Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Childhood Extracranial Germ Cell Tumors ?
    ### Response:
    Key Points
                    - Childhood extracranial germ cell tumors form from germ cells in parts of the body other than the brain.    - Childhood extracranial germ cell tumors may be benign or malignant.    - There are three types of extracranial germ cell tumors.
    