[Mature Cystic Teratoma of the Mediastinum with Carcinoid Component].

Carcinoid arising from a mature cystic teratoma of the mediastinum is extremely rare. A 30-year-old man complaining of chest pain was admitted to our hospital for abnormal shadow in right mediastinum on chest tomography. Computed tomography (CT) and magnetic resonance imaging (MRI) suggested mature teratoma. Complete resection under video-assisted thoracotomy was performed. The postoperative course was uneventful. Histological diagnosis was mature cystic teratoma containing 3 mm component of carcinoid in the capsule. There were no pathological findings of necrosis and MIB-1-index was 1 %. No recurrence has been observed for 7 months after surgery.