Mostly granulosa cell tumors are benign. Marker for granulosa cell tumor is:

Granulosa Cell Tumor: Most are benign; however, between 5 and 25% are malignant. The tumors can produce estrogen, thus leading to endometrial hyperplasia and cancer. Microscopic morphology of granulosa cell tumor shows Call-Exner bodies (appear similar to ovarian follicle), and produce inhibin, which can be identified in serum and by immunohistochemistry. Ref: Wyatt C., Moos P.J., Brown T.G. (2008). Chapter 17. Pathology of the Male and Female Reproductive Tract and Breast. In C. Wyatt, P.J. Moos, T.G. Brown (Eds), Pathology: The Big Picture.