Preoperative evaluation and triage of women with suspicious adnexal masses using risk of malignancy index Christopher A. Enakpene 1 , Akinyinka O. Omigbodun 1 , Tamme W. Goecke 2 , Akin-Tunde Odukogbe 1 and Mathias W. Beckmann 2 1 Department of Obstetrics and Gynecology, University College Hospital, Ibadan, Nigeria and 2 Friedrich-Alexander University Women’s Hospital, Erlangen, Germany Abstract Aims: To test the accuracy of risk of malignancy index (RMI) in preoperative prediction of malignancy and treatment of adnexal masses. Methods: A total of 302 women with ultrasound diagnosed adnexal masses, and serum measurement of cancer-associated antigen CA-125 levels, were studied. They all had surgical exploration between October 2001 and September 2005 at the Friedrich-Alexander University Women’s Hospital, Erlangen, Germany. The RMI was based on menopausal status, ultrasound morphology of adnexal masses and absolute level of serum CA-125. A cut-off of 250 was chosen as the threshold for determining the type of surgical operations (laparo- tomy versus laparoscopy) and the skill of the surgeons (gynecological oncologist versus general gynecologist). The data obtained were analyzed for baseline characteristics using c 2 test and analysis of variance (ANOVA). P < 0.05 were statistically significant. The various testing methods were evaluated for sensitivity, specificity, positive and negative predictive values. Results: The best individual performance was found in RMI at a cut-off of 250 with a sensitivity of 88.2%, specificity of 74.3%, positive predictive value of 71.3% and negative predictive value of 90%. When RMI was used to triage patient treatment, 81.5% of patients who had laparoscopy had histological diagnosis of benign ovarian tumor and 7.5% had malignant tumor. In contrast, 74.4% of patients who had laparotomy had histological diagnosis of malignant ovarian tumor and 16% had benign tumor. Conclusion: Risk of malignant index is a reliable, cheap, readily available and cost-effective method of pre- operative discrimination of benign from malignant adnexal masses. It is also helpful in triaging patients to different treatment groups. Key words: preoperative evaluation, risk of malignancy index, suspicious adnexal masses, triage. Introduction An ovarian mass may be neoplastic or physiologic, and most neoplastic adnexal masses are benign. Differenti- ating malignant from benign disease is critical in optimizing management for the individual and the eventual outcome of the disease process. Among pre- menopausal patients, >90% of surgically managed cases are benign, as opposed to just 60% in the postmeno- pausal population. 1 Ovarian cancer is the commonest gynecological malignancy in the developed world; it continues to kill more women than all other gyneco- logical cancers together. 1 If diagnosed early, the 5-year survival rates for stage 1a disease is 89.6%, for stage 11a disease it is 70.7%, stage 111a is 46.7%, stage 111c is 32.5% and stage 1V disease is 18.6%. 2 Although it is presently the third commonest gynecological cancer in the developing countries after cervical cancer and cho- riocarcinoma, projections suggest an increase in inci- dence. 3 Unlike the vulva, the vagina, the cervix and the Received: December 6 2007. Accepted: April 7 2008. Reprint request to: Dr ChristopherA. Enakpene, PO Box 21379, University of Ibadan Post-Office, Ibadan, Oyo State, Nigeria. Email: christdew2002@yahoo.com doi:10.1111/j.1447-0756.2008.00869.x J. Obstet. Gynaecol. Res. Vol. 35, No. 1: 131–138, February 2009 © 2008 The Authors 131 Journal compilation © 2008 Japan Society of Obstetrics and Gynecology