On T H E Production of Endometrial Moles with Steroid Hormones

It is well known since the investigations of Loeb (1) that the uterus, if it is traumatized while under the influence of an active corpus luteum, responds by the formation of a structure not unlike the maternal portion of the placenta. This growth may become quite large and assume the appearance of a decidual tumor. The hormonal mechanisms controlling deciduoma formation have been studied by Selye and McKeown (2) and it appears well established that the presence of corpus luteum hormone is indispensable for the production of the tumor, while large doses of estrogens prevent its formation. Another type of abnormal response of the endometrium to trauma has been seen in spayed rats pretreated with estrogens. In such animals large. succulent tumors develop in the endometrial stroma at the site of trauma. hlacroscopically and microscopically these tumors are rather similar in appearance to hydatidiform moles; they are translucent and of a pinkish color, and upon histologic examination prove to consist mainly of a gelatinous connective tissue* with much intercellular substance. In order to emphasize their similarity to hydatidiform moles, and at the same time to point out their endometrial origin, they have been termed " endometrial moles " (2-4). The object of this communication is to report on some recent experiments which indicate that steroid hormones other than progesterone and estrogens may likewise so modify the responsiveness of the endometrium that tumor-like masses develop at the site of mechanical stimulation. Twenty-two female albino rats weighing 137 to 172 gm. were divided into four groups on the day after their ovaries were removed. Six animals received daily injections of 100 gamma of estradiol, 6 were treated with 3 mg. of testosterone propionate, and 6 with 3 mg. of pregneninolon, also referred to as ethinyl testosterone, pregneninonol or anhydro-oxy-progesterone. The remaining four served as untreated controls. The daily dose of each of the sterol preparations employed was dissolved in 0.4 C.C. of peanut oil and was injected subcutaneously. On the ninth day of treatment, the left uterine horn of each animal was slit longitudinally in order to traumatize the endometrium. Five days later, a portion of the traumatized uterine horn was removed together with a part of the intact horn for inspection and histologic study. In all groups of experimental animals there developed macroscopically visible, gelatinous, hyperemic endometrial tumors; no such growths were detectable in the controls. Upon histologic examination these tumors showed the characteristic features of endometrial moles. The connective-tissue cells, which in most cases appeared to be star-shaped with many processes, rather than I t has, therefore, been termed a deciduoma.