Carcinoma-Like Proliferations in Vagina, Cervix, and Uterus of Mouse Treated with Estrogenic Hormones.

We have referred to the fact that in mice injected with preparations of estrogenic hormones over long periods of time abnormal proliferations of varying degrees of intensity may be induced not only in the mammary gland but also in certain parts of the vagina, cervix, and uterus. In a number of cases conditions were observed which in human beings would be considered precancerous lesions or as changes representing very early stages of cancer. In the monkey, Overholser and Allen noted that in the cervix atypical epithelial proliferations were induced through administration of ovarian hormones. However, these investigators added traumatization of the tissue to the action of the hormones, while in our experiments the tissues were left intact. In two recent publications Lacassagne described adenomatous proliferations of the uterine glands in the rabbit and in the mouse; in some cases the glands penetrated through the muscular layer. Quite recently we have autopsied a mouse in which proliferative changes had progressed further than in any of the others observed. This mouse, of the “Old Buffalo” strain in which spontaneous tumors are relatively rare, had been injected with estrogenic hormones for 24 months, 20 days, beginning at the age of 18 days. During the first 18 months this animal received 10 rat units of theelol in water daily; for the remaining 6 months, 20 days, daily injections of 30 rat units of theelin. At autopsy vagina, cervix, and uterus were very much enlarged. There were adhesions between the vagina and cervix and the surrounding pelvic tissues. Microscopic examination showed very extensive proliferation in the upper part of the vagina near the cervix, in various parts of the cervix, and in the uterus.