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Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the
uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uter ...
, grow outside the uterus. Most often this is on the
ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
, fallopian tubes, and tissue around the uterus and ovaries; in rare cases it may also occur in other parts of the body. Some symptoms include
pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in include ...
, heavy periods, pain with bowel movements, and
infertility Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal state ...
. Nearly half of those affected have
chronic pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in inclu ...
, while in 70% pain occurs during
menstruation Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hor ...
. Pain during sexual intercourse is also common. Infertility occurs in up to half of affected individuals. About 25% of individuals have no symptoms and 85% of those seen with infertility in a tertiary center have no pain. Endometriosis can have both social and psychological effects. The cause is not entirely clear. Risk factors include having a family history of the condition. The areas of endometriosis bleed each month (menstrual period), resulting in inflammation and scarring. The growths due to endometriosis are not
cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
. Diagnosis is usually based on symptoms in combination with medical imaging; however,
biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...
is the surest method of diagnosis. Other causes of similar symptoms include pelvic inflammatory disease,
irritable bowel syndrome Irritable bowel syndrome (IBS) is a "disorder of gut-brain interaction" characterized by a group of symptoms that commonly include abdominal pain and or abdominal bloating and changes in the consistency of bowel movements. These symptoms may ...
,
interstitial cystitis Interstitial cystitis (IC), a type of bladder pain syndrome (BPS), is chronic pain in the bladder and pelvic floor of unknown cause. It is the urologic chronic pelvic pain syndrome of women. Symptoms include feeling the need to urinate right aw ...
, and fibromyalgia. Endometriosis is commonly misdiagnosed and people often report being incorrectly told their symptoms are trivial or normal. People with endometriosis see an average of seven physicians before receiving a correct diagnosis, with an average delay of 6.7 years between the onset of symptoms and surgically obtained biopsies, the
gold standard A gold standard is a monetary system in which the standard economic unit of account is based on a fixed quantity of gold. The gold standard was the basis for the international monetary system from the 1870s to the early 1920s, and from the la ...
for diagnosing the condition. This average delay places endometriosis at the extreme end of diagnostic inefficiency. Tentative evidence suggests that the use of
combined oral contraceptives The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: proges ...
reduces the risk of endometriosis. Exercise and avoiding large amounts of alcohol may also be preventive. There is no cure for endometriosis, but a number of treatments may improve symptoms. This may include
pain medication An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...
, hormonal treatments or surgery. The recommended pain medication is usually a
non-steroidal anti-inflammatory drug Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
(NSAID), such as
naproxen Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain, menstrual cramps, inflammatory diseases such as rheumatoid arthritis, gout and fever. It is taken orally. It is available in immediate and delayed release formulat ...
. Taking the active component of the birth control pill continuously or using an
intrauterine device with progestogen A hormonal intrauterine device (IUD), also known as a intrauterine system (IUS) with progestogen and sold under the brand name Mirena among others, is an intrauterine device that releases a progestogenic hormonal agent such as levonorgestrel in ...
may also be useful.
Gonadotropin-releasing hormone agonist A gonadotropin-releasing hormone agonist (GnRH agonist) is a type of medication which affects gonadotropins and sex hormones. They are used for a variety of indications including in fertility medicine and to lower sex hormone levels in the treatm ...
(GnRH agonist) may improve the ability of those who are infertile to get pregnant. Surgical removal of endometriosis may be used to treat those whose symptoms are not manageable with other treatments. One estimate is that 10.8 million people are affected globally . Other sources estimate 6 to 10% of the general female population and 2 to 11% of asymptomatic women are affected. In addition, 11% of women in a general population have undiagnosed endometriosis that can be seen on magnetic resonance imaging (
MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
). Endometriosis is most common in those in their thirties and forties; however, it can begin in girls as early as eight years old. It results in few deaths with unadjusted and age-standardized death rates of 0.1 and 0.0 per 100,000. Endometriosis was first determined to be a separate condition in the 1920s. Before that time, endometriosis and adenomyosis were considered together. It is unclear who first described the disease.


Signs and symptoms

Pain and infertility are common symptoms, although 20–25% of women are asymptomatic. Presence of pain symptoms are associated with the type of endometrial lesions as 50% of women with typical lesions, 10% of women with cystic ovarian lesions, and 5% of women with deep endometriosis do not have pain.


Pelvic pain

A major symptom of endometriosis is recurring
pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in include ...
. The pain can range from mild to severe cramping or stabbing pain that occurs on both sides of the pelvis, in the lower back and rectal area, and even down the legs. The amount of pain a person feels correlates weakly with the extent or stage (1 through 4) of endometriosis, with some individuals having little or no pain despite having extensive endometriosis or endometriosis with scarring, while others may have severe pain even though they have only a few small areas of endometriosis. The most severe pain is typically associated with menstruation. Pain can also start a week before a menstrual period, during and even a week after a menstrual period, or it can be constant. The pain can be debilitating and result in emotional stress. Symptoms of endometriosis-related pain may include: * dysmenorrhea (64%) Text was copied from this source, which is available under
Creative Commons Attribution 4.0 International License
– painful, sometimes disabling cramps during the menstrual period; pain may get worse over time (progressive pain), also lower back pains linked to the pelvis *
chronic pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in inclu ...
– typically accompanied by lower back pain or abdominal pain * dyspareunia – painful
sexual intercourse Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
*
dysuria Dysuria refers to painful or uncomfortable urination. It is one of a constellation of ''irritative'' bladder symptoms (also sometimes referred to as lower urinary tract symptoms), which includes nocturia and urinary frequency. Diagnosis The c ...
– urinary urgency, frequency, and sometimes painful voiding *
mittelschmerz ''Mittelschmerz'' (German: "middle pain") is a colloquial term for "ovulation pain" or "midcycle pain". About 20% of women experience mittelschmerz, some every cycle, some intermittently. Signs and symptoms Mittelschmerz is characterized by lo ...
– pain associated with ovulation * bodily movement pain – present during exercise, standing, or walking Compared with patients with superficial endometriosis, those with deep disease appear to be more likely to report shooting rectal pain and a sense of their insides being pulled down. Individual pain areas and pain intensity appear to be unrelated to the surgical diagnosis, and the area of pain unrelated to the area of endometriosis. There are multiple causes of pain. Endometriosis lesions react to hormonal stimulation and may "bleed" at the time of menstruation. The blood accumulates locally if it is not cleared shortly by the immune, circulatory, and lymphatic system. This may further lead to swelling, which triggers inflammation with the activation of
cytokines Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...
, which results in pain. Another source of pain is the organ dislocation that arises from
adhesion Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can b ...
binding internal organs to each other. The ovaries, the uterus, the oviducts, the peritoneum, and the bladder can be bound together. Pain triggered in this way can last throughout the menstrual cycle, not just during menstrual periods. Also, endometriotic lesions can develop their own nerve supply, thereby creating a direct and two-way interaction between lesions and the
central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...
, potentially producing a variety of individual differences in pain that can, in some cases, become independent of the disease itself. Nerve fibres and blood vessels are thought to grow into endometriosis lesions by a process known as
neuroangiogenesis Neuroangiogenesis is the coordinated growth of nerves and blood vessels. The nervous and blood vessel systems share guidance cues and cell-surface receptors allowing for this synchronised growth. The term ''neuroangiogenesis'' only came into use in ...
.


Infertility

About a third of women with
infertility Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal state ...
have endometriosis. Among those with endometriosis, about 40% are infertile. The pathogenesis of infertility is dependent on the stage of disease: in early stage disease, it is hypothesised that this is secondary to an inflammatory response that impairs various aspects of conception, whereas in later stage disease distorted pelvic anatomy and adhesions contribute to impaired fertilisation.


Other

Other symptoms include diarrhea or
constipation Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...
, chronic fatigue, nausea and vomiting, migraines, low-grade fevers, heavy (44%) and/or irregular periods (60%), and hypoglycemia. There is an association between endometriosis and certain types of cancers, notably some types of
ovarian cancer Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different c ...
,
non-Hodgkin's lymphoma Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of hematological malignancy, blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include lymphadenopathy, enlarged lymph nodes, fever ...
and
brain cancer A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondar ...
. Endometriosis is unrelated to endometrial cancer. Rarely, endometriosis can cause endometrium-like tissue to be found in other parts of the body.
Thoracic endometriosis Thoracic endometriosis is a rare form of endometriosis where endometrial-like tissue is found in the lung parenchyma and/or the pleura. It can be classified as either ''pulmonary'', or ''pleural'', respectively.Rojas, J. (2014). Endometriosis pulmon ...
occurs when endometrium-like tissue implants in the lungs or pleura. Manifestations of this include coughing up blood, a
collapsed lung A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve ...
, or bleeding into the pleural space. Stress may be a cause or a consequence of endometriosis.


Complications


Physical Health

Complications of endometriosis include internal scarring,
adhesions Adhesions are fibrous bands that form between tissues and organs, often as a result of injury during surgery. They may be thought of as internal scar tissue that connects tissues not normally connected. Pathophysiology Adhesions form as a natural ...
, pelvic cysts, chocolate cysts of ovaries, ruptured cysts, and bowel and ureter obstruction resulting from pelvic adhesions.
Endometriosis-associated infertility Endometriosis and its complications are a major cause of female infertility. Endometriosis is a dysfunction characterized by the migration of endometrial tissue to areas outside of the endometrium of the uterus. The most common places to find stray ...
can be related to scar formation and anatomical distortions due to the endometriosis. Ovarian endometriosis may complicate pregnancy by
decidualization Decidualization is a process that results in significant changes to cells of the endometrium in preparation for, and during, pregnancy. This includes morphological and functional changes (the decidual reaction) to endometrial stromal cells (ESCs), ...
, abscess and/or rupture.
Thoracic endometriosis Thoracic endometriosis is a rare form of endometriosis where endometrial-like tissue is found in the lung parenchyma and/or the pleura. It can be classified as either ''pulmonary'', or ''pleural'', respectively.Rojas, J. (2014). Endometriosis pulmon ...
can be associated with recurrent thoracic endometriosis syndrome at times of a menstrual period that includes catamenial pneumothorax in 73% of women, catamenial
hemothorax A hemothorax (derived from hemo- lood+ thorax hest plural ''hemothoraces'') is an accumulation of blood within the pleural cavity. The symptoms of a hemothorax may include chest pain and difficulty breathing, while the clinical signs may incl ...
in 14%, catamenial
hemoptysis Hemoptysis is the coughing up of blood or blood-stained mucus from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia, a ...
in 7%, and pulmonary nodules in 6%. A 20-year study of 12,000 women with endometriosis found that individuals under 40 who are diagnosed with endometriosis are 3 times more likely to have heart problems than their healthy peers. Endometriosis may increase about 1% or less chance of getting ovarian, breast and thyroid cancers in women compared with those without. It results in few deaths with unadjusted and age-standardized death rates of 0.1 and 0.0 per 100,000. Sciatic endometriosis also called catamenial or cyclical sciatica is a sciatica whose cause is endometriosis and whose incidence is unknown. Diagnosis is usually made by an MRI or CT-myelography.


Mental Health

"Endometriosis is associated with an elevated risk of developing depression and anxiety disorders". Studies suggest this is partially due to the pelvic pain experienced by endometriosis patients.


Risk factors


Genetics

Endometriosis is a heritable condition that is influenced by both genetic and environmental factors. Children or siblings of people with endometriosis are at higher risk of developing endometriosis themselves; low progesterone levels may be genetic, and may contribute to a hormone imbalance.Kapoor D, Davila W (2005)
Endometriosis
''eMedicine''.
There is an approximate six-fold increased incidence in individuals with an affected first-degree relative. It has been proposed that endometriosis results from a series of multiple hits within target genes, in a mechanism similar to the development of cancer. In this case, the initial mutation may be either somatic or heritable. Individual genomic changes (found by
genotyping Genotyping is the process of determining differences in the genetic make-up (genotype) of an individual by examining the individual's DNA sequence using biological assays and comparing it to another individual's sequence or a reference sequence. ...
including
genome-wide association studies In genomics, a genome-wide association study (GWA study, or GWAS), also known as whole genome association study (WGA study, or WGAS), is an observational study of a genome-wide set of genetic variants in different individuals to see if any varian ...
) that have been associated with endometriosis include 9 locis robustly replicated in various MNAs reaching genome-wide significance : There are many findings of altered
gene expression Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ...
and
epigenetics In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "o ...
, but both of these can also be a secondary result of, for example, environmental factors and altered metabolism. Examples of altered gene expression include that of
miRNA MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miR ...
s.


Environmental toxins

Some factors associated with endometriosis include: * prolonged exposure to estrogen; for example, in late menopause or early menarche * obstruction of menstrual outflow; for example, in Müllerian anomalies Several studies have investigated the potential link between exposure to
dioxin Dioxin may refer to: * 1,2-Dioxin or 1,4-Dioxin, two unsaturated heterocyclic 6-membered rings where two carbon atoms have been replaced by oxygen atoms, giving the molecular formula C4H4O2 *Dibenzo-1,4-dioxin, the parent compound also known as ...
s and endometriosis, but the evidence is equivocal and potential mechanisms are poorly understood. A 2004 review of studies of dioxin and endometriosis concluded that "the human data supporting the dioxin-endometriosis association are scanty and conflicting", and a 2009 follow-up review also found that there was "insufficient evidence" in support of a link between dioxin exposure and developing endometriosis. A 2008 review concluded that more work was needed, stating that "although preliminary work suggests a potential involvement of exposure to dioxins in the pathogenesis of endometriosis, much work remains to clearly define cause and effect and to understand the potential mechanism of toxicity".


Pathophysiology

While the exact cause of endometriosis remains unknown, many theories have been presented to better understand and explain its development. These concepts do not necessarily exclude each other. The pathophysiology of endometriosis is likely to be multifactorial and to involve an interplay between several factors.


Formation

The main theories for the formation of the ectopic endometrium-like tissue include retrograde menstruation, Müllerianosis, coelomic metaplasia, vascular dissemination of stem cells, and surgical transplantation were postulated as early as 1870. Each is further described below.


Retrograde menstruation theory

The theory of retrograde menstruation (also called the ''implantation theory'' or ''transplantation theory'') is the most commonly accepted theory for the dissemination and transformation of ectopic endometrium into endometriosis. It suggests that during a woman's
menstrual flow Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of ho ...
, some of the endometrial debris flow backward through the Fallopian tubes and into the peritoneal cavity, attaching itself to the peritoneal surface (the lining of the abdominal cavity) where it can proceed to invade the tissue as or transform into endometriosis. It is not clear at what stage the transformation of endometrium, or any cell of origin such as stem cells or coelomic cells (see those theories below), to endometriosis begins. Proofs in support of the theory is based on retrospective epidemiological studies that an association with endometrial implants attached to the peritoneal cavity, which would develop into endometrial lesions and retrograde menstruation; and the fact that animals like rodents and non-human primates whose endometrium is not shed during the estrous cycle don't develop naturally endometriosis contrary to animals that have a natural menstrual cycle like rhesus monkeys and baboons. Retrograde menstruation alone is not able to explain all instances of endometriosis, and additional factors such as genetics, immunology, stem cell migration, and coelomic metaplasia (see "Other theories" on this page) are needed to account for disseminated disease and why many individuals with retrograde menstruation are not diagnosed with endometriosis. In addition, endometriosis has shown up in people who have never experienced menstruation including cisgender men, fetuses, and prepubescent girls. Further theoretical additions are needed to complement the retrograde menstruation theory to explain why cases of endometriosis show up in the brain and lungs. This theory has numerous other associated issues. Researchers are investigating the possibility that the
immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...
may not be able to cope with the cyclic onslaught of retrograde menstrual fluid. In this context there is interest in studying the relationship of endometriosis to autoimmune disease,
allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic der ...
reactions, and the impact of toxic materials. It is still unclear what, if any, causal relationship exists between toxic materials or autoimmune disease and endometriosis. There are immune system changes in people with endometriosis, such as an increase of macrophage-derived secretion products, but it is unknown if these are contributing to the disorder or are reactions from it. Endometriotic lesions differ in their biochemistry, hormonal response, immunology, inflammatory response when compared to endometrium. This is likely because the cells that give rise to endometriosis are a side population of cells. Similarly, there are changes in, for example, the mesothelium of the
peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesoth ...
in people with endometriosis, such as loss of
tight junction Tight junctions, also known as occluding junctions or ''zonulae occludentes'' (singular, ''zonula occludens''), are multiprotein junctional complexes whose canonical function is to prevent leakage of solutes and water and seals between the epith ...
s, but it is unknown if these are causes or effects of the disorder. In rare cases where
imperforate hymen An imperforate hymen is a congenital disorder where a hymen without an opening completely obstructs the vagina. It is caused by a failure of the hymen to perforate during fetal development. It is most often diagnosed in adolescent girls when men ...
does not resolve itself prior to the first menstrual cycle and goes undetected, blood and endometrium are trapped within the uterus until such time as the problem is resolved by surgical incision. Many health care practitioners never encounter this defect, and due to the
flu-like symptoms Influenza-like illness (ILI), also known as flu-like syndrome or flu-like symptoms, is a medical diagnosis of possible influenza or other illness causing a set of common symptoms. These include fever, shivering, chills, malaise, dry cough, loss ...
it is often misdiagnosed or overlooked until multiple menstrual cycles have passed. By the time a correct diagnosis has been made, endometrium and other fluids have filled the uterus and Fallopian tubes with results similar to retrograde menstruation resulting in endometriosis. The initial stage of endometriosis may vary based on the time elapsed between onset and surgical procedure. The theory of retrograde menstruation as a cause of endometriosis was first proposed by
John A. Sampson John Albertson Sampson (August 17, 1873–December 23, 1946) was a gynecologist who studied endometriosis. Sampson was born near Troy, New York and graduated from Johns Hopkins in 1899. After completing his training in gynecology, he sett ...
.


Other theories

* Stem cells: Endometriosis may arise from stem cells from bone marrow and potentially other sources. In particular, this theory explains endometriosis found in areas remote from the pelvis such as the brain or lungs.
Stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type o ...
s may be from local cells such as the
peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesoth ...
(see coelomic metaplasia below) or cells disseminated in the blood stream (see vascular dissemination below) such as those from the bone marrow. * Vascular dissemination: Vascular dissemination is a 1927 theory that has been revived with new studies of bone-marrow stem cells involved in pathogenesis. * Environment: Environmental toxins (e.g.,
dioxin Dioxin may refer to: * 1,2-Dioxin or 1,4-Dioxin, two unsaturated heterocyclic 6-membered rings where two carbon atoms have been replaced by oxygen atoms, giving the molecular formula C4H4O2 *Dibenzo-1,4-dioxin, the parent compound also known as ...
,
nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
) may cause endometriosis. Toxins such as
dioxins and dioxin-like compounds Dioxins and dioxin-like compounds (DLCs) are a group of chemical compounds that are persistent organic pollutants (POPs) in the environment. They are mostly by-products of burning or various industrial processes - or, in case of dioxin-like PCBs ...
tend to
bioaccumulate Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...
within the human body. Further research is needed but "it is plausible that inflammatory-like processes, caused by dioxin-like environmental chemicals, can alter normal endometrial and immune cell physiology allowing persistence and development of endometrial tissue within the peritoneal cavity, normally cleared by immune system cells". * Müllerianosis: A theory supported by foetal autopsy is that cells with the potential to become endometrial, which are laid down in tracts during embryonic development called the female reproductive (Müllerian) tract as it migrates downward at 8–10 weeks of embryonic life, could become dislocated from the migrating uterus and act like seeds or
stem cells In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of ...
. * Coelomic metaplasia:
Coelomic A body cavity is any space or compartment, or potential space, in an animal body. Cavities accommodate organs and other structures; cavities as potential spaces contain fluid. The two largest human body cavities are the ventral body cavity, and ...
cells which are the common ancestor of
endometrial The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional layer ...
and
peritoneal The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of meso ...
cells may undergo
metaplasia Metaplasia ( gr, "change in form") is the transformation of one differentiated cell type to another differentiated cell type. The change from one type of cell to another may be part of a normal maturation process, or caused by some sort of abno ...
(transformation) from one type of cell to the other, perhaps triggered by inflammation. * Vasculogenesis: Up to 37% of the microvascular
endothelium The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vesse ...
of ectopic endometrial tissue originates from
endothelial progenitor cell Endothelial progenitor cell (or EPC) is a term that has been applied to multiple different cell types that play roles in the regeneration of the endothelial lining of blood vessels. Outgrowth endothelial cells are an EPC subtype committed to endot ...
s, which result in ''de novo'' formation of microvessels by the process of
vasculogenesis Vasculogenesis is the process of blood vessel formation, occurring by a '' de novo'' production of endothelial cells. It is sometimes paired with angiogenesis, as the first stage of the formation of the vascular network, closely followed by ang ...
rather than the conventional process of angiogenesis. * Neural growth: An increased expression of new nerve fibres is found in endometriosis but does not fully explain the formation of ectopic endometriotic tissue and is not definitely correlated with the amount of perceived pain. * Autoimmune:
Graves disease Graves' disease (german: Morbus Basedow), also known as toxic diffuse goiter, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyro ...
is an autoimmune disease characterized by hyperthyroidism, goiter, ophthalmopathy, and dermopathy. People with endometriosis had higher rates of Graves disease. One of these potential links between Graves disease and endometriosis is
autoimmunity In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". ...
. *
Oxidative stress Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily Detoxification, detoxify the reactive intermediates or to repair the resulting damage. Disturbances ...
: Influx of iron is associated with the local destruction of the peritoneal mesothelium, leading to the adhesion of ectopic endometriotic cells. Peritoneal iron overload has been suggested to be caused by the destruction of
erythrocytes Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
, which contain the iron-binding protein hemoglobin, or a deficiency in the peritoneal iron metabolism system. Oxidative stress activity and
reactive oxygen species In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (). Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen. The reduction of molecular oxygen () p ...
(such as superoxide anions and
peroxide In chemistry, peroxides are a group of compounds with the structure , where R = any element. The group in a peroxide is called the peroxide group or peroxo group. The nomenclature is somewhat variable. The most common peroxide is hydrogen ...
levels) are reported to be higher than normal in people with endometriosis. Oxidative stress and the presence of excess ROS can damage tissue and induce rapid
cellular division Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are ...
. Mechanistically, there are several cellular pathways by which oxidative stress may lead to or may induce proliferation of endometriotic lesions, including the mitogen activated protein (MAP) kinase pathway and the extracellular signal-related kinase ( ERK) pathway. Activation of both of the MAP and ERK pathways lead to increased levels of c-Fos and c-Jun, which are
proto-oncogenes An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels.
that are associated with high-grade lesions.


Localization

Most often, endometriosis is found on the: *
ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
* fallopian tubes * tissues that hold the uterus in place (
ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...
s) * outer surface of the uterus Less common pelvic sites are: *
vagina In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
* cervix *
vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external sex organ, female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, bulb of vestibu ...
*
bowel The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
*
bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
*
rectum The rectum is the final straight portion of the large intestine in humans and some other mammals, and the Gastrointestinal tract, gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the s ...
Endometriosis may spread to the cervix and vagina or to sites of a surgical abdominal incision, known as "scar endometriosis." Rectovaginal or bowel endometriosis affects approximately 5-12% of those with endometriosis, and can cause severe pain with bowel movements. Deep infiltrating endometriosis has been defined as the presence of endometrial glands and stroma infiltrating more than 5 mm in the subperitoneal tissue. The prevalence of DIE is estimated to be 1 to 2%. Deep endometriosis typically presents as a single nodule in the vesicouterine fold or in the lower 20 cm of the bowel. Deep endometriosis is often associated with severe pain.


Extrapelvic endometriosis

Rarely, endometriosis appears in extrapelvic parts of the body, such as the
lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...
s,
brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...
, and
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
. "Scar endometriosis" can occur in surgical abdominal incisions. Risk factors for scar endometriosis include previous abdominal surgeries, such as a hysterotomy or cesarean section, or ectopic pregnancies, salpingostomy puerperal sterilization, laparoscopy, amniocentesis, appendectomy, episiotomy, vaginal hysterectomies, and hernia repair. Endometriosis may also present with skin lesions in
cutaneous endometriosis Cutaneous endometriosis is characterized by the appearance of papules at the umbilicus or in lower abdominal scars after gynecologic surgery in middle-aged women.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: ...
. Less commonly lesions can be found on the diaphragm or lungs. Diaphragmatic endometriosis is rare, almost always on the right hemidiaphragm, and may inflict the cyclic pain of the right
scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...
(shoulder) or cervical area (neck) during a menstrual period. Pulmonary endometriosis can be associated with a thoracic endometriosis syndrome that can include catamenial (occurs during menstruation) pneumothorax seen in 73% of women with the syndrome, catamenial
hemothorax A hemothorax (derived from hemo- lood+ thorax hest plural ''hemothoraces'') is an accumulation of blood within the pleural cavity. The symptoms of a hemothorax may include chest pain and difficulty breathing, while the clinical signs may incl ...
in 14%, catamenial
hemoptysis Hemoptysis is the coughing up of blood or blood-stained mucus from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia, a ...
in 7%, and pulmonary nodules in 6%.


Diagnosis

A health history and a physical examination can lead the health care practitioner to suspect endometriosis. There is a clear benefit for undergoing an ultrasound diagnostic procedure (TVUS) as a first step of testing for endometriosis. For many patients, there are significant delays in diagnosis. Studies show an average delay of 11.7 years in the United States. Patients in the UK have an average delay of 8 years and in Norway of 6.7 years. A third of women had consulted their GP six or more times before being diagnosed. The most common sites of endometriosis are the ovaries, followed by the Douglas pouch, the posterior leaves of the broad ligaments, and the sacrouterine ligaments. As for deep infiltrating endometriosis, TVUS, TRUS and MRI are the techniques of choice for non-invasive diagnosis with a high sensitivity and specificity.


Laparoscopy

Laparoscopy Laparoscopy () is an operation performed in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.Medlin ...
, a surgical procedure where a camera is used to look inside the abdominal cavity, is the only way to accurately diagnose the extent and severity of pelvic/abdominal endometriosis. Laparoscopy is not an applicable test for extrapelvic sites such as umbilicus, hernia sacs, abdominal wall, lung, or kidneys. Reviews in 2019 and 2020 concluded that 1) with advances in imaging, endometriosis diagnosis should no longer be considered synonymous with immediate laparoscopy for diagnosis, and 2) endometriosis should be classified a syndrome that requires confirmation of visible lesions seen at laparoscopy in addition to characteristic symptoms. Laparoscopy permits lesion visualization unless the lesion is visible externally (e.g., an endometriotic nodule in the vagina) or is extra-abdominal. If the growths (lesions) are not visible, a
biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...
must be taken to determine the diagnosis. Surgery for diagnoses also allows for surgical treatment of endometriosis at the same time. During a laparoscopic procedure lesions can appear dark blue, powder-burn black, red, white, yellow, brown or non-pigmented. Lesions vary in size. Some within the pelvis walls may not be visible, as normal-appearing peritoneum of infertile women reveals endometriosis on biopsy in 6–13% of cases. Early endometriosis typically occurs on the surfaces of organs in the pelvic and intra-abdominal areas. Health care providers may call areas of endometriosis by different names, such as implants, lesions, or nodules. Larger lesions may be seen within the ovaries as
endometrioma Endometrioma is the presence of tissue similar to, but distinct from, the endometrium in and sometimes on the ovary. It is the most common form of endometriosis. Endometrioma is found in 17–44% patients with endometriosis. More broadly, endometr ...
s or "chocolate cysts", "chocolate" because they contain a thick brownish fluid, mostly old blood. Frequently during diagnostic laparoscopy, no lesions are found in individuals with chronic pelvic pain, a symptom common to other disorders including adenomyosis, pelvic adhesions, pelvic inflammatory disease,
congenital anomalies A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can r ...
of the
reproductive tract The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical sex organs, organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pherom ...
, and ovarian or tubal masses.


Ultrasound

Vaginal ultrasound has a clinical value in the diagnosis of endometrioma and before operating for deep endometriosis. This applies to the identification of the spread of disease in individuals with well-established clinical suspicion of endometriosis. Vaginal ultrasound is inexpensive, easily accessible, has no contraindications and requires no preparation. Healthcare professionals conducting ultrasound examinations need to be experienced. By extending the ultrasound assessment into the posterior and anterior pelvic compartments the sonographer is able to evaluate structural mobility and look for deep infiltrating endometriotic nodules noting the size, location and distance from the anus if applicable. An improvement in sonographic detection of deep infiltrating endometriosis will not only reduce the number of diagnostic laparoscopies, it will guide management and enhance quality of life.


Magnetic resonance imaging

Use of MRI is another method to detect lesions in a non-invasive manner. MRI is not widely used due to its cost and limited availability, however, it has the ability to detect the most common form of endometriosis (endometrioma) with a sufficient accuracy. It is recommended for the patient to receive an anti-spasmodic agent (hyoscine butylbromide for example), a big glass of water (if bladder is empty), to undergo MRI scanning in supine position and applying abdominal strap for having a better image quality from the MRI. Phased coil arrays are also recommended.


Sequences

T1W with and without suppression of fat is recommended for endometriomas; meanwhile, sagittal, axial and oblique 2D T2W are recommended for deep infiltrating endometriosis.


Staging

Surgically, endometriosis can be staged I–IV by the revised classification of the
American Society of Reproductive Medicine The American Society for Reproductive Medicine (ASRM) is a nonprofit, multidisciplinary organization for advancement of the science and practice of reproductive medicine. The society has its headquarters in Washington, D.C and its administrati ...
from 1997. The process is a complex point system that assesses lesions and adhesions in the pelvic organs, but it is important to note staging assesses physical disease only, not the level of pain or infertility. A person with Stage I endometriosis may have a little disease and severe pain, while a person with Stage IV endometriosis may have severe disease and no pain or vice versa. In principle the various stages show these findings: Stage I (Minimal) : Findings restricted to only superficial lesions and possibly a few filmy
adhesions Adhesions are fibrous bands that form between tissues and organs, often as a result of injury during surgery. They may be thought of as internal scar tissue that connects tissues not normally connected. Pathophysiology Adhesions form as a natural ...
. Stage II (Mild) : In addition, some deep lesions are present in the cul-de-sac. Stage III (Moderate) : As above, plus the presence of endometriomas on the ovary and more adhesions. Stage IV (Severe) : As above, plus large endometriomas, extensive adhesions. Implants and adhesions may be found beyond the uterus. Large ovarian cysts are common.


Markers

An area of research is the search for endometriosis markers. In 2010, essentially all proposed biomarkers for endometriosis were of unclear medical use, although some appear to be promising. The one biomarker that has been in use over the last 20 years is
CA-125 Mucin-16 (MUC-16) also known as Ovarian cancer-related tumor marker CA125 is a protein that in humans is encoded by the ''MUC16'' gene. MUC-16 is a member of the mucin family glycoproteins. MUC-16 has found application as a tumor marker or biom ...
. A 2016 review found that this biomarker was present in those with symptoms of endometriosis; and, once
ovarian cancer Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different c ...
has been ruled out, a positive CA-125 may confirm the diagnosis. Its performance in ruling out endometriosis is low. CA-125 levels appear to fall during endometriosis treatment, but it has not shown a correlation with disease response. Another review in 2011 identified several putative biomarkers upon biopsy, including findings of small sensory nerve fibers or defectively expressed β3 integrin subunit. It has been postulated a future diagnostic tool for endometriosis will consist of a panel of several specific and sensitive biomarkers, including both substance concentrations and genetic predisposition. A 2016 review of endometrial biomarkers for diagnosing endometriosis was unable to draw conclusions due to the low quality of the evidence. MicroRNAs have the potential to be used in diagnostic and therapeutic decisions


Histopathology

For a histopathological diagnosis, at least two of the following three criteria should be present: * Endometrial type stroma * Endometrial
epithelium Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...
with glands * Evidence of chronic hemorrhage, mainly
hemosiderin Hemosiderin image of a kidney viewed under a microscope. The brown areas represent hemosiderin Hemosiderin or haemosiderin is an iron-storage complex that is composed of partially digested ferritin and lysosomes. The breakdown of heme gives rise ...
deposits Immunohistochemistry has been found to be useful in diagnosing endometriosis as stromal cells have a peculiar surface antigen, CD10, thus allowing the pathologist go straight to a staining area and hence confirm the presence of stromal cells and sometimes glandular tissue is thus identified that was missed on routine H&E staining. File:Endometriosis, abdominal wall.jpg, Endometriosis, abdominal wall File:Endometriosis of the ovary.jpg,
Micrograph A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a mic ...
showing endometriosis (right) and ovarian stroma (left) File:Endometrioma1.jpg,
Micrograph A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a mic ...
of the wall of an endometrioma. All features of endometriosis are present (endometrial glands, endometrial stroma and
hemosiderin Hemosiderin image of a kidney viewed under a microscope. The brown areas represent hemosiderin Hemosiderin or haemosiderin is an iron-storage complex that is composed of partially digested ferritin and lysosomes. The breakdown of heme gives rise ...
-laden
macrophage Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...
s).


Pain quantification

The most common pain scale for quantification of endometriosis-related pain is the visual analogue scale (VAS); VAS and numerical rating scale (NRS) were the best adapted pain scales for pain measurement in endometriosis. For research purposes, and for more detailed pain measurement in clinical practice, VAS or NRS for each type of typical pain related to endometriosis ( dysmenorrhea, deep dyspareunia and non-menstrual
chronic pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in inclu ...
), combined with the clinical global impression (CGI) and a quality of life scale, are used.


Prevention

Limited evidence indicates that the use of
combined oral contraceptives The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: proges ...
is associated with a reduced risk of endometriosis, as is regular exercise and the avoidance of alcohol and caffeine.


Management

While there is no cure for endometriosis, there are two types of interventions; treatment of pain and treatment of endometriosis-associated infertility. In many cases, menopause (natural or surgical) will abate the process. In the reproductive years, endometriosis is merely managed: the goal is to provide pain relief, to restrict progression of the process, and to restore or preserve fertility where needed. In younger individuals, some surgical treatment attempts to remove endometriotic tissue and preserve the ovaries without damaging normal tissue. Pharmacotherapy for pain management can be initiated based on the presence of symptoms and examination and ultrasound findings that rule out other potential causes. In general, the diagnosis of endometriosis is confirmed during surgery, at which time ablative steps can be taken. Further steps depend on circumstances: someone without infertility can manage symptoms with pain medication and hormonal medication that suppresses the natural cycle, while an infertile individual may be treated expectantly after surgery, with fertility medication, or with IVF. A 2020 Cochrane systematic review found that for all types of endometriosis, "it is uncertain whether laparoscopic surgery improves overrall pain compared to diagnostic laparoscopy".


Surgery

Surgery, if done, should generally be performed laparoscopically (through keyhole surgery) rather than open. Treatment consists of the ablation or excision of the endometriosis, electrocoagulation, lysis of
adhesions Adhesions are fibrous bands that form between tissues and organs, often as a result of injury during surgery. They may be thought of as internal scar tissue that connects tissues not normally connected. Pathophysiology Adhesions form as a natural ...
, resection of endometriomas, and restoration of normal pelvic anatomy as much as is possible. When laparoscopic surgery is used, small instruments are inserted through the incisions to remove the endometriosis tissue and adhesions. Because the incisions are very small, there will only be small scars on the skin after the procedure, and most individuals recover from surgery quickly and have a reduced risk of adhesions. Many endometriosis specialists believe that excision is the ideal surgical method to treat endometriosis. As for deep endometriosis, a segmental resection or shaving of nodules is effective but is associated with an important rate of complications which about 4,6% is major. Historically, a hysterectomy (removal of the uterus) was thought to be a cure for endometriosis in individuals who do not wish to conceive. Removal of the uterus may be beneficial as part of the treatment, if the uterus itself is affected by adenomyosis. However, this should only be done in combination with removal of the endometriosis by excision. If endometriosis is not also removed at the time of hysterectomy, pain may persist. Presacral neurectomy may be performed where the nerves to the uterus are cut. However, this technique is not usually used due to the high incidence of associated complications including presacral hematoma and irreversible problems with urination and constipation.


Recurrence

The underlying process that causes endometriosis may not cease after a surgical or medical intervention. A study has shown that dysmenorrhea recurs at a rate of 30 percent within a year following laparoscopic surgery. Resurgence of lesions tend to appear in the same location if the lesions were not completely removed during surgery. It has been shown that laser ablation resulted in higher and earlier recurrence rates when compared with endometrioma cystectomy; and recurrence after repetitive laparoscopy was similar to that after the first surgery. Endometriosis can come back after hysterectomy and bilateral salpingo-oophorectomy. It has 10% recurrent rate. Endometriosis recurrence following conservative surgery is estimated as 21.5% at 2 years and 40-50% at 5 years. Recurrence rate for DIE after surgery is less than 1%.


Risks and safety of pelvic surgery

Risk of developing complications following surgery depend on the type of the lesion that has undergone surgery. 55% to 100% of individuals develop Adhesion (medicine)#Pelvic adhesions, adhesions following pelvic surgery, which can result in infertility, chronic abdominal and pelvic pain, and difficult reoperative surgery. Trehan's temporary ovarian suspension, a technique in which the ovaries are suspended for a week after surgery, may be used to reduce the incidence of adhesions after endometriosis surgery. Removal of cysts on the ovary without removing the ovary is a safe procedure.


Hormonal medications

* Hormonal birth control therapy: Birth control pills reduce the menstrual pain and recurrence rate for endometrioma following conservative surgery for endometriosis. A 2018 Cochrane systematic review found that there is insufficient evidence to make a judgement on the effectiveness of the combined oral contraceptive pill compared with placebo or other medical treatment for managing pain associated with endometriosis partly because of lack of included studies for data analysis (only two for COCP vs placebo). * Progestogens: Progesterone (medication), Progesterone counteracts estrogen and inhibits the growth of the endometrium. Danazol (Danocrine) and gestrinone (Dimetrose, Nemestran) are suppressive steroids with some androgenic activity. Both agents inhibit the growth of endometriosis but their use has declined, due in part to masculinization, virilizing side effects such as hirsutism, excessive hair growth and voice changes. There is tentative evidence based on cohort studies that dienogest and norethisterone acetate (NETA) may help patients with DIE in terms of pain. There is tentative evidence based on a prospective study that vaginal danazol reduces pain in those affected by DIE. * Gonadotropin-releasing hormone modulator, Gonadotropin-releasing hormone (GnRH) modulators: These drugs include GnRH agonists such as leuprorelin (Lupron) and GnRH antagonists such as elagolix (Orilissa) and are thought to work by decreasing estrogen levels. A 2010 Cochrane review found that GnRH modulators were more effective for pain relief in endometriosis than no treatment or placebo, but were not more effective than danazol or intrauterine progestogen, and had more side effects than danazol. A 2018 Swedish systematic review found that GnRH modulators had similar pain-relieving effects to gestagen, but also decreased bone density. * Aromatase inhibitors are medications that block the formation of estrogen and have become of interest for researchers who are treating endometriosis. Examples of aromatase inhibitors include anastrozole and letrozole. Evidence for aromatase inhibitors is confirmed by numerous controlled studies that show benefit in terms of pain control and quality of life when used in combination with gestagens or oral contraceptives with less side-effects when used in combination with oral contraceptives like norethisterone acetate. Despite multiple benefits, there are lot of things to consider before using AIs for endometriosis, as it is common for them to induce functional cysts as an adverse effects. Moreover, dosages, treatment length, appropriate add-back therapies and mode of administration is still being investigated. * Progesterone receptor modulators like mifepristone and gestrinone have the potential (based on only one RCT each) to be used as a treatment to manage pain caused by endometriosis.


Other Medicines

* Melatonin, there is tentative evidence for its use (at a dose of 10 mg) in reducing pain related to endometriosis. * Opioids: Morphine sulphate tablets and other opioid painkillers work by mimicking the action of naturally occurring pain-reducing chemicals called "endorphins". There are different long acting and short acting medications that can be used alone or in combination to provide appropriate pain control. * Chinese herbal medicine was reported to have comparable benefits to gestrinone and danazol in patients who had had laparoscopic surgery, though the review notes that the two trials were small and of "poor methodological quality" and results should be "interpreted cautiously" as better quality research is needed. * Serrapeptase, a Digestive enzyme found in the intestines of silkworms. Serrapeptase is widely used in Japan and Europe as an anti-inflammatory treatment. More research is needed but serrapeptase may be used by endometriosis patients to reduce inflammation. * Angiogenesis inhibitors lack clinical evidence of efficacy in endometriosis therapy. Under experimental ''in vitro'' and ''in vivo'' conditions, compounds that have been shown to exert inhibitory effects on endometriotic lesions include growth factor inhibitors, endogenous angiogenesis inhibitors, fumagillin analogues, statins, cyclo-oxygenase-2 inhibitors, phytochemical compounds, immunomodulators, dopamine agonists, peroxisome proliferator-activated receptor agonists, progestins, danazol and gonadotropin-releasing hormone agonists. However, many of these agents are associated with undesirable side effects and more research is necessary. An ideal therapy would diminish inflammation and underlying symptoms without being contraceptive. * Pentoxifylline, an immunomodulating agent, has been theorized to improve pain as well as improve pregnancy rates in individuals with endometriosis.There is not enough evidence to support the effectiveness or safety of either of these uses. Current American Congress of Obstetricians and Gynecologists (ACOG) guidelines do not include immunomodulators, such as pentoxifylline, in standard treatment protocols. * NSAIDs are anti-inflammatory medications commonly used for endometriosis patients despite unproven efficacy and unintended adverse effects. * Neuromodulators like gabapentin did not prove to be superior to placebo in managing pain caused by endometriosis. The overall effectiveness of manual physical therapy to treat endometriosis has not yet been identified.


Comparison of interventions

A 2021 meta-analysis found that GnRH analogues and combined hormonal contraceptives were the best treatment for reducing dyspareunia, menstrual and non menstrual pelvic pain. A 2018 Swedish systematic review found a large number of studies but a general lack of scientific evidence for most treatments. There was only one study of sufficient quality and relevance comparing the effect of surgery and non-surgery. Cohort studies indicate that surgery is effective in decreasing pain. Most complications occurred in cases of low intestinal anastomosis, while risk of fistula occurred in cases of combined abdominal or vaginal surgery, and urinary tract problems were common in intestinal surgery. The evidence was found to be insufficient regarding surgical intervention. The advantages of physical therapy techniques are decreased cost, absence of major side-effects, it does not interfere with fertility, and near-universal increase of sexual function. Disadvantages are that there are no large or long-term studies of its use for treating pain or infertility related to endometriosis.


Treatment of infertility

Surgery is more effective than medicinal intervention for addressing infertility associated with endometriosis. Surgery attempts to remove endometrium-like tissue and preserve the ovaries without damaging normal tissue. Receiving hormonal suppression therapy after surgery might be positive regarding endometriosis recurrence and pregnancy. In-vitro fertilization (IVF) procedures are effective in improving fertility in many individuals with endometriosis. During fertility treatment, the ultralong pretreatment with GnRH-agonist has a higher chance of resulting in pregnancy for individuals with endometriosis, compared to the short pretreatment.


Research

Preliminary research on mouse models showed that monoclonal antibodies, as well as inhibitors of MyD88 downstream signaling pathway, can reduce lesion volume. Thanks to that, clinical trials are being done on using a monoclonal antibody directed against IL-33 and using anakinra, an IL-1 receptor antagonist. Promising preclinical outcomes is pushing clinical trials into testing cannabinoid extracts, dichloroacetic acid and curcuma capsules.


Epidemiology

Determining how many people have endometriosis is challenging because definitive diagnosis requires surgical visualization through laparoscopic surgery. Criteria that are commonly used to establish a diagnosis include pelvic pain, infertility, surgical assessment, and in some cases, magnetic resonance imaging. An ultrasound can identify large clumps of tissue as potential endometriosis lesions and ovarian cysts but it is not effective for all patients, especially in cases with smaller, superficial lesions. These studies suggest that endometriosis affects approximately 11% of women in the general population. Endometriosis is most common in those in their thirties and forties; however, it can begin as early as 8 years old. Endometriosis is estimated to affect over 190 million women in their reproductive years. It chiefly affects adults from menarche, premenarche to menopause, postmenopause, regardless of race or ethnicity or whether or not they have had children. It is primarily a disease of the reproductive years. Incidences of endometriosis have occurred in postmenopausal individuals, and in less common cases, individuals may have had endometriosis symptoms before they even reach menarche. The rate of recurrence of endometriosis is estimated to be 40-50% for adults over a 5-year period. The rate of recurrence has been shown to increase with time from surgery and is not associated with the stage of the disease, initial site, surgical method used, or post-surgical treatment.


History

Endometriosis was first discovered microscopically by Carl von Rokitansky, Karl von Rokitansky in 1860, although the earliest antecedents may have stemmed from concepts published almost 4,000 years ago. The Hippocratic Corpus outlines symptoms similar to endometriosis, including uterine ulcers, adhesions, and infertility. Historically, women with these symptoms were treated with leeches, straitjackets, bloodletting, chemical douches, Female genital mutilation, genital mutilation, pregnancy (as a form of treatment), hanging upside down, surgical intervention, and even killing due to suspicion of demonic possession. Hippocratic doctors recognized and treated chronic pelvic pain as a true organic disorder 2,500 years ago, but during the Middle Ages, there was a shift into believing that women with pelvic pain were mad, immoral, imagining the pain, or simply misbehaving. The symptoms of inexplicable chronic pelvic pain were often attributed to imagined madness, female weakness, promiscuity, or hysteria. The historical diagnosis of hysteria, which was thought to be a psychological disease, may have indeed been endometriosis. The idea that chronic pelvic pain was related to mental illness influenced modern attitudes regarding individuals with endometriosis, leading to delays in correct diagnosis and indifference to the patients' true pain throughout the 20th and into the 21st century. Hippocratic doctors believed that delaying childbearing could trigger diseases of the uterus, which caused endometriosis-like symptoms. Women with dysmenorrhea were encouraged to marry and have children at a young age. The fact that Hippocratics were recommending changes in marriage practices due to an endometriosis-like illness implies that this disease was likely common, with rates higher than the 5-15% prevalence that is often cited today. If indeed this disorder was so common historically, this may point away from modern theories that suggest links between endometriosis and dioxins, PCBs, and chemicals. The early treatment of endometriosis was surgery, surgical and included oophorectomy (removal of the ovaries) and hysterectomy (removal of the uterus). In the 1940s, the only available hormonal therapies for endometriosis were high-dose testosterone (medication), testosterone and high-dose estrogen therapy. High-dose estrogen therapy with diethylstilbestrol for endometriosis was first reported by Karnaky in 1948 and was the main medication, pharmacological treatment for the condition in the early 1950s. Pseudopregnancy (high-dose estrogen–progestogen therapy) for endometriosis was first described by Kistner in the late 1950s. Pseudopregnancy as well as progestogen (medication), progestogen monotherapy dominated the treatment of endometriosis in the 1960s and 1970s. These agents, although efficacious, were associated with intolerable side effects. Danazol was first described for endometriosis in 1971 and became the main therapy in the 1970s and 1980s. In the 1980s GnRH agonists gained prominence for the treatment of endometriosis and by the 1990s had become the most widely used therapy. Oral GnRH antagonists such as elagolix were introduced for the treatment of endometriosis in 2018.


Society and culture


Public figures

A number of public figures have spoken about their experience with endometriosis, including: * Halsey (singer), Halsey * Emma Bunton * Whoopi Goldberg * Mel Greig * Abby Finkenauer * Julianne Hough * Bridget Hustwaite * Padma Lakshmi * Dolly Parton * Daisy Ridley * Emma Roberts * Kirsten Storms * Chrissy Teigen * Emma Watkins * Danielle Collins * Emma Barnett *Jennifer Boyce - bass player of Ball Park Music


Economic burden

The economic burden of endometriosis is widespread and multifaceted. Endometriosis is a chronic disease that has direct and indirect costs which include loss of work days, direct costs of treatment, symptom management, and treatment of other associated conditions such as depression or chronic pain. One factor which seems to be associated with especially high costs is the delay between onset of symptoms and diagnosis. Costs vary greatly between countries. Two factors that contribute to the economic burden include healthcare costs and losses in productivity. A Swedish study of 400 endometriosis patients found "Absence from work was reported by 32% of the women, while 36% reported reduced time at work because of endometriosis". An additional cross sectional study with Puerto Rican women, "found that endometriosis-related and coexisting symptoms disrupted all aspects of women's daily lives, including physical limitations that affected doing household chores and paid employment. The majority of women (85%) experienced a decrease in the quality of their work; 20% reported being unable to work because of pain, and over two-thirds of the sample continued to work despite their pain."


Medical culture

There are a number of barriers that those affected face to receiving diagnosis and treatment for endometriosis. Some of these include outdated standards for laparoscopic evaluation, stigma about discussing menstruation and sex, lack of understanding of the disease, primary care physicians lack of knowledge, and assumptions about typical menstrual pain. On average, those later diagnosed with endometriosis waited 2.3 years after the onset of symptoms before seeking treatment and nearly three quarters of women receive a misdiagnosis prior to endometriosis. Self-help groups say practitioners delay making the diagnosis, often because they do not consider it a possibility. There is a typical delay of 7–12 years from symptom onset in affected individuals to professional diagnosis. There is a general lack of knowledge about endometriosis among primary care physicians. Half of general health care providers surveyed in a 2013 study were unable to name three symptoms of endometriosis. Health care providers are also likely to dismiss described symptoms as normal menstruation. Younger patients may also feel uncomfortable discussing symptoms with a physician.


Race and ethnicity

Race and ethnicity may play a role in how endometriosis affects one's life. Endometriosis is less thoroughly studied among Black people, and the research that has been done is outdated. Black people with endometriosis may face barriers in receiving care due to misconceptions about how Black people feel pain. Since pain is the primary symptom of endometriosis, this makes it increasingly possible for doctors to dismiss pain symptoms when their patient is Black. An inaccurate diagnosis is also more likely since Black women are at a higher risk for other related conditions such as uterine fibroids. Cultural differences among ethnic groups also contribute to attitudes toward and treatment of endometriosis, especially in Hispanic or Latino communities. A study done in Puerto Rico in 2020 found that health care and interactions with friends and family related to discussing endometriosis were affected by stigma. The most common finding was a referral to those expressing pain related to endometriosis as "changuería" or "changas", terms used in Puerto Rico to describe pointless whining and complaining, often directed at children.


References


External links

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Endometriosis fact sheet
from womenshealth.gov
Fact Sheet Endometriosis Fact Sheet
from the World Health Organization {{Authority control Noninflammatory disorders of female genital tract Menstrual cycle Wikipedia medicine articles ready to translate