Pediatric Germ Cell Tumors

What are 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.
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.