Slide 1

Gross:  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).  Almost total ulceration occurs in severe cases, in which the surface is intensely hemorrhagic.  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).  A histologic section taken across the pseudopolyps and ulcers in the plane of the black bar would have the appearance shown in Slide 2.

Slide 2

This is a low power view of the actual slide in your class set which shows two pseudopolyps separated by shallow ulcers.  Note that the ulcers do not penetrate into the muscularis propria.

Slide 3

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.