Production of beta-human chorionic gonadotropin by germ cell tumors in vivo and in vitro.

Production of the beta-subunit of human chorionic gonadotropin (beta-hCG) by human germ cell tumors was studied in surgical specimens, cultured cells and xenografted tumors. beta-hCG was identified most frequently in the syncytiotrophoblastic and intermediate trophoblastic components of choriocarcinoma, and it was also detected in syncytiotrophoblastic giant cells, occasionally in association with embryonal carcinoma, and less frequently with yolk sac tumor, seminoma and dysgerminoma. Our experimental data suggest that beta-hCG production by syncytiotrophoblastic giant cells in association with embryonal carcinoma is a result of trophoblastic differentiation of embryonal carcinoma. Moreover, it was proved that the production of beta-hCG by human embryonal carcinomas is regulated by more factors than is the case for human choriocarcinomas.