The utility of systemic immune inflammatory index in discriminating between gallbladder cancer and xanthogranulomatous cholecystitis: A single-tertiary center experience

Xanthogranulomatous cholecystitis (XGC) and gallbladder carcinoma (GBC) are rare diseases with several similarities. This study aimed to evaluate the utility of the systemic immune inflammatory index (SII), a novel index that more accurately depicts inflammatory and immunological balance, in distinguishing between XGC and GBC. This retrospective study included 33 XGC, 22 GBC patients diagnosed according to histopathological findings and 33 age-sex-matched healthy controls at Hacettepe University Faculty of Medicine, General Surgery Department. The demographic, clinical and laboratory findings were recorded. Neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, monocyte to lymphocyte ratio and SII were calculated from preoperative complete blood count parameters. The receiver operating characteristic curve was performed to evaluate the utility of SII in differentiating GBC and XGC. A P value < .05 was accepted as statistically significant. The preoperative neutrophil to lymphocyte ratio, monocyte to lymphocyte ratio, platelet to lymphocyte ratio and SII were significantly higher in patients with GBC compared to XGC patients and healthy controls (P < .001, P = .001, P = .001, P < .001, respectively). When receiver operating characteristic analysis was made, the optimal cutoff value of SII was 640 for differential diagnosis of XGC and GBC preoperatively with a sensitivity of 77.3% and a specificity of 66.7%, among which the positive likelihood ratio was 2.32, and Youden index was 0.44 (P = .006). The positive predictive value was 60.7%, the negative predictive value was 81.5%, and the diagnostic accuracy was 79.9%. SII may be a valuable, practical, and affordable method to differentiate between XGC and GBC, in addition to clinical and radiological signs, prior to surgery. When supported by prospective trials with a larger study population, distinguishing GBC from XGC using SII preoperatively may lead to a change in the management practice of GBC.