Introduction/Background Granulosa cell tumors (CGT) are the most common type of potentially malignant ovarian sex cord-stromal being usually diagnosed in the early stages, with 5-year survival rates for completely resected stage I disease close to 90% and tendency for late relapse.

Methodology All CGT cases diagnosed and treated at the Ramon y Cajal University Hospital in Madrid, Spain from 2000–2019 were retrospectively analyzed.

Results A total of 16 patient were included.Mean age was 52.4 years (range 14–67) Patients presented mainly with abnormal bleeding (37,5%). 25% of the patients started with abdominal pain and/or abdominal mass, finding 2 cases of acute abdomen requiring urgent surgery.93,75% of the cases were diagnosed in FIGO stage I disease (86,6% stage IA, 13.4% stage IC), and one case of IVC stage with pulmonary involvement. Primary treatment was surgery in all cases, 12 patient underwent total hysterectomy with bilateral salpingoophorectomy. Complete staging surgery was performed in 33,3% of these patients. In 25% of cases, unilateral adnexectomy was performed.

Median tumor size was 5.3 cm. 92.3% of the cases were of adult subtype. Mitotic index was measured in 11 patients, being low in 54,5% of cases. Cellular atypia was objected in 5 cases.

Only one patient received adjuvant therapy with tamoxifen due to treatment of a previous breast cancer. Adjuvant chemotherapy was offered to the patient with IVC stage disease, denying treatment.

The median follow-up time was 8.4 years. Inhibin determinations in blood were carried out in 5 patients since 2017. Abdominopelvic relapses were reported in 2 patient with FIGO stage I (12.5%).Surgery with optimal resection and platinum based adjuvant chemotherapy were given.The mean relapse free survival was 4.2 years (3–84 months).

Conclusion GCT tumors are uncommon neoplasm with a late recurrences rate. Therefore, long active follow up is recommended.

Disclosure Nothing to disclose.