Germ cell tumors are growths of cells that form from reproductive cells. The tumors may be cancerous or not cancerous. Most germ cell tumors occur in the testicles or the ovaries.
Some germ cell tumors occur in other areas of the body, such as the abdomen, brain and chest, though it's not clear why. Germ cell tumors that occur in places other than the testicles and ovaries (extragonadal germ cell tumors) are very rare.
Treatment options for germ cell tumors may include surgery to remove the tumor, chemotherapy with drugs that kill cancer cells and radiation therapy with powerful energy beams.