In contrast, secretory-phase endometrium often demonstrates subtle changes and, in many cases, combinations of morphologic changes, resulting in most instances in errors of 4–5 days.The pathologist can improve this to 2–3 days, however, by acquiring expertise in endometrial dating (all cases of normal endometria are to be dated regardless of reasons for sampling), and by basing the dating on those endometrial morphologic alterations that represent the most advanced phase of the menstrual cycle.For example, if an endometrial biopsy contains changes consistent with postovulatory days (POD) 2, 3 and 4, the pathologist should report the diagnosis as ' POD 4 or 18-day secretory endometrium'.Endometrial biopsies are not to be taken at the onset of bleeding in the following two conditions: if luteal phase defect (LPD) is suspected clinically and is desired to be confirmed histologically, when the biopsy should be taken between POD 7 (21st) and POD 9 (23rd) cycle days to demonstrate a 3–4 day delay in endometrial maturation; or if there are asynchrony of gland/stromal development and dissimilar maturation in different regions of the endometrial specimen.In premenopausal women with regular menstrual cycles, histological preparations include the upper portion of the functional layer of the endometrium.This is necessary, for in most instances morphological changes occur in the functionalis as opposed to the basalis layer, and, by inference, provide a clinically useful diagnosis.Steroid hormone control of endometrial, epithelial, stromal, and presumably endothelial cells is mediated by estrogen receptors and progesterone receptors. They have high affinity to bind estradiol and progesterone, respectively.These steroid receptors are specific proteins concentrated exclusively in the nuclei of both endometrial epithelial and stromal cells, as well as the endothelial cells of stromal capillaries. This chapter contains a review of the technical procedures for handling endometrial tissues and a discussion of the morphologic aspects of the endometrium, focusing on the interpretation and understanding of the physiomorphology of the endometrial cycle.
In current practice, the device that is most often used is the Pipelle endometrial aspirator.
In cases in which little or no tissue is obtained but the endometrium was penetrated with the aspirator, a repeat procedure should be performed.
If the repeat aspiration still yields little tissue, one can assume severe endometrial atrophy or obstructing endometrial polyp.
Taking an endovaginal ultrasonography of the uterus may solve this dilemma.
If the aspirator is 'blocked' at the lower uterine segment (internal os), traction may be applied on the uterus with either a single-toothed tenaculum or preferably an Emmet tenaculum placed about half a centimetre into the anterior endocervical canal. The pathology requisition should contain all pertinent information, including date of last menstrual period.