Endoscopic removal of a large residual rectal adenoma with extension into the anal canal: a case report

Objective. To assess the feasibility and clinical efficacy of endoscopic resection of large (≥5 cm) rectal epithelial neoplasms with extension into the anal canal. Case report. A 58-year-old male patient presented to the A.S. Loginov Moscow Clinical Scientific and Practical Center with complaints of intermittent mucus discharge during defecation. One month prior, an attempt at transanal resection of a rectal adenoma had been performed at another medical institution in Moscow but was unsuccessful. Endoscopic evaluation revealed an exophytic villous neoplasm of the rectum extending proximally from the anal canal for up to 7 cm and involving approximately two-thirds of the rectal circumference. A central area of scarring corresponding to the site of previous partial resection was noted. En bloc endoscopic resection was performed using the pocket-creation method of endoscopic submucosal dissection. The procedure was technically challenging due to pronounced fibrosis and submucosal scarring resulting from the prior intervention. Over a two-year follow-up period, the patient remained asymptomatic, with no evidence of anal incontinence or tumor recurrence on endoscopy. Conclusion. This case demonstrates both the oncological and functional efficacy of endoscopic resection for large epithelial rectal neoplasms extending into the anal canal, including cases following unsuccessful transanal surgical attempts.