A 49-year-old man was admitted to our clinic for management of hyperlipemia, gout, diabetes, and obesity.
A circumferentially growing asymptomatic tumor was found in the ileum at just oral side of the ileocecal valve on a screening colonoscopy. The tumor was located in the ileum end on barium enhanced colonography. No lymph node enlargement or metastasis lesion was detected on an abdominal CT scan. We judged that surgery might result in radical treatment and laparoscopic and video-assisted resection of the tumor was performed. Pathologically, monoclonal lymphocyte with mild atypia increased and permeated in germ center of the tumor on H & E staining. Immunohistochemical staining of the tumor celles by monoclonal antibody of L26, Bcl-2, and CD10 was positive. The tumor was diagnosed as mucosa-associated lymphoid tissue lymphoma (MALToma). Post-operative course of the patient was uneventful. The patient was discharged from the hospital on 13^th day after the surgery.