Evaluation of factors predicting appendiceal tumoral lesions in patients undergoing appendectomy for acute appendicitis

BACKGROUND: Tumoral lesions are a relatively rare cause of acute appendicitis. Accurate pre-operative diagnosis is essential to provide appropriate treatment. The aim of this study was to evaluate factors that may increase diagnostic rate of appendiceal tumoral lesions in patients undergoing appendectomy. METHODS: A retrospective review of a large cohort of patients who underwent appendectomy for acute appendicitis from 2011 to 2020 was undertaken. Demographics, clinicopathologic findings, and pre-operative laboratory values were recorded. Univariate and multivariate logistic regression and receiver-operating characteristic curve analysis were performed to identify the factors that predict appendiceal tumoral lesions. RESULTS: A total of 1400 patients were included in the study, with median age of 32 (range, 18–88) years, and of whom 54.4% were male. Overall, 2.9% (n=40) of patients had appendiceal tumoral lesions. Multivariate analysis revealed that age (Odds Radio [OR] 1.06, 95% confidence interval [CI] 1.03–1.08) and WBC count (OR 0.84, 95% CI 0.76–0.93) were independent predictors of appendiceal tumoral lesions. The optimal cutoff age was 37 years old (AUC: 0.79; sensitivity: 82.0%; specificity: 62.0%). WBC count <10×10(9)/L was another independent predictive factor (AUC: 0.69, sensitivity: 74%; specificity: 60%). CONCLUSION: Predicting an appendiceal tumoral lesion preoperatively is critical to ensure a favorable post-operative outcome. Higher age and low WBC counts appear to be independent risk factors for an appendiceal tumoral lesion. In case of doubt and in the presence of these factors, wider resection should be favored over appendectomy only to provide a clear surgical margin.