Morphological parameters of ovarian masses and accuracy of the risk of malignancy index in diagnosing ovarian malignancy

Introduction
To detect the morphological parameters of ovarian masses and the accuracy of the risk of malignancy index (RMI) in diagnosing ovarian malignancy.

Material and methods
264 women in 3 groups (reproductive, premenopausal, and postmenopausal) presented with ovarian masses and scheduled for surgery were included in this study. The participants’ preoperative RMI was compared to the postoperative histology (gold standard) to detect the accuracy of RMI in diagnosing ovarian malignancy.

Results
The incidence of malignant and benign ovarian tumours in the reproductive group was 9.1% and 90.9%, respectively, while it was 35.2% and 64.8%, respectively, in the premenopausal group, and 35.2%, and 64.8%, respectively, in the postmenopausal group. The incidence of malignant ovarian tumours was significantly higher in the premenopausal (35.2%) and postmenopausal (35.2%) groups compared to the reproductive group (9.1%), (p = 0.0008, and p = 0.0008, respectively). The receiver operating characteristic curve showed that RMI at cut-off value > 247.5 had 82.9% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 98.1% negative predictive value (NPV) in diagnosing ovarian malignancy in the 3 studied groups (AUC 0.955, p < 0.001). There was significant positive correlation between the participants’ age, and RMI (p = 0.001), and between participants’ cancer antigen-125 (CA-125) and RMI (p < 0.0001) in the ovarian malignancy group.

Conclusions
The multimodal RMI is an effective tool for primary evaluation of suspected ovarian masses. Risk malignancy index at cut-off value > 247.5 had the best performance (82.9% sensitivity, 100% specificity, 100% PPV, and 98.1% NPV) in diagnosing ovarian malignancy in the 3 studied groups. There was significant positive correlation between participants’ age, and RMI, and between participants’ CA-125 and RMI, in the studied malignant ovarian tumours.