Right Atrial Calcified Ball Thrombus Mimicking a Myxoma.

An 80-year-old woman was admitted to our hospital because of congestive heart failure. Transthoracic echocardiography revealed severe aortic valve stenosis, and a mobile calcified mass was attached to the interatrial septum in the right atrium. We suspected that the mass was cardiac myxoma. We urgently performed aortic valve replacement and resection of the mass. The histological diagnosis of the mass was thrombus, and her post-operative course was uneventful. Although the mechanism of right atrial thrombus formation in our case was unclear, it is important to continue anticoagulation therapy after surgery to avoid recurrence. Furthermore, strict follow-up in this patient is needed.