Tabulation of myeloid, lymphoid and intestinal malignancies in Crohn's disease.

A variety of malignant complications occur in Crohn's disease, and previous studies have recorded an increased intestinal cancer risk. The present investigation tabulated myeloid and lymphoid malignancies compared with intestinal cancers in 1000 consecutively evaluated patients with Crohn's disease who were followed over an extended period by a single clinician. Myeloid and lymphoid neoplasms were present in 0.5% of patients, while cancer in the intestinal tract was detected in 1%. Most of these patients with a malignancy had Crohn's disease for a prolonged period of more than 20 years and had negative outcomes, including death or presentations with advanced disease. In this cohort, lymphoma was not detected in a single patient after definition of Crohn's disease, possibly reflecting the limited use of immunosuppressives or infused biological agents in this clinical practice. Bypassed rectal 'stumps' were associated with subsequent colorectal cancer in half of all males with colon cancer in this series, suggesting an important risk factor following colectomy in Crohn's disease. Epithelial dysplasia was detected in only a single male patient before colorectal cancer, implying that this histopathological marker may be a poor predictor of subsequent colon cancer development in Crohn's disease, an inflammatory bowel disease process that is typically patchy or focal in distribution in the intestinal tract.