Unusual Histopathologies of the Appendix

Abstract

Background: Typically, appendicitis 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. Objective: This study aimed to identify the incidence and type of unusual (uncommon) histopathology of appendicitis at three tertiary academic hospitals in the urban population of Johannesburg, South Africa. Methods: A retrospective review was undertaken of histopathological reports of appendix specimens obtained during appendectomies between January 2012 and December 2014, in the three academic hospitals of Johannesburg. Results: A total of 2408 histopathology results were obtained from the National Health Laboratory Services (NHLS), of which 164 specimens were excluded from the study because they were part of colonic resection for unrelated conditions. Of the 2244 specimens included, a normal histopathology was found in 8.8%, 52.7% had acute appendicitis, 30.1% had complicated appendicitis, 3% reported serositis and the unusual pathology was found in 5.3% (119/2244). Among the unusual pathologies, the most common histopathological result was parasites (37%) which was predominated by schistosomiasis (24.3%), followed by neoplasm (20%) and fibrous obliteration (14.2%). Conclusion: Unusual histopathologies represented 5.3% of the appendix specimens in this study with parasites and neoplasms as the leading aetiologies. All appendectomy specimens must be submitted to the pathologist for histological diagnosis, and the result is checked before the patient is discharged or for a more pragmatic recommendation in a public hospital setting, to ensure that the histology result is discussed when the patient returns to the outpatient setting for post-operative follow-up.

Neurogenic Appendicitis: A Reappraisal of the Clinicopathological Features and Pathogenesis

“…In the fibrotic phase (fibrous obliteration of the appendix), the appendix exhibits lumen obliterated by varying proportions of nerve tangles and fibrous tissue [ 4 , 10 , 30 ]. Although the mechanisms underlying fibrosis are largely unknown, serotonin seems to play an important role in the development of this phase.…”

“…The term “chronic appendicitis” is one of several terminologies used to describe cases of NA with fibrosis, but lacking an acute inflammatory reaction. NA represents from 0.16% [ 8 ] to17.1% of all cases of surgically treated appendicitis [ 5 , 9 , 10 ]. It is more common in females than in males.…”

Surgical Infections in Low- and Middle-Income Countries: A Global Assessment of the Burden and Management Needs

“…More than 200 million people worldwide are infected with Schistosoma [55]. Acute operative conditions such as appendicitis, Meckel's diverticulitis, and cholecystitis in endemic regions are rarely described [7,[56][57][58][59]. More common chronic conditions amenable to operation are bladder cancer [60] and portal hypertension [61][62][63].…”

Impact of Endemicity of Ascariasis on Diagnosis of Acute Appendicitis

“…6,7 The parasitic infestation of appendicular lumen can be asymptomatic most of the times. 8 Many parasites have been identified infesting the vermiform appendix; including Ascaris lumbricoides, Enterobius vermicularis, Schistosoma spp, Oxyuris vermicularis (pinworm) and Entamoeba histolyica. 9 This study was carried out in Skardu, which is endemic area for Ascaris lumbricoides.…”