Germ Cell Tumors

Germ cell tumors are masses of tissue formed by immature cells that normally would have developed into mature eggs (in a female) or sperm (in a male). Ninety percent of germ cell tumors are gonadal, which means they begin in the reproductive cells of the testes (testicular tumors) or ovaries (ovarian tumors). Germ cell tumors that appear in other parts of the body — including the abdomen, chest, neck, head, and brain (the areas where the cells migrate within a developing embryo) — are called extragonadal germ cell tumors.

Although these tumors are rare in children under age 15, they are the most common solid tumors in adolescents, accounting for 14 percent of all cancers among those 15 to 19 years old. Germ cell tumors of the brain are a type of extragonadal germ cell tumor but are treated differently than germ cell tumors in other parts of the body. This page is focused on extracranial (outside of the brain) germ cell tumors.

Germ cell tumors can cause a variety of symptoms in children based primarily on the size and location of the tumor. Keep in mind symptoms of a germ cell tumor may resemble other more common conditions or medical problems. It is important to consult your child's physician for a diagnosis.

Each child may experience germ cell tumor symptoms differently, but your child's symptoms may include:

• A tumor, swelling, or mass that can be seen or felt
• Constipation, incontinence, and leg weakness if the tumor is located in the pelvis or abdomen
• Shortness of breath if the tumor is located in the chest
• Elevated levels of certain proteins secreted by the tumors into the blood  

Doctors do not understand the cause of most germ cell tumors. Scientists do know that they can be associated with a number of other inherited defects of the ovaries or testes. For example, patients with Klinefelter syndrome have an increased risk of developing extragonadal germ cell tumors. However, it’s important to understand that germ cell tumors most often occur with no known cause.

The first step in treating your child is forming an accurate and complete diagnosis. Some germ cell tumors can be seen on a prenatal ultrasound. After birth, they are typically diagnosed using a combination of imaging and biopsy.

Your child’s physician may order a number of different diagnostic tests for germ cell tumors, including:

• Prenatal ultrasound
• A physical exam and complete medical history
• Biopsy, which involves taking a sample of the tumor's tissue and analyzing it under a microscope
• A complete blood count
• Additional blood tests may include blood chemistries, genetic testing, and an evaluation of liver and kidney function
• Magnetic resonance imaging (MRI)
• Computerized tomography scan (CT or CAT scan)
• X-ray
• Ultrasound

There may be other diagnostic tests that your doctor will discuss with you depending on your child's individual situation.

Your child's physician will determine a specific course of germ cell tumor treatment based on several factors, including your child's age, overall health, and medical history, and the type, location, and size of the germ cell tumor. Germ cell tumor treatment generally includes surgery. Pediatric surgeons will biopsy the tumor and attempt to remove it.

If the tumor is malignant, treatment may also include:

• Chemotherapy
• Radiation
• Supportive care throughout your child's treatment

Survival rates for children with germ cell tumors have increased significantly in the last several decades. This is largely due to results from germ cell tumor clinical trials, some of which build off of effective treatments developed for adults with testicular germ cell tumors. As physician scientists continue to build our understanding of the molecular mutations within germ cell tumors, treatments tailored to the specific characteristics of each child’s tumor may be developed, which could further improve survival rates.

Survival rates vary depending on the particular type of germ cell tumor and the stage of disease (how far it has progressed) when diagnosed. Overall, the survival is close to 90 percent for most children. Certain patients with more advanced disease have a worse prognosis, and these patients in particular may want to consider enrollment in a clinical trial. Mature and immature teratomas can usually be surgically removed, The surgery should be done by an experienced surgeon to minimize possible long-term effects of surgery. Chemotherapy for malignant germ cell tumors, however, may result in various late effects (side effects that appear later in adulthood), such as partial loss of hearing, cardiovascular concerns, or a secondary cancer later in life.

Children treated for a malignant germ cell tumor should visit a cancer survivorship clinic every year to manage disease complications, screen for recurrence, and manage late treatment side effects. A typical follow-up visit is likely to include a physical exam, laboratory testing, and imaging scans. The David B. Perini Jr. Quality of Life Clinic at Dana-Farber provides care and advocacy for survivors of childhood cancer, conducting research on the long-term effects of cancer treatments, and offering education and support for survivors of cancer.

Children with germ cell tumors are treated at Dana-Farber/Boston Children's Cancer and Blood Disorders Center through our Solid Tumor Center. Our specialists have extensive expertise in treating even the rarest of pediatric tumors, including germ cell tumors. Our solid tumor treatment team includes medical oncologists, surgical oncologists, radiation oncologists, and pediatric subspecialists who have unique expertise in treating germ cell tumors.

Various research studies are underway to help build our understanding of how treatment types and dosages can be modified according to the tumor sub-type, stage, location on the body and the age and gender of the child to provide the best possible outcome. Due to the rarity of germ cell tumors in children, however, statistically meaningful data with multivariate analysis is difficult to achieve. To address that, the Malignant Germ Cell International Collaborative (MaGIC) was formed. This consortium, led by A. Lindsay Frazier, MD, a pediatric oncologist at Dana-Farber/Boston Children’s, is a collaboration of the world’s experts in germ cell tumors, including pediatric, gynecologic, and genito-urinary oncologists.

For many children with rare or hard-to-treat conditions, such as germ cell tumors, clinical trials — research studies evaluating new treatment approaches — provide new options. Participation in any clinical trial is completely voluntary. We will take care to fully explain all elements of the treatment plan prior to the start of the trial, and you may remove your child from the medical study at any time.