UNUSUAL HISTOPATHOLOGIES OF THE APPENDIX.

BACKGROUND: Acute appendicitis is a very common surgical emergency. Most commonly, the histopathological findings of the appendix reflect the normal pathophysiology of appendicitis that starts with the luminal obstruction and culminates in florid suppurative, gangrenous or perforated appendix. The treatment is usually straightforward and consists of surgery and antibiotics. Uncommonly, unusual pathologies are identified and require specific management. The literature is scanty about the unusual findings. In a worldwide review of 128 articles, Sami Akbulut has established 1.7% incidence of unusual histopathology led by Enterobius vermicularis (28.4%) followed by carcinoid (21.9%) and schistosomiasis (12.7%).

METHOD: A retrospective review of histopathological reports of appendix specimens obtained during appendectomies done between January 2012 and December 2014 in the three academic hospitals of Johannesburg (CHBAH, CMJAH, HJH). All specimens were examined by the National Health Laboratory Services (NHLS).

RESULTS: A total of 2408 histopathologies were obtained from the national health laboratory system. 164 specimens were excluded because they were part of colonic resection for conditions unrelated to the appendicitis. From the 2244 specimens analysed, 8.1%, 52.7% and 30.1% were due to normal appendix, acute appendicitis and complicated appendicitis respectively, and the incidence of unusual histopathological findings was 5.3% (119/2244). Of the 2244 specimens analysed the mean age was 25.6 years (2-88yrs) and the gender distribution was 61.9 % males and 38.1% females. The most common unusual causes were parasites (37%) led by schistosomiasis (24.3%), followed by neoplasm (20%) and fibrous obliteration (14.2%).

CONCLUSION: Although uncommon (5.3%), the unusual causes of appendicitis may result in an adverse patient outcome and/ or require specific treatment that may be overlooked if histopathology reports are not checked routinely.