Diagnostic value of preoperative inflammatory indices in adnexal torsion: a focus on the systemic immune-inflammation index

Adnexal torsion is a gynecological emergency in which delayed diagnosis may result in ovarian necrosis and loss of fertility. This study aimed to evaluate the diagnostic and predictive value of preoperative inflammatory indices—neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and the systemic immune-inflammation index (SII)—in patients operated on for suspected adnexal torsion, with particular emphasis on their role in the pre-imaging clinical setting. This retrospective observational study included 231 patients who underwent surgery for adnexal pathology between 2018 and 2024. Based on intraoperative findings, patients were classified into an adnexal torsion group ( n = 90) and a control group with adnexal masses without torsion ( n = 141). Preoperative complete blood count parameters obtained within 24 h before surgery were recorded, and NLR, PLR, and SII were calculated. Receiver operating characteristic (ROC) curve analysis and two-step multivariable logistic regression analyses (with and without Doppler ultrasonography findings) were performed to assess diagnostic performance and independent predictive value. Patients with adnexal torsion were significantly younger than controls ( p < 0.001). NLR and SII values were significantly higher in the torsion group ( p < 0.001 and p = 0.001, respectively), whereas PLR showed no significant difference. ROC analysis demonstrated moderate diagnostic performance for NLR (AUC = 0.680; 95% CI: 0.615–0.739) and SII (AUC = 0.658; 95% CI: 0.593–0.719). In multivariable analysis excluding Doppler findings, higher NLR values (OR = 1.70, p = 0.008) and younger age (OR = 0.95, p = 0.001) were independently associated with adnexal torsion, whereas SII did not retain independent predictive value. Preoperative NLR is an independent, inexpensive, and readily available biomarker that may assist in the early identification of adnexal torsion, particularly in the absence of definitive imaging findings. Although SII reflects the systemic inflammatory response and demonstrates moderate diagnostic performance, it should be interpreted as a complementary rather than a standalone diagnostic marker.