A Case of Retroperitoneal Mucinous Cancer Arising in a Duplication of the Ascending Colon

A 59-year-old Japanese woman complained of swelling and pain in the right lumbar region of the abdomen and intermittent high fever. She was admitted to the Department of Surgery, Minoo City Hospital. Abdominal computerized tomography revealed a retroperitoneal mass communicating with a subcutaneous mass. Echo-guided puncture and drainage were performed on this lesion on the suspicion of abscess formation. Seventy ml of purulent fluid was discharged. Despite continuous drainage, the retroperitoneal mass did not diminish. Laboratory data showed a high level of serum CEA (17 ng/ml). Further examinations were carried out on the lung, stomach, gallbladder, pancreas, large intestine and ovaries to detect the primary lesion. Nothing abnormal, however, was observed except a small diverticulum of the ascending colon revealed by a barium enema. An exploratory laparotomy revealed a retroperitoneal mucous tumor located in the postero-medial part of the ascending colon. Histological examination of the specimen revealed mucinous cancer arising in a duplication of the ascending colon. Curettage only was performed because of post-inflammatory adhesion. Her serum CEA level had normalized postoperatively, but gradually increased again. Twenty months later, the retroperitoneal tumor recurred. The tumor was curatively resected by the methods of right hemicolectomy, and resection of the right lumbar muscles, periostium of the iliac bone and the right transverse process of the IVth lumbar vertebra. The postoperative course was uneventful and the results of follow-up examinations were normal. The patient was healthy with no evidence of recurrens 3 years after the second operation.