Villous Adenoma : Gross
Villous adenomas show slender finger-like processes on the surface in 75% or more of the tumor. This accounts for granular appearance often seen in gross specimens. Pure villous adenomas are quite uncommon and make up between 3% and 15% of all colonic adenomas. Villous architecture is more frequently seen as a component in Tubulovillous adenomas. The larger the adenoma, the greater the frequency of villous component. Villous adenomas tend to be large and have greater degree of dysplasia. Distribution: Tubular adenomas 80-85%; Tubulovillous adenomas 8-16%; Villous adenomas 3-15%.