Incidence of occult appendiceal neoplasm in patients over 40 years with acute appendicitis: A single-institution review.

Objective: To investigate the incidence of occult appendiceal neoplasm in patients aged 40 years and over who underwent appendicectomy for appendicitis.

Methods: The clinical coding electronic database was used to identify patients aged 40 years and over who were diagnosed with appendicitis from September 2010 to September 2022. Patients were included if they were managed operatively.

Design: Retrospective cohort study.

Setting: Modified Monash category 3 (large rural town).

Participants: Patients aged 40 years and over undergoing appendicectomy for appendicitis.

Main Outcome Measures: Incidence of appendiceal neoplasm within appendicectomy specimen.

Results: A total of 279 patients aged 40 years and over underwent appendicectomy, with a median age of 53 years (range 40-95). Nineteen patients (7%) were found to have a primary neoplastic lesion within the appendix: seven neuroendocrine neoplasms (37%), six sessile serrated lesions (32%), two colonic-type adenocarcinoma (11%), two goblet cell adenocarcinoma (11%) and two appendiceal mucinous neoplasms (11%). Additionally, one patient had a metastatic adenocarcinoma of pancreaticobiliary aetiology.

Conclusions: Occult appendiceal neoplasm was higher than reported in the literature in our cohort. This would support appendicectomy as the treatment of choice for patients aged 40 years and over with acute appendicitis and caution against nonoperative management in this demographic.