Fibroids
A fibroid is a noncancerous tumor composed of muscle and
fibrous tissue. It is located in the uterus.
Fibroids can cause pain, abnormal vaginal bleeding,
constipation, repeated miscarriages, and an urge to urinate frequently or
urgently.
Doctors do a pelvic examination and usually ultrasonography
to confirm the diagnosis.
Treatment is necessary only if fibroids cause problems.
Doctors may prescribe drugs to control the symptoms, but
surgery or a procedure to destroy the fibroids is often needed to relieve symptoms
or to make childbirth possible.
Fibroids
fibroids_high
Fibroids are also called leiomyomas or myomas.
The Uterus, Cervix, and Cervical Canal
Fibroids in the uterus are the most common noncancerous tumor of the female reproductive tract. By age 45, about 70% of women develop at least one fibroid. Many fibroids are small and cause no symptoms. But about one fourth of white women and one half of black women eventually develop fibroids that cause symptoms. Fibroids are more common among women who are overweight.
Did You Know...
By age 45, about 7 out of 10 women develop fibroids of the
uterus.
What causes fibroids to grow in the uterus is unknown. High levels of estrogen and possibly progesterone (female hormones) seem to stimulate their growth. Fibroids may become larger during pregnancy (when levels of these hormones increase), and fibroids tend to shrink after menopause (when levels decrease drastically).
If fibroids grow too large, they may not be able to get enough blood. As a result, they begin to degenerate and cause pain.
Fibroids may be microscopic or as large as a basketball.
Fibroids may grow in different parts of the uterus, usually in the wall (which has three layers):
Under the outer surface of the uterus (subserosal fibroids)
In the wall of the uterus (intramural fibroids)
Under the inside layer (lining or endometrium) of the uterus
(submucosal fibroids)
Subserosal fibroids are the most common type.
Some fibroids grow from a stalk (called pedunculated
fibroids). Some submucosal fibroids extend into the interior of the uterus
(called intracavitary fibroids). Fibroids that grow in the wall or just under
the endometrium can distort the shape of the interior of the uterus.
Often, women have more than one fibroid.
Very rarely, fibroids become cancerous.
Where Fibroids Grow
Fibroids can grow in different parts of the uterus:
Under the outer surface of the uterus (subserosal fibroids)
In the wall of the uterus (intramural fibroid)
Under the lining of the uterus (submucosal fibroid)
Some fibroids grow on a stalk. They are called pedunculated
fibroids.
Symptoms of Fibroids
Symptoms depend on
The number of fibroids
Their size
Their location in the uterus
Many fibroids do not cause symptoms. The larger the fibroid,
the more likely it is to cause symptoms. Fibroids, particularly those just
under the lining, commonly make menstrual bleeding heavier or last longer than
usual. Anemia may result from the loss of blood.
Large fibroids may cause pain, pressure, or a feeling of heaviness in the pelvic area during or between menstrual periods. Fibroids may press on the bladder, making a woman need to urinate more frequently or more urgently. They may press on the rectum, causing discomfort and constipation. They may interfere with how organs function—for example, by blocking the urinary tract and thus the flow of urine out of the body. Large fibroids may cause the abdomen to enlarge.
A fibroid growing on a stalk may twist, cutting off its
blood supply, and cause severe pain.
Fibroids that are growing or degenerating can cause pressure
or pain. Pain due to degenerating fibroids can last as long as they continue to
degenerate.
Fibroids that cause no symptoms before pregnancy may cause
problems during pregnancy. Problems include
Miscarriage
Early (preterm) labor
Abnormal positioning (presentation) of the baby before
delivery
Excessive blood loss after delivery (postpartum hemorrhage)
Fibroids can cause infertility by blocking the fallopian
tubes or by distorting the shape of the uterus, making attachment to the lining
of the uterus (implantation) of a fertilized egg difficult or impossible (see
figure From Egg to Embryo).
Fewer than 1% of fibroids become cancerous.
Diagnosis of Fibroids
Imaging, usually ultrasonography
Doctors may suspect fibroids based on results of a pelvic
examination. However, imaging tests are often needed to confirm the diagnosis
of uterine fibroids.
Imaging tests include
Transvaginal ultrasonography: An ultrasound device is
inserted into the vagina.
Saline infusion sonography (sonohysterography):
Ultrasonography is done after a small amount of fluid is infused into the
uterus to outline its interior.
If results of either test are unclear, magnetic resonance
imaging (MRI) is done. MRI can clearly show fibroids.
If women have had any bleeding other than that during their
menstrual periods, doctors may want to exclude cancer of the uterus. So they
may do the following:
A Papanicolaou (Pap) test
A biopsy of the uterine lining (endometrial biopsy)
Transvaginal ultrasonography, sonohysterography,
hysteroscopy, or a combination
For hysteroscopy, a viewing tube is inserted through the
vagina and cervix into the uterus. A local, regional, or general anesthetic is
often used. During hysteroscopy, a sample of tissue may be removed and examined
(biopsied).
Treatment of Fibroids
Drugs to relieve symptoms or shrink fibroids
Sometimes surgery to remove the entire uterus or only the
fibroids
Sometimes procedures to destroy the fibroids
For most women who have fibroids but no bothersome symptoms
or other problems, treatment is not required. They are reexamined every 6 to 12
months so that doctors can determine whether symptoms are worsening or
lessening and whether fibroids are growing. Such periodic monitoring is
sometimes called watchful waiting.
Several treatment options, including drugs and surgery, are
available if bleeding or other symptoms worsen or if fibroids enlarge
substantially.
Drugs for fibroids
A few drugs may be used to relieve symptoms or to shrink
fibroids, but their effects are only temporary. No drug can permanently shrink
a fibroid.
Rarely, if women have gone through menopause or are starting
to go through it, a drug to shrink the fibroid may be used. But it may not be
needed because fibroids may continue to shrink on their own after menopause.
The following drugs are commonly used:
Gonadotropin-releasing hormone agonists
Progestins
Gonadotropin-releasing hormone (GnRH) agonists (analogs) are
most commonly used. These drugs are synthetic forms of a hormone produced by
the body (GnRH). Leuprolide and goserelin are most commonly used. They can
shrink fibroids and reduce bleeding by causing the body to produce less
estrogen (and progesterone). Because they shrink the fibroids and reduce
bleeding, doctors may give GnRH agonists before surgery to make removal of
fibroids easier, reduce blood loss, and thus reduce the risks of surgery. The
drugs may be injected once a month or implanted as a pellet under the skin.
Nafarelin, another GnRH agonist, can be used as a nasal spray.
GnRH agonists are usually taken for less than 6 months. If
taken for a long time, they may reduce bone density and increase the risk of
osteoporosis. Low doses of estrogen, usually combined with a progestin (a drug
that is similar to the hormone progesterone), may be given with GnRH agonists
to help prevent loss of bone density.
Within 6 months after GnRH agonists are stopped, fibroids
may become as large as they were before treatment.
Progestins (such as medroxyprogesterone acetate or
megestrol) can control bleeding in some women, but these drugs may not shrink
fibroids as much as GnRH agonists. They reduce bleeding by preventing the
lining of the uterus from growing too much. When the uterine lining grows too
much, there is more of it to break down and be shed during menstruation. As a
result, menstrual bleeding may be heavier than usual.
Progestins are taken by mouth. They may be taken every day
or only for 10 to 14 consecutive days each menstrual cycle. Or doctors may give
women injections of medroxyprogesterone acetate every 3 months or insert an
intrauterine device (IUD) that releases a progestin called levonorgestrel. If
taken by mouth every day, injected, or released by an IUD, progestins also
provide contraception. However, these drugs may have bothersome side effects,
such as weight gain, depression, and irregular bleeding.
Rarely, other drugs can be prescribed. They can be used if a
GnRH agonist or progestin has been ineffective or has bothersome side effects.
These drugs include
Mifepristone and related drugs (called antiprogestins):
These drugs inhibit the activity of the hormone progesterone. As a result, the
uterus and fibroids shrink.
Raloxifene and related drugs (called selective estrogen
receptor modulators, or SERMs): These drugs reverse some of estrogen’s effects.
They may not be as effective as other drugs.
Danazol (a synthetic hormone related to testosterone):
Danazol inhibits the activity of estrogen and progesterone. It has many side
effects, such as weight gain, acne, increased body hair (hirsutism), swollen
ankles, loss of scalp hair, vaginal dryness, and lowering of the voice.
Tranexamic acid: This drug works by preventing blood clots
(which are made by the body to help stop bleeding) from breaking down as
quickly. As a result, bleeding decreases.
Nonsteroidal anti-inflammatory drugs (NSAIDs) may relieve
pain but may not reduce bleeding.
Surgery for fibroids
Surgery is usually considered for women who have any of the
following:
Fibroids that are rapidly enlarging
Bleeding that continues or recurs despite treatment with
drugs
Severe or persistent pain
Large fibroids that cause problems, such as the need to
urinate frequently, constipation, pain during sexual intercourse, or blockage
of the urinary tract
For women who want to conceive, fibroids that have caused
infertility or repeated miscarriages
If women do not want to have any more children or want a
definitive cure, surgery may be a good option.
Several types of surgery can be done. Which one is
recommended depends on the size, number, and location of fibroids. However,
before making a decision about treatment, women should talk to their doctor
about the problems that can result from each type of surgery so that they can
make an informed decision.
Surgery to treat fibroids traditionally involves one of the
following:
Hysterectomy: The uterus is removed, but the ovaries are
not. Hysterectomy is the only permanent solution to fibroids. However, after
hysterectomy, women cannot have children. Thus, hysterectomy is done only when
women do not wish to become pregnant.
Myomectomy: Only the fibroid or fibroids are removed. In
contrast to a hysterectomy, most women who have a myomectomy can have children.
Also, some women feel psychologically better when they keep their uterus.
However, after myomectomy, new fibroids may grow, and about 25% of women need a
hysterectomy about 4 to 8 years later.
For hysterectomy, surgeons may use one of the following
methods:
Laparotomy: They make an incision that is several inches
long in the abdomen.
Laparoscopy: They make one or a few small incisions near or
above the navel, then insert a viewing tube (laparoscope) and surgical
instruments through the incisions.
Vaginal hysterectomy: The uterus is removed through the
vagina, sometimes assisted by laparoscopy. An incision is made in the vagina.
An abdominal incision is not needed.
Laparoscopic surgery can be done with robotic assistance.
The robot is a device used to control and manipulate surgical instruments
inserted with the laparoscope. The laparoscope sends a three-dimensional image
of the body's interior to a console. Surgeons sit at a console to view this
image, and a computer translates their hand movements into precise movements of
the surgical instruments.
For myomectomy, surgeons may use
Laparotomy
Laparoscopy
Hysteroscopy: Surgeons insert a telescope-like lighted
device (hysteroscope) through the vagina into the uterus. Using instruments
inserted through this tube, surgeons can cut tissue and remove fibroids on the
inside of the uterus.
Laparoscopy and hysteroscopy are outpatient procedures, and
recovery is faster than recovery after laparotomy. However, sometimes removing
fibroids using laparoscopy or hysteroscopy may be difficult or impossible—for
example, when there are many fibroids, when they are very large, or when they
are embedded deeply in the wall of the uterus. In such cases, doctors do a
laparotomy.
Hysterectomy may be preferred to myomectomy or may be
required for several reasons:
After myomectomy, fibroids may begin to grow again.
Women have disorders that make removal of fibroids harder.
These disorders include endometriosis and abnormal bands of scar tissue in the
uterus or pelvis (adhesions).
Hysterectomy may reduce the risk of other disorders that
women have or have risk factors for. These disorders include endometriosis,
precancerous disorders of the cervix or lining of the uterus (endometrium), and
ovarian cancer. For example, women who have a mutation in the BRCA gene are at
increased risk of ovarian cancer. In such cases, the uterus and both ovaries
may be removed.
Other treatments have been ineffective.
A procedure called morcellation is often done during
myomectomy or hysterectomy. For this procedure, surgeons cut the fibroids or
uterine tissue into small pieces so that the pieces can be removed through a
smaller incision. Very rarely, women with fibroids have cancer of the uterus
that is unsuspected and undiagnosed. If morcellation is done in such women, the
cancer cells may be spread into the abdomen and pelvis. In such cases, cancer
can develop in other locations unless a bag is used to catch all of the pieces
of the fibroid, which are then removed from the body. When morcellation is
done, such a bag must be used. Women should be informed of the very small risk
of spreading cancerous cells if morcellation is done.
Other treatments for fibroids
Other treatments can be used to destroy rather than remove
fibroids. These treatments may relieve symptoms, but how long symptom relief
lasts has not been determined. These procedures include
Uterine artery embolization
High-intensity focused ultrasonography
Radiofrequency ablation
Cryoablation
Magnetic resonance-guided focused ultrasonography
After having one of these procedures, women should not
become pregnant. Whether pregnancy after these procedures is safe is unclear.
For uterine artery embolization, doctors use an anesthetic
to numb a small area of the thigh and make a small puncture hole or incision
there. Then, they insert a thin, flexible tube (catheter) through the incision
into the main artery of the thigh (femoral artery). The catheter is threaded to
the arteries that supply blood to the fibroid, and small synthetic particles
are injected. The particles travel to the small arteries supplying the fibroid
and block them. As a result, the fibroid dies, then shrinks. Most of the rest
of the uterus appears to be unaffected. However, whether the fibroid will
regrow (because blocked arteries reopen or new arteries form) is unknown.
After uterine artery embolization, most women have pain and
cramping in the pelvis, nausea, vomiting, fever, fatigue, and muscle aches.
These symptoms develop within 48 hours after the procedure and gradually lessen
over 7 days. An infection may develop in the uterus or surrounding tissues.
Women recover more quickly after this procedure than after a hysterectomy or
myomectomy, but they tend to have more complications and more return visits to
the doctor. If fibroids continue to be a problem or grow back after embolization,
hysterectomy is recommended.
Ultrasound-guided high-intensity focused sonography and
magnetic resonance-guided focused ultrasonography use sound waves to destroy
fibroids.
In radiofrequency ablation, doctors insert a needle that
transmits an electrical current or heat into the fibroid and use it to destroy
the core of the fibroid.
In cryoablation, a cold probe is used to destroy the
fibroid.
Ultrasonography or magnetic resonance imaging may be used
with radiofrequency ablation or cryoablation to locate the fibroids.
After these treatments, fibroids may grow back. In such
cases, another treatment or a hysterectomy may be recommended.
Choice of treatment for fibroids
Choice of treatment for fibroids depends on the woman's
situation, but doctors may use the following general guidelines:
If the fibroids do not cause any symptoms: No treatment
If the woman is going through or has passed through
menopause: Watchful waiting (because symptoms tend to lessen as fibroids
decrease in size after menopause)
If fibroids cause symptoms, particularly if the woman wants
to become pregnant: A procedure that destroys rather than removes fibroids
(such as uterine artery embolization or high-intensity focused sonography) or
myomectomy
If symptoms are severe and other treatments are ineffective,
particularly if the woman does not want to become pregnant: Hysterectomy,
possibly preceded by treatment by drugs (such as GnRH agonists)