Morphological Aspects of Human Endometrium during Hormone Replacement Therapy

The multiple benefits of hormonal replacement therapy (HRT) in postmenopausal women are well k n ~ w n , l ~ but it is recognized that the use of cyclic progestogen is necessary to prevent estrogen-related endometrial hyperplasia and, in the long term, the development of adenocar~inoma.~.~ The follow-up and, in more detail, the endometrial sampling of women on HRT is an important and controversial issue. Many physicians sample the endometrium before initiating the treatment, although genital atrophy and cervical stenosis in postmenopausal women may sometimes preclude this approach. Unanimity on follow-up schedule for HRT patients is far from being reached. Most authors consider irregular bleeding as the uterine symptom requiring endometrial evaluation in the postmenopausal woman receiving combined treatment^.^.' Quite often, however, blind endometrial biopsies may not be technically adequate, and do not allow the pathologist to express a definitive Hysteroscopy may help identify pathologic findings missed by endometrial biopsy and/or reassure that a negative biopsy is the result of an atrophic rnucosa.'O More recently, an increasing amount of data has been reported about HRT-induced endometrial changes, but the multiple variables involved (different hormonal formulations, timing and method of biopsy, length of follow-up, etc.) make very difficult the critical evaluation of endometrial response in this group of The aim of this study was to evaluate the endometrial response to different formulations of HRT, focusing on the morphological aspects by employing hysteroscopy and direct-vision biopsy to properly define the histological patterns.