Severe Aortic Stenosis Due to a Unicommissural Unicuspid Aortic Valve with Commissural Intraleaflet Hemorrhage and Inflammation.

A unicuspid aortic valve (UAV) is a rare congenital anomaly that can cause aortic stenosis in young patients. We present the case of a 44-year-old woman who demonstrated an asymptomatic progression of severe aortic stenosis and ascending aortic dilatation originally detected during pregnancy, and who underwent valve and ascending aortic replacement to reduce the perioperative risk of breast cancer surgery. A gross examination revealed a unicommissural UAV with marked commissural thickening and intraleaflet hemorrhage. A histological examination confirmed micro-intraleaflet hemorrhage and macrophage-rich chronic inflammation. Repetitive commissural mechanical stress may contribute to remodeling and stenosis progression in the UAV.