Teratoma, Mediastinal

Synonyms

Mature cystic teratoma of the mediastinum; Primary benign mediastinal teratoma; Pure mediastinal teratoma

Definition

Mediastinal teratomas are usually cystic benign tumors resembling their more common ovarian namesakes. Like the ovarian teratomas, they are composed of somatic tissues corresponding to the differentiated derivatives of all three embryonic germ layers, i.e., ectoderm, mesoderm, and endoderm.

Clinical Features

• Incidence

  Mature teratomas are the most common mediastinal GCT (Wick et al. 2004). However, since mediastinal GCTs are quite rare, it follows that these extragonadal teratomas are also uncommon (see also mediastinal germ cell tumors). Mature teratomas in a pure form account for approximately one third of all mediastinal GCT in adult males, over one half of all GCT in prepubertal males, and for more than 90% of mediastinal GCT in females (Williamson and Ulbright 2014). Teratomas may form components of malignant mixed germ cell tumors, and in prepubertal...