The authors report a case of right atrial angiosarcoma in a 29 year old man
presenting with massive pericardial effusion. This case illustrates the va
lue of MRI in the preoperative evaluation, providing accurate information a
bout the site and extension of the tumor, and even about the malignant natu
re of the lesion. Multiplanar transesophageal echocardiography did not prov
ide any additional information in this case.