Search for a specific marker of mucosal dysplasia in chronic ulcerative colitis.

We have tried to identify a histochemical or immunohistochemical marker that would reliably detect mucosal dysplasia in chronic ulcerative colitis. Colonic biopsy specimens were taken from patients with long-standing ulcerative colitis undergoing surveillance colonoscopy. Control tissue was obtained from the margins of colonic resections performed for neoplastic or nonneoplastic diseases. Sections of the specimens were examined by periodic acid-Schiff staining, high iron diamine Alcian blue staining for sialomucins and sulfomucins, and binding of the lectins peanut agglutinin, Ulex europeus agglutinin I, and Ricinis communis I agglutinin. Sections were reacted also with anticarcinoembryonic antigen antibodies to determine whether a nonpolar surface distribution of the antigen was a feature of dysplasia. We found that changes in colonic mucin, characterized by periodic acid-Schiff-positive mucin outside of goblet cells, an increase in binding of peanut agglutinin, and an increase in the relative amount of sialylated mucin, were associated with morphologic dysplasia. However, identical alterations were observed, albeit less commonly, in colitis without dysplasia, particularly in the presence of active inflammation. No abnormality in the surface distribution of carcinoembryonic antigen or Ricinis communis I agglutinin was observed. Thus, we did not identify a reliable corollary test to the histologic diagnosis of mucosal dysplasia in ulcerative colitis. With regard to these histochemical markers, the colonic mucosa appears to respond similarly to inflammation and neoplasia.