Diverticular disease of the appendix.

A retrospective study of diverticular disease of the appendix was made in 3,343 consecutive instances of appendectomies. A 2 per cent incidence of diverticular disease was found. These instances were classified into four morphologic types: 1, acute diverticulitis; 2, acute appendicitis with acute diverticulitis; 3, acute appendicitis with diverticulum, and 4, appendix with diverticulum. Types 1, 2 and 3 were divided into subgroups with or without perforation. The elements of clinical behavior in each group were examined in detail. Diverticulitis of the appendix is presented as a clinically variant form of the inflamed appendix. Some followed the pattern of typical acute appendicitis. However, most were distinctive at a later age of onset, longer interval of disease, fewer or absent symptoms of the gastrointestinal tract, failure of typical abdominal pain progression, delay in surgical treatment and a remarkably high incidence of perforation. In a chi-square analysis of 56 patients with acute diverticulitis of the appendix compared with 2,503 patients with acute appendicitis, more than a fourfold incidence of perforation in acute diverticulitis was significant beyond the 0.001 level. These findings of variant behavior and high incidence of perforation are cautionary features of this frequently overlooked disease.