Colonic duplication presenting as a huge abdominal mass in an adult female

Introduction Duplications of the alimentary tract are a rare congenital malformation. Most of the cases are symptomatic and diagnosed before 2 years of age. Here, we report a young female presented with a huge abdominal mass, and colonic duplication was confirmed during laparotomy. Case presentation A 29-year-old female had chronic constipation treated with laxative agents. She presented to the emergency room with abdominal cramping for 3 days, accompanied with intermittent fever and vomiting. A huge movable abdominal mass was noted during physical examination. Computerized tomography showed a long segmental dilated bowel lumen with stool impaction and bowel wall thickening of the dilated lumen in the left abdomen, highly suggestive of a long tubular colon duplication. The patient underwent subtotal colectomy. Specimen subsequently confirmed the diagnosis for colonic duplication from cecum to sigmoid colon, and the duplicated colon was found on the antimesenteric side of the native colon. She had a stable postoperative course and was discharged 9 days later. Discussion Duplications of the alimentary tract are a rare congenital anomaly. Colonic duplication is an even more unusual malformation of this type. It can be classified into cystic or tubular type according to the gross morphology and may or may not be associated with other congenital anomalies. Most common presentation includes abdominal distention, refractory constipation, and bowel obstruction like many other colorectal conditions. Thus, its indistinct symptoms make it difficult to be diagnosed preoperatively. The recommended treatment is surgical resection of the duplicated lumen along with the attached native colon.