Primary Crohn's disease of the appendix: report of 14 cases and review of the literature.

Fourteen patients with primary Crohn's disease of the appendix have been seen in a 12 year period. These patients represent 12.8% of the total number undergoing surgical resection because of Crohn's disease. Twenty-three cases of appendiceal Crohn's disease have been previously reported in the literature. A correct preoperative diagnosis is rarely made; the usual diagnosis is that of acute appendicitis or appendiceal abscess. The removed appendix in twelve of our 14 cases had marked thickening of the wall with transmural fibrosis and often with granulomatous inflammation. The enlarged appendix had an external appearance similar to that of ileal Crohn's disease, and we consider a correct surgical diagnosis might be possible with better awareness of its existence. The diagnosis might be suspected earlier when the clinical course of apparent appendicitis is protracted or atypical. Contrary to the previous estimation of high recurrence rate, this series and the cumulative evidence in the literature show a relatively low rate at 14%. The feared fistula formation following the removal of the appendix has not been seen in either our series or the literature. These patients, however, merit long-term follow-up.