Today the treatment of gonadal germ cell tumors is standardized. The cisplatin containing chemotherapy and the multi-modal therapy strategies have increased the rate of successful treatment enormously. Germ cell tumors are almost always treated surgically. Following the rare, primary chemotherapy, the residual tumor must be classified according to the WHO as accurately as possible. A binding system for the documentation of tumor regression does not exist. The diagnostic retroperitoneal lymphadenectomy is also rare. Here as well, the classification is performed according to the WHO and the TNM classification. The examination of the tissue samples from a retroperitoneal lymphadenectomy after chemotherapy is problematic. The morphology is often bizarre, preparatory and terminological standards do not exist. Is there still vital tumor present then it can most often be diagnosed as a teratoma. In that case a classification takes place as to whether it is "mature" or "immature". If a tissue sample contains other differentiations, the classification is performed in detail according to the WHO classification of germ cell tumors. Sarcomas or carcinomas must be reliably distinguished and classified, as they lead to different therapeutic consequences. The terminology must be defined in a binding manner between both the pathology and the clinic, due to the lack of global definitions.