A 79-year-old man was admitted with increasing shortness of breath and general deterioration. The results of routine haematology and biochemistry tests on admission were unremarkable. A non-electrocardiogram-gated computerized tomography (CT) scan of his chest was arranged to investigate his symptoms. The CT showed a small pericardial effusion and raised the suspicion of a mass in the myocardium. A transthoracic echo showed a small global pericardial effusion with no echocardiographic evidence of tamponade. The echo scan also revealed a very thickened pericardium and a large mass arising in the interventricular septum with frond-like projections into the left ventricular cavity ( Fig. 1 , movies 1 and 2 ). A decision not to operate to try to obtain a sample for tissue diagnosis was made with the patient. The patient’s condition deteriorated rapidly and he died several days later. A hospital postmortem was performed and this confirmed the presence of a large mass in the septum, as seen on the transthoracic echo ( Fig. 2 ). This was in continuity with a pale and haemorrhagic fleshy tumour that encased the heart. Small tumour deposits were present in both lungs but not in any lymph nodes. The results of histological analysis confirmed the presence of a high-grade B-cell lymphoma.
