Mediastinal Teratoma

**Semantic type:** Neoplastic Process

**Definition:** An extragonadal germ cell tumor that arises from the mediastinum. It is characterized by the presence of somatic tissues derived from two or three of the germ layers (ectoderm, endoderm, and mesoderm).

**Synonyms:** - Teratoma of Mediastinum - Teratoma of the Mediastinum - Thymic Teratoma