Tumor encasement of the heart simulating pericardial effusion

A 56-year-old woman with breast carcinoma was referred for an urgent two-dimensional echocardiogram. An anterior and posterior echo-free space suggesting pericardial effusion and a new right atrial mass were detected. A few hours later the patient died suddenly. Necropsy revealed neoplastic encasement of the heart without pericardial effusion.