Appendiceal diverticulitis and acute appendicitis: differences and similarities.

INTRODUCTION Acute appendiceal diverticulitis is an unusual cause of acute abdomen, considered clinically indistinguishable from acute appendicitis. MATERIAL AND METHODS In a historic cohort study with 27 cases of appendiceal diverticulitis and 54 cases of acute appendicitis, we compared clinical characteristics, diagnostic tests and pathology findings of the two processes. RESULTS Mean age at presentation was lower in acute appendicitis (37.24 +/- 19.98 vs. 54.81 +/- 17.55 years, p < 0.001), with significant differences between men (33.33 +/- 15.89 vs. 57 +/- 18.02 years, p < 0.001) but not between women (41.76 +/- 24.87 vs. 50.44 +/- 16.69 years, p = 0.34). In the diverticulitis group, 48.15 % had leukocytosis vs. 81.48 % in the appendicitis group (p = 0.02); there was no difference in leukocyte count (13770.37 +/- 4382.55 vs. 14279.63 +/- 4268.59, p = 0.61). Patients with appendiceal diverticulitis had a higher incidence of appendiceal mucocele (p = 0.01) and a lower proportion of appendiceal gangrene (p = 0.03). There were no differences in appendiceal perforation or ulceration. Symptom duration before emergency department attendance (71.61 +/- 85.25 hours vs. 36.84 +/- 33.59 hours; Z = -3.1 p = 0.002), duration of surgery (85 +/- 40 minutes vs. 60 +/- 21 minutes, Z = -3.2, p = 0.001) and the presence of appendicular plastron was higher in patients with diverticulitis vs. appendicitis (8 vs. 5 patients [p = 0.01, Odds ratio 2.2]). CONCLUSIONS Appendiceal diverticulitis presents a series of clinical, epidemiological and pathological differences with respect to acute appendicitis. The former shows a more indolent course with delayed diagnosis.