Echocardiographic differentiation of mediastinal tumors from primary cardiac disease.

Three cases of mediastinal tumors (thymic cyst, fibrosarcoma, fibrolipoma) mimicking primary cardiac disease were studied by echocardiography. The echocardiographic findings of the thymic cyst are presented and the echocardiograms in the other two patients discussed. Intrinsic cardiac pathology was excluded and discovery of abnormal extracardiac echoes prompted further investigation. In each instance, the echocardiographic interpretation of the nature and position of each extracardiac mass was confirmed by surgery or autopsy. We conclude that echocardiography is a useful noninvasive technique in differentiating between cardiac and extracardiac disease, and should be performed whenever an unusual or enlarged cardiac silhouette is encountered.