Immature teratoma

Alternative names
Dermoid cyst - malignant; Nonseminomatous germ cell tumor - teratoma; Malignant teratoma

Malignant teratoma is a type of cancer consisting of cysts that contain one or more of the three main types of cells present in embryos - ectoderm, mesoderm, and endoderm cells.

Causes, incidence, and risk factors

Malignant teratoma occurs most often in young men in their 20’s - 30’s. It is often located in the anterior mediastinum (in the chest). Most malignant teratomas have spread (metastasized) by the time of diagnosis and they can spread throughout the body.

A number of other cancers are often associated with these tumors including:

  • Acute myelogenous leukemia (AML)  
  • Myelodysplasia (MDS)  
  • Malignant histiocytosis  
  • Embryonal rhabdomyosarcoma  
  • Small cell undifferentiated carcinoma


Symptoms result from spread of the tumor into surrounding tissues and include:

  • Cough  
  • Shortness of breath  
  • Chest pain  
  • Limited exercise tolerance  
  • Fatigue

Signs and tests

On physical examination, a physician may see signs of congestive heart failure and increased pressure in the chest cavity. Diagnosis is made using the following tests:

  • History and physical examination  
  • CT scans of the chest, abdomen, and pelvis  
  • Elevated levels of b-HCG and AFP in the blood  
  • Mediastinoscopy and biopsy - use of a special scope to look in the mediastinuman (mediastinoscopy) and remove a piece of the tumor (biopsy)  
  • Anterior mediastinotomy - open surgery to remove the tumor or part of it


Because malignant teratomas have often spread by the time of diagnosis, anticancer chemotherapy is usually needed. Cisplatin, etoposide, and bleomycin are commonly used as a combination of chemotherapy.

After chemotherapy is complete, CT scans are repeated. If there is a residual mass in the area of the tumor, surgery is recommended because of the possibility that the cancer will grow back in that area.

Support Groups

There are many support groups available for people with cancer. Contact the American Cancer Society or search the Internet to find one near you. Research has shown that women with breast cancer survive longer if they participate in a support group and the same may be true for other cancers.

Expectations (prognosis)
The prognosis for people with malignant teratomas is based on the size of the tumor, its location, and the age of the patient. In young patients, less than 15 years of age, teratomas are more likely to be benign. For adults, complete remission is possible in 50 - 70% of patients, and about 42% will see long-term survival.


The cancer can spread throughout the body and there may be complications of surgery or related to chemotherapy.

Calling your health care provider
Call your health care provider if you have symptoms suggestive of malignant teratoma.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

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