Discordance of human chorionic gonadotropin and alpha‐fetoprotein in testicular teratocarcinomas

Human chorionic gonadotropin (hCG) and elevated levels of alpha‐fetoprotein (αFP) were present in the plasma of three patients with metastatic testicular teratocarcinoma. Initial chemotherapy resulted in the disappearance of the hCG and a decrease in the αFP levels in all three patients. Two of the patients had persistently elevated levels of αFP with undetectable hCG, while the αFP in the third patient decreased to and remained in the normal range despite reemergence of high plasma levels of hCG. The discordant behavior of these two proteins indicates that their cells of origin are probably different. When both hCG and αFP are present in the blood of patients with testicular tumors, each should be followed in order to determine the adequacy of therapy.