Role of a Risk of Malignancy Index in Clinical Approaches to Adnexal Masses

Objective: The aim of this study was to evaluate predictive role of risk of malignancy index in discriminating between benign and malignant adnexal masses preoperatively. Methods: This retrospective study was conducted with a total of 569 patients with adnexal masses/ovarian cysts managed surgically at our clinic between January 2006 and January 2012. Obtained data from patient files were age, gravidity, parity, menopause status, ultrasound findings and CA125 levels. For all patients ultrasound scans were performed. For the assessment of risk of malignancy index (RMI) Jacobs' model was used. Histopathologic results of all patients were recorded postoperatively. Malignancy status of the surgically removed adnexal mass was the gold standard. Results: Of the total masses, 245 (43.1%) were malignant, 316 (55.5%) were benign and 8 (1.4%) were borderline. The mean age of benign cases was lower than malign cases ($35.2{\pm}10.9$ versus $50.8{\pm}13.4$, p<0.001). Four hundred and five of them (71.2%) were in premenopausal period. Malignant tumors were more frequent in postmenopausal women (81% versus 29%, p<0.001). All ultrasound parameters of RMI were statistically significantly favorable for malignant masses. In our study ROC curve analysis for RMI provided maximum Youden index at level of 163.85. When we based on cutoff level for RMI as 163.85 sensitivity, specificity, PPV, NPV was calculated 74.7%, 96.2%, 94% and 82.6%, respectively. Conclusions: RMI was found to be a significant marker in preoperative evaluation and management of patients with an adnexal mass, and was useful for referring patients to tertiary care centers. Although utilization of RMI provides increased diagnostic accuracy in preoperative evaluation of patient with an adnexal mass, new diagnostic tools with higher sensitivity and specificity are needed to discriminate ovarian cancer from benign masses.