Is dysplasia visible during surveillance colonoscopy in patients with ulcerative colitis?

Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer. It was widely believed that dysplastic lesions are invisible on colonoscopy and can only be detected by random biopsies, as 95% of dysplastic lesions occur in flat colonic mucosa indistinct from surrounding tissue. The aim of this study was to determine whether dysplasia is visible during routine surveillance colonoscopy by evaluating only patients who had dysplasia without overt carcinoma.

The medical records, endoscopy and pathology databases were systematically reviewed between 1997 and 2004 at the University of Pennsylvania Health System. Patients with inflammatory bowel disease and dysplasia were identified and their medical charts reviewed.

Of the 113 patients with colonic dysplasia confirmed by pathology at our center, 102 (90%) had UC. Forty-nine of the 102 (48%) patients with UC underwent colonoscopic evaluation prior to dysplasia detection. This group was selected as our study cohort. Overall, 72 macroscopic abnormalities were detected at 49 colonoscopies, including 55 polypoid lesions, 12 areas of ulceration, 3 areas of nodularity, 1 irregular hemicircumferential lesion and 1 area of stricture. Overall, 58 dysplastic sites were detected; 51 were macroscopically visible (87.9%) and 7 were macroscopically invisible (12.1%).

Most of the dysplasia in UC is endoscopically visible, but further prospective evaluation of a large number of patients is needed to validate the current observations. Our findings have the potential to modify current recommendations for surveillance biopsies in UC if validated by prospective studies.