FIGO Stage IC3 Adult Granulosa Cell Tumor of the Ovary: A Case Report and Review of Contemporary Management

Background: Adult granulosa cell tumor (AGCT) is a rare ovarian sex cord- stromal neoplasm. Surgery remains the cornerstone of treatment for early- stage disease, whereas the benefit of adjuvant chemotherapy in FIGO stage IC remains uncertain. Case presentation: A 49-year-old postmenopausal woman presented with a one-year history of pelvic pain and progressive abdominal distension. Imaging showed a large left adnexal mass with solid-cystic and hemorrhagic features, raising suspicion of a granulosa cell tumor. Serum CA-125 was elevated at 136.4 U/mL. The patient underwent total hysterectomy with bilateral salpingo-oophorectomy, omentectomy, and appendectomy. Histopathological examination revealed an adult granulosa cell tumor with capsular rupture. Immunohistochemistry showed expression of CD99 and calretinin, whereas cytokeratin, epithelial membrane antigen, CD30, and alpha-fetoprotein were negative. Peritoneal cytology revealed atypical cell clusters that were initially indeterminate; after multidisciplinary review, the cytology was considered positive for malignant cells, and the disease was classified as FIGO stage IC3. The patient received four cycles of adjuvant carboplatin and paclitaxel, which were well tolerated, followed by oncological surveillance. Conclusion: This case highlights the importance of integrated clinicopathological assessment in AGCT and the limited evidence guiding adjuvant treatment in FIGO stage IC3 disease. The potential for late recurrence further supports prolonged oncological surveillance, although the optimal follow-up strategy remains to be defined