Unusual histopathologies of the appendix

Appendicitis is the most common surgical emergency. Most commonly it is a result of luminal occlusion that leads to ischaemia and eventually to perforation with resultant localised or diffuse peritonitis. Unusual causes have been documented including viral infections, parasites, tuberculosis and neoplasms. These conditions are important to recognise, as they may need additional specific management. This study endeavours to identify the incidence and type of unusual histopathology of appendicitis.

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 - Chris Hani Baragwanath Academic Hospital (CHBAH), Charlotte Maxeke Johannesburg Academic Hospital (CMJAH), and Helen Joseph Hospital (HJH). All specimens were examined by pathologists of the National Health Laboratory Services (NHLS).

A total of 2 408 histopathology results were obtained from the NHLS. 164 specimens were excluded because they were part of colonic resection for unrelated conditions. Of the 2 244 specimens included, 8.1% were normal, 52.7% showed acute appendicitis and 30.1% showed complicated appendicitis. Unusual pathology comprised 5.3% (119/2 244). The median age of all patients was 25.6 years (0-88yrs) and the gender distribution was 61.9% males and 38.1% females. The most common unusual causes were parasites (37%), mainly schistosomiasis (24.3%), followed by neoplasm (20%) and fibrous obliteration (14.2%).

All appendectomy specimens must be submitted to the pathologist for histological diagnosis. It is important that the result be checked before the patient is discharged as further specific treatment may be indicated.