DESCRIPTION An 80-year-old man presented to the facility, describing 6 months of increasing shortness of breath. Prior to admission, he had been bed bound for 5–7 days due to a chest infection. Observations revealed a pulse 79/min, blood pressure 119/79 mm Hg and a respiratory rate of 16/min. Oxygen saturation levelswere 95%on roomair, and hewas apyrexial. Aside from a 5-cm raised, jugular-venous pressure and left-sided basal crepitations, physical examination was unremarkable. The full blood count, inflammatory makers and coagulation profile were normal. An ECG showed atrial fibrillation at 85 beats/min, and the chest x-ray taken was normal. An echocardiogram showed a large, mobile, lobulated, right-atrial mass (figure 1), an ejection fraction of 41–50%, but no wall-motion abnormalities. The right ventricle was not dilated, but the pulmonary pressure was elevated at 46 mm Hg + jugular venous pulse. Treatment dose of lowmolecular-weight heparin was initiated. The following day, a CT pulmonary angiogram showed large, bilateral, pulmonary emboli involving the bifurcation of both pulmonary trunks (figure 2). This scan showed no evidence of the right-atrial mass, whichwas also confirmed on repeat echo. Despite this, the patient remained haemodynamically stable with unchanged oxygen saturations and an improvement in his breathing. The patient was loaded with warfarin. To date, no internal malignancy has been found to explain this thromboembolic event.