Adenoma refers broadly to any benign tumor of glandular tissue. This activity will address specifically adenomas of the colon, occurring within polyps. Colon polyps are a common entity, increasing in prevalence with age. Adenomatous polyps are the most common type of polyp in the colon, accounting for about 60 to 70% of all colonic polyps. Conventional type adenomatous polyps can be classified as tubular, villous, or tubulovillous. Villous adenomas are characterized by more than 75% villous features, where villous refers to finger-like or leaf-like epithelial projections. Tubulovillous adenomas have between 25 and 75% villous features. Less than 25% villous features indicate a tubular adenoma. Adenomas are usually asymptomatic and found on routine colorectal cancer screening. Adenomas with villous features may be associated with a slight increase in the development of more advanced neoplasia or dysplasia compared to other types of adenomas. Villous adenomas tend to occur more frequently in the rectosigmoid area but can occur elsewhere in the colon.