without acoustic shadowing. This mass was more discrete than that of rhabdomyoma, which are often more bulky. The etiology is unknown and familial incidence has not been described. There is some debate as to the pathogenesis of the cardiac fibroma.
Some investigators believe it to represent non-neoplastic proliferation of fibrous tissue.
They point to the lack of a distinct capsule and presence of myocardial fibers within the proliferation as evidence for this view. Others believe this to represent a true neoplasm of fibroblastic origin. Associated anomalies Congenital cardiac tumors can be associated with severe obstruction of blood flow, hypoplasia of the cardiac chambers or great vessels, atresias of the cardiac valves, disturbances of the conduction system, nonimmunologic hydrops fetalis, pericardial effusion and embolic phenomena. Fibroma has been associated with orofacial cleft in one case 3 and cystic renal dysplasia in another 27 . The differential diagnosis of a cardiac tumor includes rhabdomyoma, myxoma, teratoma and hemangioma.