Crohn's disease and intestinal carcinoma. A report of 11 cases with emphasis on associated epithelial dysplasia.

Eleven patients with intestinal carcinoma complicating Crohn's disease are reported. In the 4 patients with small intestinal carcinoma, carcinomas were poorly differentiated or signet-ring cell type in 3 cases and mucinous type in 1 case. All 4 patients had high-grade dysplasia in the mucosa immediately adjacent to the carcinoma only. In the 7 patients with colonic carcinoma, tumors were mucinous type in 3, signet-ring cell type in 1, and well or moderately differentiated in 3. Dysplasia could be assessed in 6 patients. In 4 patients it was both adjacent to and distant from the invasive carcinoma. This distant dysplasia was focal in 2 cases. One patient showed dysplasia adjacent to the carcinoma only and in 1 other patient no dysplasia was seen. In a comparison group, all 7 cases of carcinoma associated with ulcerative colitis showed dysplasia adjacent to and distant from the invasive carcinomas. The authors conclude that (a) associated dysplasia is prevalent enough in Crohn's disease-associated carcinomas to support a dysplasia-carcinoma sequence and (b) dysplasia is more limited with carcinoma in Crohn's disease than ulcerative colitis, and this may make dysplasia less useful as a cancer surveillance marker in Crohn's disease.