Endoscopic submucosal dissection of multiple flat adenomas in the radiated rectum.

We report a case of multiple flat adenomas and cancer of the rectum that occurred 15 years after pelvic irradiation following surgery for uterine cancer. Adenoma borders were diagnosed accurately by magnifying chromoendoscopy, leading to their adequate excision using endoscopic submucosal dissection. This enabled minimal dissection of the irradiated pelvis that would have otherwise been difficult. Furthermore, our approach probably helped minimize loss of bowel function, thereby preserving the patient's quality of life as much as possible. Pathology of the resected specimens revealed thickened walls of the submucosal layer vessels, indicating chronic radiation proctitis. Pelvic irradiation of the bowel carries a high risk of causing flat adenomas and cancer. Close and long-term surveillance may be useful in such cases, using not only conventional colonoscopy but also chromoendoscopy with indigo carmine dye spray and magnifying endoscopy.