[Mediastinal germ cell tumors: anatomopathology, classification, teratomas and malignant tumors].

Mediastinal germ cell tumors are rare tumors. It is classic to divide those tumors into two categories, seminomas and nonseminomatous germ cell tumors: teratomas (mature or immature), embryonal carcinomas, yolk sac tumors, and choriocarcinomas. Each histological sub-type can be associated to another sub-type that realise a so-called mixed germ cell tumor. Diagnosis strategy is currently well codified for malignant mediastinal germ cell tumors. It greatly benefits from tumoral markers (alpha-fetoprotein and beta human chorionic gonadotrophin). For instance, the treatment strategy still raises some specific problems to each histological type. The treatment of seminomatous tumors is standardised--chemotherapy/surgery on residual tumor greater than 3 cm/radiotherapy on viable persistent residual tumors--and provides very satisfying results. As for the nonseminomatous germ cell tumors, the situation is dramatically different. The treatment strategy is less standardised--association of chemotherapy and surgery--and the prognosis is very severe.