Mediastinal mature teratoma with spontaneous malignant transformation

Introduction. - Malignant teratomas can be either immature teratomas or they can develop after treatment of other malignant germ cell tumors with chemotherapy or radiotherapy. Spontaneous malignant transformation of mature teratomas is very rare. Observation. - We report the case of a patient complaining of atypical chest pain. Chest plain radiography showed a right anterior mediastinal mass. Computed tomography revealed a heterogeneous mediastinal mass with fat areas and calcification. There were hilar and mediastinal lymph nodes as well as lung parenchymal nodules. CT-guided and then surgical biopsies confirmed the diagnosis of a mature teratoma, which had degenerated into a digestive adenocarcinoma. Conclusion. - Spontaneous malignant transformation of mature mediastinal teratoma is very rare. The diagnosis of malignant transformation is based on radiological examinations, laboratory tests and histological studies. (C) 2013 Published by Elsevier Masson SAS on behalf of SPLF.