Overview

Type of disease: Rare conditions

A teratoma with malignant transformation (TMT) is a tumor that develops from germ cells when they grow and divide abnormally, forming a mass.  Approximately 6% of teratomas develop into TMTs by a process called malignant transformation, when some of the cells in the teratoma become cancerous.  TMTs can occur anywhere in the body, but most are located in the testes in men or ovaries in women.  The cause of TMT is unknown.  Treatment may include surgery and chemotherapy. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.