Appendiceal abscess in cystic fibrosis. A diagnostic challenge.

A patient with cystic fibrosis who developed appendicitis, rupture, and a periappendiceal abscess is presented. A retrospective chart review revealed 5 other cases that demonstrate a spectrum of clinical presentation of periappendiceal abscess in patients with cystic fibrosis. Three patients were symptomatic for less than 5 days, but the remaining 3 patients were symptomatic for 8, 12, and 30 days before diagnosis. There were two deaths due to respiratory failure. Other complications included a perirectal fistula and 2 cases of recurrent abscess. This demonstrates the difficulty with which this diagnosis is reached in this patient population and the relatively high incidence of abscess formation compared with normal populations. A retrospective autopsy review of 51 cystic fibrosis patients showed that in 49 of 51 instances, the mucosa of the appendix was hyperplastic, and the mucosal glands were distended with eosinophilic secretions. In 12 cases (24%), the appendix itself was grossly firm, dilated, and distended, although the mucosal wall was free of inflammation. This lends credence to the suggestion that these inspissated secretions may be protective against the occurrence of appendicitis, the incidence of which may be as low as 1%-2% among cystic fibrosis patients.