Microscopic examination of a tumor shows Call-Exner bodies. They are seen in:

Microscopic examination of granulosa cell tumor shows predominantly granulosa cells with pale, grooved, "coffee bean" nuclei. The characteristic microscopic feature is the Call-Exner body -- a rosette arrangement of cells around an eosinophilic fluid space. Ref: Hoffman B.L., Schorge J.O., Schaffer J.I., Halvorson L.M., Bradshaw K.D., Cunningham F.G., Calver L.E. (2012). Chapter 36. Ovarian Germ Cell and Sex Cord-Stromal Tumors. In B.L. Hoffman, J.O. Schorge, J.I. Schaffer, L.M. Halvorson, K.D. Bradshaw, F.G. Cunningham, L.E. Calver (Eds), Williams Gynecology, 2e.