Rectal duplication cyst successfully treated by laparoscopic total mesorectal excision using the prolapsing technique.

Congenital alimentary tract duplication is a rare disease. It most frequently occurs in the ileum, with the rectum being the rarest site. Herein, we report a 38-year-old woman who was referred to our hospital because of severe anal pain. On digital examination, a smooth, round, rubbery mass was palpable; it was located 5 cm from the anal verge in the posterior rectal wall. A CT scan demonstrated a 5-cm cystic lesion located anterior to the sacrum that was displacing the rectum anteriorly. Spontaneous remission of the tumor was evident; however, after 5 months of follow-up, the patient experienced the same severe anal pain. MRI demonstrated a recurrent cystic lesion. To prevent further complications and to confirm or deny malignancy, laparoscopic total mesorectal excision using the prolapsing technique was performed. Pathologically, the cystic lesion was diagnosed as a rectal duplication cyst. This is the first report of a rectal duplication cyst successfully treated by laparoscopic total mesorectal excision.