Table of Contents
What is Endometriosis
Endometriosis is a condition in which endometrial tissue (the tissue that forms the lining of the UTERUS) grows abnormally in areas outside the uterus. The most common sites are the OVARIES, FALLOPIAN TUBES, peritoneal (abdominal) cavity, gastrointestinal tract (particularly the COLON), and BLADDER, though endometrial tissue may appear in other locations throughout the body. Endometrial growths, also called implants or tumors, respond to the body’s changing hormonal environment through the MENSTRUAL CYCLE in the same ways as endometrial tissue within the uterus: They engorge with BLOOD, atrophy, and slough (bleed). Because there is no pathway for bleeding from these distant endometrial implants to leave the body, the blood accumulates in the surrounding tissues. INFLAMMATION develops as part of the IMMUNE RESPONSE, initiating a HEALING process that results in the formation of SCAR tissue.
The growth of endometrial tissue in the fallopian tubes or ovaries blocks the ability of these structures to properly function, a primary consequence of which is impaired FERTILITY. Endometriosis also appears to instigate an abnormal immune response in which phagocytic cells (cells that engulf and consume cellular debris), primarily macrophages, target and kill SPERM and OVA (eggs). About 40 percent of women who seek treatment for INFERTILITY have endometriosis. Endometriosis affects more than five million women in the United States.
Causes of Endometriosis
Researchers do not know what causes endometriosis or how endometrial tissue arises in sites other than the uterus. Many women who have endometriosis often also have AUTOIMMUNE DISORDERS such as atopic DERMATITIS, ASTHMA, and allergies, giving rise to the suspicion of a dysfunction within the immune system. Some researchers believe endometrial cells escape from the uterus via the fallopian tubes, then migrate through the LYMPH or blood circulation to implant and grow in other locations. Endometriosis tends to progressively worsen over time because the endometrial implants grow under the influence of ESTROGENS, though this growth usually abates with MENOPAUSE. For most women menopause, natural or induced, ends endometriosis.
Symptoms of Endometriosis and Diagnostic Path
The primary symptoms of endometriosis are PAIN and infertility. Pain is typically cyclic, following the pattern of the menstrual cycle, and may be moderate to debilitating, especially during MENSTRUATION. Distant endometrial implants also cause pain as they swell and then bleed. The diagnostic path includes comprehensive medical examination with pelvic examination and often pelvic ULTRASOUND. Exploratory laparoscopy provides the definitive diagnosis, allowing the gynecologist to directly visualize the endometrial implants. Diagnostic imaging procedures such as COMPUTED TOMOGRAPHY (CT) SCAN or MAGNETIC RESONANCE IMAGING (MRI) often can detect distant endometrial implants.
Endometriosis Treatment Options and Outlook
At present there is no cure for endometriosis, though various treatment approaches, medical and surgical, can control symptoms and improve fertility. NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), which block the inflammatory response as well as relieve pain, are often adequate to treat mild symptoms in women who wish to become pregnant. HORMONE THERAPY is highly effective to treat moderate to significant symptoms in women who do not desire to become pregnant. Common hormone therapies include
- estrogen and progestin in combination, such as oral contraceptives (birth control pills)
- progestin alone, such as in progestin oral contraceptives or DepoProvera injections
- danazol, an androgen analog (synthetic, weak male HORMONE) that suppresses the menstrual cycle
- GONADOTROPIN-RELEASING HORMONE (GNRH) antagonists such as leuprolide, which shut down the ovaries to prevent them from producing estrogen
Laparoscopic surgery to remove endometrial implants from pelvic structures and the peritoneal cavity may be the only treatment that effectively mitigates symptoms in women who have severe, disabling endometriosis. Therapeutic laparoscopy for endometriosis can provide long-term relief. However, it does not remove distant endometrial implants, which often continue to produce symptoms. As well, endometrial implants will regrow if a few endometrial cells remain.
Endometriosis – Risk Factors and Preventive Measures
Factors that increase a woman’s risk for endometriosis are unclear. Because endometriosis tends to run in families, researchers believe it may be the result of GENETIC PREDISPOSITION in combination with other, undetermined factors. However, any woman who menstruates can develop endometriosis. There are no measures to prevent endometriosis.