Etiology
First, the theory of implantation was the earliest (1921). Some people think that the occurrence of pelvic endometriosis is caused by the reverse flow of endometrial debris with menstrual blood, which enters the pelvic cavity through the fallopian tube and is implanted in the ovary or other parts of the pelvic cavity. Clinically, menstrual blood can be found in pelvic cavity during laparotomy during menstrual period, and endometrium can be found in menstrual blood. Endometriosis caused by abdominal scar after cesarean section is a good example of implantation theory.
Second, serosa theory is also called metaplasia theory, which holds that ovarian and pelvic endometriosis is metaplasia from peritoneal mesothelium. The accessory mesonephric duct is developed from the original peritoneal invagination, and it is differentiated from the epithelial body cavity with the germinal epithelium of ovary, pelvic peritoneum and occluded peritoneal depression, such as the peritoneal sheath process (Nuke's duct) in inguinal region, rectovaginal septum and umbilicus. All tissues that originate from body cavity epithelium have the potential to generate tissues that are almost indistinguishable from endometrium, so peritoneal mesothelial cells may easily metaplasia into ectopic endometrium under the stimulation of mechanical factors (including tubal ventilation, uterine retroposition, cervical obstruction), inflammation, ectopic pregnancy and so on. The germinal epithelium on the surface of ovary belongs to primitive body cavity epithelium, which has more differentiation potential. Under the influence of hormones and inflammation, it can differentiate into various tissues that can be formed during embryo, including endometrium. Ovary is the most easily involved part in external endometriosis, which can be easily explained by metaplasia theory. Implantation theory can't explain the cause of endometriosis beyond pelvic cavity.
3. Immunology Theory In 198, Weed and others reported that lymphocytes and plasma cells infiltrated around ectopic endometrium, and macrophages contained hemosiderosis and fibrosis in different degrees. They believe that it is due to ectopic endometrial lesions as foreign bodies that activate the immune system of the body. Since then, many scholars have explored the etiology and pathogenesis of endometriosis from cellular immunity and humoral immunity.
(1) cellular immune dysfunction 1.T lymphocyte dysfunction; 2. Functional defects of natural killer cell: NK cells are a group of heterogeneous and multifunctional immune cells, which can kill some tumor cells or virus-infected cells without antibody and antigen sensitization, and play an important role in in-vivo immune monitoring.
(II) Humoral immune deficiency There are also theories about endometriosis: ① Lymphatic dissemination theory. It is believed that endometrium can spread through lymphatic channels, and it has been found that uterine lymph nodes and internal iliac lymph nodes contain endometrial tissue. However, the weakness of this theory is that intimal tissue is rarely seen in the center of regional lymph nodes, and the frequent sites are not in line with normal lymphatic drainage; ② blood flow spreading theory. According to literature reports, ectopic endometrium has been found in veins, pleura, liver parenchyma, kidney, upper arm and lower limb. Some scholars believe that it is most likely that the intima spreads to the above tissues and organs through blood flow, and it has caused experimental endometriosis in rabbit lungs. However, some people think that although these cases may be caused by hematogenous spread, the factor of local metaplasia cannot be ruled out, because pleura is also differentiated from body cavity epithelium. When germ and mesonephric duct are produced in embryonic stage, it is possible that body cavity epithelium is located in them, and tissues can metaplasia in the future to form endometriosis in each part.
regardless of the origin of ectopic endometrium, its growth is related to ovarian endocrine. Clinical data can show that this disease mostly occurs in women in reproductive period (more than 8% in 3-5 years old) and is often complicated with ovarian dysfunction. After ovariectomy, ectopic endometrium atrophy. The growth of ectopic endometrium mainly depends on estrogen, and more progesterone is secreted during pregnancy, so ectopic endometrium is inhibited. Long-term oral administration of synthetic progestogen, such as ethinylonone, can cause pseudopregnancy and atrophy of ectopic endometrium.
pathological changes
1. Endometriosis endometrium grows from the basal part to the muscular layer and is confined to the uterus, so it is also called adenomyosis. Ectopic endometrium often spreads throughout the uterine muscle wall, and the invasion of endometrium causes reactive proliferation of fibrous tissue and muscle fibers, which makes the uterus swell uniformly, but rarely exceeds the full-term fetal head. Uneven or focal distribution is generally more common in the posterior wall. Because it is confined to one part of the uterus, it often makes the uterus irregularly enlarged, resembling uterine fibroids. It can be seen that the hyperplastic muscle tissue is also like a myoma with a vortex-like structure, but there is no capsule-like tissue separated from the normal muscle fibers around the myoma. There is a softening area in the middle of the lesion, and occasionally small cavities containing a small amount of old hematocele can be seen. Microscopically, the endometrial gland is the same as the endometrial gland, and it is surrounded by endometrial stroma. Ectopic endometrium changes with menstrual cycle, but the change of secretory phase is not obvious, indicating that ectopic endometrial glands are less affected by progesterone. When pregnant, the interstitial cells of ectopic endometrium can show obvious decidual changes, as mentioned above.
2. Interstitial endometriosis is a special type of endometriosis, which is rare, that is, ectopic endometrium only has endometrial interstitial tissue, or the range and degree of interstitial tissue development after endometrial invasion into the muscular layer far exceed the glandular components. Generally, the consistency of uterus increases, ectopic cells are scattered in the myometrium or concentrated in a certain area, which is yellow, often with elastic rubber-like hardness and softer than myoma, and cord-like worm-like protrusions can often be seen in the section, so as to establish the diagnosis. Ectopic tissue can also develop into the uterine cavity to form a polypoid mass, which is multiple and has a smooth surface. The pedicle width has a large area of direct connection with the uterine muscle wall, and can protrude from the uterine wall to the uterine cavity or along the uterine blood vessels into the broad ligament. Causing menorrhagia or even postmenopausal bleeding to those with uterine cavity protrusion; Protrusion of the broad ligament can be detected by gynecological Shuang Hezhen. Interstitial endometriosis can spread in the lungs, even years after hysterectomy. Because of this feature, some people think that interstitial endometriosis is a malignant sarcoma of the low floor.
3. Exogenous endometriosis invades tissues outside the uterus (including ectopic endometrium invading the serosa layer of the uterus from the pelvic cavity) or organs, often involving multiple organs or tissues.
Ovary is the most common site of external endometriosis, accounting for 8%, followed by peritoneum of hysterorectal fossa, including uterosacral ligament. The anterior wall of hysterorectal fossa is equivalent to the posterior fornix of vagina, and the posterior wall of cervix is equivalent to the internal opening of cervix. Sometimes ectopic endometrium invades the anterior wall of rectum, causing the intestinal wall to form dense adhesion with the posterior wall of uterus and ovary, which is difficult to separate during operation. Exogenous endometriosis can also invade the rectovaginal septum and form scattered black and purple spots on the mucosa of the posterior fornix of vagina, and even form cauliflower-like protrusions, which resemble cancerous tumors. Endometriosis can only be confirmed by biopsy. In addition, as mentioned above, ectopic endometrial growth may occur in fallopian tubes, cervix, vulva, appendix, umbilicus, abdominal incision, hernia sac, bladder, lymph nodes, even pleura and pericardium, upper limbs, thighs and skin.
Ectopic endometrium in the uterine and rectal fossa can also form purple-black bleeding spots or blood sacs on the peritoneum, which are embedded in fibrous tissue with severe adhesion. Microscopic examination shows typical endometrium. The ectopic endometrial tissue can still expand to the rectovaginal septum and uterosacral ligament to form tender solid nodules. Or penetrate the mucosa of the posterior fornix of the vagina, forming a blue-purple papillary mass, and many small bleeding spots may appear during menstruation. If the anterior wall of the rectum is involved, menstrual stool pain may occur, and sometimes endometrial lesions spread around the rectum to form a narrow ring, which is very similar to cancer, and intestinal invasion accounts for about 1% of endometriosis. Lesions are often located in serosa and muscularis, and few mucous membranes are invaded and ulcers occur. Occasionally, intestinal obstruction occurs due to the formation of a lump on the intestinal wall or the excessive flexion of the intestinal canal caused by fibrous stenosis or adhesion, and irritating symptoms may occur, such as intermittent diarrhea, and menstrual period is more serious.
clinical manifestations
the symptoms and signs of endometriosis vary with the position of ectopic endometrium and are closely related to menstrual cycle.
symptoms
(1) dysmenorrhea: it is a common and prominent symptom, mostly secondary, that is, since the occurrence of endometriosis, patients complained that they had no pain during menstrual cramps in the past, but began to have dysmenorrhea from a certain period. Can occur before menstruation, during menstruation and after menstruation. Some dysmenorrhea is severe and unbearable, and it is necessary to stay in bed or use drugs to relieve pain. Pain often increases with menstrual cycle. Due to the rising level of estrogen, ectopic endometrium will proliferate and swell, and if it is affected by progesterone again, it will bleed and stimulate local tissues, resulting in pain. If it is endometriosis, it can promote uterine muscle contracture, and dysmenorrhea is bound to be more significant. In the case of ectopic tissue without bleeding, dysmenorrhea may be caused by vascular congestion. After menstruation, ectopic endometrium gradually shrinks and dysmenorrhea disappears. In addition, in pelvic endometriosis, many inflammatory processes can be found, and it is likely that local inflammatory processes are accompanied by active peritoneal lesions, thus producing prostaglandins, kinins and other peptides that cause pain or tenderness. < P > However, the degree of pain often does not reflect the degree of diseases detected by laparoscopy. Clinically, endometriosis is significant, but there is no dysmenorrhea, accounting for about 25%. Women's psychological status can also affect pain.
(2) Hypermenorrhea: Endometriosis, the menstrual flow often increases and the menstrual period is prolonged. It may be caused by endometrial hyperplasia, but it is often accompanied by ovarian dysfunction.
(3) Infertility: Patients with endometriosis are often accompanied by infertility. According to reports from Tianjin and Shanghai, primary infertility accounts for 41.5 ~ 43.3%, and secondary infertility accounts for 46.6 ~ 47.3%. The causal relationship between infertility and endometriosis is still controversial. Pelvic endometriosis can often cause adhesion around fallopian tubes, affect oocyte pickup or lead to lumen blockage. Or infertility caused by ovarian lesions affecting the normal ovulation. However, some people think that long-term infertility and menstrual period can cause the opportunity of endometriosis; Once pregnant, the ectopic endometrium is inhibited and atrophied.
(4) Sexual pain: Endometriosis that occurs in the uterine and rectal fossa and the vaginal and rectal septum causes the surrounding tissues to swell, which affects sexual life, and the sexual discomfort in the premenstrual period is aggravated.
(5) Stool heaving: It usually occurs in premenstrual period or after menstruation, and patients feel unbearable pain when feces pass through rectum, but not at other times, which is a typical symptom of endometriosis in the uterine and rectal fossa and near rectum. Occasionally, ectopic endometrium reaches the rectal mucosa, and there is menstrual rectal bleeding. Endometriosis is similar to cancer because it causes stricture around rectum, which has symptoms of acute interior, severe back pain and obstruction.
(6) Bladder symptoms: it is more common in patients with endometriosis to the bladder, with periodic frequent urination and painful urination; Periodic hematuria may occur when bladder mucosa is invaded. < P > Abdominal wall scar and endometriosis in umbilical region have periodic local lump and pain.
Zhang Linghao reported that among 49 cases of infertility, 229 cases were endometriosis at different stages. Tubal patency was found in 5 cases (21.8%), one side patency, the other side patency or obstruction in 73 cases (31.7%), bilateral patency or one side patency and one side obstruction in 72 cases (31.3%), and bilateral patency in 49 cases (21.3%). Bilateral tubal nowhere certainly cannot naturally cause pregnancy, accounting for 1/5 of endometriosis infertility; One-third of the patients were weak in bilateral or unilateral communication; 1/5 both sides are connected or 1/3 is weak. Obstruction or obstruction of the fallopian tube and adhesion around the umbrella tip all affect the entry of eggs into the fallopian tube. However, if one side of fallopian tube is unobstructed, even if both sides are open, infertility also occurs. In addition, the destruction of ovary by ectopic endometrium also affects the development or ovulation of egg cells and the unhealthy function of corpus luteum. These changes can easily explain the mechanism of infertility. The autoimmune reaction of patients with endometriosis is also unfavorable to sperm and fertilized eggs.
The abortion rate of patients with endometriosis is also high. According to Jones, Jones and Naples, the abortion rate of ectopic pregnancy can reach 44 ~ 47%. Naples also reported that the abortion rate of patients with endometriosis dropped to 8% after surgical treatment.
2. Signs Endometriosis patients often have enlarged uterus, but rarely exceed 3 months of pregnancy. Most of them are consistent swelling, and they may also feel that some parts are more prominent like uterine fibroids. If it is a posterior uterus, it is often adhered and fixed. In utero-rectal fossa, uterosacral ligament or cervical posterior wall can often touch one or more hard nodules, such as mung bean or soybean size, with obvious tenderness, especially anal diagnosis, which is very important. Occasionally, dark purple bleeding spots or nodules can be seen in the posterior fornix of vagina. If there are many lesions in the rectum, it can touch a hard lump and even be misdiagnosed as rectal cancer.
Ovarian hematoma is often adhered and fixed with the surrounding area. In gynecological Shuang Hezhen, it can touch a mass with high tension and tenderness, which is easily misdiagnosed as adnexitis combined with infertility history. Internal bleeding occurred after rupture, showing acute abdominal pain.
Diagnosis
This disease mostly occurs in women aged 3-4. The chief complaint is secondary progressive severe dysmenorrhea, which should be highly suspected of endometriosis. Patients are often accompanied by infertility, menorrhagia and sexy unhappiness. Endometriosis can be diagnosed when the uterus swells slightly and the uterosacral ligament or the posterior wall of the cervix is touched by nodules. When ovarian endometrioid cyst exists, Shuang Hezhen can touch one or both cystic or cystic-solid masses, which are generally within 1cm in diameter and have a sense of adhesion with the surrounding area.
periodic bleeding of rectum and bladder, painful defecation during menstrual period, endometriosis of rectum and bladder should be considered first, cystoscopy or colonoscopy can be done if necessary, and tissue should be taken for pathological examination when ulcer occurs.
The diagnosis can also be established if the abdominal wall scar has periodic induration and pain, and there is abdominal wall suspension, caesarean section or cesarean section in the medical history.
suspicious cases can also be diagnosed if they are effectively treated with drugs.
whoever forms a local mass close to the body surface can take tissue as much as possible (cut off or take it with a liver puncture needle) and send it for pathological examination, so that the diagnosis can be made.
The sonogram of endometrioid cyst by B-ultrasound showed granular fine echo. If the cystic fluid is viscous and there are intimal fragments floating inside, it is easy to be similar to the echo characteristics of hair contained in the fat in teratoma, that is, small thin bands of light are seen in the fluid, which are distributed in parallel dotted lines. Sometimes there is a separation inside, which is divided into several cysts with different sizes. The echoes of each cyst are inconsistent, and they often adhere to the uterus, but the boundary between them is unclear. Teratomas generally have clear cyst boundaries. Endometrioid cyst of ovary is also easy to be associated with adnexitis.