Physiological changes in the mammary gland are normal
Breast tumors are found in most women, either by accident or by periodic self-examination. It is estimated that 2/3 of tumor-like formations identified using all methods of research in childbearing age are benign and are represented by cystic changes, dysplasia, fibroadenomas and papillomas.
However, 50% of the palpable formations in perimenopausal women and the majority of postmenopausal tumors are malignant tumors. Cystic changes and dysplasia of the mammary glands are widespread, often have clinical manifestations and require proper treatment. The frequency of benign changes reaches a maximum in women aged 30-50 years and may be due to estrogen stimulation in the absence of a cyclical formation of the corpus luteum and progesterone.
Prolonged estrogenic stimulation may be a factor in the development of so-called macrocast. The fact that the tension and tenderness of the mammary glands often occur before menstruation suggests that insufficient secretion of progesterone may play a role in the development and manifestations of cystic changes in the breast tissue. However, the expected impact of each of these hormones on the development of benign breast diseases is unclear and requires further clarification.
A more complete understanding of the development of the mammary gland in the embryonic and prepubertal period may be helpful in studying this benign disease. The mammary glands are highly specialized derivatives of the skin of ectodermal origin. The epithelial bud that develops into the breast tissue undergoes a series of divisions, forming the milky passages. The development of primary breast tissue is under the control of androgens formed in the gonads of the fetus, which inhibit the growth of the mammary glands during the entire period of pregnancy, when this tissue is under the simultaneous influence of increasing levels of estrogen and progesterone stimulating their growth.
After birth, the baby’s breast tissue remains inactive until the onset of adolescence, during which the epithelium of the ducts begins to proliferate under the action of estrogens and there is a rapid increase in acini due to the action of progesterone. However, the growth and development of the mammary glands depend not only on the level of estrogen and progesterone. Insulin, cortisol, thyroxin, growth hormone, and prolactin are also required to fully transform into functioning tissue.