About 2% of ovary tumors are granulosa cell tumors, of the malignant ovary tumors they make up about 10%. They occur in all age groups, but seldom before puberty. The majority of granulosa cell tumors produce estrogens. Production of androgens, in conjunction with signs of virilization, has been observed in individual cases. Granulosa cell tumors usually develop unilateral, occur in all age groups and are solid or multicystic. When dissected, the surface is gray, white or yellowish.