The value of electron microscope studies in diagnosing malignant change in ulcerative colitis.

Ultrastructural and histological appearances were studied in normal rectal and colonic mucosa, in the mucosa immediately adjacent to neoplasms (transitional mucosa), in neoplasms themselves, and in ulcerative colitis to try to determine whether any changes found in colitis might be recognized as premalignant. Two of the ulcerative colitis specimens showed histological evidence of premalignant change and these changes were reflected at the ultrastructural level. No electron microscopical premalignant changes were found which could not more easily be detected by simple histology, and it is concluded that attempts to detect premalignant changes in ulcerative colitis using electron microscopical techniques are likely to be unrewarding.