[Immunohistochemical localization of chorionic gonadotropin and alpha fetoprotein in polyembryomas: description and interpretation].

As polyembryomas are special forms of human teratomas in which numerous structures mimicking the early stages of the human embryo are conspicuous, immunoperoxidase staining of these embryoid bodies (EB) has been used to reveal the initial appearance and localization of beta HCG and AFP, respectively, in amnion and in primary yolk-sac. EB are involved in the building of various questionable patterns of teratomatous germ-cell tumours. Special emphasis has been placed on tracking yolk-sac tumour patterns through dislocating EB, using a specific anti-human AFP serum.