Diagnosis: Granulosa cell tumors are the most common sex cord–stromal tumor and typically present as large, unilateral, solid and cystic ovarian masses. They may show a multilocular, sponge-like or “swiss-cheese” appearance due to macrofollicular growth. They are usually confined to the ovary at diagnosis, are rarely bilateral, and are considered low-grade malignancies with an overall excellent prognosis.

Teaching Points:

• Granulosa cell tumor is the most common sex cord–stromal tumor.
• Usually unilateral and confined to the ovary at diagnosis.
• Appears as a multilocular cystic mass with a sponge-like / swiss-cheese appearance.
• Hormone-producing (estradiol), often causing abnormal uterine bleeding and thickened endometrium.
• Tumor markers Inhibin and AMH are elevated and helpful for diagnosis and follow-up.
• Prognosis is generally excellent but late recurrence can occur, requiring long-term surveillance.