Intussusception due to a colon adenoma associated with Streptococcus bovis meningitis

Streptococcus bovis (S. bovis) is a member of the human gastrointestinal tract flora. The relation between S. bovis bacteremia and colorectal neoplasm is well known in foreign countries but hardly known in Japan. We present a case of colon adenoma associated with meningitis caused by S. bovis. A 39-year-old man was admitted to our hospital because of severe headache and was given a diagnosis of meningitis. CT showed intussusception in the ascending colon. The intussusception reduced spontaneously. His cerebrospinal fluid cultures and blood cultures were positive for S. bovis. A colonoscopy showed an adenoma in the ascending colon. We considered that colon adenoma and S. bovis bacteremia were related, therefore ileocecal resection was performed after meningitis was cured. The pathological findings showed tublovillous adenoma with severe atypia of the ascending colon.