Mediastinal mature teratoma with complete gastrointestinal and bronchial walls.

An extremely rare case of anterior mediastinal mature teratoma with almost complete gastrointestinal and bronchial walls is described. A 65-year-old woman presented with left precordial pain. Chest computed tomography showed a huge anterior mediastinal tumor, 15 cm × 21 cm, occupying the left thoracic cavity. Post-resection histopathological examination confirmed the diagnosis of mature teratoma and demonstrated almost complete gastrointestinal and bronchial walls. Although mature teratomas of the ovary and sacrococcygeal area are known to rarely contain organoid structures with various degrees of differentiation, this is the first case of an anterior mediastinal mature teratoma that contained well-developed organoid structures.