[A Case of Micropapillary Carcinoma in the Sigmoid Colon]

In Japan, the number of the patients with colorectal carcinomas is increasing. Micropapillary carcinoma(MPC)is a rare adenocarcinoma that shows a characteristic histological feature. The first case of MPC was reported in 1993, which originated in the breast. It has been reported that MPC also rarely arises in the colon. In this report, we showed a case of MPC arising in the sigmoid colon in a 73-year-old man with adenosquamous carcinoma in the lung. The patient consulted a home physician due to cough, and a tumor on the right lung of the patient was detected by chest radiography and CT. The lung tumor was histologically diagnosed as adenosquamous carcinoma. FDG-PET/CT revealed hot spots in not only the right lung but also the sigmoid colon. Carcinoma was detected in the sigmoid colon through a colorectal endoscopic examination, and the carcinoma with regional lymph node metastasis was resected. The histological examination of the colon carcinoma revealed that it was MPC without any other histological types and with marked metastasis to the lymph nodes. For the treatment of lung cancer, additional treatment for colon cancer was not performed. Since pure MPC arising in the colon is extremely rare, the patient is followed carefully.