Diagnostic Accuracy of Risk of Malignancy Index (RMI) in Evaluation of Ovarian Masses

Abstract

Objectives: To determine the diagnostic accuracy of RMI in predicting malignancy in patients presenting with ovarian masses, using histopathology of the mass as the gold standard.

Methodology: This cross-sectional study was conducted at the Department of Gynecology & Obstetrics, BBH, Rawalpindi, from August 23, 2019, to August 22, 2020. A total of 92 patients aged 25-75 years, with ovarian masses detected on ultrasound, were included. Those with previously diagnosed secondary metastatic disease were excluded. RMI was calculated in all these patients using ultrasound scores and CA-125 levels. Histopathology of the mass was performed after complete surgical removal, and the histopathology reports were compared with RMI values to determine its accuracy.

Results: The mean age was 48.78 ± 12.45 years. RMI supported the diagnosis of malignant adnexal masses in 53 (57.61%) patients. Histopathology findings confirmed malignant adnexal masses in 56 (60.87%) cases. Among RMI-positive patients, 49 were true positives and 4 were false positives. Among the 39 RMI-negative patients, 7 were false negatives, while 32 were true negatives (p = 0.653). Overall, RMI had a sensitivity of 87.50%, specificity of 88.89%, positive predictive value of 92.45%, negative predictive value of 82.05%, and diagnostic accuracy of 88.04% in predicting malignancy in patients presenting with ovarian masses.

Conclusion: This study concluded that RMI has a high diagnostic accuracy in predicting malignancy in patients presenting with ovarian masses.

Keywords: Ovarian masses, ovarian malignancy, malignant, risk of malignancy index.