A 62-year-old woman came to our clinic with a 2 month history of severe exertional dyspnoea. Investigations showed chronic pulmonary embolism and atrial septal defect, along with a right ventricular 3 × 2 cm mobile mass arising from the apex as seen on the preoperative transoesophageal echocardiography (appendix). A subsequent MRI showed the mass to be completely intracavitary and not infi ltrating into the wall (appendix). After standard median sternotomy and cardiopulmonary bypass, a right atriotomy was done. The tricuspid valve was retracted and a long elliptical mass arising from papillary muscles just at the apex was identifi ed (fi gure). It was not infi ltrating the wall, but extended almost to the right ventricular outfl ow tract. The mass was excised in total along with its base, and then sent for further pathological examination. Histology confi rmed a cardiac calcifi ed amorphous tumour (CAT) (appendix). First classifi ed as non-neoplasmic intracardiac masses in 1997, CATs can arise in all four chambers of the heart, and are characterised by nodular calcium deposits over a fi brinous matrix background. The pathogenesis of CATs remains uncertain, and excision is necessary for diff erential diagnosis against common cardiac myxomas. Excision of CATs serves both diagnostic and therapeutic purposes. Lancet 2014; 383: 815