Definition

A rare tumor that is made up of more than one type of cell found in the gonads (testicles and ovaries), including germ cells, stromal cells, and granulosa cells. Gonadoblastomas are usually benign (not cancer), but they may sometimes become malignant (cancer) if not treated. Most patients with gonadoblastoma have certain chromosome abnormalities and abnormal gonads. Gonadoblastomas occur most often in children and young adults.