Twenty-one patients having ulcerative colitis (U.C.) for a period of seven or more years, and considered as being in the risk group for developing large bowel neoplasia, were studied according to the following procedures: 1) colonoscopic examination for macroscopic identification of mucosal alterations and obtainment of multiple biopsies; 2) histologic examination of mucosal biopsies; 3) quantification of mucosal-cell DNA using digital cytometry. The duration of disease in these patients ranged from seven to 33 years, with an average of 14 years. In three patients colonoscopic images showed vegetant lesions suggestive of malignancy. The association of UC with cancer occurred in 14% of cases. Colonoscopy was efficient in providing accurate diagnosis in all cases and also allowed a successful endoscopic resection of an aneuploid neoplastic lesion. Digital cytometry revealed diploid DNA histogram in all phases of U.C. and aneuploid in cases with association of UC and neoplastic development.
Conclusion: these three methods together should be utilized in the follow-up of patients with long standing ulcerative colitis.