Pediatric Germ Cell Tumors

Germ cell tumors are malignant (cancerous) or nonmalignant (benign, noncancerous) tumors that are comprised mostly of germ cells. Germ cells are the cells that develop in the embryo (fetus, or unborn baby) and become the cells that make up the reproductive system in males and females. These germ cells follow a midline path through the body after development and descend into the pelvis as ovarian cells or into the scrotal sac as testicular cells. Most ovarian tumors and testicular tumors are of germ cell origin. The ovaries and testes are called gonads.

Tumor sites outside the gonad are called extragonadal sites. The tumors also occur along the midline path and can be found in the head, chest, abdomen, pelvis and sacrococcygeal (lower back) area.

Germ cell tumors are rare. Germ cell tumors account for about 2 - 4% of all cancers in children and adolescents younger than age 20.

Germ cell tumors can spread (metastasize) to other parts of the body. The most common sites for metastasis are the lungs, liver, lymph nodes and central nervous system. Rarely, germ cell tumors can spread to the bone, bone marrow and other organs.

The cause of germ cell tumors isn't completely understood. A number of inherited defects have also been associated with an increased risk for developing germ cell tumors including the central nervous system and genitourinary tract malformations and major malformations of the lower spine. Specifically, males with cryptorchidism (failure of the testes to descend into the scrotal sac) have an increased risk to develop testicular germ cell tumors. Cryptorchidism can occur alone; however, and is also present in some genetic syndromes.

Some genetic syndromes caused by extra or missing sex chromosomes can cause incomplete or abnormal development of the reproductive system.

The following are the most common symptoms of germ cell tumors. However, each child may experience symptoms differently. Symptoms vary depending on the size and location of the tumor. Symptoms may include:

• A tumor, swelling or mass that can be felt or seen
• Elevated levels of alpha-fetoprotein (AFP)
• Elevated levels of beta-human chorionic gonadotropin (ß-HCG)
• Constipation, incontinence and leg weakness can occur if the tumor is in the sacrum (a segment of the vertebral column that forms the top part of the pelvis) compressing structures
• Abdominal pain
• Abnormal shape, or irregularity in, testicular size
• Shortness of breath or wheezing if tumors in the chest are pressing on the lungs

The symptoms of germ cell tumors may resemble other conditions or medical problems. Always consult your child's doctor for a diagnosis.

The healthcare provider will ask questions about your child's medical history and current symptoms. A physical exam will be done, and close attention will be paid to areas with lumps, pain, or other symptoms. Your child may need to see a cancer specialist (pediatric oncologist). Your child may need certain tests. The tests done depend on where the tumor is and can include:

• Blood tests. These tests check for signs of disease, look at liver and kidney functions, measure hormone levels, and look for tumor cell markers (such as AFP and beta hCG).
• Biopsy. A tiny piece (called a sample) of tissue is removed from the tumor and tested for cancer cells. This can be done during surgery or by using a needle to take out a sample. A biopsy is the only way to know for sure if the tumor is or isn't cancer.
• CT scan. A series of X-rays taken from different angles and a computer are used to make 3-D images of the inside of the body. 
• MRI. Large powerful magnets, radio waves, and a computer are used to make detailed images of the inside of the body.
• X-ray. A small amount of radiation is used to make images of internal tissues, bones, and organs.
• Ultrasound (sonography). Sound waves and a computer are used to create images of blood vessels, tissues, and organs. 

After a diagnosis of germ cell tumor, your child will need more tests. These help healthcare providers learn more about your child's overall health and the tumor. They're used to find out the stage of the cancer. The stage is how much cancer there is and how far it has spread (metastasized) in your child's body. A stage grouping is then assigned. In some cases, a stage grouping isn't assigned until after surgery is done to remove the tumor.

Stage groupings give an overall description of the cancer. A stage grouping is listed as a Roman numeral and can have a value of I (1), II (2), III (3), or IV (4). The higher the number, the more advanced the tumor is. Letters and numbers can be used after the Roman numeral to give more details.

The stage of a cancer is one of the most important things to know when deciding how to treat the cancer. Be sure to ask your child's healthcare provider to explain the details of your child's cancer to you in a way you can understand.

Specific treatment for germ cell tumors will be determined by your child's doctor based on:

• Your child's age, overall health and medical history

• Extent of the disease

• Your child's tolerance for specific medications, procedures or therapies

• Expectations for the course of the disease

• Your opinion or preference

Treatment may include (alone or in combination):

• Surgery (to remove the tumor and involved organs)

• Chemotherapy

• Radiation

• Bone marrow transplantation

• Supportive care (for the effects of treatment)

• Hormonal replacement (if necessary)

• Antibiotics (to prevent or treat infections)

• Continuous follow-up care (to determine response to treatment, detect recurrent disease and manage the late effects of treatment)

Prognosis greatly depends on:

• The extent of the disease

• The size and location of the tumor

• Presence or absence of metastasis

• The tumor's response to therapy

• The age and overall health of your child

• Your child's tolerance of specific medications, procedures or therapies

• New developments in treatment

As with any cancer, prognosis and long-term survival can vary greatly from individual to individual. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a child diagnosed with a germ cell tumor. Side effects of radiation and chemotherapy, as well as second malignancies, can occur in survivors of germ cell tumors. New methods are continually being discovered to improve treatment and to decrease side effects.