Introduction/Background Borderline tumors of the ovary represent 10 to 20% of malignant tumors of the ovary and concern young women for whom the preservation of fertility is a major therapeutic issue.

Histologically, they are defined by the WHO as a category of tumors intermediate between morphologically benign lesions and those that are obviously malignant.

Methodology This retrospective cohort study included 10 women with borderline ovarian tumor treated in at chu hassan II Uni between 2019 and 2023. Clinicopathological characteristics, treatment, recurrence and survival data were collected

Results The average age is 38 years, 30% of our patients were nulligest, the serous subtype represents 70% and the mucinous 20%, all our patients have benefited from a surgical treatment

Conclusion OBRT most often affects young women. The majority are diagnosed at an early stage (stage I). The prognosis is excellent and the overall survival rate of OBRT is much higher compared to ovarian carcinomas.

Disclosures Frontier tumors of the ovary are clinically distinguished from malignant tumors by an earlier age of onset (mean age: 35–38 years) and a better prognosis. These tumors are almost always limited to the ovary (stage I) and often require less radical treatment than carcinomas, because of their non-invasive character.