The significance of alpha-fetoprotein in the serum of patients with malignant teratomas and related gonadal neoplasms.

Sera from eleven patients with gonadal germ cell tumors were tested for alpha-fetoprotein (AFP) by counterelectrophoresis. Ovarian neoplasms containing either the endodermal sinus tumor (EST) or dysgerminoma and half of the testicular embryonal carcinomas elaborated the protein into the serum. The presence of AFP in the serum seemed to correlate with early metastasis or a fatal outcome. That the highest levels of AFP were found in cases of EST was in keeping with the theory that the tumor originates in cells of the yolk sac, a principal embryonic site of AFP synthesis.