Endometrial Glands - Histology

What are Endometrial Glands?

Endometrial glands are specialized structures located within the endometrium, the inner lining of the uterus. These glands play a crucial role in the reproductive system, particularly in the menstrual cycle and pregnancy.

Structure of Endometrial Glands

Endometrial glands are tubular and can vary in shape and size depending on the phase of the menstrual cycle. They are composed of a single layer of columnar epithelial cells and are surrounded by a stroma rich in fibroblasts, immune cells, and blood vessels.

Function of Endometrial Glands

The primary function of endometrial glands is to secrete substances necessary for the survival and implantation of the embryo. During the menstrual cycle, these glands undergo changes to prepare the endometrium for potential pregnancy.

Histological Phases of Endometrial Glands

The endometrial glands exhibit distinct histological features during the different phases of the menstrual cycle:

Proliferative Phase: In this phase, the glands are relatively straight and narrow. Estrogen stimulates the proliferation of glandular epithelial cells.
Secretory Phase: Following ovulation, under the influence of progesterone, the glands become more tortuous and increase in size, secreting glycoproteins and lipids.
Menstrual Phase: If pregnancy does not occur, the glands degenerate, leading to the shedding of the endometrial lining.

Pathological Conditions Involving Endometrial Glands

Several pathological conditions can affect the endometrial glands, including:

Endometrial Hyperplasia: An abnormal thickening of the endometrial lining due to excessive proliferation of the glands, often caused by prolonged estrogen exposure without progesterone.
Endometrial Cancer: A malignancy originating from the glandular epithelial cells, commonly linked to genetic mutations and hormonal imbalances.
Endometriosis: A condition where endometrial tissue, including glands, grows outside the uterus, causing pain and infertility.

Diagnostic Techniques

Histological examination of endometrial biopsies is a critical diagnostic tool for evaluating the health and pathology of the endometrial glands. Techniques include:

Hematoxylin and Eosin (H&E) Staining: The most common method for visualizing the general structure and pathology of tissues.
Immunohistochemistry: Utilized to detect specific markers indicating cellular proliferation, hormonal receptors, and other significant proteins.
Electron Microscopy: Provides detailed visualization of the ultrastructure of the glandular cells.

Conclusion

Endometrial glands are vital components of the reproductive system, playing essential roles in the menstrual cycle and pregnancy. Their structure and function are significantly influenced by hormonal changes, and various pathological conditions can disrupt their normal activity. Histological techniques are indispensable for diagnosing and understanding diseases involving endometrial glands.