Abstract

An immunohistochemical study on the tissue localization of human chorionic gonadotropin (HCG), human placental lactogen (HPL), and human pregnancy specific bata-1 glycoprotein (SP-1) in the non-neoplastic (5 incomplete abortion, 5 ectopic pregnancy) and neoplastic (hydatidiform mole 3 cases, 5 ectopic pregnancy) and neoplastic (hydatidiform mole 3 cases, choriocarcinoma 2 cases) gestational status, and germ cell tumors of the ovary (dysgerminoma 2 cases, immature teratoma 1 case) and the testis (seminoma 2 cases, endodermal sinus tumor 1 case) by means of sensitive peroxidase-antiperoxidase method. The results were as follows. 1) Cytoplasmic HCG, HPL, and SP-1 were readily identified in syncytiotrophoblasts of chorionic villi of the incomplete abortion and ectopic pregnancy, as moderate to strong positive reactions. In the cytoplasm of the neoplastic syncytiotrophblasts of hydatidiform mole and choriocarcinoma, positive reactions were stronger than in non-neoplastic syncytiotrophblasts. but the cytotrophoblasts and villous stromal cells showed negative reactions to these hormones. 2) All of the tumor cells of dysgerminoma and immature teratoma of the ovary, and seminoma and endodermal sinus tumor of the testis showed negative reactions to HCG, HPL, and SP-1. According to these results, HCG, HPL, and SP-1 are specifically synthesized and secreted by normal or neoplastic syncytiotrophoblasts Malignant tumors originated from other cells or tissues than trophoblastic cells show elevated serum concentration of these hormones are only evident in the presence of syncytiotrophoblastic giant cells among the tumor cells.