[Ischemic-granulomatous colitis: a new differential diagnosis from Crohn's colitis?]

In patients with inflammatory bowel disease the presence of epitheloid cell granuloma is considered to be the most reliable single criterion for the presence of Crohn's disease. We report on 6 patients (5 female, 1 male, mean age 73.5 years) with acute onset of inflammatory bowel disease, in whom the presence of epitheloid cell granuloma led to the diagnosis of Crohn's disease. However, concomitant major bleeding (4/6), absence of small intestinal involvement, and absence of extraintestinal manifestations suggested the presence of ischemic colitis. Histologic findings including thrombosed vessels (6/6), mucosal (5/6) and submucosal (3/4) hemorrhage, and mucosal (3/6) and submucosal (3/4) fibrosis supported this diagnosis. A review of the literature suggests that many clinical features of assumed Crohn's disease in elderly patients are atypical and would be most consistent with an ischemic pathogenesis: rarity of fistula, low recurrence rate, low rate of small intestinal involvement and extra-intestinal manifestations, and increased incidence of major colonic bleeding would best fit with an ischemic pathogenesis in at least some of these patients. We suggest that in elderly patients with "Crohn's colitis", even in the presence of epitheloid cell granuloma, an ischemic etiology should be considered.