Estrogen and progesterone receptors in smooth muscle component of deep infiltrating endometriosis

To analyze the expression of estrogen (ER) and progesterone (PR) receptors in the smooth muscle component (SMC) of deep infiltrating endometriosis (DIE).

A prospective clinical and pathologic study of 60 cases of DIE.

University Hospital Department of Gynacology.

Sixty patients with symptomatic DIE (uterosacral endometriosis n = 14; bladder endometriosis n = 10; colonic endometriosis n = 16; rectovaginal endometriosis n = 20).

Laparoscopic surgery.

The expression of ER and PR was studied by immunohistochemistry in the SMC directly around endometriotic foci and at distance (at least >1.5 cm) from them in correlation with proliferative and secretory phases of cycle.

The ER and PR were present in the SMC of DEI in each location excepting colonic endometriosis where ER were absent. Independently of cycle's phases the PR were more abundant than ER. With the exception of rectovaginal endometriosis, where the ER and PR were more abundant in the proliferative than in the secretory phase, in other locations the ER and PR did not differ significantly with cycle's phases. Last, if ER and PR were more abundant in SMC around endometriotic foci than at a distance from them. However, the difference was not significant.

Our data substantially confirm for the first time that in various forms of DIE, ER and PR are present not only in glands and stroma but also in the smooth muscle major histologic component of this disease.