Rectal Tailgut Cyst treated with Endoscopic Mucosal Resection: A Case Report and Literature Review.

A tailgut cyst is a rare tumor arising from the persistent embryonic remnants of the postanal gut. The cyst is usually located in the retrorectal space, lying anterior to the sacrum and posterior to the rectum. In rarer cases, it is occasionally found at the perirenal, perianal, subcutaneous, and intradural sites. A 60-year-old woman visited the authors' clinic for a routine health screening examination. Colonoscopy revealed a subepithelial tumor, measuring 5 mm in diameter and located in the lower rectum near the anal sphincter, which may be a neuroendocrine tumor. An endoscopic mucosal resection (EMR) was performed for an accurate histologic diagnosis and treatment, and the rectal lesion was completely removed en bloc and then diagnosed as a tailgut cyst. This paper reports a case of a rectal tailgut cyst treated with EMR in a 60-year-old woman. The 12-month follow-up showed no evidence of recurrence. To the best of the authors' knowledge, this is the second reported case worldwide of a rectal tailgut cyst successfully treated with an EMR, and the first such case reported in Korea.