Background: To determine the cut-off values of the preoperative risk of malignancy index (RMI) used indifferentiating benign or malignant adnexal masses and to determine their significance in differential diagnosisby comparison of different systems. Materials and
Methods: 191 operated women were assessed retrospectively.RMI of 1, 2, 3 and 4; cut-off values for an effective benign or malignant differentiation together with sensitivity,specificity, negative and positive predictive values were calculated.
Results: Cut-off value for RMI 1 was foundto be 250; there was significant (p<0.001) compatibility at this level with sensitivity of 60%, positive predictivevalue (PPV) of 75%, specificity of 93%, negative predictive value (NPV) of 88% and an overall compliance rateof 85%. When RMI 2 and 3 was obtained with a cut-off value of 200, there was significant (p<0.001) compatibilityat this level for RMI 2 with sensitivity of 67%, PPV of 67%, specificity of 89%, NPV of 89%, histopathologiccorrelation of 84% while RMI 3 had significant (p<0.001) compatibility at the same level with sensitivity of63%, PPV of 69%, specificity of 91%, NPV of 88% and a histopathologic correlation of 84%. Significant(p<0.001) compatibility for RMI 4 with a sensitivity of 67%, PPV of 73%, specificity of 92%, NPV of 89% anda histopathologic correlation of 86% was obtained at the cut-off level 400.
Conclusions: RMI have a significantpredictability in differentiating benign and malignant adnexal masses, thus can effectively be used in clinicalpractice.