What Are Germ Cell Tumors?

Medically Reviewed by Melinda Ratini, MS, DO on November 01, 2022
5 min read

If you just found out that you or your child has a germ cell tumor, you may have a lot of questions about what it means and what comes next. There are many kinds of germ cell tumors, and only some of them are cancer.

Germ cells don’t have anything to do with germs. They get their name from the word “germinate,” which means to begin to grow. That’s because as a baby develops before birth, germ cells move into place and become either eggs in the ovaries or sperm in the testicles.

Sometimes, a group of germ cells grows in a way that’s not normal. A tumor forms. This usually happens in an ovary or testicle. You can also get a germ cell tumor in your brain, chest, belly, pelvis, or lower back, but it’s not as common.

Changes in the genes of a germ cell can cause it to grow out of control, which leads to a tumor. Doctors aren’t sure what triggers that change.

Still, you may be more likely to get a germ cell tumor if you have:

Anyone can get an ovarian germ cell tumor. But those who are 30 or younger are more likely to develop it.

Things that raise your risk of developing testicular germ cell tumors include:

  • Being white
  • Poor sperm quality
  • Testicular cancer
  • Testicular microlithiasis. It’s a condition in which small lumps of calcium form in the testicles.
  • HIV
  • Orchitis. It’s a condition that causes one or both of your testicles to become inflamed. 
  • A weakened immune system caused by an organ transplant


There are several, but five are more common than others:

  • Teratomas, also called “dermoid cysts,” are not usually cancer, but they can be. They’re the most common germ cell tumors found in the ovaries. Usually, they’re treated with surgery.
  • Germinomas are typically cancer, though they tend to grow slowly and can usually be cured. They are most often found in the brain and spinal cord, although they can also grow in the ovaries or testicles as well. 
  • Yolk sac tumors, (also called endodermal sinus tumors) are usually cancer. They form in the testicles and ovaries. It’s often an aggressive cancer that spreads quickly to the lymph nodes and other parts of the body. They’re typically treated with surgery and chemotherapy.
  • Embryonal carcinoma has cancer cells that usually mix with another type of germ cell tumor. For example, embryonal carcinoma cells could mix with a teratoma and make it cancer.
  • Choriocarcinoma is a rare cancer that happens in the placenta. It can affect both the mother and baby.

Extragonadal germ cells are tumor cells that form in body parts outside of the ovaries or testicles. These are rare. Types of extragonadal germ cell tumors include:

  • Mediastinal germ cell tumors. These form in the area between the chest and the spine, where the heart is located.  
  • Pineal region tumors form in the middle of the brain behind the brain stem. 
  • Retroperitoneal germ cell tumors form in the back of your belly.
  • Sacrococcygeal germ cell tumors form in the lower part of your spine. 

It depends on the type of tumor and where it’s located. Common signs of germ cell tumors include:

  • A mass on your ovaries or testicles
  • Belly pain and swelling (caused by tumor)
  • Bathroom troubles (a hard time pooping or holding in your pee, if the tumor is near your pelvis)
  • Breast growth, pubic hair, or vaginal bleeding at an earlier age than normal
  • Belly or chest pain
  • Lump or a mass in the belly or testicles
  • Testicles that aren’t the right shape or size
  • Weakness in your legs (if the tumor is in the lower back)
  • Wheezing or shortness of breath (if the tumor is near the lungs)

They’ll start by asking questions about your health and symptoms, and then do a physical exam. After that, you may get:

  • A biopsy. Your doctor takes a sample of the tumor to test it for cancer and help guide your treatment.
  • Blood tests. You may get different tests to check the overall health of your blood, kidneys, and liver. Your doctor may also test for signs of a tumor, like high hormone levels. And if they think you have a genetic condition, you may also get a genetic test.
  • Imaging. CT, MRI, X-ray, ultrasound, and bone scans can show where the tumor is and whether it has spread.

It depends on the kind of tumor you have, where it is, and if it has spread. Germ cell tumors can spread to other parts of your body such as lymph nodes, the lungs, liver, or brain. Your doctor will also take your age and overall health into account. You may need more than one type of treatment. Your doctor will help you figure out the best approach.

Treatment options usually include:

  • Surgery to remove the tumor. If it’s cancer, your doctor needs to remove all of the cancer cells. That could mean removing the testicle or ovary and fallopian tube where the tumor is located.
  • Chemotherapy (chemo), uses drugs to kill cancer. It’s often used if the tumor is cancer and has spread to other parts of your body.
  • Radiation uses high energy from X-rays or other sources to kill cancer cells. Newer kinds of radiation focus as closely as possible on the tumor to help limit side effects.

The 5-year survival rate looks at your or your child’s likelihood of surviving 5 years after the cancer was first found. 

For children under 15 with germ cell tumors, the outlook is good, and the 5-year survival rate is high at 90%. For those between the ages of 15-19, the 5-year survival rate is 93%. 

After you or your child complete treatments, it’s possible for the tumor to come back. This is called a relapse. Talk to your doctor about what to watch out for, and make sure to go to your follow-up appointments.