Primary cardiac angiosarcoma of the right atrium undiagnosed by transvenous endocardial tumor biopsy

A 50-year-old man was admitted with acute pericarditis, Echocardiography de monstrated a large mass on the right atrial free wall along with a pericard ial effusion. We performed transvenous biopsy of this mass under transesoph ageal echocardiographic guidance. Though the biotome obtained the mass, the pathological findings were of organized thrombus. Two weeks later, a new p recordial mass appeared around the left third rib and was suspected to be a metastasis. Incisional biopsy of this mass gave the diagnosis of angiosarc oma.