Immunocytochemical evidence of heterogeneous origin of alpha-fetoprotein in immature teratoma of the ovary.

alpha-Fetoprotein (AFP) has been found to be clinically important in the management of patients with gynecologic malignancies. Serum AFP levels are used as tumor markers for ovarian tumors, namely endodermal sinus tumors (EST) and embryonal tumors. In two cases of immature teratoma of the ovary without a yolk sac component, evidence for AFP production was found in a wide variety of cells of both endodermal and ectodermal origin suggesting a heterogeneous origin of AFP. To complement this finding, a summary of the ontology of AFP along with current and potential uses of an antigenically active tumor marker are presented.