[Caseous Calcification of Mitral Valve Annulus;Report of a Case].

We report a case of an 80-year-old female presenting with a mitral valve tumor. Postoperatively, pathologic diagnosis was caseous calcification of the mitral annulus. In surgery, she successfully underwent a mitral valve replacement with a 20 mm mechanical valve. The importance of correctly making a preoperative diagnosis cannot be over-emphasized. Technical discussion on possibility of mitral valve repair and patient-prosthesis mismatch after mitral valve replacement is also made.