Endometriosis definition and facts
Endometriosis is the abnormal growth of cells (endometrial cells) similar to those that form the inside of the uterus, but in a location outside of the uterus. Endometriosis is most commonly found on other organs of the pelvis.
The exact cause of endometriosis has not been identified. Endometriosis is more common in women who are experiencing infertility than in fertile women, but the condition does not necessarily cause infertility.
Most women with endometriosis have no symptoms. However, when women do experience signs and symptoms of endometriosis they may include:
- Pelvic pain that may worsen during menstruation
- Painful intercourse
- Painful bowel movements or urination
- Pelvic pain during menstruation or ovulation can be a symptom of endometriosis, but may also occur in normal women.
Endometriosis can be suspected based on the woman’s pattern of symptoms, and sometimes during a physical examination, but the definite diagnosis is usually confirmed by surgery, most commonly by laparoscopy.
Treatment of endometriosis includes medication and surgery for both pain relief and treatment of infertility if pregnancy is desired.
What is endometriosis?
Endometriosis is the abnormal growth of endometrial tissue similar to that which lines the interior of the uterus, but in a location outside of the uterus. Endometrial tissue is shed each month during menstruation. Areas of endometrial tissue found in ectopic locations are called endometrial implants. These lesions are most commonly found on the ovaries, the Fallopian tubes, the surface of the uterus, the bowel, and on the membrane lining of the pelvic cavity (i.e. the peritoneum). They are less commonly found to involve the vagina, cervix, and bladder. Rarely, endometriosis can occur outside the pelvis. Endometriosis has been reported in the liver, brain, lung, and old surgical scars. Endometrial implants, while they may become problematic, are usually benign (i.e. non-cancerous).
What are the stages of endometriosis?
Endometriosis is classified into one of four stages (I-minimal, II-mild, III-moderate, and IV-severe) based upon the exact location, extent, and depth of the endometriosis implants as well as the presence and severity of scar tissue and the presence and size of endometrial implants in the ovaries. Most cases of endometriosis are classified as minimal or mild, which means there are superficial implants and mild scarring. Moderate and severe endometriosis typically result in cysts and more severe scarring. The stage of endometriosis is not related to the degree of symptoms a woman experiences, but infertility is common with stage IV endometriosis.
Endometriosis can be associated with severe pain and fertility problems. About 30% to 40% of women with endometriosis have some trouble conceiving. The reason for this is not well understood, and scarring of the reproductive tract, or hormonal factors may be involved. Over time endometrial implants may grow, or cysts may result because of endometriosis, which also may cause fertility problems.
What are the signs and symptoms endometriosis?
Most women who have endometriosis, in fact, do not have symptoms. Of those who do, the most common include:
- Pain (usually pelvic) that usually occurs just before menstruation and lessens after menstruation
- Painful sexual intercourse
- Cramping during intercourse
- Cramping or pain during bowel movements or urination
- Pain with pelvic examinations
The intensity of the pain can vary from month to month, and can vary greatly among affected individuals. Some women experience progressive worsening of symptoms, while others can have resolution of pain without treatment.
Pelvic pain in women with endometriosis depends partly on where endometrial implants of endometriosis are located.
- Deeper implants and implants in areas of high nerve density are more apt to produce pain.
- The implants may also release substances into the bloodstream which are capable of eliciting pain.
- Pain can result when endometriotic implants incite scarring of surrounding tissues. There appears to be no relationship between severity of pain and the amount of anatomical disease which is present.
Endometriosis can be one of the reasons for infertility for otherwise healthy couples. When laparoscopic examinations are performed during evaluations for infertility, implants are often found in individuals who are totally asymptomatic. The reasons diminished fertility in many patients with endometriosis are not understood. Endometriosis may incite scar tissue formation within the pelvis. If the ovaries and Fallopian tubes are involved, the mechanical processes involved in the transfer of fertilized eggs into the tubes may be altered. Alternatively, the endometriotic lesions may produce inflammatory substances which adversely affect ovulation, fertilization, and implantation.
Other symptoms that can be related to endometriosis include
lo* wer abdominal pain,
- diarrhea and/or constipation,
- low back pain,
- chronic fatigue
- irregular or heavy menstruation,
- painful urination, or
- bloody urine (particularly during menstruation).
Rare symptoms of endometriosis include chest pain or coughing blood due to endometriosis in the lungs and headache and/or seizures due to endometriosis in the brain.
Does endometriosis increase a woman’s risk of getting cancer?
Some studies have postulated that women with endometriosis have an increased risk for development of certain types of ovarian cancer, known as epithelial ovarian cancer (EOC). This risk is highest in women with both endometriosis and primary infertility (those who have never conceived a pregnancy). The use of combination oral contraceptive pills (OCPs), which are sometimes used in the treatment of endometriosis, appears to significantly reduce this risk.
The reasons for the association between endometriosis and ovarian epithelial cancer are not clearly understood. One theory is that the endometriosis implants themselves undergo malignant transformation to cancer. Another possibility is that the presence of endometriosis may be related to other genetic or environmental factors that serve to increase a women’s risk of developing ovarian cancer.
What causes endometriosis?
The cause of endometriosis is unknown. One theory is that the endometrial tissue is deposited in unusual locations by the retrograde flow of menstrual debris through the Fallopian tubes into the pelvic and abdominal cavities. The cause of this retrograde menstruation is not clearly understood. It is clear that retrograde menstruation is not the only cause of endometriosis, as many women who have retrograde menstruation do not develop the condition.
Another possibility is that areas lining the pelvic organs possess primitive cells that are able to develop into other forms of tissue, such as endometrium. (This process is termed coelomic metaplasia.)
It is also likely the direct transfer of endometrial tissues at the time of surgery may be responsible for the endometriosis implants occasionally found in surgical scars (for example, episiotomy or Cesarean section scars). Transfer of endometrial cells via the bloodstream or lymphatic system is the most plausible explanation for the rare cases of endometriosis that are found in the brain and other organs remote from the pelvis.
Finally, there is evidence that some women with endometriosis have an altered immune response in women with endometriosis, which may affect the body’s natural ability to recognize ectopic endometrial tissue.
Does endometriosis cause infertility?
Endometriosis is more common in infertile women, as opposed to those who have conceived a pregnancy. However, many women with confirmed endometriosis are able to conceive without difficulty, particularly if the disease is mild or moderate. It is estimated that up to 70% of women with mild or moderate endometriosis will conceive within three years without any specific treatment.
The reasons for a decrease in fertility when endometriosis is present are not completely understood. It is likely that both anatomical and hormonal factors are contributory to diminished fertility. The presence of endometriosis may incite significant scar (adhesion) formation within the pelvis which can distort normal anatomical structures. Alternatively, endometriosis may affect fertility through the production of inflammatory substances that have a negative effect on ovulation, fertilization of the egg, and/or implantation of the embryo. Infertility associated with endometriosis is more common in women with anatomically severe forms of the disease.
Does diet affect endometriosis?
There are no well-established data that show that dietary modifications can either prevent or reduce the symptoms of endometriosis. One study showed that a high consumption of green vegetables and fruit was associated with a lower risk of developing endometriosis, while a higher intake of red meats was associated with a higher risk. No association was seen with alcohol, milk, or coffee consumption. Further studies are needed to determine whether diet plays a role in the development of endometriosis.
Is there a test to diagnose endometriosis?
Endometriosis is most commonly treated by obstetrician-gynecologists (OB-GYNs).
Endometriosis can be suspected based on symptoms of pelvic pain and findings during physical examinations. Occasionally, during a rectovaginal exam (one finger in the vagina and one finger in the rectum), the doctor can feel nodules (endometrial implants) behind the uterus and along the ligaments that attach to the pelvic wall. At other times, no nodules are felt, but the examination itself causes unusual pain or discomfort.
Unfortunately, neither the symptoms nor the physical examinations can be relied upon to conclusively establish the diagnosis of endometriosis. Imaging studies, such as ultrasound, can be helpful in ruling out other pelvic diseases and may suggest the presence of endometriosis in the vaginal and bladder areas, but they cannot reliably diagnose endometriosis. For an accurate diagnosis, a direct visual inspection inside of the pelvis and abdomen, as well as tissue biopsy of the implants are necessary.
As a result, the only definitive method for diagnosing endometriosis is surgical. This requires either laparoscopy or laparotomy (opening the abdomen using a large incision).
Laparoscopy is the most common surgical procedure most commonly employees used for the diagnosis of endometriosis. This is a minor surgical procedure performed under general anesthesia, or in some cases under local anesthesia. It is usually performed as an out-patient procedure (the patient does not stay in the facility overnight). Laparoscopy is performed by first inflating the abdominal cavity with carbon dioxide through a small incision in the navel. A thin, tubular viewing instrument (laparoscope) is then inserted into the inflated abdominal cavity to inspect the abdomen and pelvis. Endometrial implants can then be directly seen.
During laparoscopy, biopsies (removal of tiny tissue samples for examination under a microscope) can also be performed in order to obtain a tissue diagnosis. Sometimes random biopsies obtained during laparoscopy will show microscopic endometriosis, even though no implants are visualized.
Pelvic ultrasound and laparoscopy are also important in excluding malignancies (such as ovarian cancer) which can cause many of the same symptoms that mimic endometriosis symptoms.