UTERINE FIBROIDS DEFINITION
Uterine fibroids are noncancerous growths of the uterus that often appear during childbearing years. Also called leiomyomas (lie-o-my-O-muhs) or myomas, uterine fibroids aren’t associated with an increased risk of uterine cancer and almost never develop into cancer.
Uterine fibroids develop from the smooth muscular tissue of the uterus (myometrium). A single cell divides repeatedly, eventually creating a firm, rubbery mass distinct from nearby tissue. The growth patterns of uterine fibroids vary — they may grow slowly or rapidly, or they may remain the same size. Some fibroids go through growth spurts, and some may shrink on their own. Many fibroids that have been present during pregnancy shrink or disappear after pregnancy, as the uterus goes back to a normal size.
Fibroids range in size from seedlings, undetectable by the human eye, to bulky masses that can distort and enlarge the uterus. They can be single or multiple, in extreme cases expanding the uterus so much that it reaches the rib cage.
As many as 3 out of 4 women have uterine fibroids sometime during their lives, but most are unaware of them because they often cause no symptoms. Your doctor may discover fibroids incidentally during a pelvic exam or prenatal ultrasound.
UTERINE FIBROIDS CAUSES
We do not know exactly why women develop these tumors. Genetic abnormalities, alterations in growth factor (proteins formed in the body that direct the rate and extent of cell proliferation) expression, abnormalities in the vascular (blood vessel) system, and tissue response to injury have all been suggested to play a role in the development of fibroids.
Family history is a key factor, since there is often a history of fibroids developing in women of the same family. Race also appears to play a role. Women of African descent are two to three times more likely to develop fibroids than women of other races. Women of African ancestry also develop fibroids at a younger age and may have symptoms from fibroids in their 20s, in contrast to Caucasian women with fibroids, in whom symptoms typically occur during the 30s and 40s. Early pregnancy decreases the likelihood that fibroids will develop. Fibroids have not been observed in girls who have not reached puberty, but adolescent girls may rarely develop fibroids. Other factors that researchers have associated with an increased risk of developing fibroids include having the first menstrual period (menarche) prior to age 10, consumption of alcohol (particularly beer), uterine infections, and elevated blood pressure (hypertension).
Estrogen tends to stimulate the growth of fibroids in many cases. During the first trimester of pregnancy, about a third of fibroids will enlarge and then shrink after the birth. In general, fibroids tend to shrink after menopause, but postmenopausal hormone therapy may cause symptoms to persist.
Overall, these tumors are fairly common and occur in about 70% to 80% of all women by the time they reach age 50. Most of the time, uterine fibroids do not cause symptoms or problems, and a woman with a fibroid is usually unaware of its presence.with a fibroid is usually unaware of its presence.
UTERINE FIBROIDS PATHOPHYSIOLOGY
Studies have revealed the role of the extracellular matrix, transforming growth factor beta, and collagen structure in leiomyoma formation, providing evidence for molecular similarities between leiomyomas and keloids. Additionally, a model of development was created based on an abnormal response to tissue repair, disordered healing, and formation of an altered extracellular matrix.
Uterine fibroids arise from the myometrial layer of the uterine corpus or, less commonly, the uterine cervix, and may occur singly or multiply. Fibroids may remain within the muscular layer (intramural) or protrude outwardly to become subserosal in location or inwardly towards the endometrial cavity, where they become known as submucous fibroids. Subserosal and submucosal fibroids may become pedunculated. Abnormal vaginal bleeding that often accompanies the presence of fibroids is felt to occur as a result of distortion of the endometrial lining and therefore is seen much more commonly with submucous fibroids. For the same reason, cavity distortion can cause recurrent second trimester loss. Uterine fibroids that obstruct menstrual flow can cause dysmenorrhoea. Large uterine fibroids, regardless of location, can cause mass effects on contiguous organs such as the bowel and bladder and cause symptoms of urinary frequency, urgency, and incontinence as well as constipation. They can outstrip their blood supply and cause acute or chronic pain as they degenerate. Pedunculated submucous uterine fibroids can dilate the uterine cervix and prolapse into the vagina where they can become infected.
Various mechanisms have been proposed to explain the strong association between heavy menses and uterine fibroids. They have included ulceration over the surface of submucous uterine fibroids, anovulation associated with uterine fibroids, increased endometrial surface area, and interference with normal uterine contractility. To date, none of these explanations have been conclusively validated by clinical research.
More recently, research into this area has centred on a vascular dysregulation, thought to be mediated by a number of growth factors. It is now hypothesised that fibroid-associated bleeding is related to dilatation of the small veins (venules) within the myometrium and endometrium of uteri containing fibroids, thus interfering with the haemostatic actions of platelets and fibrin plugs. Nevertheless, a cause and effect has not been established.
UTERINE FIBROIDS SYMPTOMS
In women who have symptoms, the most common symptoms of uterine fibroids include:
- Heavy menstrual bleeding
- Prolonged menstrual periods — seven days or more of menstrual bleeding
- Pelvic pressure or pain
- Frequent urination
- Difficulty emptying your bladder
- Backache or leg pains
Rarely, a fibroid can cause acute pain when it outgrows its blood supply. Deprived of nutrients, the fibroid begins to die. Byproducts from a degenerating fibroid can seep into surrounding tissue, causing pain and, rarely, fever. A fibroid that hangs by a stalk inside or outside the uterus (pedunculated fibroid) can trigger pain by twisting on its stalk and cutting off its blood supply.
Fibroid location, size and number influence signs and symptoms:
- Submucosal fibroids. Fibroids that grow into the inner cavity of the uterus (submucosal fibroids) are more likely to cause prolonged, heavy menstrual bleeding and are sometimes a problem for women attempting pregnancy.
- Subserosal fibroids. Fibroids that project to the outside of the uterus (subserosal fibroids) can sometimes press on your bladder, causing you to experience urinary symptoms. If fibroids bulge from the back of your uterus, they occasionally can press either on your rectum, causing a pressure sensation, or on your spinal nerves, causing backache.
- Intramural fibroids. Some fibroids grow within the muscular uterine wall (intramural fibroids). If large enough, they can distort the shape of the uterus and cause prolonged, heavy periods, as well as pain and pressure.
UTERINE FIBROIDS DIAGNOSIS
Uterine fibroids are diagnosed by pelvic exam and even more commonly by ultrasound. Often, a pelvic mass cannot be determined to be a fibroid on pelvic exam alone, and ultrasound is very helpful in differentiating it from other conditions such as ovarian tumors. MRI and CT scans can also play a role in diagnosing fibroids, but ultrasound is the simplest, cheapest, and best technique for imaging the pelvis. Occasionally, when trying to determine if a fibroid is present in the uterine cavity (endometrial cavity), a hysterosonogram (HSG) is done. In this procedure, an ultrasound exam is done while contrast fluid is injected into the uterus through the cervix. The fluid within the endometrial cavity can help outline any masses that are inside, such as submucosal fibroids.
UTERINE FIBROIDS TREATMENT
There’s no single best approach to uterine fibroid treatment — many treatment options exist. If you have symptoms, talk with your doctor about options for symptom relief.
Many women with uterine fibroids experience no signs or symptoms, or only mildly annoying signs and symptoms that they can live with. If that’s the case for you, watchful waiting could be the best option. Fibroids aren’t cancerous. They rarely interfere with pregnancy. They usually grow slowly — or not at all — and tend to shrink after menopause, when levels of reproductive hormones drop.
Medications for uterine fibroids target hormones that regulate your menstrual cycle, treating symptoms such as heavy menstrual bleeding and pelvic pressure. They don’t eliminate fibroids, but may shrink them. Medications include:
- Gonadotropin-releasing hormone (Gn-RH) agonists.Medications called Gn-RH agonists (Lupron, Synarel, others) treat fibroids by blocking the production of estrogen and progesterone, putting you into a temporary postmenopausal state. As a result, menstruation stops, fibroids shrink and anemia often improves. Your doctor may prescribe a Gn-RH agonist to shrink the size of your fibroids before a planned surgery. Many women have significant hot flashes while using Gn-RH agonists. Gn-RH agonists typically are used for no more than three to six months because symptoms return when the medication is stopped and long-term use can cause loss of bone.
- Progestin-releasing intrauterine device (IUD). A progestin-releasing IUD can relieve heavy bleeding caused by fibroids. A progestin-releasing IUD provides symptom relief only and doesn’t shrink fibroids or make them disappear.
- Other medications. Your doctor might recommend other medications. For example, oral contraceptives or progestins can help control menstrual bleeding, but they don’t reduce fibroid size. Nonsteroidal anti-inflammatory drugs (NSAIDs), which are not hormonal medications, may be effective in relieving pain related to fibroids, but they don’t reduce bleeding caused by fibroids. Your doctor also may suggest that you take vitamins and iron if you have heavy menstrual bleeding and anemia.
MRI-guided focused ultrasound surgery (FUS) is:
- A noninvasive treatment option for uterine fibroids that preserves your uterus, requires no incision and is done on an outpatient basis.
- Performed while you’re inside an MRI scanner equipped with a high-energy ultrasound transducer for treatment. The images give your doctor the precise location of the uterine fibroids. When the location of the fibroid is targeted, the ultrasound transducer focuses sound waves (sonications) into the fibroid to heat and destroy small areas of fibroid tissue.
- Newer technology, so researchers are learning more about the long-term safety and effectiveness. But so far data collected show that FUS for uterine fibroids is safe and effective.
Minimally invasive procedures
Certain procedures can destroy uterine fibroids without actually removing them through surgery. They include:
- Uterine artery embolization. Small particles (embolic agents) are injected into the arteries supplying the uterus, cutting off blood flow to fibroids, causing them to shrink and die. This technique can be effective in shrinking fibroids and relieving the symptoms they cause. Complications may occur if the blood supply to your ovaries or other organs is compromised.
- Myolysis. In this laparoscopic procedure, an electric current or laser destroys the fibroids and shrinks the blood vessels that feed them. A similar procedure called cryomyolysis freezes the fibroids. Myolysis is not used often. Another version of this procedure, radiofrequency ablation, is being studied.
- Laparoscopic or robotic myomectomy. In a myomectomy, your surgeon removes the fibroids, leaving the uterus in place. If the fibroids are small and few in number, you and your doctor may opt for a laparoscopic or robotic procedure, which uses slender instruments inserted through small incisions in your abdomen to remove the fibroids from your uterus. Your doctor views your abdominal area on a monitor using a small camera attached to one of the instruments. Robotic myomectomy gives your surgeon a magnified, 3-D view of your uterus, offering more precision, flexibility and dexterity than is possible using some other techniques.
- Hysteroscopic myomectomy. This procedure may be an option if the fibroids are contained inside the uterus (submucosal). Your surgeon accesses and removes fibroids using instruments inserted through your vagina and cervix into your uterus.
- Endometrial ablation and resection of submucosal fibroids. This treatment, performed with a specialized instrument inserted into your uterus, uses heat, microwave energy, hot water or electric current to destroy the lining of your uterus, either ending menstruation or reducing your menstrual flow. Typically, endometrial ablation is effective in stopping abnormal bleeding. Submucosal fibroids can be removed at the time of hysteroscopy for endometrial ablation, but this doesn’t affect fibroids outside the interior lining of the uterus.
Traditional surgical procedures
Options for traditional surgical procedures include:
- Abdominal myomectomy. If you have multiple fibroids, very large fibroids or very deep fibroids, your doctor may use an open abdominal surgical procedure to remove the fibroids. Many women who are told that hysterectomy is their only option can have an abdominal myomectomy instead.
- Hysterectomy. This surgery — the removal of the uterus — remains the only proven permanent solution for uterine fibroids. But hysterectomy is major surgery. It ends your ability to bear children. And if you also elect to have your ovaries removed, it brings on menopause and the question of whether you’ll take hormone replacement therapy. Most women with uterine fibroids can choose to keep their ovaries.
Risk of developing new fibroids
For all procedures, except hysterectomy, tiny tumors (seedlings) that your doctor doesn’t detect during surgery could eventually grow and cause symptoms that warrant treatment. This is often termed the recurrence rate. New fibroids, which may or may not require treatment, also can develop.