Causes of pelvic endometriosis

Many female friends may not know the cause of pelvic endometriosis, so we recommend that you understand the cause of pelvic endometriosis so that you can prevent the occurrence of pelvic endometriosis in your life. Let me tell you what are the causes of its disease.

When endometrial tissue appears outside the uterine cavity, it is called endometriosis. It undergoes periodic bleeding under the influence of changes in ovarian hormones, accompanied by proliferation of surrounding fibrous tissue and adhesion formation. The vast majority of endometriosis is located on the peritoneal surface of the reproductive organs and adjacent organs in the pelvic cavity, which is often clinically referred to as pelvic endometriosis; when the endometrium appears in the myometrium, it is called adenomyosis, which was previously called intrinsic endometriosis.

1. Implantation theory: the occurrence of pelvic endometriosis is caused by the backflow of endometrial fragments with menstrual blood, entering the pelvic cavity through the fallopian tubes and implanting in the ovaries or other parts of the pelvic cavity. Clinically, during laparotomy during the menstrual period, menstrual blood can be found in the pelvic cavity, and the endometrium can be found in the menstrual blood. Endometriosis in the abdominal wall scar formed after cesarean section is a good example of the implantation theory.

2. The serosal theory, also known as the metaplastic theory, believes that ovarian and pelvic endometriosis arise from the metaplasia of the mesothelial cell layer of the peritoneum. The paramesonephric duct develops from the primitive peritoneal invagination, and is differentiated from the coelomic epithelium along with the germinal epithelium of the ovary, the pelvic peritoneum, and closed peritoneal invaginations, such as the processus vaginalis (Nook's duct) in the inguinal region, the rectovaginal septum, and the umbilicus. All tissues arising from the epithelium of the body cavity have the potential to metaplasia into tissues that are almost indistinguishable from the endometrium. Therefore, peritoneal mesothelial cells may be easily stimulated by mechanical factors (including fallopian tube ventilation, retroverted uterus, cervical obstruction), inflammation, ectopic pregnancy, etc., and may easily undergo metaplasia and become ectopic endometrium. The germinal epithelium on the surface of the ovary is a primitive coelomic epithelium and has greater potential for differentiation. Under the influence of hormones and inflammation, it can differentiate into various tissues that can be formed during the embryo, including the endometrium. The ovary is the most easily affected site in external endometriosis, which can be easily explained by the metaplastic theory. The implantation theory cannot explain the occurrence of endometriosis beyond the pelvic cavity.

3. There is infiltration of lymphocytes and plasma cells around the ectopic endometrium, and the macrophages contain hemosiderin deposition and varying degrees of fibrosis. They believe that this is because the ectopic endometrial lesions act as foreign bodies and activate the body's immune system. Since then, many scholars have explored the etiology and pathogenesis of endometriosis from the aspects of cellular immunity and humoral immunity.

(I) Cellular immune function defects 1. T lymphocyte function defects; 2. Natural killer cell function defects: NK cells are a group of heterogeneous and multifunctional immune cells. Their functional characteristics are that they can kill certain tumor cells or virus-infected cells without the presence of antibodies or antigen sensitization, and play an important role in the body's immune monitoring.

(B) Other theories regarding the occurrence of endometriosis due to humoral immune deficiency include: ① Lymphatic dissemination theory. It is believed that the endometrium can spread through the lymphatic channels, and some people have discovered that the parauterine lymph nodes and internal iliac lymph nodes contain endometrial tissue. However, the weakness of this theory is that endometrial tissue is rarely seen in the center of regional lymph nodes, and the common sites do not conform to normal lymphatic drainage; ② Theory of blood flow dissemination. According to literature reports, ectopic endometrium has been found in veins, pleura, liver parenchyma, kidneys, upper arms, lower limbs, etc. Some scholars believe that the most likely cause is the spread of the endometrium to the above-mentioned tissues and organs through the bloodstream, and that it has caused experimental endometriosis in rabbit lungs. However, some people believe that although these situations may be caused by hematogenous dissemination, the factor of local metaplasia cannot be ruled out because the pleura is also differentiated from the body cavity epithelium. When the germ and mesonephric duct are produced during the embryonic period, ectopic location of the coelomic epithelium may occur therein, and the tissue may later metaplasia to form endometriosis in these areas.

Regardless of the source of ectopic endometrium, its growth is related to ovarian endocrine secretion. Clinical data show that such a condition mostly occurs in women of childbearing age (more than 80% between 30 and 50 years old), and is often complicated by ovarian dysfunction. After ovarian removal, the ectopic endometrium atrophies. The growth of ectopic endometrium mainly depends on estrogen. During pregnancy, the secretion of progesterone is relatively high, which inhibits the ectopic endometrium. Long-term oral use of synthetic progestins such as ethinyl isosterol can cause pseudopregnancy and atrophy of the ectopic endometrium.

For the disease of pelvic endometriosis introduced in the article, we recommend that you should receive timely treatment in your life so that you can avoid the harm of the disease in your life. Pelvic endometriosis can cause many diseases and harm to female friends. I hope you can understand.