Demonstration of perycriptal fibroblasts in inflammatory-regenerative and dysplastic epithelial lesions of the flat colonic mucosa.
The aim of the paper is the definition of perycriptal fibroblasts (PCFs) distribution in inflammatory-regenerative and dysplastic epithelial lesions of flat bowel mucosa. The relationship between the presentation of PCFs and the grade of inflammatory-regenerative and dysplastic process in the flat colon mucosa is also examined. Biopsy specimens from 270 patients were examined: 74 were classified as inflammatory-regenerative and 196 as dysplastic lesions (108 mild, 58 moderate, and 30 severe dysplasia). The demonstration of PCFs in biopsy specimens was performed by immunohistochemistry using monoclonal antibody for alpha smooth muscle actin, muscle-specific actin (HHF-35), vimentin and desmin, in comparison with normal mucosa and adenocarcinoma. The PCFs were reduced in inflammatory-regenerative and dysplastic mucosa. The reduction was significantly related with the grade of epithelial dysplasia. The carcinomas tended to lack PCF network. During inflammatory-regenerative and dysplastic process in flat bowel mucosa, PCFs express alpha smooth muscle actin, muscle specific actin, vimentin and desmin, showing the phenotypical growing expression of potentially present smooth muscle differentation features of fibroblasts. These findings suggest that the reduction of PCFs in dysplastic epithelial lesions may relate to the development of dysplasia in flat bowel mucosa. Reduced number of PCFs in dysplastic mucosa may be a marker for the risk of preneoplastic and neoplastic progression in bowel mucosa.