[A Case of Medullary Carcinoma of the Colon with Poor Prognosis].

An 87-year-oldwoman was referredowing to lightheadedness. Severe anemia(Hb 3.9 g/dL)was detected, and colonoscopy revealeda circumferential elevatedlesion at the transverse colon(Group 5, por). The patient was diagnosed with colon cancer(cT4a, N0, M0, Stage Ⅱ), andright hemicolectomy was performed. Immunochemical analysis showedthat the lesion was MLH1- andPMS2- and confirmed a diagnosis of medullary carcinoma. Although the patient was discharged 48 days after surgery without any incident, she was readmitted because of lower leg edema. Liver metastasis and peritoneal dissemination were suspectedon performing computedtomography, andthe patient died3 5 days after readmission. Medullary carcinoma has molecular pathological features such as methylation of the promoter region andassociatedattenuation of MLH1 protein expression, as well as microsatellite instability. The prognosis for medullary carcinoma is relatively good comparedto that for poorly differentiatedad enocarcinoma, though the present case hada poor prognosis. Herein, we report a literature review.