Objective: To compare the diagnostic accuracy of Risk of malignancy Index (RMI) with final histopathological diagnosis and to find out the role of RMI in preoperative evaluation of ovarian mass. Materials and Methods: Prospective study with 50 subjects who underwent surgical removal of ovarian tumour and performed histopathological examination in GRH, Madurai for a period of six months from January to June 2018. Results: The best cut off value of RMI was 100 with a sensitivity 96%, specificity 92% and accuracy 94%. Conclusion: The RMI is a simple scoring system and has a high sensitivity and specificity for the detection of malignant adnexal masses. Application of the RMI in clinical practice may provide a rational basis for speciduals to treat patients with adnexal masses before diagnostic surgery.

Keywords: Aadnexal masses; RMI scoring system; Tumour.