Abstract

Although the mediastinum is the second favorite location of primary teratoma in adults, primary malignant teratoma in mediastinum is rare in incidence. Malignant teratoma includes teratocarcinoma, immature teratoma and malignant transformation in benign teratoma. The latter is rarer than others types, and undifferentiated or squamous cell carcinoma are the major incidence. We experience a case of unique adenocarcinoma composed of signet ring cells in mature teratoma of mediastinum and brief review of the literatures are included.