Germ Cell Tumor (Extracranial)

What is a germ cell tumor?

Germ cell tumors are formed by germ cells, a type of reproductive cell. They are the cells that become eggs in females or sperm in males. Germ cells develop as a baby grows inside the mother. Sometimes, germ cells can form tumors, called germ cell tumors. Germ cell tumors may be benign (not cancer) or malignant (cancer).

Germ cell tumors can occur in the:

• Ovary or testicle (gonadal germ cell tumor)
• Neck
• Chest area between the lungs (mediastinal)
• Back part of the abdomen (retroperitoneal)
• Lower part of the spine or tailbone (sacrum, coccyx)
• Brain (see Intracranial Germ Cell Tumors)

Extracranial germ cell tumors are germ cell tumors that form outside of the brain. They are often found in reproductive organs (ovaries or testicles). These are called gonadal germ cell tumors.

Germ cell tumors that form outside of the ovaries and testicles are called extragonadal germ cell tumors. These tumors usually grow along the center of the body.

Germ cell tumors can develop at any age. In pediatric patients, they occur most often in young children and in teens. They account for about 3% of childhood cancers.

Surgery is the main treatment for germ cell tumor. In some cases, germ cell tumor can be treated with surgery alone. Chemotherapy may be used with surgery. If surgery can completely remove the tumor, children have an excellent chance of cure.

Symptoms of germ cell tumor

Signs and symptoms of a germ cell tumor depend on the tumor size and location.

Symptoms may include:

• Abdominal pain
• Lump or swelling in the abdomen, lower back, or testicle
• Constipation
• Cough or trouble breathing
• Early onset of puberty

Risk factors of germ cell tumor

Germ cell tumors are most common in young children and in teens. An increase in germ cell tumors is seen in adolescents between 15–20 years old.

The cause of germ cell tumors is largely unknown. Certain inherited syndromes can increase the risk of germ cell tumor. These include Klinefelter syndrome, Swyer syndrome, and Turner syndrome.
In boys, having an undescended testicle can increase risk for gonadal germ cell tumor in that testicle.

Germ cell tumors in infants and young children

Germ cell tumors in young children are usually benign. Malignant tumors are less common in younger children.

Extragonadal tumors in young children most often occur in the lower spine or tailbone. In some cases, part of the tumor may be seen outside the body. If a germ cell tumor develops before birth, there is a risk for preterm delivery. It can also cause problems during birth including tumor rupture and bleeding. Some tumors may be found on routine ultrasound imaging during pregnancy.

Germ cell tumors in teens and young adults

Germ cell tumors in teens and young adults are usually gonadal. These occur within the testes or ovary. They may be benign or malignant. Extragonadal tumors in older children and adolescents often occur in the mediastinum (chest).

Diagnosis of germ cell tumor

Doctors use several types of tests to diagnose germ cell tumor. Tests may include:

• Physical exam and health history
• Blood tests to check blood counts, liver and kidney function, and hormones
• Tests for tumor markers including alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (β-HCG)
• Tests of fluid in the abdomen or chest to look for cancer cells
• Imaging tests to learn about the size and location of the tumor
  • Ultrasound 
  • Computed tomography (CT or CAT) scan
  • Magnetic resonance imaging (MRI)
  • Bone scan
  • Positron emission tomography (PET) scan
• Biopsy to identify the specific type of germ cell tumor

Types of germ cell tumor

Germ cell tumors are classified by how the cells look under a microscope.

Types of germ cell tumors include:

Stages of germ cell tumor

Staging of germ cell tumor is based on:

• Type of tumor
• Tumor location
• Spread of disease
• Outcome of surgery

In general, there are 4 stages of germ cell tumor.

Each type of germ cell tumor has guidelines used for staging. 

Find more information on germ cell tumor including Stages of Childhood Extracranial Germ Cell Tumor. 

Treatment of germ cell tumor

Treatment for germ cell tumor depends on several factors including:

• Your child’s age
• Type of tumor
• Location of the tumor
• Stage of disease

The main treatments for germ cell tumors are surgery and chemotherapy.

Radiation therapy is not usually used because surgery and chemotherapy are most effective. However, germ cell tumors can be treated with radiation, especially if the tumor has come back or is harder to treat.

Chemotherapy

Chemotherapy may be used alone or with surgery to treat germ cell tumors. The type of chemotherapy depends on several factors including:

• Your child’s age
• Type of tumor
• Location of the tumor
• Response to therapy  

Chemotherapy for pediatric germ cell tumor usually includes bleomycin, etoposide, and cisplatin.

Chemotherapy before surgery may be used to shrink the tumor. That can make it is easier to remove. Chemotherapy also may be used after surgery to kill any remaining cancer cells. 

High-dose chemotherapy with stem cell transplant may be a treatment option for disease that comes back. Patients with germ cell tumor that has spread or come back after treatment may consider treatment as part of a clinical trial. 

Prognosis for germ cell tumor

The prognosis for germ cell tumor is quite good when the cancer can be fully removed by surgery. With proper treatment, children with stage 1 or 2 disease have a cure rate of more than 90%. For more advanced disease (stages 3 or 4), survival rates are about 80–85%. But many factors influence the chance of cure.

Factors that influence outlook for germ cell tumor include:

• Type of germ cell tumor
• Location and size of the tumor
• Age of the child
• How the tumor responds to treatment
• If surgery can completely remove the tumor
• If there is spread of disease
• If the tumor is new or has come back

About 1 in 5 patients have spread of disease (metastasis) at diagnosis. The most common places for germ cell tumor to spread are the lung, liver, and lymph nodes. Less often, germ cell tumor may spread to the brain or bone.

Support for patients with germ cell tumor

For most children with germ cell tumor, the chance of cure is good. After treatment, imaging tests and monitoring of tumor markers are used to watch for return of the germ cell tumor.

Side effects of treatment

Talk to your care team about the treatments your child received and how to manage any side effects. Long-term problems depend on the specific type of germ cell tumor and the type of treatment. Children with gonadal germ cell tumors may have problems with fertility (having children) or hormone function. 

Late effects of therapy

Childhood cancer survivors treated with chemotherapy or radiation should be monitored at least once a year for long-term side effects or late effects of therapy. It is important to have regular physical checkups and screenings by a primary physician familiar with late effects and survivorship issues.  

Adopting healthy habits such as eating a balanced diet and being active can help survivors protect their health.  

Your care team may prepare a survivorship care plan. This plan is a complete record of treatment, medical concerns, and suggested screenings and health care.

Questions to ask your care team

• What are the treatment options?
  
• What are the possible risks or side effects of each treatment?
• What will the impact of my child’s diagnosis and treatment be on their fertility? Should we be referred to a fertility clinic?
• What can be done to manage side effects?
• Will my child need to be in the hospital for treatment?
• What tests and monitoring will be needed long-term?