False-positive echocardiographic diagnosis of pericardial effusion. Result of tumor encasement of the heart simulating constrictive pericarditis.

A 46-year-old man had advanced squamous cell carcinoma of the lung and apparent constrictive pericarditis. Echocardiographic studies twice demonstrated apparent pericardial effusions, but pericardiocenteses were unsuccessful. Tumor encasement of the heart was diagnosed clinically and at necropsy. This entity is yet another cause of a false-positive echocardiographic diagnosis of pericardial effusion.