Slide 1 
As the crypt abscesses of ulcerative colitis increase in size, they undermine the adjacent mucosa, which sloughs to form numerous, closely placed, shallow ulcers covered by fibrinopurulent exudate (U). Note that the ulcers do not penetrate into the muscularis propria. Almost total ulceration occurs in severe cases, in which the surface is intensely hemorrhagic. The healing of extensively ulcerated areas is initiated by granulation tissue. Residual inflamed mucosa and exuberant granulation tissue often form nodules elevated above the surrounding mucosa that are called "inflammatory pseudopolyps" (P).

Slide 2
Shows a pseudopolyp at higher magnification. The overlying mucosa of the polyp is hyperplastic. The connective tissue core of the polyp is chronically inflamed. It shows active granulation tissue characterized by the dilated capillary vessels.