[Mitral Valve Infective Endocarditis Caused by Parvimonas Micra].

We encountered a rare case of infective endocarditis caused by a common Gram-positive anaerobic coccus Parvimonas micra, originating from colorectal cancer. The patient was a 78-year-old female, presented with fever, speech disorder, and right hemiplegia resulting from stroke. Transthoracic echocardiography revealed mitral regurgitation and a mobile vegetation on the mitral valve. Computed tomography( CT) of the abdomen revealed a mass lesion or abscess in the abdomen that was highly suggestive of relevance with infective endocarditis. An urgent surgery was initially performed to prevent further cerebral infarction, with abdominal surgery planned as the second stage. During the cardiac surgery, we observed a large defect following the partial resection of an infected posterior leaflet, and the adjacent calcified annulus was repaired using autologous pericardium. This effectively controlled mitral regurgitation. Both blood cultures yielded Parvimonas micra, which has recently become known as a biomarker for colorectal cancer. Subsequently, the patient's colorectal cancer was excised. Following the surgery, the patient was free from infection and underwent a rehabilitation program.