Cellular Localization of AFP and HCG in Germ Cell Tumors of the Testis and Ovary

Abstract

An immunohistologic study of AFP and HCG in malignant germ cell tumors of the testis and ovary was undertaken to correlate the type of neoplasm with the presence of the markers. Twenty‐one patients with testis tumors and measured serum levels of AFP and HCG and 48 patients with ovarian tumors with no availability of serum were studied utilizing an immunoperoxidase technique. AFP was demonstrated in mononuclear embryonal carcinoma cells and in endodermal sinus tumors. HCG was identified in the syncytiotrophoblastic component of choriocarcinoma and also within syncytiotrophoblastic giant cells in embryonal carcinoma frequently and in endodermal sinus tumor and seminoma rarely. In the testis tumors there was tissue localization of HCG in 13 of 14 patients (93%) with elevated serum HCG while AFP was identified in the tumor of 10 of 14 patients (71%) with elevated AFP. Based on these findings a tentative immunohistologic classification of malignant germ cell tumors utilizing AFP and HCG was proposed. Thus, embryonal carcinoma is frequently associated with both AFP and HCG, endodermal sinus tumor with AFP and choriocarcinoma with HCG, whereas pure seminoma, dysgerminoma and teratoma are unlikely to be associated with either marker.