A case of aortic bicuspid valve with thrombus formation without severe stenosis and calcification.

We encountered a patient with a history of juvenile cerebral infarction with an unknown cause in whom a mass adhering to the aortic valve (AV) surface was observed on echocardiography performed upon the development of heart failure. Mild AV stenosis (AS) with moderate regurgitation was noted, and valve repair was applied. It was found during surgery that the AV was a bicuspid valve (BAV) without calcification, and the mass was an organized thrombus. Thrombus formation on the AV with severe AS in BAV has been reported, but the organic lesion in the AV was mild in this patient.