[Quadricuspid Aortic Valve: Report of a Case].

A 69-year-old woman with general fatigue was admitted to our hospital for further examination of mediastinal lymph node swelling. Mediastinal lymph node sampling was planned. Preoperative transthoracic echocardiography revealed severe aortic regurgitation, and aortic valve replacement combined with mediastinal lymph node sampling was performed. Following lymph node sampling, the ascending aorta was opened, and the aortic valve was found to be quadricuspid. An accessory cusp was existed between the left coronary cusp and the non coronary cusp. Aortic valve replacement was successfully performed. A quadricuspid aortic valve is a very rare anomaly.