The Endometrial Mole

Abstract

It is well known since the classical experiments of Loeb that the uterine mucosa is sensitized by the corpus luteum hormone in such a manner that it reacts to traumatization with the formation of a deciduoma, a tumor closely resembling in its structure the maternal part of the placenta. It has been noted, however, that while deciduomata form readily during the first part of gestation, they will not form during the later stages of pregnancy although active corpora lutea are present in the ovary. We have repeated and confirmed these observations on rats, placing silk threads into the uterus as a local irritant, and we found that deciduomata may only be produced if the threads are placed between the fifth and eighth day of gestation, while later on in pregnancy the trauma does not call forth any local reaction. This, however, does not mean that the uterus is insensitive to trauma during the second half of gestation, for in another group of animals in which we slit the uterus open on one side, instead of merely irritating it with thread, the mucosa showed a very marked and rather curious reaction here described briefly.

In 12 rats one horn of the uterus was slit open between the 12th and 13th days of gestation while the other horn with its gestation sacs was not touched. Biopsy specimens taken 2 days later showed that the uterine mucosa of these rats is much thicker on the traumatized side than usual, and histologically this thickening proves to be due to a hydrops of the stroma mucosae. Five days later the mucosa is enormously enlarged and transformed into a translucent gelatinous tumor with a more or less irregular surface.