Remnant Mucous Nodules after Endoscopic Mucosal Piecemeal Resection for Rectal Cancer, Report of a Case

Abstract

A 69-year-old man underwent colonoscopy due to a positive fecat occult blood test and a sessile polyp with central depression in the rectosigmoid area was found. Endoscopic mucosal resection was conducted piecemeal. Histological examination of the endoscopic resected specimen showed cancer invasion with mucous nodules into the deep submucosal layer. The patient was referred to our hospital and additional anterior resection of the rectum was conducted. Histological examination revealed no residual cancer cells and several mucous nodules in the submucosal layer. Endoscopic mucosal resection as complete biopsy is thus useful, but piecemeal resection may make it difficult to evaluate cancer invasion into the submucosal layer and metastasis risk. When endoscopically removed specimens histologically show mucous nodules, we strongly recommend surgical resection with lymph node dissection.