Transverse Colon Duplication Mimicking Adult Megacolon

A seventeen-year-old young female patient presented with intermittent abdominal pain associated with severe constipation since early childhood. Barium enema films revealed a severely dilated colon. Adult Hirschsprung’s Disease (megacolon) was first impressed. Exploratory laparotomy surprisingly found an 18 × 18 × 16 cm-size cystic type duplication of the transverse colon, with a patent proximal, but closed distal end. Except for the history of mild anemia, no congenital anomalies were found in other organs or in the urogenital system. Pathologic examination of the resected specimen found a normal colonic structure, including mucosa, submucosa, muscle layer, and serosa. Ganglionic cells were also present. Therefore, colonic duplication was confined. Postoperative hospital course was relatively smooth without major complications, and the patient was discharged on the 10th ay after surgery. The cystic form dilatation of the duplicated transverse colon may have been because of its closed distal end, causing a dead-end type obstruction of its content, and consequently the symptomatology of chronic constipation.