[Tricuspid Valve Aneurysm Preoperatively Diagnosed with Right Atrial Tumor;Report of a Case].

A 79-year-old woman visited a hospital with coronary vasospastic angina and supraventricular tachycardia. Periodic inspection of echocardiography suggested a right atrial tumor which was not pointed out 6 months ago, but magnetic resonance imaging suggested a valve aneurysm. These findings were contradictory. We preoperatively diagnosed a cardiac tumor because of its new onset and mobility. Tumor resection and valve repair was planned in consideration of the risk of embolism. As a result, we finally diagnosed tricuspid valve aneurysm from the intraoperative findings and histopathological findings. We assumed that valve aneurysm was formed in the healing process of subclinical infective endocarditis. It was inferred that preoperative diagnosis of valve aneurysm is very difficult.