Abstract
A polyp is a discrete mass of tissue that protrudes into the lumen of the bowel. Anorectal polyps may be divided into two major groups: neoplastic (the adenomas and carcinomas) and non-neoplastic.
The adenomas and carcinomas share a characteristic—cellular dysplasia. The non-neoplastic polyps may be grouped into several distinct categories: hyperplastic polyps, “mucosal polyps,” juvenile polyps, inflammatory polyps, and others.
Submucosal lesions also can impart a polypoid appearance to the overlying mucosa, but they are not true polyps.