Definition of Malignant teratoma:

Malignant teratoma is a type of cancer that involves cysts that contain one or more of the three main types of cells found in a developing baby (embryo). These cells are callled ectoderms, mesoderms, and endoderms.

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