Pathologies of the appendix: a 10-year review of 4670 appendicectomy specimens

Debate surrounds the management of the macroscopically normal appendix. Current literature recommends its removal given the high incidence of microscopic appendicitis, and other unusual pathologies in the normal-looking appendix. Negative appendicectomies are reported on the decline with increased use of diagnostic radiological adjuncts.

This study analysed pathologies of the appendix over 10 years in the Pathology Department in Canberra. A positive appendicectomy was defined as acute appendicitis, faecoliths, worms, endometriosis or appendiceal tumours. We reviewed the positive appendicectomy rate over this time period.

There were 4670 appendicectomy specimens in 2386 males (51.1%) and 2284 (49%) females. The incidence of acute appendicitis was 71.3% and the positive appendicectomy rate was 76.3%. There were significantly fewer negative appendicectomies in males (16.8%) compared with females (31.0%). There was no appreciable change in this trend over the study period. Of the positive appendicectomies, there were 129 (3.6%) faecoliths. Of these, only 39.5% had concomitant appendicitis. There were 44 (1.2%) specimens identified with worms. Of these, 40.9% had concomitant appendicitis. There were 14 cases of endometriosis of the appendix of which 36% had concomitant appendicitis. There were 58/3562 (1.6%) appendiceal tumours within the positive appendicectomy group the majority of which were carcinoid tumours (65.5%).

There is a higher incidence of negative appendicectomies in women compared with men, which is similar to other published studies. Faecoliths and worms are a known cause of appendiceal colic and in our series were identified mostly in the absence of histological evidence of appendicitis.