Childhood central nervous system germ cell tumors rarely spread outside of the brain and spinal cord.

Staging is the process used to find out how much cancer there is and if cancer has spread. There is no standard staging system for childhood central nervous system (CNS) germ cell tumors. The treatment plan depends on the type of germ cell tumor and if the tumor has spread within the CNS or to other parts of the body. The information from tests and procedures done to detect (find) childhood CNS germ cell tumors is also used to plan treatment. The tumors are grouped as newly diagnosed or recurrent.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

• Through tissue. Cancer invades the surrounding normal tissue.
• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.