Tumour antigens associated with primary mediastinal choriocarcinoma.

Various biochemical markers of cancer were investigated in two men aged 26 and 45 years with primary mediastinal choriocarcinoma. The daily excretion of urinary human chorionic gonadotropin (HCG) and the serum concentration of the beta-subunit of HCG were elevated in both patients, but carcinoembryonic antigen, Regan isoenzyme, alpha1-fetoprotein, serum pregnancy-associated globulin and human chorionic somatomammotropin were not detectable. Comparison of the results of the investigation of biochemical markers of this rare neoplasm in these two men with those published previously illustrates the discordance in the expression of biochemical markers of primary mediastinal choriocarcinoma.