eMedicine Specialties > Emergency Medicine > Obstetrics & Gynecology

Endometriosis

Author: Turandot Saul, MD, Staff Physician, Department of Emergency Medicine, Bellevue Hospital Center/New York University Medical Center
Coauthor(s): Ami K Davé, MD, Assistant Professor, Department of Emergency Medicine, New York University School of Medicine; Assistant Residency Director, Department of Emergency Medicine, New York University/Bellevue Hospital Center
Contributor Information and Disclosures

Updated: Feb 14, 2008

Introduction

Background

Endometriosis is the presence of endometrial-like tissue outside the uterine cavity, which induces a chronic inflammatory reaction. It can occur in various pelvic sites such as on the ovaries, fallopian tubes, vagina, cervix, or uterosacral ligaments or in the rectovaginal septum. It can also occur in distant sites including laparotomy scars, pleura, lung, diaphragm, kidney, spleen, gallbladder, nasal mucosa, spinal canal, stomach, and breast.

This condition is often associated with pelvic pain and infertility, but it is most often asymptomatic. It is a frequently encountered gynecologic disorder in the emergency department (ED) as well as in the outpatient setting. Because it is enigmatic, endometriosis can present as a diagnostic and therapeutic challenge for emergency physicians in their approach to the female patient with pelvic pain.

Pathophysiology

Previous theories suggest that endometriosis results from the transport of viable endometrial cells through retrograde menstruation. Cells flow backwards through the fallopian tubes and deposit on the pelvic organs where they seed and grow. A population of cells reside in the endometrium, which retain stem cell properties. It may be these properties that allow these cells to survive in ectopic locations.

Retrograde menstruation is a common physiologic event. Diagnostic laparoscopy during the perimenstrual period has shown that as many as 90% of women with patent fallopian tubes have bloody peritoneal fluid. Since most women do not have endometriosis, perhaps immunologic or hormonal dysfunction leaves some women predisposed.

Recent research has suggested involvement of the immune system in the pathogenesis of endometriosis. Women with this disorder appear to exhibit increased humoral immune responsiveness and macrophage activation while showing diminished cell-mediated immunity with decreased T-cell and natural killer cell responsiveness.

Transtubal dissemination is the most common route, although other routes have been observed. These include lymphatic and vascular channels. This may explain how endometrial tissue can be found at distant locations in the body.

Metaplasia, or the changing from one normal type of tissue to another normal type of tissue, is another theory. The endometrium and the peritoneum are derivatives of the same coelomic wall epithelium. Peritoneal mesothelium has been postulated to retain its embryologic ability to transform into reproductive tissue. Such transformation may occur spontaneously, or it may be facilitated by exposure to chronic irritation by retrograde menstrual fluid.

Another theory states that remnant mullerian cells may remain in the pelvic tissues during development of the mullerian system. Under situations of estrogen stimulation, they may be induced to differentiate into functioning endometrial glands and stroma.

Finally, iatrogenic deposition of endometrial tissue has been found in some cases following gynecologic procedures and cesarean sections.

Some women may have a genetic predisposition to endometriosis. Studies have shown that first-degree relatives of women with this disease are more likely to develop it as well. The search for an endometriosis gene is currently underway.

Many theories exist as to why endometriosis occurs, and it is likely a combination of these factors that cause and determine severity of disease.

Frequency

United States

The incidence of endometriosis has not increased in the last 30 years. The prevalence is approximately 6-8% but estimates vary. It is usually diagnosed during laparoscopic surgery for evaluation of pelvic pain. Most prevalence studies are based on a surgical population in which the likelihood of disease is greater. Of the surgical population, endometriosis was diagnosed in 25% of women who had a laparoscopy for pelvic pain and in 20% of women who underwent surgery for infertility. No large-scale laparoscopic evaluation of asymptomatic women has been undertaken.

Mortality/Morbidity

Mortality is negligible.

• Acute or chronic pelvic pain is common in patients with endometriosis.
• Infertility is also common. Thirty to forty percent of women with endometriosis will be subfertile.
• Cases have been reported of extrapelvic involvement in virtually every other organ system including the central nervous system (CNS), lungs, pleura, kidney, and bladder. The gastrointestinal (GI) tract is the most common extrapelvic site of endometriosis, and symptoms include bowel obstruction, rectal bleeding, and constipation. Symptoms in other locations are related to the site and size of endometrial implants.

Race

Most research and case studies have been performed in white populations; however, no difference appears to exist among ethnic or social groups.

Sex

Endometriosis occurs in women. Rare reports of endometriosis have been documented in men undergoing estrogen therapy.

Age

Pelvic endometriosis typically occurs in women aged 25-30 years. Extrapelvic manifestations of this disorder occur in woman aged 35-40 years. Women younger than 20 years with this disease often have anomalies of the reproductive system. Endometriomas and symptoms related to them regress significantly after menopause.

Clinical

History

• Patients with endometriosis present with a variety of symptoms including the following:
  • Dysmenorrhea
  • Heavy or irregular bleeding
  • Pelvic pain
  • Lower abdominal or back pain
  • Dyspareunia
  • Dyschezia (pain on defecation) often with cycles of diarrhea and constipation
  • Bloating, nausea, and vomiting
  • Inguinal pain
  • Pain on micturition and/or urinary frequency
  • Pain during exercise
• The most common symptom is dysmenorrhea, which may precede the onset of menstruation. In addition to pain, patients present with nonspecific symptoms of fatigue, generalized malaise, and sleep disturbances.
• Intensity of pain and discomfort does not correlate with extent of disease because the location and depth of endometrial implants affect the symptomatology. Pain is thought to be related to the degree of peritoneal inflammation rather than the volume of implants. Associated intrapelvic/intra-abdominal adhesions are also important determinants of the degree of pain experienced. 
• Ureteral obstruction and hydronephrosis can result from endometrial implants on the ureter or mass effect from an endometrioma.
• Extra-abdominal manifestations can include cyclical hemoptysis and pneumothorax (catamenial).
• Symptoms usually improve during pregnancy and after menopause. They can recur postpartum or with postmenopausal hormone replacement therapy.
• In 15% of cases of pelvic pain, endometriosis is the underlying cause. It should be considered in women with chronic pelvic pain who do not respond to standard NSAID or oral contraceptive therapy.
• One third of women with endometriosis are asymptomatic.

Physical

The physical examination usually correlates with the extent of disease.

• The most common finding is nonspecific pelvic tenderness. In one study, 22% of adolescents had abnormal physical findings consistent with anatomic lesions found during surgery.
• The hallmark finding on examination is the presence of tender nodular masses along thickened uterosacral ligaments, the posterior uterus, or the posterior cul-de-sac.
• Ovarian involvement may present with adnexal tenderness or masses.
• Obliteration of the cul-de-sac in conjunction with fixed uterine retroversion implies extensive disease.
• Rupture of an ovarian endometrioma may present as an acute abdomen.
• Extensive involvement of the rectum and other areas of the GI tract may cause adhesions and obstruction.
• Examination should include evaluation for cervicitis, abnormal discharge, and sexually transmitted diseases (STDs).

Causes

Refer to Pathophysiology for more detail.

• Retrograde menstruation
• Lymphatic/vascular metastases
• Coelomic metaplasia
• Remnant mullerian cells induced by estrogen
• Direct implantation
• Genetic predisposition
• Risk factors
  • Family history of endometriosis
  • Early age of menarche
  • Short menstrual cycles (<27 d)
  • Long duration of menstrual flow (>7 d)
  • Heavy bleeding during menses
  • Inverse relationship to parity
  • Delayed childbearing
  • Defects in the uterus or fallopian tubes
  • Hypoxia and iron deficiency may contribute to the early onset of endometriosis

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