Morgante G1, La Marca A, Ditto A, De Leo V. Abstract OBJECTIVE: To evaluate the ability of two malignancy risk indices (RMI 1 and RMI 2) incorporating menopausal status, serum CA125 level and ultrasound findings, to discriminate a benign from a malignant pelvic mass. DESIGN: A retrospective study. SETTING: Department of Obstetrics and Gynaecology, University of Siena, Italy. POPULATION: One hundred and twenty-four women over 30 years of age admitted consecutively between January 1995 and December 1997 for surgical excision of ovarian masses. MAIN OUTCOME MEASURES: The sensitivity, specificity, and positive predictive value of serum CA125, ultrasound findings and menopausal status, separately and combined into the RMI 1 and RMI 2, to diagnose ovarian cancer. RESULTS: The RMI 1 and RMI 2 were more accurate than menopausal status, ultrasound findings, and CA 125 separately in diagnosing cancer. For all cut off values between 80 and 250, RMI 2 performed better than RMI 1. The RMI 2 at a cut off level of 125 gave a sensitivity of 81%, specificity of 90%, and positive predictive value of 74%. CONCLUSIONS: We found that RMI 2 was more reliable in discriminating benign and malignant ovarian disease than RMI 1. RMI is a simple method which can be used in gynaecology clinics and less specialised centres.