Assessment of morphological changes and steroid receptors in the uteri of postmenopausal women.

The morphology of the endometrium constantly changes in the reproductive period, depending on the levels of ovarian steroid hormones, and undergoes atrophic changes during menopause as a result of their insufficiency. The purpose of this study was to analyze morphological and morphometric changes in the mucous and muscle layers of the uterine wall in postmenopausal women, and to assess localization and number of cells showing the expression of steroid hormone receptors, namely estrogen receptor α (ER-α), progesterone receptor (PR), and androgen receptor (AR) in glandular epithelial cells and smooth muscle cells in particular groups of women. The study material consisted of uterine specimens sectioned across the full thickness of the uterine wall, and embedded in 164 paraffin blocks. The specimens came from women without menopausal hormone therapy (MHT) operated due to reproductive organ prolapse or uterine myomas. The material was divided into four groups depending on the time interval from menopause to surgery: group I - from 1 to 5 years after menopause, group II - from 6 to 10 years after menopause, group III - more than 11 years after menopause, and group IV - women over 70 years of age. The sections were stained by standard HE, Masson's trichrome, and immunohistochemical methods (ERα, PR, AR). Quantitative assessment of the results was based on computer image analysis. Analysis of morphological changes in the endometrium and myometrium revealed the presence of increasing regressive changes, such as various types of atrophy, fibrosis, and calcification, augmented over time from the last menstruation. Furthermore, endometrial polyps, foci of endometriosis, and leiomyomas were observed. Based on the results of morphometric measurements, a constant decrease in the endometrial and myometrial thickness was noticed in the studied groups (I-IV). Significant differences between the groups were observed in the number of ER-α positive cells in the myometrium, but not in the endometrial glandular epithelium. Statistically significant differences in the number of AR positive cells were detected in the endometrial epithelium and in the uterine muscle. The analysis the number of PR positive cells demonstrated differences between the groups in the endometrial stroma and the myometrium. The uterus of postmenopausal woman undergo major morphological changes (mainly atrophic lesions in the endometrium and myometrium), leading to a decline in their morphometric parameters over time from the last menstruation. Localization and number of cells showing the expression of steroid receptors: ER-α, PR, and AR in the uterus of postmenopausal women, depending on the time interval from the last menstruation.