Abstract
An immunohistologic study on 13 of 97 patients with germ cell tumors of the testis having elevated serum pregnancy-specific .beta.-1 glycoprotein was undertaken to correlate the presence of this marker in the various cell types of this tumor. Four placentas were obtained from patients in the 1st trimester of pregnancy and studied for the presence of pregnancy-specific .beta.-1 glycoprotein in various cells of this organ using an indirect immunoperoxidase technique. Specific .beta.-1 glycoprotein was demonstrated in the syncytiotrophoblastic component of choriocarcinoma. This placental marker was localized in syncytiotrophoblastic giant cells occasionally associated with embryonal carcinoma, with or without teratoma. All 13 patients were chosen for the presence of an elevated level of pregnancy-specific .beta.-1 glycoprotein in the sera. There was tissue localization of pregnancy-specific .beta.-1 glycoprotein in 3 of 4 cases of choriocarcinoma (75%), 4 of 4 samples of placenta (100%), 4 of 5 cases of embryonal carcinoma (80%) and 2 of 4 cases of teratocarcinoma (50%).