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Ectopic Endometrium

What is Endometriosis?

Endometriosis occurs when tissue of the uterine lining (endometrium) grows in areas outside the uterus. Endometrial tissue consists of glands, blood cells and connecting tissue called stromal cells.

During a woman's monthly cycle, the endometrium responds to changing levels of the hormones estrogen and progesterone. The endometrium thickens to prepare for possible pregnancy. If a woman becomes pregnant, the endometrium provides a place for the fertilized egg to implant in the uterus and develop. If a woman does not become pregnant, the endometrium breaks down and is shed during the menstrual period.

In cases of endometriosis, endometrial tissue grows in other areas of the body. The tissue responds to the woman's monthly hormonal changes, whether it is in the uterus or located elsewhere. The displaced tissue of endometriosis (called endometrial implants or lesions) grows and expands as it would in the uterus. But it cannot leave the body the way the uterine tissue does during menstruation. As a result, the implants can bleed into other areas or inflame other organs and form scar tissue or adhesions.

Endometrial implants usually occur in the pelvic region, including the:

  • Ovaries
  • Fallopian tubes
  • Peritoneum (the lining of the pelvic cavity)
  • Outside of the uterus and on its ligaments
  • Lymph nodes
Many women with endometriosis have lesions in more than one location. Endometriosis sometimes occurs in other parts of the abdomen, such as the rectum and bladder. In rare cases, endometrial tissue is discovered in other body parts such as the arms, legs or lungs.

Endometrial growths begin microscopically small, often as clear lesions. With time, they become larger and darker and can take many shapes. The colors vary, ranging from red, brown or black to clear, white, yellow or pink. The prevailing color may depend on the blood supply, age of the lesion and other nearby tissue. Some endometrial lesions look like other scars or inflammations and may need an experienced physician to recognize them as endometriosis.

The endometrial implants adhere to organs and can affect their function. For example, lesions growing on the ovary or fallopian tube may stick the ovary to the pelvic wall and block the movement of an egg.

More than half of endometriosis cases involve implants that grow within the ovaries, called endometriomas. These endometriomas can fill with blood and other fluids and become darker as they age. The endometriomas are sometimes called endometrial cysts, blood cysts or chocolate cysts for their dark color. They are unrelated to cancers of the ovary.

Endometriosis usually occurs during a woman's years of menstruation. The condition is very rarely seen before a girl's first menstrual period (menarche). It is most commonly diagnosed among women in their late 20s, but women may have the condition for years prior to diagnosis.

Many women discover that they have endometriosis only when they seek treatment for infertility. For other women, severe pain causes them to seek treatment. At menopause, the growths can shrink and symptoms lessen in many cases. However, if a menopausal woman uses hormone replacement therapy, which mimics the menstrual hormone cycle, she may continue to experience endometriosis symptoms.

For some women, the pain associated with endometriosis is debilitating and it may worsen over time. The damage to reproductive organs caused by endometriosis is a major cause of infertility among women. It is also largely responsible for hysterectomies and oophorectomies (ovariectomies) performed on premenopausal women. Many women experience recurring symptoms even after extensive medical or surgical treatments for endometriosis.

More than 5.5 million women in the United States have endometriosis, which is about 10 to 15 percent of all women in their reproductive years, according to the National Institutes of Health (NIH). However, the exact incidence of the condition is unknown because women without symptoms or fertility problems may have endometriosis but never seek diagnosis or treatment.

How is it diagnosed?

Endometriosis signs and symptoms

The following symptoms may begin abruptly or develop over many years:

  • Increased pelvic pain during menstrual periods, especially the last days, or the pelvic pain may occur at anytime.
  • Pain with sexual intercourse.
  • Premenstrual spotting.
  • Blood in the urine; blood in the stool (sometimes).
  • Back pain; pain with intestinal contractions
  • Infertility.

A physician, often a gynecologist (GYN), will begin by taking a complete medical history and perform a physical examination, including a pelvic examination, to diagnose endometriosis. During the pelvic exam, the GYN may be able to detect masses on the ovaries or uterus. These may be endometrial cysts or implants, or may be related to other conditions. Physicians may also determine that a patient experiences pain when pelvic organs are moved. This can occur when there are a number of adhesions. In some cases, the uterus may become tilted back because of adhesions from the implants. Endometriosis can only be diagnosed by seeing the implants, which requires a surgical procedure, usually laparoscopy.

During this procedure, an incision is made in the abdomen and a small lighted viewing device is inserted into the pelvis. The surgeon can look for endometrial implants and possibly remove them at the same time by excising (cutting) them or burning them off with a laser or cautery (a heating device). Laparoscopy is the more common and less invasive method of diagnosis. An open abdominal surgery called a laparotomy may also diagnose endometriosis, but is less common in the United States. Surgeons can also remove lesions during a diagnostic laparotomy.

After laparoscopy, the physician can determine the stage of endometriosis. A system designed by the American Society for Reproductive Medicine (ASRM) helps classify the severity of the condition. However, the stages may not correspond to a woman's level of pain. The stages are:

  • Stage I. Minimal lesions. Isolated superficial implants.
  • Stage II. Mild lesions. Several small implants and a few adhesions.
  • Stage III. Moderate lesions. Superficial and deep implants with prominent adhesions.
  • Stage IV. Severe lesions. Multiple superficial and deep implants, large endometriomas and prominent adhesions.
In addition, imaging tests may be used to rule out conditions that share similar symptoms. These tests can indicate severe cases of endometriosis, but do not provide a definitive diagnosis. For instance, imaging studies (e.g., ultrasound, CAT scan, MRI) of the pelvic region can identify certain endometrial implants or cysts, but not all.

How is Endometriosis treated?

Goals for endometriosis treatment include alleviating pain, minimizing organ damage and preserving a woman's fertility (if desired). Treatment is very individualized and depends on a woman's age, the severity of her symptoms and her plans for future pregnancy. Pain is the most common reason women seek treatment for endometriosis.

Women with mild or no symptoms who do not want to become pregnant may choose no treatment. Women who want children may be encouraged to try to become pregnant sooner rather than later because the negative effects of endometriosis on infertility may increase with age. In addition, it was formerly thought that pregnancy can reduce the condition's symptoms. However, recent studies indicate that pregnancy does not alleviate symptoms and symptoms may return after pregnancy for many women.

Studies have not proven the best method for treating pelvic pain, but medical treatment options for endometriosis include:

Pain medication (analgesics)

Over-the-counter anti-inflammatory medications can provide relief for mild to moderate pain. However, they cannot change or remove any endometrial implants. Physicians may prescribe narcotic painkillers for severe endometriosis pain. These medications are used to alleviate symptoms, but do not have an impact on the underlying condition.

Birth control pills

Endometrial lesions respond to hormones, including the estrogen and progestin usually found in birth control pills or patches. Therefore, these medications may lessen the severity of symptoms. Symptoms may return when a woman stops taking the medication because it does not have an impact on the underlying condition (scarring and adhesions). Birth control pills may have side effects, including nausea and mild weight gain.

Other hormonal treatments

Hormone therapy can produce the same effects as menopause or pregnancy. The goal is to stop menstruation, which can take several months. Hormonal treatments may minimize endometrial symptoms and shrink implants, but will not affect any scarring or adhesions that have already formed. They are rarely effective in women with severe endometriosis. Hormonal treatments include:
  • Progesterone. A synthetic form of progestin that may be taken as pills or injections. It may control symptoms by reducing or stopping menstruation and stopping ovulation. Side effects include weight gain and mood changes. Progesterone is administered as a daily pill or in periodic shots. Progesterone may not be recommended for a woman who wants to become pregnant. Return of ovulation may be delayed after progesterone therapy has stopped. Ovulation may take up to a year to return after progesterone injections.
  • GnRH agonists. These are synthetic drugs similar to the natural gonadotrophin releasing hormone (GnRH), which induce a chemical menopause. They are administered as a nasal spray or an injection. GnRH agonists are usually prescribed for only six months because they increase the risk of bone loss that may lead to osteoporosis. Side effects are similar to symptoms of menopause, including hot flashes, vaginal dryness, loss of bone density and insomnia. Most women with severe cases of endometriosis who are treated with GnRH agonists will experience recurrent pain after discontinuing use.
  • Synthetic androgens. Medications (such as danazol) that are similar to male hormones (androgens) affect the production of female hormones and stop menstruation. These hormones are taken as pills for six to nine months. Some side effects include acne, weight gain and hirsutism (growth of facial or body hair). Some of these side effects may not reverse after the medication is discontinued. Androgens should not be taken by women with certain types of liver, kidney or heart disease because it can worsen those conditions.

All these hormonal treatments can affect an embryo and women must take steps to avoid pregnancy during the treatments. Because birth control pills may not be used in combination with the other hormonal treatments, a woman should use another method of contraception (e.g., condoms) with any of these treatments. When the treatments are complete and menstruation returns, a woman may attempt to become pregnant. Patients may experience a recurrence of endometriosis symptoms after hormonal treatments stop.

Physicians consider surgery for endometriosis when there are advanced adhesions and scarring or when medical therapy has not alleviated symptoms, such as severe pain. There are several surgical options for endometriosis:

Conservative surgery

Involves removing the endometrial implants while maintaining the reproductive organs. This is the preferred surgical treatment for endometriosis. The patient is sedated with anesthesia and a surgeon performs a laparoscopy or laparotomy to remove the implants by heat, laser or excision (cutting them out). Excision is the preferred method because it allows the lesions to be examined in a biopsy. Surgeons can also correct the position of any organs (e.g., ovaries) that may have become displaced because of the adhesions.

Adhesions around the organs can be cut, and at times blocked fallopian tubes can be repaired. These procedures may involve removing one ovary, but no other organs, so a woman may still be able to have children. Many women are able to become pregnant after conservative surgery, depending on the severity of the endometriosis before the surgery. Damage to the inside of the fallopian tube from endometriosis can result in a woman requiring in vitro fertilization (IVF) to become pregnant. Symptoms may still recur after surgery and some women have repeated laparoscopies or laparotomies.

Laparoscopic uterosacral nerve ablation (LUNA)

This procedure involves cutting a nerve between the uterus and the ligaments that hold it in place. It may help women with a specific type of pain, but studies show that many women experience no pain relief. Any severing of nerves is permanent and cannot be reversed.


This procedure removes a woman's uterus. For endometriosis, surgeons also remove the ovaries and fallopian tubes (bilateral salpingo-oophorectomy) and any implants or adhesions. Hysterectomy usually ends the endometriosis symptoms, but also ends the possibility of childbearing. It is considered a treatment of last resort. After removal of the ovaries, a woman begins menopause because her body no longer produces estrogen. Although the surgery may alleviate the endometriosis symptoms, the surgical menopause will create other symptoms such as hot flashes, weight gain and vaginal dryness. Surgical menopause caused by hysterectomy may cause more severe symptoms than those from natural menopause. After a hysterectomy, a woman will usually be prescribed estrogen replacement therapy.
With all endometriosis treatments, the condition may recur and the pain may return, although it is uncommon after hysterectomy. Some women are able to get pregnant naturally after conservative surgical treatment for endometriosis. Others are able to become pregnant using assisted reproductive technology (ART). An obstetrician can best discuss fertility options with a patient and her partner.

There is no cure for endometriosis. A woman may consult with her physician to determine the best course of treatment for the disease, its symptoms and her fertility. Cost of treatment may be a consideration. Some hormone therapies such as GnRH agonists are extremely expensive, as are repeated surgeries.

There are no known methods to prevent endometriosis. The disease usually continues unless it is interrupted by pregnancy or treated with some form of therapy. It can recur with all treatments, though some are more effective than others. At menopause, the symptoms may lessen in many women. The effect of hormone replacement therapy in women with endometriosis who reach natural menopause is unknown.


  • You may use non-prescription drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), to relieve minor pain.
  • Stronger pain relievers may be prescribed.
  • Oral contraceptives, progestrogens, danazol and gonadotropin-releasing hormones (Gn-RH) are commonly used drugs for treating endometriosis by suppressing ovarian function.

Motrin (Ibuprofen), Soma (Carisoprodol),Danazol tablets, Femara (Letrozole), Apri (Desogestrel), Alesse (Levonorgestrel), Arimidex (Anastrozole), Aygestin (Norethindrone), Ovral (Norgestrel)


  • Exercise, such as walking, helps in relieving pain and reduces estrogen levels that may slow the growth of endometriosis.
  • Some activity restrictions may apply following surgical therapies.


Avoid caffeine because it seems to aggravate pain in some women.

What might complicate it?

Scar tissue (adhesions) can form, causing intestinal obstruction. Growths on or near the bladder can interfere with urinary function. Blood trapped inside the ovary can build up, causing a non-cancerous tumor (endometrioma). The disease can result in infertility. Recurring chronic pain or infertility may lead to depression and emotional issues. Side effects are frequent with hormonal treatment.

Predicted outcome

Most women are able to obtain significant relief from pain and remain able to bear children. Current treatment offers relief from symptoms but not a cure. Endometriosis may even recur following surgery. The course of endometriosis in any individual cannot be predicted.


Other possibilities include pelvic inflammatory disease, ovarian cysts or cancer, dysmenorrhea, a pelvic tumor, urinary tract infection, ectopic pregnancy, functional bowel disease, diverticulitis, and chronic appendicitis.

Appropriate specialists

Gynecologist and general surgeon.

Notify your physician if

  • You or a family member has symptoms of endometriosis.
  • The following occur during treatment:
    • Intolerable pain.
    • Unusual or excessive vaginal bleeding.
  • New, unexplained symptoms develop. Drugs used in treatment may produce side effects.
  • Symptoms recur after treatment.

Last updated 2 July 2015