Germ Cell Tumors

Germ cell tumors develop from cells that normally produce eggs or sperm in the reproductive organs -- the testicles in men and ovaries in women. Germ, meaning "seed," refers to the role the germ cells play in producing egg and sperm cells. When abnormal growth and development occurs, these cells may produce a germ cell tumor. These relatively rare tumors can be cancerous or benign.

When the tumors occur in the ovary or testes, which are the gonad glands, they are called gonadal germ cell tumors. Most ovarian and testicular tumors in children originate from germ cells.

When germ cell tumors occur outside the reproductive organs, they are called extragonadal germ cell tumors. These usually occur because misplaced cells fail to migrate to their proper location in the body. Many researchers believe that extragonadal germ cell tumors are related to developmental problems that occur before birth.

Germ cell tumors represent about 3 percent of all childhood cancers. Researchers have not identified any toxic or environmental factors that increase the risk of this cancer. Among children, cure rates are generally good -- above 90 percent -- except for only a few of the germ cell tumors.

For more information or to make an appointment, please call:
Children's Cancer and Blood Disease Program (415) 476-3831

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Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007