High grade dysplasia in Crohn's colitis characterized by flow cytometry.

A patient with Crohn's ileocolitis had high grade dysplasia. Preoperative evaluation of colonoscopic biopsies by flow cytometry demonstrated aneuploidy, a marker of malignancy. In the surgical specimen, however, carcinoma was not demonstrated despite extensive sampling. The detection of abnormal DNA content in this premalignant lesion suggests a useful role for this technique in selecting those patients with inflammatory bowel disease at risk for carcinoma.