A 67-year-old cachectic patient presented with a 6-week history of increasing breathlessness, loss of weight and appetite. Examination showed peripheral oedema and signs of cardiac tamponade. Transthoracic echocardiography demonstrated a thick walled cystic mass in the anterior pericardium (see online supplementary video 1), compressing the right ventricle (RV) and right atrium (RA). Further evaluation, including bubble contrast echocardiography, suggested a haematogenous connection between the RA and tumour cavity (see online supplementary video 2). This was confirmed on a contrast enhanced CT scan, with late contrast …