Endometrial biopsy

Endometrial biopsy is a relatively common test currently, which has a great impact on the health of many people. The biopsy is to take the soft tissue of the endometrium for pathological examination, mainly to check whether there are any lesions in the endometrium. The results of the examination will be different depending on each person's physical condition. However, everyone needs to pay attention to what steps the endometrial biopsy is divided into?

Function

rium refers to the layer that makes up the lining of the uterus of mammals. The endometrium responds to both estrogen and progesterone and can therefore change significantly during the sexual cycle (estrus, menstrual cycle). Estrogen can cause uterine hypertrophy, and progesterone can promote special changes in the endometrium in early pregnancy, or change the properties of the endometrium so that it has the ability to produce decidua.

The endometrium is covered with mucosa, which is composed of the mucosal epithelium and the underlying lamina propria. The mucosal epithelium is columnar epithelium, cuboidal epithelium or stratified columnar epithelium. When estrogen is secreted, each epithelial cell will grow and divide, increasing in number.

The portion of the lamina propria below the mucosal epithelium is called the functional layer, into which epithelial cells enter to form uterine glands and respond to estrogen. The lower layer of the functional layer is called the basal layer, which is rich in blood vessels.

form

The endometrium is divided into three layers: the compact layer, the spongy layer, and the basal layer. The dense layer and spongy layer of the 2/3 endometrial surface are collectively called the functional layer, which are shed periodically under the influence of ovarian sex hormones. The basal layer is the 1/3 of the endometrium close to the myometrium. It is not affected by ovarian hormones and does not undergo cyclical changes.

Pathological mechanism

Programmed cell death (PCD), also known as apoptosis. PCD occurs in many tissues and organs including the reproductive tract. Animal experiments have observed that PCD occurs in organs such as the uterus, ovaries, fallopian tubes, testicles, and prostate. Early light microscopy and electron microscopy studies have shown that apoptotic bodies also exist in the human endometrium.

When ladder-band DNA was detected by agarose gel electrophoresis and DNA chromosome technology, it was found that DNA breakage with PCD characteristics could be seen in the human endometrium in the early hyperplasia period (6-10 days), secretory period (25-28 days) and menstrual period (1-5 days); while no DNA breakage occurred in the late hyperplasia period (11-14 days), early secretory period (15-20 days) and mid-secretory period (21-24 days).

The main thing is large molecular DNA. The cyclical occurrence of PCD suggests that it plays an important regulatory role in women's menstrual cycle.

The mechanism of PCD in the endometrium is still unclear, but it is related to the cyclic changes in ovarian steroid hormones. The estrogen and progesterone receptors of the endometrium act as a transcription factor to regulate the expression of genes related to estrogen and progesterone, thereby causing proliferation and secretion changes in the endometrium.

At the same time, some polypeptide growth factors and their receptors synthesized by the uterus, such as EGF, PDGF, IGF-1, IGF-2, etc., may be the mediators of the effects of estrogen, promoting cell proliferation and differentiation.

Through immunocytochemistry technology, it was found that the human uterus produces cell death inhibitors, such as BCL-2, as early as the embryonic period. The expression of BCL-2 in adult endometrium is mainly in interstitial cells and changes periodically, reaching a peak in the late proliferative stage, decreasing in the early secretory stage, and disappearing in the late secretory stage and during the menstrual period. Therefore, it is speculated that the disappearance of BCL-2 in the late secretory phase and menstrual period is closely related to the death of endometrial cells and the occurrence of menstruation.