Cyclic changes of human mammary gland epithelium in relation to the menstrual cycle—an ultrastructural study

Abstract

The ultrastructure of resisting human female mammary gland epithelium was studied in 21 females of reproductive age (15–36 years) with regular menstrual cycles. Grossly and light microscopically normal appearing breast tissue contiguous to benign lesions was selected and processed at the time of frozen section diagnosis. Acino‐ductular epithelium was ultrastructurally classifiable into two major categories: Phase I—non‐secretory, and Phase II—potentially secretory. The above cells were often further classifiable into Phase IA cells, whose main feature was prominent intracellular fluid retention, and Phase IIA epithelium, characterized by cytoplasmic glycogen deposits. The preovulatory phase of the menstrual cycle was associated with a peak number of Phase I cells, while in the postovulatory phase there was a preponderance of Phase II cells. In the late preovulatory phase, Phase IA cells, and in the early postovulatory phase, Phase IIA cells were more commonly found. The relationship between the menstrual stage and cyclic changes in the ultrastructural morphology of mammary gland epithelium presumably represents the effects of ovarian steroid activity on the cellular physiology of an endocrine‐sensitive end organ; this is a cell biological phenomenon parallel to the better known cyclic cellular alterations occurring in the endometrium during the normal menstrual cycle. An understanding of the cyclic ultrastructural changes of mammary gland epithelium may lay the basis for a sounder and more meaningful interpretation of breast pathology and its pathogenesis.

Effects of Progestins and Menstrual Cycle on Fatty Acid Synthetase and Progesterone Receptor in Human Mammary Glands*

“…They are shown according to the day of menstrual cycle. The physiological significance of FAS regulation is not known, but could have a role in the histological changes observed in the normal breast relative to endocrine variations of the menstrual cycle (18,19), with a maximal secretory aspect at the luteal phase. PR labeling was exclusively nuclear and very heterogeneously distributed in different ducts and lobules of the same biopsy, in agreement with other studies (15)(16)(17).…”

Assessment of the proliferative, apoptotic and cellular renovation indices of the human mammary epithelium during the follicular and luteal phases of the menstrual cycle

“…The parenchymal mammary tissue removed (at least 1 cm from the lesion) was without any gross microscopic alterations [17]. …”

Efeitos de diferentes doses de tamoxifeno sobre a proliferação celular do epitélio mamário

“…O ato operatório foi efetuado entre 10:00 e 12:00 horas, com o intuito de minimizar a variação circadiana na cinética celular. Os espécimes de tecido mamá-rio foram obtidos em área adjacente ao fibroadenoma, sem qualquer alteração macroscópica, conforme preconizaram Fanger e Ree 19 , e distando dois centímetros do nódulo, sem tecido adiposo, como preconizaram Russo et al 20 .…”