[Mediastinal teratoma with malignant transformation of the somatic component. Clinical report].

Mediastinal germ cell tumours (M-GCT) are rare forms of neoplasms compared with other tumours of the same location. They are classified in seminomas, malignant non-seminomatous GCT and teratomas. The malignant transformation of the somatic component of the teratoma, with sarcomatous or carcinomatous degeneration, is even more uncommon. We report the clinical case of a 32 year old man who presented with severe chest pain on the right hemithorax. The image exams revealed the existence of a large heterogeneous lesion with a diameter of 7.7 cm, with areas of lipomatous density and a calcic image with the appearance of a tooth, in the right projection of the anterior mediastinum, in the vicinity of the large vessels, compatible with teratoma. The transthoracic biopsy (CT guided) showed morphologic aspects of sarcoma. The patient was operated on with the en bloc resection of the mediastinal mass, right lung, a segment of the pericardium and the thymus. The pathological studies showed a teratoma with malignant transformation of the mesenquimatous component, with muscular differentiation into leiomiosarcoma and rabdomiosarcoma. After surgery, the patient was treated with a scheme of doxorubicin and ifosfamide. The most prominent concepts related to this clinical entity, as well as its treatment, are debated in this article, based on the most recent publications dedicated to the subject.