A 19-year-old male was admitted because of exertional dyspnoea. The imaging studies revealed epicardial, pericardial and mediastinal masses. The tumours could not be resected through a minor thoracotomy, only biopsies could be taken. Analyses led to the final diagnosis of a monophasic synovial sarcoma. The patient preferred a conservative and palliative approach. Three months later he died at home. Autopsy demonstrated dramatic extension of the tumour masses. We conclude this report with a discussion on primary cardiac tumours. (Neth Heart J 2007;15:226-8.)Keywords: distress, sarcoma, heart I n May 2005, a 19-year-old male was admitted to our hospital suffering from exertional dyspnoea and a swollen abdomen. After a cold in January 2005 he started to lose weight and became progressively more dyspnoeic. He had not been exposed to asbestos.On physical examination, he was afebrile, sweaty, and in some distress. He had a blood pressure of 135/80 mmHg, with no pulsus paradoxus. Furthermore, he had congested jugular veins, diminished basal pulmonary breathing sounds, hepatomegaly, ascites and ankle oedema. The electrocardiogram showed a sinus rhythm, 90 beats/min, an intermediate axis and nonspecific repolarisation abnormalities.The laboratory data revealed mild liver function abnormalities (serum aspartate aminotransferase 108 U/l, alanine aminotransferase 97 U/l, lactate dehydrogenase 724 U/l, bilirubin 23 µmol/l), and a moderately elevated plasma pro-brain natriuretic peptide (95.8 pmol/l).Chest radiography demonstrated a widened cardiac shadow, bilateral pleural effusion and atelectasis of the left lung.An echocardiogram showed a normal left ventricular systolic function and a grade 3 mitral incompetence; a large amount of pericardial effusion was seen, without signs of tamponade, and a large mass within the pericardium. Furthermore, a large mass on top of the left atrium, posterior to the ascending aorta, could be observed. In addition, several small tumours were located on the epicardial surface (figure 1).A computed tomography and a magnetic resonance imaging scan (MRI) confirmed the pericardial and pleural effusions and clearly showed the epicardial, pericardial and mediastinal masses. A large mediastinal mass was present around the aorta and pulmonary artery (figure 2). These imaging studies, as well as the physical examinations, failed to reveal other masses in the trunk or extremities.The patient underwent surgery to obtain biopsies or excise the tumours. He was haemodynamically unstable and single lung ventilation was insufficient due to external compression of the right main stem bronchus. Via a minor anterior lateral thoracotomy, 1100 ml of haemorrhagic pericardial fluid was evacuated and a large pericardial window was created. A massive glassy tumour (measuring 10 cm x 10 cm x 15 cm) with extensive areas of necrosis and haemorrhage was found on the diaphragm within the thickened pericardium. The restrictive epicardium was interlaced with multiple small glassy tumours that bled easily. A lymphoid mass wa...