Introduction/Background The WHO allowed the classification of ovarian tumors of which epithelial ovarian tumors constitute 2/3 of cases; When these epithelial tumors are malignant, they represent particular characteristics, notably thickened irregular walls and partitions with significant vascularization. These tumors can be diagnosed at an early stage as well as at a late stage with extension towards the uterus, the pelvic organs or at a stage of carcinomatosis.

Methodology 25 cases of primary malignant epithelial ovarien tumors treated in the department of gynecology-obstetrics I at the CHU Hassan II in Fez between 2021 and 2023 were analyzed retrospectively.

Results The average age is 56.7 years. 44% consulted for chronic pelvic pain, 32% for increased abdominal volume, 8% for deterioration in general condition while 16% had an incidental discovery. 44% received neoadjuvant chemotherapy. the pathological study found serous carcinoma in 72% of cases; 12% mucinous carcinoma; 8% endometrioid carcinoma; an association of mucinous carcinoma and ring-shaped carcinoma in 1 case and a final case of association of serous carcinoma with clear cell component.

Conclusion Malignant invasive epithelial tumors of the ovary are tumors with a poor prognosis. Surgery is the essential stage in the staging and treatment of these tumors. In advanced stages, this surgery can be preceded by neoadjuvant chemotherapy in order to reduce tumor volumes and therefore the importance of excision procedures.

Disclosures The authors declare that they have no conflict of interest.