Colonic Mucosubmucosal Elongated Polyp in the Sigmoid Colon on Surveillance Colonoscopy

Colonic mucosubmucosal elongated polyp (CMSEP) is a newly designated colorectal polyp. It has unique endoscopic features of a worm- or drumstick-shaped appearance. Histologically, it is composed of normal colonic mucosa and expanded submucosa with a prominent vascular component and no significant inflammation. CMSEP is usually detected incidentally on screening colonoscopy or colonoscopy for other causes. Differential diagnoses that need to be considered include mucosal prolapse syndrome, filiform polyposis, hamartomatous polyp, colon leiomyoma, inverted diverticulum, and residual stalk of a pedunculated adenoma. We present a case of CMSEP on surveillance colonoscopy and literature review.