Introduction/Background The diagnosis of ovarian cancer is often established at a late stage of the evolution of the disease with the absence of universal screening method. The RMI1 (Risk of malignancy index 1) is a score to predict the risk of malignancy of a suspicious ovarian mass. The purpose of our work was to evaluate the performance of the RMI1 score in the evaluation of the risk of malignancy of suspicious ovarian masses in our service.

Methodology This was a descriptive, longitudinal, retrospective and mono-centric study conducted in the department of gynecology ’C’, spread over a period of 03 years (from January 2019 to December 2021) conducted among women operated for suspected ovarian mass and meeting the criteria of suspicion. 89 patients were included in the work.

Women who were lost to follow-up were excluded.

Results The average age of the patients was 45.6 years. Concerning the circumstances of discovery, chronic abdominopelvic pain was the most frequent reason for consultation of the patients (n=39), i.e. 44.3% of the cases. A score greater than or equal to 200 suggestive of malignancy was observed in 70.5% of the cases. The suspected ovarian mass was malignant in 60.2% of cases. The malignant tumor was primary in 88.7% of cases and secondary in 11.3% of cases. The median RMI score was equal to 405 (IQR= [118.5–2034]).The RMI 1 score was significantly higher for malignant tumors (P=0.003).with an area under the ROC curve at 68.9%. 90% of the malignant epithelial tumors (n=27) had an RMI1 score higher than 200. On the other hand, 41.7% of borderline tumors had an RMI1 score < 200, i.e. a rate of about 50% of cases.

Conclusion The diagnostic contribution of the RMI1 score in our series is low compared to the literature data, and a prospective multicenter study is needed.

Disclosures The author and the co-authors have not potential conflict of interest to report