A 75-year-old man was admitted to the hospital because of a pericardial effusion.After 3 L of blood-stained pericardial fluid was drained, clinical examination together with echocardiography and chest computed tomography showed a tumor in the right atrium. At operation a pedunculated vascular tumor was found with a broad base which was embedded in the atrial wall and extended into the pericardium.A wide resection was performed resulting in a large defect of the right atrial wall. The defect was reconstructed with a pericardial patch. The patient did well postoperatively, but bloody pleural effusion developed later, presumably because of pulmonary metastasis. The patient died 2 months after surgery as a result of respiratory failure