[Epithelial dysplasia in ulcerative colitis. Histological possibility for the early diagnosis of "colitis"-carcinoma (author's transl)].

From 249 histologically examined cases with ulcerative colitis (within the years 1967 to 1974) 20 cases were selected, which had an onset of the disease before the 20th year of age and/or a duration of more than 10 years. These cases were checked-up for "prae-cancerous" epithelial dysplasia. Four of these 20 cases showed medium to severe epithelial dysplasia together with carcinoma (= 1.61% of the entire collective). In 2 cases low grade to severe dysplasia occurred in different parts of the colon without demonstrable carcinoma. In 1 case epidermoid epithelial metaplasia were found in the splenic flexure and in the rectum. The biological significance of these metaplasia remains unclear. With reference to the formal pathogenesis these lesions are probably "indirect" metaplasia. The early diagnosis of "colitis"-carcinoma can be improved by systematic colonoscopic examinations resp. by colonoscopic biopsies. "Prae-cancerous" epithelial dysplasias, which occur in a high rate together with carcinoma, are found not only in the rectum but also in other parts of the colon. Multiple biopsies from different parts of the colon as well as the rectum would thus seem to be desirable if mucosal sampling is to be employed as a screening test.