Causes of pelvic endometriosis

Pelvic endometriosis is a disease that many women may not know what causes it, so we recommend that you better understand the causes of pelvic endometriosis so that you can prevent the occurrence of pelvic endometriosis. Now let us tell you what causes it.

Causes of pelvic endometriosis

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

1. The implantation theory holds that pelvic endometriosis is caused by endometrial fragments with blood reflux entering the pelvic cavity through the fallopian tubes and implanting in the ovaries or other parts of the pelvic cavity. Clinically, laparotomy can reveal menstrual blood in the pelvic cavity and endometrium during menstruation. Endometriosis in the abdominal wall scar formed after cesarean section is a good example of the implantation theory.

2. The serosa theory is also called the metaplasia theory. Ovarian and pelvic endometriosis are caused by the peritoneal mesothelial layer. The paramesonephric duct originates from the primitive peritoneal invagination. The peritoneal processus vaginalis (nuclear duct), recto-vaginal septum, umbilical cord, etc. in the inguinal region are distinguished from the ovarian germinal epithelium, pelvic peritoneum, and peritoneal atresia. Tissues derived from the coelomic epithelium have the potential to produce tissues that are almost indistinguishable from the endometrium. Therefore, peritoneal mesothelial cells are very likely to metaplasia into the endometrium of ectopic diseases under the stimulation of mechanical factors (including fallopian tube ventilation, posterior uterus, cervical obstruction, inflammation, ectopic pregnancy, etc.). The surface of the ovary belongs to the primitive coelomic epithelium and has a strong differentiation potential. Under the influence of hormones and inflammation, it can differentiate into various tissues formed during embryonic development, including the endometrium. The ovary is the most vulnerable site for exogenous endometriosis, which can be explained by the metaplasia theory. The implantation theory cannot explain the cause of endometriosis outside the pelvic cavity.

3. There are lymphocytes and plasma cells infiltrating around the ectopic endometrium, and hemosiderin deposition and fibrosis in the macrophages. They believe that this is because the ectopic endometrial lesions act as foreign bodies and activate the human immune system. Since then, many scholars have explored the etiology and pathogenesis of endometriosis from the perspectives of cellular immunity and humoral immunity.

(1) Cellular Immunity Deficiency 1. T lymphocyte function defect 2. Natural Killer Cell Function Defect 2. Natural Killer Cell Function Defect: NK cells are a group of heterogeneous multifunctional immune cells, whose functional characteristics are to kill certain tumor cells or virus-infected cells in the absence of antibody and antigen sensitization. Important role.

(2) Theories of the occurrence of endometriosis related to lack of humoral immune function include: (1) Lymphatic dissemination theory. It is believed that the endometrium can spread through the lymphatic channels, and the endometrial tissue is present in the parauterine lymph nodes and iliac lymph nodes in turn. However, the shortcomings of this theory are that endometrial tissue rarely appears in the center of the regional lymph nodes, and the multiple sites do not conform to normal lymphatic drainage. 2) Blood flow dissemination theory. According to literature reports, ectopic endometrium is found in veins, pleura, liver parenchyma, kidneys, upper arms and lower limbs.

Some scholars believe that the most likely cause of endometriosis is the spread of endometrium to the above-mentioned tissues and organs through the bloodstream, and has caused experimental endometriosis in rabbit lungs. However, others believe that these conditions may be caused by hematogenous dissemination, but the factor of local metaplasia cannot be ruled out, because the pleura is also differentiated from the coelomic epithelium. Embryonic endometriosis can occur in the coelomic epithelial cells when the reproductive tract and mesonephric duct are formed. In the future, tissue metaplasia may occur, and endometriosis may occur in every part.