In 1994 Fujinuma et al. reported that mucosal polyp consist of normal submucosa tissue with normal membrane. So far, 16 cases were reported. A 73 year-old man took total colonoscopy. He had multiple diverticulosis and a polyp with normal membrane in the sigmoid colon. We recommended that the polyp would be followed up. Total colonoscopy was performed after 14 months. The polyp did not change in size and shape. We performed endoscopic mucosal resection of the polyp depending on his request. The pathological finding of the polyp was normal membrane without muscularis mucosae. We diagnosed the polyp as mucosal polyp in colon. There was only case report about a mucosal polyp in colon pathologically without muscularis mucosae. This is the first report to follow up on mucosal polyp.
