Quadricuspid aortic valve.

A case of quadricuspid aortic valve is described. The anomaly was unexpectedly found during operation for aortic valve replacement in a 70-year-old woman. Macroscopic and histological examinations of the valve showed no sign of previous inflammatory disease. Quadricuspid aortic valve must be considered, therefore, a malformation capable of leading to severe valve failure in later life.