Development of teratomas from embryos transplanted into outbred and inbred adult hamsters.

Six- to 8 1/2-day inbred MHA/SsLak and outbred Syrian golden hamster embryos and 14-day fetal lungs, testes, and portions of small intestine were transplanted into cheek pouches or under kidney capsules of adult recipients. Embryonic grafts gave rise to benign teratomas, irrespective of the age of the embryo, transplantation site, and the strain or stock of recipient. Fetal lung and testis grew little in extrauterine sites, whereas fetal intestine formed large mucus-filled cysts lined with proliferating and apparently functionally active epithelium.