Other names or types of germ cell tumors include embryonal carcinoma, yolk sac tumor, germinoma, teratoma, mixed germ cell tumor, and endodermal sinus tumor.
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)
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
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:
Mature teratomas (noncancerous)
Mature teratomas are benigntumors. The cells of the tumor look much like normal cells. They are the most common type of extracranial germ cell tumor. They usually form in the sacrum or coccyx in newborns. They also occur in the ovaries of girls as they enter puberty.
Immature teratomas (cancerous)
Immature teratomas are malignant tumors. The cells of the tumor look quite different from normal cells. They are most often found in the sacrum or coccyx in newborns and in the ovaries of girls during puberty.
Malignant germ cell tumors (cancerous)
Malignant germ cell tumors include germinomas and nongerminomas.
Germinomas are cancerous germ cell tumors that tend to be slow growing. These tumors make a hormone called beta-human chorionic gonadotropin (β-HCG). This hormone can help diagnose and monitor the tumor.
Types of germinomas include dysgerminomas (ovary), seminomas (testicle), and extragonadal germinomas.
Nongerminomas are cancerous germ cell tumors that tend to grow more quickly. Types of nongerminoma tumors include yolk sac tumor, choriocarcinomas, embryonal carcinoma, and mixed germ cell tumor. A nongerminoma that is found in the testes is called a nonseminoma.
Yolk sac tumors (also known as endodermal sinus tumor) can be gonadal or extragonadal. They most often occur in the ovaries or testes and make up about 25% of germ cell tumors. It is the most common testicular cancer in boys under 3 years of age. Yolk sac tumors make the hormone alpha-fetoprotein (AFP). The survival rate for childhood yolk sac tumor is over 90%.
Choriocarcinomas can be gonadal or extragonadal. They make the hormone beta-human chorionic gonadotropin (β-HCG).
Embryonal carcinomas can occur in the testicle or other parts of the body. They do not form in the ovary. They can make β-HCG, AFP, or a combination.
Mixed germ cell tumors can be gonadal or extragonadal. They are made up of malignant germ cell tumor and teratoma.
Malignant Germ Cell Tumor Subtypes
Where they form
Seminoma
Testicle
Dysgerminoma
Ovary
Germinoma
Extragonadal
Yolk Sac Tumor
Extragonadal, Ovary, Testicle
Choriocarcinoma
Extragonadal, Ovary, Testicle
Embryonal Carcinoma
Extragonadal, Ovary, Testicle
Mixed germ cell tumors
Extragonadal, Ovary, Testicle
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.
Stage 1
The tumor is completely removed with surgery.
Stage 2
The tumor is removed by surgery, but microscopic cells are left behind.
Stage 3
Surgery could not completely remove the tumor, or there is spread of disease to nearby tissues or lymph nodes.
Stage 4
The tumor has spread to other parts of the body such as liver or lungs.
Each type of germ cell tumor has guidelines used for staging.
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.
Surgery
Surgery to remove the tumor is a main treatment for germ cell tumors. When possible, the goal is complete removal of the tumor. In some cases, if the tumor can be fully removed, your child may not need other treatment.
Germ cell tumor often needs special care during surgery. Germ cell tumors can grow near vital organs. They can also break apart easily. If parts of the tumor break off (tumor spill), then the cancer is a higher stage.
Chemotherapy
Chemotherapy may be used alone or with surgery to treat germ cell tumors. The type of chemotherapy depends on several factors including:
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?
Key points about germ cell tumor
Germ cell tumors are rare tumors that develop from germ cells, a type of reproductive cell.
Germ cell tumors can be found in different parts of the body including the ovary, testicle, chest, abdomen, lower spine, and brain.
Surgery is the main treatment for germ cell tumor; chemotherapy may also be used.
Prognosis for germ cell tumor is very good if surgery can completely remove the tumor.
Germ cell tumors of the brain and spinal cord are rare but are most often diagnosed in young adults. Learn about symptoms, diagnosis, treatment, prognosis, and care for germ cell brain tumors.
The treatments that cure cancer can also have certain long-term and late side effects. Learn about which treatments are linked to certain late effects.
