Streptococcus Mitis Endocarditis Associated with Early Gastric Carcinoma.

We report a case of Streptococcus mitis endocarditis associated with early gastric carcinoma. A 71-year-old man who had been diagnosed with aortic regurgitation (AR) two years previously was referred for valve surgery and evaluation of elevated inflammatory markers. Four months previously, atrophic gastritis, early gastric adenocarcinoma, and colon polyp had been identified in the patient during endoscopy. However, Helicobacter pylori testing was negative. On admission, he had no dental diseases or recent oral procedures. Echocardiography demonstrated severe AR and mobile vegetation on the aortic valve. Magnetic resonance imaging revealed cerebral embolism and spondylodiscitis. Blood cultures grew Streptococcus mitis. At surgery, destruction of the left cusp with vegetation and a perforation of the non-coronary cusp were found; in addition, aortic valve replacement was performed. Although the association between Streptococcus bovis bacteremia and colon neoplasm is well recognized, the association between Streptococcus mitis endocarditis and gastrointestinal carcinoma should also be kept in mind.