Extragonadal Germ Cell Tumors

by National Cancer Institute

Extragonadal germ cell tumors form from developing sperm or egg cells that travel from the gonads to other parts of the body.

"Extragonadal" means outside of the gonads (sex organs). When cells that are meant to form sperm in the testicles or eggs in the ovaries travel to other parts of the body, they may grow into extragonadal germ cell tumors. These tumors may begin to grow anywhere in the body but usually begin in organs such as the pineal gland in the brain, in the mediastinum, or in the abdomen.

Extragonadal germ cell tumors can be benign (noncancer) or malignant (cancer). Benign extragonadal germ cell tumors are called benign teratomas. These are more common than malignant extragonadal germ cell tumors and often are very large.

Malignant extragonadal germ cell tumors are divided into two types, nonseminoma and seminoma. Nonseminomas tend to grow and spread more quickly than seminomas. They usually are large and cause symptoms. If untreated, malignant extragonadal germ cell tumors may spread to the lungs, lymph nodes, bones, liver, or other parts of the body.

Age and gender can affect the risk of developing extragonadal germ cell tumors.

Risk factors for malignant extragonadal germ cell tumors include the following:

• Being male.
• Being age 20 or older.
• Having Klinefelter's syndrome.

Possible signs of extragonadal germ cell tumors include chest pain and breathing problems.

Malignant extragonadal germ cell tumors may cause symptoms as they grow into nearby areas. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

• Chest pain.
• Breathing problems.
• Cough.
• Fever.
• Headache.
• Change in bowel habits.
• Feeling very tired.
• Trouble walking.
• Trouble in seeing or moving the eyes.

Imaging and blood tests are used to detect (find) and diagnose extragonadal germ cell tumors.

The following tests and procedures may be used:

Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. The testicles may be checked for lumps, swelling, or pain. A history of the patient's health habits and past illnesses and treatments will also be taken.

Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

Serum tumor marker test: A procedure in which a sample of blood is examined to measure the amounts of certain substances released into the blood by organs, tissues, or tumor cells in the body. Certain substances are linked to specific types of cancer when found in increased levels in the blood. These are called tumor markers. The following three tumor markers are used to detect extragonadal germ cell tumor:

• Alpha-fetoprotein (AFP).
• Beta-human chorionic gonadotropin (β-hCG).
• Lactate dehydrogenase (LDH).

Blood levels of the tumor markers help determine if the tumor is a seminoma or nonseminoma.

CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs, such as the testicles, and make echoes. The echoes form a picture of body tissues called a sonogram.

Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. The type of biopsy used depends on where the extragonadal germ cell tumor is found.

• Excisional biopsy: The removal of an entire lump or suspicious tissue.
• Incisional biopsy: The removal of part of a lump or suspicious tissue.
• Core biopsy: The removal of part of a lump or suspicious tissue using a wide needle.
• Needle biopsy or fine-needle aspiration biopsy: The removal of part of a lump, suspicious tissue, or fluid using a thin needle.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

• Whether the tumor is nonseminoma or seminoma.
• The size of the tumor and where it is in the body.
• The blood levels of AFP, β-hCG, and LDH.
• Whether the tumor has spread to other parts of the body.
• The way the tumor responds to initial treatment.
• Whether the tumor has just been diagnosed or has recurred (come back).

Stages of Extragonadal Germ Cell Tumors

After an extragonadal germ cell tumor has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body.

The extent or spread of cancer is usually described as stages. For extragonadal germ cell tumors, prognostic groups are used instead of stages. The tumors are grouped according to how well the cancer is expected to respond to treatment. It is important to know the prognostic group in order to plan treatment.

The following prognostic groups are used for extragonadal germ cell tumors:

Good prognosis

A nonseminoma extragonadal germ cell tumor is in the good prognosis group if:

• the tumor is in the back of the abdomen; and
• the tumor has not spread to organs other than the lungs; and
• the levels of tumor markers AFP and β-hCG are normal and LDH is slightly above normal.

A seminoma extragonadal germ cell tumor is in the good prognosis group if:

• the tumor has not spread to organs other than the lungs; and
• the level of AFP is normal; β-hCG and LDH may be at any level.

Intermediate prognosis

A nonseminoma extragonadal germ cell tumor is in the intermediate prognosis group if:

• the tumor is in the back of the abdomen; and
• the tumor has not spread to organs other than the lungs; and
• the level of any one of the tumor markers (AFP, β-hCG, or LDH) is more than slightly above normal.

A seminoma extragonadal germ cell tumor is in the intermediate prognosis group if:

• the tumor has spread to organs other than the lungs; and
• the level of AFP is normal; β-hCG and LDH may be at any level.

Poor prognosis

A nonseminoma extragonadal germ cell tumor is in the poor prognosis group if:

• the tumor is in the chest; or
• the tumor has spread to organs other than the lungs; or
• the level of any one of the tumor markers (AFP, β-hCG, or LDH) is high.

Seminoma extragonadal germ cell tumor does not have a poor prognosis group.

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