The demonstration of pericryptal fibroblasts in background mucosa and dysplasia complicating ulcerative colitis.

The demonstration of pericryptal fibroblasts in background mucosa and dysplasia in ulcerative colitis was investigated by immunohistochemistry using monoclonal antibody for alpha-smooth muscle actin. Pericryptal fibroblasts were reduced in 18 (26%) of the 68 sections of non-dysplastic mucosa. The reduction was significantly correlated with goblet cell depletion and villous change. Pericryptal fibroblasts were more frequently reduced (50%) in dysplastic mucosa, the reduction being greater in villous than in non-villous dysplasia. Pericryptal fibroblast development was not related to grade of dysplasia (low or high-grade), distance from carcinoma (adjacent to or distant from carcinoma) or growth pattern (polypoid or non-polypoid). These findings suggest that: 1 reduction of pericryptal fibroblasts in background mucosa may relate to the development of dysplasia in ulcerative colitis, 2 reduction of pericryptal fibroblasts in villous regeneration, analogous to that in dysplasia, reinforces the hypothesis that villous change may be a marker for risk of development of carcinoma in ulcerative colitis.