Malignant teratoma

Alternative names

Dermoid cyst - malignant; Nonseminomatous germ cell tumor - teratoma; Immature teratoma

Definition

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

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
  

Treatment

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.