Human chorionic gonadotropin and alpha-fetoprotein in testicular germ cell tumors. An immunohistochemical study in comparison with tissue concentrations.

The relation between immunohistochemical demonstration and tissue concentration of humanchorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) was examined in 17 testicular germ cell tumors. There was a good correlation between their results; e.g., a tumor with high hCG concentration contained numerous hCG positive cells, and vice versa. The immunoperoxidase localization of hCG and AFP was investigated in 57 tumors including above 17. HCG was revealed in syncytiotrophoblastic giant cells of seminoma or embryonal carcinoma as well as syncytial cells of choriocarcinoma, and on rare occasion in mononuclear cells. AFP was localized in tumor cells of yolk sac tumor or embryonal carcinoma and occasionally hyaline globules. No cell was stained concomitantly with hCG and AFP. Pathogenetical significance of cells positively stained was discussed.