Histological evaluation of canine deciduoma induced by silk suture.

Deciduoma was induced in 5 bitches by introducing a silk suture into their uteri which were in the nonpregnant luteal stage of their estrous cycles. The histological changes in the uteri were characterized by the cystic glandular hyperplasia of the endometrium, although, this condition varied according to the positional relations between the endometrium and the inserted suture. As notable histological features in these variations, regulated proliferation and dilatation of the uterine glands were seen in all the animals and these had a very similar structure to normal differentiation of the glands in the early placentation. These histological findings suggested that silk suture might act as a similar biological stimulus to fertilized ova and thus could induce a deciduoma which was closed to normal implantation "decidual reaction".