Right Atrial Angiosarcoma Presenting With Cardiac Tamponade, Hemorrhagic Pericardial Effusion, and Pulmonary Embolism: A Case Report.

Primary cardiac angiosarcoma is a rare and aggressive malignancy most commonly arising from the right atrium. We report a 43-year-old male patient who had no known comorbidities and was not receiving any regular medications. He presented with abdominal and epigastric pain and was found to have severe pericardial effusion, cardiac tamponade, a large right atrial mass, hemorrhagic pericardial effusion, and bilateral pulmonary emboli. He underwent urgent pericardiocentesis followed by open-heart surgery for excision of the right atrial mass, pericardial window creation, and mediastinal lymph node biopsy. Histopathology confirmed angiosarcoma infiltrating the right atrium, pericardium, and associated thrombus. Postoperative recovery was uneventful, and oncology recommended systemic chemotherapy. This case highlights atypical presentations of cardiac angiosarcoma and outlines the surgical and diagnostic approach.