[Accessory Mitral Valve Tissue Combined with Double-orifice Mitral Valve in an Elderly Patient:Report of a Case].

A 73-year-old man underwent echocardiography in order to assess any cardiac risk prior to surgery for renal cancer, and a large mobile mass was incidentally identified in his left ventricular outflow tract. Since a metastatic cardiac tumor was suspected, surgical resection of the mass was performed under cardiopulmonary bypass and hypothermic circulatory arrest. The mass had peduncles in the anterior leaflet of the mitral valve, the interventricular septum, and the papillary muscles. They were carefully removed by approaching through the aortic valve, and macroscopically suspected to be accessory mitral valve tissue. We observed the mitral valve via a transseptal approach to assess the function of the mitral valve and, as a result, a double-orifice mitral valve was identified. We should bear in mind that asymptomatic accessory mitral valve tissue can sometimes be detected in elderly patients, and is commonly associated with other congenital cardiac anomalies.