Clinical introduction An 82-year-old woman suspected of a cardiac tumour was referred for evaluation. Patient's medical history included atrial fibrillation, implantation of a VVI (ventricular stimulation) pacemaker 3 years earlier due to advanced atrioventicular (AV) block, arterial hypertension and hypothyroidism. Patient was adequately anticoagulated with warfarin (international normalized ratio (INR) 3.0 at admission). She reported occasional palpitations and a 2 kg weight loss in the last 2 years, but denied shortness of breath, chest pain, malaise, fever, chills or cough. Blood samples were taken for tests and cultures. Red blood cells, haemoglobin, white blood cells, platelets, C- reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were within normal ranges. Blood cultures were negative. Echocardiogram (figure 1A) (see online supplementary videos 1 and 2) and cardiac CT were performed (figure 1B).

Question Which of the following is the most likely diagnosis?

1. Caseous calcification of the mitral annulus

2. Coconut left atrium

3. Mitral valve myxoma

4. Periannular abscess

Question