Comparison of three risk of malignancy indices in evaluation of pelvic masses.

Objectives: The aims of this study were to validate the risk of malignancy index (RMI) incorporating menopausal status, serum CA 125 levels, and ultrasound features for discriminating benign from malignant pelvic masses and to evaluate the performance of the three different risk of malignancy indices (RMI 1, RMI 2, and RMI 3).

Methods: This is a retrospective study of 152 women admitted at Kasturba Hospital, Manipal, between January 1997 and August 1999 for surgical exploration of pelvic masses. The sensitivity, specificity, and positive predictive value of serum CA 125 levels, ultrasound findings, and menopausal status were taken separately and combined into the RMI 1, RMI 2, and RMI 3 to diagnose ovarian cancer. The risk of malignancy index is the product of menopausal score, ultrasound score, and serum CA 125 levels.

Results: The study confirms that the malignancy risk index is more accurate than the menopausal status, serum CA 125 levels, and ultrasound features separately in diagnosing malignancy. There was no statistically significant difference in the performance of these three different malignancy risk indices in identifying malignancy.

Conclusions: The risk of malignancy index is able to identify malignant and benign pelvic masses efficiently to optimize therapy. The risk of malignancy index is a simple scoring system which can be used in less specialized gynecology centers. We recommend the use of any of these risk of malignancy indices to facilitate the selection of cases for referral to an oncological unit for adequate staging and optimal debulking.