An unusual case of colonic duplication cyst in an adult with dysplasia.

Duplication cysts are rare benign congenital malformations typically identified in children by the age of 2 years. We report a rare case of colonic duplication cyst with dysplasia in an adult. A 32-year-old male was diagnosed with non-specific abdominal symptoms. Abdominopelvic computed tomography scan demonstrated a submucosal cystic lesion in the right colon. He underwent laparoscopic right hemicolectomy. Histopathology showed colonic duplication cyst with low grade dysplasia. He is due for a surveillance colonoscopy in 3 years. Duplication cyst in an adult colon with dysplasia is extremely rare. They are usually present in the terminal ileum. They have non-specific abdominal symptoms or can be asymptomatic. They are often identified incidentally or intraoperatively. Imaging may demonstrate a cystic lesion. Histopathology is required for definitive diagnosis. There are no guidelines or consensus on managing duplication cysts in adults. We recommend an oncological resection of the involved colon. Surveillance with routine colonoscopy is advisable.