A retrospective cohort study published in JAMA Surgery has evaluated the prevalence and clinical significance of incidental appendiceal tumours in patients undergoing appendectomy for presumed acute appendicitis, providing important context for evolving non-operative management strategies.
The single-centre study included 2293 patients who underwent appendectomy, with histopathological analysis identifying appendiceal neoplasms in 37 cases (1.6%). The majority of tumours were low-grade neuroendocrine tumours measuring less than 2 cm, consistent with indolent biology. Clinically aggressive neoplasms were uncommon.
Importantly, tumours with higher-risk features were not randomly distributed. Increasing age, particularly ≥60 years, longer symptom duration, larger appendiceal diameter on imaging, and features of complicated appendicitis (including abscess or mass) were associated with a greater likelihood of underlying neoplasia. In contrast, patients without these features had a very low probability of clinically significant malignancy.
CLINICAL SUMMARY
What was examined
A retrospective cohort study assessed the prevalence and predictors of incidental appendiceal tumours in patients undergoing appendectomy for acute appendicitis.
Key findings
- Appendiceal tumours were identified in 1.6% of cases, most commonly low-grade neuroendocrine tumours
- Clinically aggressive tumours were rare and associated with identifiable high-risk features
- Older age, prolonged symptoms, larger appendiceal diameter, and complicated imaging were associated with increased risk
Clinical implications
- Careful preoperative risk stratification may help identify patients at higher risk of underlying malignancy
- Findings support the oncologic safety of non-operative management in appropriately selected patients
- Ongoing vigilance and follow-up remain important, particularly in higher-risk groups
These findings highlight the limitations of clinical presentation alone in identifying appendiceal tumours, but also demonstrate that higher-risk cases may be identifiable through routine clinical and radiological assessment. Notably, the study found that aggressive tumours were consistently associated with identifiable preoperative risk factors, suggesting that they may not be easily missed when appropriate evaluation is undertaken.
The results are particularly relevant in the context of increasing interest in non-operative management of uncomplicated appendicitis. While concerns have been raised regarding the potential for missed malignancy with antibiotic-first approaches, this analysis suggests that the risk of clinically significant tumour may be low in carefully selected patients, particularly younger individuals without high-risk features.
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From a clinical perspective, the study supports a risk-stratified approach to management. Surgical intervention remains important in patients with concerning features, while non-operative strategies may be appropriate in selected low-risk populations. The findings also reinforce the ongoing role of histopathological assessment in confirming diagnosis and guiding further management when surgery is performed.
Overall, these data provide reassurance that, with appropriate patient selection and clinical assessment, evolving management strategies for appendicitis can be implemented without substantially increasing the risk of missed clinically significant malignancy.
Paper: Germes M, Collard MK, Laroche S, et al. Oncologic Risk of Missed Appendiceal Tumors in Acute Appendicitis. JAMA Surg. Published online March 25, 2026. Access online here.
