What is an Intracranial Germ Cell Tumor?

Germ cell tumors (GCTs) form in germ cells, which are cells that develop into sperm or ova (eggs). GCTs can be either benign or malignant and usually form in the center of the brain, near the pineal gland (a tiny organ in the brain that makes melatonin, which is a substance that helps control the sleeping and waking cycle). Germ cell tumors can spread to other parts of the brain and spinal cord. GCTs mainly occur in adolescents and young adults, with the peak incidence of 10 to 12 years of age and more commonly seen in boys.

There are two types intracranial GCTs:

Germinomas

  • Make up two-thirds of all GCTs
  • Malignant
  • More commonly seen in boys

Non-germinomatous germ cell tumors (NGGCT)

  • Make up one-third of all GCTs
  • Most are malignant
  • Several subtypes
    • Endodermal sinus tumor (yolk sac tumor)
    • Embryonal carcinoma
    • Choriocarcinoma
    • Teratoma
    • Mixed germ cell tumors

Intracranial germ cell tumors account for less than four percent of pediatric brain tumors in North America. For unknown reasons the incidence of GCTs is higher in Japan and Taiwan where they account for up to 11 percent of pediatric brain tumors.

What are the symptoms of an Intracranial Germ Cell Tumor?

The symptoms of GCTs depend on the location of the tumor. Pineal region tumors usually cause difficulty with eye movement such as looking up; increased intracranial pressure may also cause headache, vomiting, poor balance and lethargy. Tumors located in other regions of the brain may cause excessive urination and thirst due to diabetes insipidus (DI), growth failure, and precocious (early) or delayed puberty.

How is an Intracranial Germ Cell Tumor diagnosed?

A magnetic resonance imaging MRI scan of the brain and spine help define the location of the tumor and whether or not the disease has spread. Some germ cell tumors secrete proteins called “tumor markers” which aid in diagnosis. Blood and spinal fluid may be analyzed for the presence of tumor markers. If diagnosis cannot be made using tumor markers, a biopsy of the tumor is required to make the final diagnosis. A spinal tap (lumbar puncture) is done to assess for spread of the tumor in the spinal fluid.

How is an Intracranial Germ Cell Tumor treated?

Germinomas that are diagnosed using tumor markers require no surgery, because chemotherapy  and radiation are curative, and surgical removal does not improve outcome and adds risk. In cases where a diagnosis cannot be made using tumor markers, a surgery is required to biopsy the tumor to make the diagnosis. Chemotherapy and radiation therapy  are both required for the best outcome and the least long-term side effects.

Non-germinomatous germ cell tumors that are diagnosed using tumor markers require no surgery initially. In cases where a diagnosis cannot be made using tumor markers, a surgery is required to biopsy the tumor to make the diagnosis. Depending on the location of the tumor, surgeons may attempt to remove the tumor at the initial surgery. Chemotherapy and radiation therapy are both required for the best outcome and the least long-term side effects.

About treatment for Intracranial Germ Cell Tumor at Children’s Hospitals and Clinics of Minnesota

Our cancer and blood disorders program consistently achieves excellent results ranking it in the top 10 programs in the United States. Children’s Hospitals and Clinics of Minnesota treats the majority of children with cancer and blood disorders in Minnesota and provides patients access to a variety of clinical trials using ground-breaking new treatments. Through our renowned program, patients experience unparalleled family support, a nationally recognized pain management team, and compassionate, coordinated care.

Contact us

If you are a family member looking for a Children’s Hospitals and Clinics of Minnesota neuro-oncologist, please call our clinic at (612) 813-5940.

If you are a health professional looking for consultation or referral information, please call Children's Physician Access at 1-866-755-2121 (toll-free) and ask for the on-call hematologist/oncologist.

Additional information on Intracranial Germ Cell Tumor

For additional information, check out these web sites:

National Cancer Institute

American Brain Tumor Association

CureSearch

Pediatric Brain Tumor Foundation