Summary

A 76-year-old immunocompetent woman presented to our hospital with general fatigue. Her blood pressure was 60/40 mm Hg and pulse rate was 110 bpm. An electrocardiogram showed ST-elevation in the II, III and aVF leads with complete atrioventricular block. An echocardiogram and CT revealed pericardial effusion and a 6 cm solid tumour lying anterior to the heart. The right coronary artery (RCA) ran through the centre of the tumour, which bulged into the right atrium for 35 mm and vibrated. Emergent coronary angiography revealed 99% stenosis with delay at the proximal RCA; however, intravascular ultrasound showed no atheromatous changes, and the RCA was compressed by the extravascular mass. Successful coronary stenting improved the coronary flow. The following day, a biopsy was performed via thoracotomy without any events, the results of which showed diffuse-type large B-cell lymphoma histologically. Chemotherapy gradually reduced the tumour size, and the patient became stable haemodynamically.