Morphological and functional aspects of the endometrium of asymptomatic post-menopausal women: does the endometrium really age?

The morphological and functional aspects of the endometrium were investigated in 28 asymptomatic post-menopausal women to evaluate the ageing phenomenon of this tissue. Haematoxylin-eosin staining showed an atrophic endometrium in 12 cases and a hyperplastic endometrium in the other 16 cases. Masson's trichrome identified moderate fibrosis in all post-menopausal endometrial stroma. Immunohistochemical analyses were performed on the endometrial specimens to evaluate the distribution of the capillary system, the cellular proliferation index and the presence of oestrogen and progesterone receptors. Our data showed a discrepancy between the morphological pictures and the functional aspects of the post-menopausal endometrium. In fact, the morphological pictures suggested an involution of this tissue according to the increase in collagen fibres, the decrease in vascular distribution and the frequent atrophic patterns. On the other hand, data from steroid receptors and the cell proliferation index suggest that post-menopausal endometrium is an active structure. So, endometria from normal post-menopausal women appear to be in a more quiescent state than in a really atrophic condition. This leads to the question: does the endometrium really age?