[Dysplasia in ulcerative colitis detected by surveillance colonoscopy].

A total of 222 surveillance colonoscopies were performed in 84 patients with ulcerative colitis between 1979-1989. In 60 patients with total colitis, 3 carcinomas, 2 high-grade, 4 low-grade and 8 indefinite for dysplasia were found. In 24 with left-sided colitis, 1 low-grade and 1 indefinite for dysplasia were found. The overall incidence of dysplasia in patients with total colitis was 28%, similar to the reported incidence from the Western countries. A sequence of dysplasia development was recorded in 14 cases. Progression of dysplasia was found in some of the low-grade or indefinite cases, however regression was also recorded in another cases. These results suggest the usefulness of surveillance colonoscopy for early detection of carcinoma in long-standing ulcerative colitis.