This month's paper assessed the importance of interval appendectomy in detection of appendiceal neoplasm adults with complicated appendicitis in adults.
Appendiceal neoplasm detection after interval appendectomy for complicated appendicitis in adults: a systematic review and age-stratified meta-analysis
Zhuo-Jia Wu, Miao-Bing Wu, Yong-Qin Ye & Bin Wang. Int J Colorectal Dis. 18 August 2026. doi: 10.1007/s00384-026-05218-3
What is known about the subject?
In selected patients with complicated appendicitis, usually defined by gangrenous or perforated appendicitis with or without abscess or phlegmon formation, non-operative management with antibiotics, with or without percutaneous drainage, can be used because immediate surgery may be technically difficult and associated with increased morbidity or more extensive bowel resection. Whether subsequent interval appendectomy (IA) should routinely follow successful non-operative management of complicated appendicitis remains controversial. Although recurrence after conservative treatment is relatively uncommon and routine IA entails additional morbidity and cost, IA provides definitive histopathological assessment and may reveal an occult appendiceal neoplasm.
This oncologic rationale has become increasingly relevant, a previous systematic review by Peltrini et al. (doi.org/10.1016/j.surge.2021.01.010) reported an 11% pooled neoplasm detection rate among 455 patients undergoing IA. Since then, several studies have provided additional evidence, including more detailed age-stratified data and contemporary pathological classification.
What does this study add?
This study is a systematic review and age-stratified meta-analysis. Eligible studies reported histopathologically confirmed appendiceal neoplasms among adults undergoing IA after complicated appendicitis.
12 studies (published 2012-2025) including 1340 patients and 162 neoplasms were included. Risk assessment of the included studies revealed high risk in 2, moderate risk in 9, and low risk in 1 study.
Among adults selected for IA and histopathological assessment:
- The pooled IA-based detection rate of appendiceal neoplasm was 12.2% (95% CI, 9.3%-15.5%), with moderate heterogeneity
- Age-stratified data from three studies/subsets showed detection rates of 2.1% in patients aged < 40 years and 15.2% in those aged ≥ 40 years (Q = 32.53, p < 0.0001).
- Mucinous neoplasms were the most frequently reported histological subtype.
Implications for colorectal practice
- The IA-based appendiceal neoplasm detection rate of 12.2% among adults selected for interval appendectomy after complicated appendicitis should be interpreted within the context of selection into IA. Patients undergoing surgery may have been older or may have had persistent symptoms, recurrent episodes, suspicious imaging findings, or other clinical concerns. The rate therefore represents pathological detection in selected IA cohorts rather than the true prevalence among all patients initially managed non operatively.
- The GRADE certainty of evidence for the overall IA-based detection-rate estimate was rated as low, downgraded for risk of bias, inconsistency, and suspected small-study effects or publication bias. The certainty for the age-stratified comparison was rated as moderate, downgraded for risk of bias but not for inconsistency because the age-related difference was large and consistent across available studies/subsets.
- The findings should not be interpreted as evidence that all patients require routine IA. However, the higher IA-based neoplasm detection rates observed in older adults may help identify patients in whom interval appendectomy or structured surveillance warrants closer consideration, particularly when persistent or recurrent symptoms or suspicious imaging findings are present.
- The 2025 WSES Jerusalem Guidelines similarly emphasize that structured follow-up is essential after non-operative management of complicated appendicitis with abscess to detect occult appendiceal neoplasms.