Primary Cardiac Angiosarcoma Accompanying Cardiac Tamponade.

A de novo cardiac malignant tumor is rare and sometimes challenging to diagnose. We encountered a 67-year-old man without any medical history complaining of dyspnea on effort. On admission, his hemodynamics were deteriorated due to cardiac tamponade, which was improved by percutaneous drainage of 1,200 mL pericardial effusion, showing 11.0 g/dL of hemoglobin. We suspected primary cardiac malignancy following multidisciplinary tests, and a cardiac biopsy via sternotomy demonstrated the definitive diagnosis of primary malignant tumor (angiosarcoma) infiltrating the right atrial myocardium. We initiated weekly paclitaxel therapy. Further studies are warranted to establish the optimal diagnostic and therapeutic strategy for de novo cardiac malignancy.