Uterine fibroids are very common noncancerous (benign) growths that develop in the muscular wall of the uterus. They can range in size from very tiny (a quarter of an inch) to larger than a cantaloupe. Occasionally, they can cause the uterus to grow to the size of a five-month pregnancy. In most cases, there is more than one fibroid in the uterus. While fibroids do not always cause symptoms, their size and location can lead to problems for some women, including pain and heavy bleeding.
Fibroids can dramatically increase in size during pregnancy. This is thought to occur because of the increase in estrogen levels during pregnancy. After pregnancy, the fibroids usually shrink back to their pre-pregnancy size. They typically improve after menopause when the level of estrogen, the female hormone that circulates in the blood, decreases dramatically. However, menopausal women who are taking supplemental estrogen (hormone replacement therapy) may not experience relief of symptoms.
Fibroid tumors of the uterus are very common; but for most women, they either do not cause symptoms or cause only minor symptoms. Fibroids can cause very heavy menstrual bleeding and pelvic pain, leading many women to seek treatment. Fibroids often fail to respond to medical therapy and then surgical procedures are often recommended.
Twenty to 40 percent of women age 35 and older have uterine fibroids of a significant size. African American women are at a higher risk for fibroids: As many as 50 percent have fibroids of a significant size. Uterine fibroids are the most frequent indication for hysterectomy in pre-menopausal women and, therefore, are a major public health issue. Of the 600,000 hysterectomies performed annually in the United States, one-third of these are due to fibroids.
Fibroid Tumors of the Uterus – An Overview
What are uterine fibroids?
What are typical symptoms?
Who is most likely to have uterine fibroids?
How are uterine fibroids diagnosed?
Q. What are uterine fibroids?
Uterine fibroids are the most common tumors of the female genital tract. You might hear them referred to as "fibroids" or by several other names, including leiomyoma, leiomyomata, myoma and fibromyoma. Fibroids are noncancerous (benign) growths that develop in the muscular wall of the uterus. While fibroids do not always cause symptoms, their size and location can lead to problems for some women, including pain and heavy bleeding.
The exact causes for fibroid development are unclear, but researchers have linked them to both a genetic predisposition and a subsequent development of susceptibility to hormone stimulation. Women may have a genetic predisposition to fibroid development and then subsequently develop factors that allow fibroids to grow under the influence of a number of hormones. This would explain why certain ethnic groups or racial groups are more likely to develop fibroids and also why there tends to be genetic predisposition in some families.
Fibroids range greatly in size from very tiny to the size of a cantaloupe or larger. In some cases, they can cause the uterus to grow in the size of a five-month pregnancy or more. Fibroids may be located in various parts of the uterus. In most cases, there is more than one fibroid in the uterus. There are three primary types of uterine fibroids.
Subserosal fibroids, which develop under the outside covering of the uterus and expand outward through the wall, giving the uterus a knobby appearance. They typically do not affect a woman's menstrual flow, but can cause pelvic pain, back pain and generalized pressure. The subserosal fibroid can develop a stalk or stem-like base, making it difficult to distinguish from an ovarian mass. These are called pedunculated. The correct diagnosis can be made with either an ultrasound or magnetic resonance (MR) exam.
Intramural fibroids, which develop within the lining of the uterus and expand inward, increasing the size of the uterus, and making it feel larger than normal in a gynecologic internal exam. These are the most common fibroids. Intramural fibroids can result in heavier menstrual bleeding and pelvic pain, back pain or the generalized pressure that many women experience.
Submucosal fibroids, which are just under the lining of the uterus. These are the least common fibroids, but they tend to cause the most problems. Even a very small submucosal fibroid can cause heavy bleeding – gushing, very heavy and prolonged periods.
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Q. What are typical symptoms?
Most fibroids don't cause symptoms – only 10-20 percent of women who have fibroids ever require treatment. Depending on location, size and number of fibroids, a woman might experience the following:
- Heavy, prolonged menstrual periods and unusual monthly bleeding, sometimes clots. This often leads to anemia.
- Pelvic pain.
- Pelvic pressure or heaviness caused by the bulk or weight of the fibroids pressing on nearby structures.
- Pain in the back or legs as the fibroids press on nerves that supply the pelvis and legs.
- Pain during sexual intercourse.
- Bladder pressure leading to a constant urge to urinate.
- Pressure on the bowel, leading to constipation and bloating.
- Abnormally enlarged abdomen.
If you are experiencing these types of symptoms, consult with your personal physician.
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Q. Who is most likely to have uterine fibroids?
Uterine fibroids are very common, although often they are very small and cause no problems. –Twenty to 40 percent of women age 35 and older have uterine fibroids of a significant size.
African-American women are at a higher risk: As many as 50 percent have fibroids of a significant size.
Fibroid tumors may start in women when they are in their 20s, however, most women do not begin to have symptoms until they are in their late 30s or 40s. Physicians are not able to predict if a fibroid will grow or cause symptoms.
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Q. How are uterine fibroids diagnosed?
Typically, fibroids are first diagnosed during a gynecologic examination. Your doctor will conduct a pelvic exam to feel if your uterus is enlarged. The presence of fibroids is most often confirmed by an abdominal ultrasound. Fibroids also can be confirmed using MR and computed tomography (CT) imaging techniques.
Abdominal ultrasound is a painless procedure in which a radiologist or technician moves an instrument (transducer/receiver) about the size and shape of a computer mouse across the outside surface of the abdomen. Sound waves are transmitted through the skin and allow the technician to "see" the size, shape and texture of the uterus. A picture is displayed on a computer screen as the radiologist or technician takes the ultrasound.
In some cases, a transvaginal ultrasound may be necessary. The radiologist inserts an ultrasound probe into the vagina so the inside of the uterus can be seen even more clearly than with the abdominal procedure. There is generally little if any discomfort associated with this procedure
Fibroids also can be confirmed using magnetic resonance imaging (MRI) or CT. MR and CT also are painless diagnostic tests that can give accurate and clear information on the presence of fibroids.
Diagnostic hysteroscopy also is an option, particularly to evaluate the presence of submucosal fibroids. A long, thin, probe-like instrument is passed through the vagina and cervix into the uterus, where the physician can check for growths and take samples of tissue. The lighted hysteroscope illuminates the uterus. This procedure, which can cause some discomfort, is generally performed by a gynecologist, and can be done without anesthesia or with a local anesthetic in an office.
Other Uterine Fibroid Embolization Facts
- An estimated 13,000-14,000 uterine fibroid embolization (UFE) procedures are performed annually in the United States (as of 2004).
- The embolic particles are approved by the FDA specifically for UFE, based on comparative trials showing similar efficacy with less serious complications compared to hysterectomy and myomectomy (the surgical removal of fibroids).
- Embolization of the uterine arteries is not new. While embolization to treat uterine fibroids has been performed since 1995, it has been used successfully by interventional radiologists for more than 20 years to treat heavy bleeding after childbirth.
- Embolization of fibroids was first used as an adjunct to help decrease blood loss during myomectomy. To the surprise of the initial users of this method, many patients had spontaneous resolution of their symptoms after only the embolization and no longer needed the surgery.
- UFE is covered by most major insurance companies and is widely available across the country.
- Most women with symptomatic fibroids are candidates for UFE and should obtain a consult with an interventional radiologist to determine whether UFE is a treatment option for them. An ultrasound or MRI diagnostic test will help the interventional radiologist to determine if the woman is a candidate for this treatment.
- Many women wonder about the safety of leaving particles in the body. The embolic particles most commonly used in UFE have been available with FDA approval for use in people for more than 20 years. During that time, they have been used in thousands of patients without long-term complications.
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Reprinted with permission of the Society of Interventional Radiology © 2004, www.SIRweb.org. All rights reserved.