Germ Cell Tumors of the Ovary

Abstract

Germ cell tumors are composed of a number of histologically different tumor types derived from the primitive germ cells of the embryonic gonad. The concept of germ cell tumors as a specific group of gonadal neoplasms has evolved in the last five decades. It is based on (1) the common histogenesis of these neoplasms, (2) the relatively frequent presence of histologically different neoplastic elements within the same tumor mass, and (3) the presence of histologically similar neoplasms in extragonadal locations along the line of migration of the primitive germ cells from the wall of the yolk sac to the gonadal ridge,³⁸⁴ as well as on the remarkable homology between the various tumors in the male and the female. In no other group of gonadal neoplasms is this homology better illustrated. Although the strong morphologic resemblance between the testicular seminoma and its ovarian counterpart, the dysgerminoma, was noted soon after these neoplasms were first described, for a long time there was no agreement as to their histogenesis. Nevertheless, these were the first neoplasms to become accepted as originating from germ cells. It was not until the studies by Teilum^339,340 on the homology of ovarian and testicular neoplasms, the studies by Friedman and Moore⁹⁵ and Dixon and Moore⁷⁶ on testicular tumors, and those by Friedman⁹⁴ on related extragonadal neoplasms that the germ cell origin of other neoplasms belonging to this group was suggested. These views were supported by the embryologic studies of Witschi³⁸⁴ and Gillman,¹⁰⁷ and later by the experimental work of Stevens^305–307 and Pierce et al.^{238,239,241,244} on germ cell tumors in rodents.