Risk of Malignancy Index (RMI) in Evaluation of Adnexal Mass.

BACKGROUND The discrimination between benign and malignant adnexal masses is central to decisions regarding clinical management and surgical planning in such patients. PURPOSE OF STUDY To determine if the RMI (RMI 2) can distinguish between benign and malignant adnexal masses. METHODS A prospective cohort study was conducted of 58 women with an adnexal mass referred to a teaching hospital for diagnosis and management. RESULTS RMI > 200 had a sensitivity of 70.5 % (95 % CI 46.87-86.72), a specificity of 87.8 % (95 % CI 74.46-94.68), a positive predictive value of 70.5%, and negative predictive value of 87.8 %. ROC showed that cut off value of 25 achieved a sensitivity and specificity of 82.35 and 43.9 %, respectively, and a cut off value of 1,000 gave a sensitivity and specificity of 58.81 and 97.56 %, respectively. The association between RMI and disease status was not statistically significant for mucinous tumors. CONCLUSION RMI is a reliable tool in differentiating benign from malignant adnexal masses. It is simple, easy to use and cost effective. However it's predictive accuracy was less for mucinous as compared to serous epithelial ovarian cancers. The study is limited by its small sample size.