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Ovarian Germ Cell Tumors

Medically Reviewed.Last updated on 07/15/2026.

Ovarian germ cell tumors are growths that typically occur in females under 40 years old. The tumors are usually benign (noncancerous), but they can be cancerous. Most ovarian germ cell tumors are treatable with surgery. For malignant (cancerous) tumors, your prognosis depends on the tumor type and whether the cancer has spread.

What Are Ovarian Germ Cell Tumors?

Ovarian germ cell tumors develop from reproductive cells (germ cells) inside your ovaries. There are many types. About 95% of cases are noncancerous (benign). Rarely, an ovarian germ cell tumor can be cancerous (malignant).

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Anyone with ovaries can develop these tumors. But they most commonly affect young women and children, ages 10 to 30. They’re less common in women over 40.

Surgical removal is the main treatment. If it’s cancerous, you may need further treatment.

Types

There are many types of ovarian germ cell tumors. The most common type is a mature cystic teratoma (dermoid cyst). It’s noncancerous.

Cancerous types of ovarian germ cell tumors are uncommon. They include:

  • Dysgerminoma: Among cancerous ovarian germ cell tumors, dysgerminomas are the most frequent. Most of these tumors aren’t aggressive (fast-spreading) and respond extremely well to treatment. It most commonly affects adolescents and young women, with the average age of diagnosis between 20 and 24 years.
  • Immature teratoma: This is a fast-growing tumor that can spread to other parts of your body. It’s typically a large tumor when found. Immature teratomas can affect infants, children and adults. These are most commonly diagnosed in young adults, with an average age range of 24 to 27 years.
  • Yolk sac tumors (endodermal sinus tumors): These tumors grow quickly and spread fast. They’re rare and can affect any age. The majority of people are diagnosed in their 20s, with the average age at diagnosis being 21.
  • Mixed germ cell tumors: These tumors contain a mix of other tumor types, usually dysgerminoma and yolk sac tumors.
  • Embryonal carcinoma: This is a very rare, aggressive tumor. The average age of diagnosis is 14.
  • Choriocarcinoma: This tumor can spread quickly. It’s usually diagnosed due to gestational risk factors, meaning it can form after any pregnancy event (like miscarriage, molar pregnancy, normal delivery, ectopic pregnancy). Having a molar pregnancy is the greatest risk factor. It’s extraordinarily rare to be diagnosed with a non-gestational choriocarcinoma.
  • Polyembryoma: This tumor is considered one of the rarest germ cell tumors. These tumors are typically large at the time of diagnosis.

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Symptoms and Causes

Symptoms of ovarian germ cell tumors

It may be hard to spot signs of ovarian germ cell tumors early on. Benign tumors may not cause symptoms unless they’re large. Symptoms of malignant tumors may not appear until the cancer has spread.

Symptoms to look out for include:

  • Abdominal pain, discomfort or tenderness, which may be severe and sudden
  • Bloated belly
  • Changes in pooping habits, like diarrhea or constipation
  • Loss of appetite
  • Abnormal uterine bleeding, like bleeding when you’re not on your period

Some tumor types release hormones that may cause:

  • Symptoms of early pregnancy, like fatigue, nausea or breast tenderness
  • Early puberty (rare)

Ovarian germ cell tumor causes

Ovarian germ cell tumors form when germ cells undergo changes (mutations) that cause them to grow uncontrolled. Experts don’t know why this happens. But they continue to research these tumors, including who is most likely to develop them.

There isn’t anything you can do to prevent ovarian germ cell tumors.

Complications of this condition

A noncancerous ovarian germ cell tumor (mature teratoma) can rupture. If it bursts, it may cause acute severe pain. If the tumor grows large enough or quickly, this can lead to ovarian torsion. Torsion usually causes severe pain and can cut off blood supply to your ovary, causing it to die without quick intervention. Surgical removal of the teratoma can help prevent this complication.

Cancerous germ cell tumors can spread (metastasize) to other parts of your body. This can cause other symptoms, such as shortness of breath, bloating or pain in other areas. The risk of complications depends on the tumor type and cancer stage. The most common cancerous type, dysgerminoma, has a good prognosis. It’s often slow-growing and curable.

Diagnosis and Tests

How doctors diagnose ovarian germ cell tumors

Healthcare providers use several tests to diagnose ovarian germ cell tumors. Your provider will start with a pelvic exam to check for growths and other abnormalities. Other tests include:

  • Imaging tests: A transvaginal ultrasound is often the first imaging test. You may also need a CT scan or MRI, which show more detail than an ultrasound.
  • Blood tests: You may need tumor marker tests. High levels of alpha-fetoprotein (AFP), lactate dehydrogenase (LDH) or human chorionic gonadotropin (HCG) can be signs of ovarian germ cell tumors.
  • Surgery: Your provider will need to remove the tumor or the entire affected ovary to make a definitive diagnosis. A pathologist will test the cells in a lab to determine the type of tumor and whether it’s benign or malignant.

Ovarian germ cell tumor staging

If a tumor is cancerous, healthcare providers classify it using a process called staging. This information helps your provider determine what treatments you’ll need. Usually, the lower the stage, the more treatable the cancer is.

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Stages for malignant ovarian germ cell tumors include:

  • Stage I (1): It’s just in your ovary.
  • Stage II (2): It has spread to other tissues in your pelvis, including your fallopian tubes or uterus.
  • Stage III (3): It has spread to your lymph nodes or the tissue lining your pelvic organs or abdominal cavity (peritoneum). But it hasn’t spread beyond your abdomen.
  • Stage IV (4): It has grown into your liver or spleen or spread to tissues and organs outside your abdomen, like your lungs.

Management and Treatment

How is it treated?

Most ovarian germ cell tumors are treatable. Your treatment plan will depend on your stage and whether it’s benign or malignant.

Healthcare providers remove tumors with surgery. Sometimes, they need to remove your entire ovary or part of it to get rid of the growth.

Treatment for cancerous tumors depends on the type and stage. Common treatments include surgery and chemotherapy.

Malignant tumors may be curable depending on the type of tumor and the stage. For example, the cure rate for early-stage dysgerminoma treated with chemotherapy is nearly 100%. More aggressive types, like yolk sac tumors, aren’t curable. But treatment can slow tumor growth and cancer spread.

Outlook / Prognosis

What can I expect if I have this condition?

The outlook for benign ovarian germ cell tumors is excellent. Benign tumors usually don’t grow back after removal.

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The outlook for malignant germ cell tumors varies depending on the tumor type and cancer stage. If cancer hasn’t spread beyond your ovaries, there’s a 94% to 98% five-year survival rate. Cancers that have spread farther away from the original tumor site have a lower five-year survival rate.

Your provider can further explain survival rates and the prognosis for ovarian germ cell cancer (including the possibility of a cure) based on your diagnosis.

A note from Cleveland Clinic

Learning that you have a tumor can feel unsettling and scary. When it comes to ovarian germ cell tumors, most of them are noncancerous. But you may still need surgery to protect the health of your ovary. If the tumor is cancerous, your care team will be by your side. They’ll guide you through your treatment options and what the next steps look like.

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Experts You Can Trust

Medically Reviewed.Last updated on 07/15/2026.

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References

Cleveland Clinic’s health articles are based on evidence-backed information and review by medical professionals to ensure accuracy, reliability and up-to-date clinical standards.

Care at Cleveland Clinic

Ovarian germ cell tumors may be benign or cancerous. Cleveland Clinic’s experts care for all ovarian germ cell tumor types, like dermoid cysts and dysgerminomas.

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