Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Ovarian Germ Cell Tumors ?
    ### Response:
    Key Points
                    - Ovarian germ cell tumor is a disease in which malignant (cancer) cells form in the germ (egg) cells of the ovary.     - Signs of ovarian germ cell tumor are swelling of the abdomen or vaginal bleeding after menopause.     - Tests that examine the ovaries, pelvic area, blood, and ovarian tissue are used to detect (find) and diagnose ovarian germ cell tumor.
    