Appendiceal Neoplasm in Conservatively Managed Acute Appendicitis: A Retrospective Observational Study

Area of Science:

• Gastroenterology
• Surgical Oncology
• Abdominal Imaging

Background:

• Appendiceal neoplasms are more common in patients over 40 with complicated appendicitis, particularly those managed non-operatively.
• The COVID-19 pandemic led to increased use of non-operative management (NOM) for acute appendicitis, creating a cohort for studying unexpected appendiceal malignancy.
• Current recommendations do not favor routine interval appendicectomy but suggest follow-up bowel screening with CT and colonoscopy.

Purpose of the Study:

• To compare the incidence of appendiceal malignancy in patients aged 40 and older managed non-operatively versus operatively for acute appendicitis.
• To evaluate the efficacy of standard follow-up bowel screening (CT and colonoscopy) in detecting malignancies.
• To assess re-admission rates in patients undergoing NOM for acute appendicitis.

Main Methods:

• A retrospective observational study included 211 patients aged 40+ diagnosed with acute appendicitis between January 2020 and December 2021.
• Patients were divided into operative management (125 cases) and non-operative management (86 cases) cohorts.
• Outcomes of interest included appendiceal malignancy incidence, screening efficacy, and re-admission rates.

Main Results:

• Appendiceal malignancy was detected in 7% (6/86) of the NOM cohort versus 1.6% (2/125) in the operative cohort.
• Routine follow-up colonoscopy failed to detect any malignancies; all six cases in the NOM group were found upon interval appendicectomy.
• 45% (39/86) of NOM patients experienced at least one re-admission, with 37% occurring within the first year.

Conclusions:

• Non-operative management of acute appendicitis in adults aged 40 and older is associated with a higher incidence of unexpected appendiceal malignancy.
• Standard follow-up colonoscopies are inadequate for detecting these malignancies.
• Closer surveillance and potentially more aggressive follow-up strategies, such as routine interval appendicectomy, are recommended for older patients undergoing NOM.