Endometrium, Menstrual endometrium

Endometrium undergoes regular cyclical changes under the influence of hormones, estrogen and progesterone, produced by the ovaries. The cycle is divided into two major phases, proliferative and secretory, followed by shedding of the endometrial functionalis layer during menstruation. Here, menstrual endometrium is shown in a patient that had hysterectomy for multiple leiomyomas who happened to be menstruating at the time of the surgery. Menorrhagia, as seen clinically in this case, may also arise from the presence of leiomyomas.

Histologically, one can appreciate glandular and stromal breakdown, consistent with menstrual endometrium.