[Germ cell tumors of testis: histological classification of 552 cases according to the WHO-nomenclature].

Using the WHO-nomenclature 552 germ cell tumors of testis were reclassified. The analysis revealed the following: germ cell tumors occur in early childhood at the age of 3 months to 3 years, in adult hood (26-35) the occurrence shows a peak, and in old aged men only some tumors are registered. No germ cell was found between 4 to 13 years. Our material comprised 245 seminomas (44.4%) and 307 non-seminomatous germ cell tumors (55.6%). In the group of tumors of one histologic type, 245 cases of seminomas represent the main part. The following subgroups were recognized: typical seminomas--229 cases (93.5%), spermatocytic seminomas--9 cases (3.7%), and anaplastic seminomas--7 cases (2.8%). In 10 seminomas (4.1%() we have found syncytiothrophoblastic giant cells. In comparison to other investigations, the number of anaplastic seminomas is very low, but on the other hand the diagnosis Of this tumor is problematic, especially, the differential diagnosis of solid variants of embryonal carcinomas. The most common non-seminomatous tumor in this group is the embryonal carcinoma (16.8%). No polyembryoma and choriocarcinoma were observed, and only 2 yolk-sac-tumors occurred in infants. The occurrence of teratomas was also low, i.e. 15 cases of mature teratoma and 13 cases of immature teratoma. In the group of tumors of more than one histologic type, cases showing embryonal carcinoma and teratoma prevail (83 tumors). In addition to this combination other common tumors of this group (contained structures of seminomas (25 cases), yolk-sac-tumors (22 cases), an choriocarcinomas (19 cases) and embryonal carcinomas and yolk-sac-tumors (13 cases). Altogether, this group comprised 72.8% of the non-seminomatous tumors. Furthermore, the peculiarities of germ cell tumors of childhood are described. In this group the mature teratomas prevail. No seminoma could be registered in infancy. The distribution of our cases among the various types and the subgroups agreed in the main classes with that reported in literature but in special differentiations there are some discrepancies. The problem of classification of germ cell tumors is discussed.