Uterine fibroids, also known as myomas, leiomyomas or fibromas, are benign tumours that grow within the uterine walls and originate from the smooth muscle cells which make up the uterus.
In general, tumours develop when a specific cell of the human body multiplies itself more than it should and forms a mass of tissue. Fibroids are made of uterine muscle cells.
Benign tumours eventually stop growing and do not spread to other areas of the body as opposed to malignant tumours or cancer that never stop growing and invade other organs.
Fibroids are benign tumours and are almost always limited to the uterus.
Fibroids mostly appear as round, well circumscribed, pale white to pink nodules that vary greatly in size from a few millimetres to many centimetres.
It is not completely clear why fibroids appear in the first place, but they have oestrogen receptors and grow in response to oestrogen stimulation. They are very rare before puberty and after menopause, periods when the ovarian oestrogen production is low.
Incidence and Symptoms
Fibroids are present in about 30 to 50% of women of reproductive age. They are symptomatic in about half of those. During their lifetime, one in four to one in five women will see a doctor because of symptoms caused by fibroids
Most fibroids do not cause any symptoms initially and about half of them never will. Depending on the size and position within the uterus, fibroids can cause heavy bleeding or pressure/pain symptoms.
The most common form of abnormal bleeding is periods that become very heavy and last for many days. Any form of irregular or increased bleeding in women in their 30s and 40s could be caused by fibroids.
Fibroids don't usually cause severe pain and normally do not require pain killers. They can cause pain if their blood supply is reduced- a condition known as necrosis or degeneration of fibroids.
Fibroids are not usually associated with infertility but can cause miscarriages.
According to their position within the uterine wall, fibroids are classified as:
Subserosal - near the outer layer or serosa of the uterus.
Submucous - near the internal layer or mucosa of the uterus and protruding into the uterine cavity.
Intramural - predominantly within the width of the uterine muscle or myometrium.
Pedunculated - fibroids that grow on a stalk either to the outside of the uterus or inside the uterine cavity
This classification is not perfect and is limited by the fact that most fibroids are big enough to fall into at least two and sometimes three categories, but it helps clinicians make the diagnosis and plan treatment.
The diagnosis is suspected on clinical symptoms. Physical examination in the form of an internal examination done by a gynaecologist reveals an enlarged and sometimes irregular uterus.
Ultrasound is the most common diagnostic test and is very sensitive and accurate to show the presence of fibroids. Ultrasound can measure the size of fibroids and indicate their position within the uterus.
In selected cases when the ultrasound is not conclusive or a more a precise diagnosis is necessary, the doctor may order an MRI (Magnetic Resonance Imaging), a hysteroscopy or a laparoscopy.
Treatment may vary according to symptoms, type and size of fibroids, rate of growth, desire for future fertility and personal preference.
Possible options are:
Asymptomatic fibroids usually don't require any treatment. They can be monitored for growth by periodic visits to the doctor and ultrasound exams. If consecutive examinations don't show significant change and the woman remains asymptomatic, there is no need for surgery or other treatment.
Medication can be used to treat symptoms caused by fibroids. For example, bleeding symptoms which usually respond to hormone based medication and pain/pressure symptoms which can be treated with regular pain killers.
Progesterone based medication is used not so much to remove or reduce the size of fibroids, but to control heavy bleeding. They work on the lining of the uterine cavity reducing the shedding of endometrial cells that causes menstruation, thus reducing the blood loss.
GnRh analogues (Leuprolide, Goserelin, Nafarelin,etc) are drugs that block the ovarian function inducing a state of artificial menopause. Fibroids have been shown to decrease up to 40% in size with the use of GnRh analogues. There are two important considerations with their use. Firstly, fibroids tend to grow back as soon as the medication is discontinued and second, GnRh analogues are not recommended for prolonged use because of their side effects. Currently, the use of GnRh analogues for fibroids is limited to 3 to 4 months prior to surgery. Reducing the size of fibroids prior to surgery has the potential benefits of making it easier, reducing intra-operative bleeding and making a myomectomy or a laparoscopic hysterectomy possible where it previously would not have been.
Endometrial ablation is the destruction of the endometrial layer of the uterine cavity using some form of thermal energy (please see the page on Endometrial Ablation under Minimally Invasive Surgery for more details). There is a limit on the size of the uterus and position of fibroids as to which patients can have a successful ablation. In selected cases it is a good way to avoid more aggressive surgery. Endometrial ablation does not treat the fibroid itself, but by removing the endometrium it may reduce or completely stop the bleeding caused by the fibroids. It is not recommended for women who still plan to have children.
Uterine Artery Embolization
This is a procedure done through interventionist radiology. A catheter is inserted through the femoral artery and advanced through X-ray guidance near the uterus. Small particles are then injected into the arteries feeding the fibroid to block them. Starved of their blood supply, the fibroid cells die and the fibroid stops growing.
Uterine artery embolization has good success in reducing fibroid induced heavy bleeding. The procedure has some side effects such as pain, nausea, bleeding, and vaginal discharge. These are mostly temporary and resolve after a few days or weeks. Variables that may influence its success are number and size of fibroids and the woman’s age. It is not recommended for women who still want to fall pregnant.
The procedure is done in radiology clinics. In Melbourne, you can look up The Royal Melbourne Hospital Imaging (https://www.thermh.org.au/health-professionals/clinical-services/imaging/radiology/private-imaging and Epworth Radiology (https://epworthmedicalimaging.com.au/).
MRI guided Focused Ultrasound (MRgFUS)
This is another way of destroying fibroid cells to try to make it shrink and stop growing. The MRI is used to find the precise position of the fibroid. A beam of ultrasound energy is then directed to the core of the fibroid. The increase in temperature destroys the central portion of the fibroid making it shrink in size. Like other conservative treatments, MRgFUS does not remove the fibroids and future growth and recurrence of symptoms can occur.
There are set criteria as to who is eligible for the procedure or not. This is based on the number of fibroids, size and position within the uterus. Women interested in the procedure need to have an MRI to check whether they are suitable.
The procedure is done in radiology clinics that have specialized equipment. In Melbourne, it is offered to public patients at the Royal Women’s Hospital in Parkville (https://www.thewomens.org.au) and privately at Future Medical Imaging Group (http://www.fmig.com.au).
Myomectomy is an operation where incisions are made on the uterus to completely remove one or more fibroids. It is mostly recommended for women who have an indication for surgical treatment because of their symptoms and who want to preserve the uterus for future fertility or other personal reasons. It can be done through an open incision or through a laparoscopy (keyhole surgery). Please see the myomectomy page for more details.
Hysterectomy is the removal of the whole uterus, including the fibroids. Only a small proportion of women with fibroids will require a hysterectomy. The indications for a hysterectomy include fibroids of large size or when many are present, as well as cases where medical treatment to control symptoms have failed. It is the most successful treatment for fibroids with 100% resolution of bleeding and no growth of further fibroids. The main implication of a hysterectomy is the termination of a woman’s ability to fall pregnant. It should therefore only be considered by women who have completed their family or have no desire to fall pregnant. For some women, the uterus has a very important influence on their personal image and identity. This varies a lot and is personal to each woman. If a hysterectomy is being considered, it is very important to assess the possible emotional implication beforehand. A laparoscopic hysterectomy when feasible is the preferred option given its lower surgical trauma and enhanced recovery (please see the Hysterectomy page under Minimally Invasive Surgery).
Hysteroscopic Resection of Fibroid
When the fibroid is submucosal, i.e., most of the fibroid is growing inside the uterine cavity, it is possible to remove it using a hysteroscope. The hysteroscope is an instrument that goes inside the uterus from below, through the natural opening of the cervix. This procedure does not require any incisions to the abdomen or to the uterus itself. It is a day procedure and has excellent results. It is limited by the size and position of the fibroid. As a general rule it is possible when more than 50% of the fibroid is inside the uterine cavity and when the maximum diameter of the fibroid is less than 5 cm. (please see the Hysteroscopic Resection of Fibroid page under Minimally Invasive Surgery).
Frequently Asked Questions
Do all fibroids need treatment?
No, only the ones that cause symptoms, mainly heavy bleeding or pressure symptoms, require treatment. Fibroids found incidentally on physical examination or ultrasound do not need to be treated.
I have fibroids, do I need a hysterectomy?
Not necessarily. A hysterectomy is usually the last resort. It may be required in cases where less invasive options fail to control symptoms or when fibroids are too big or growing too fast. Even then, women who still want to preserve their fertility can avoid a hysterectomy by having a myomectomy, an operation that removes only the fibroids while preserving the uterus.
I have fibroids, can I fall pregnant?
Most likely yes. Each case is different, but most fibroids do not cause infertility and most pregnancies in fibroid uteruses tend to develop well. There can be problems and complications and close ante-natal care by an obstetrician is recommended. Some fibroids can cause miscarriages. If you are having trouble falling pregnant or fell pregnant and miscarried and the fibroids seem to be the cause, a myomectomy should be considered.
I have fibroids and never had symptoms. I now have this terrible pain. What is happening?
In some cases fibroids can suffer degeneration or necrosis. This usually happens when the fibroid grows too quickly and the blood supply doesn't form at the same speed. Without enough blood to nourish and support the fibroid cells some of them die. This is a rare situation, but it is very acute and you should look for medical attention straight away. It is somewhat more frequent during pregnancy as some fibroids can experience significant growth stimulated by the pregnancy hormones.
If I have a hysterectomy, will I have a big cut on my stomach?
No, in most cases it is possible to do a laparoscopic hysterectomy using 4 little incisions less than 1 cm each.
Can I fall pregnant after a myomectomy?
Although it is not possible to guarantee until you try, the aim of a myomectomy is to preserve fertility. In the absence of other problems or complications you should be able to have a normal pregnancy.
Can I have a normal delivery after a myomectomy?
It depends on the position of the fibroid and the size of the incision made on the uterus. Fibroids that require surgery are usually large and embedded into the uterine wall. Therefore, most women who had a myomectomy end up with a uterine incision and a scar. If this is the case, they should not labour and should have a caesarean section. In some cases of either mostly subserosal fibroids (growing outside the uterus) or mostly submucosal fibroids (growing inside the uterine cavity) large incisions are not necessary and labour followed by vaginal delivery is possible. The best way to know is to ask for the advice and recommendation of the surgeon who performed the myomectomy.
Can fibroids become cancer?
No. It was thought in the past that fibroids could become malignant, but the theory most accepted at present is that the malignant tumour grew side by side and independent from the fibroid. Also, in some cases a tumour is removed thinking it was a fibroid but then the pathology shows it is actually cancer. In general, if the history, examination and ultrasound suggest it is a fibroid, cancer is found in only about 1/1000 cases.
Can fibroids come back?
Fibroids that have been removed through a myomectomy do not come back. Nevertheless, a uterus that grew fibroids once is prone to developing new ones. Recurrence rates vary, but are believed to be around 20%. Up to one in ten women who have had a myomectomy may require another operation in the future. Factors influencing the chance of recurrence include number of fibroids and age at the time of treatment. After a hysterectomy there are no recurrences.
Can I use alternative treatments to reduce my fibroids?
Alternative therapies such as vitamins, dietary supplements, acupuncture, and Chinese herbs have not been shown to decrease the size or to remove fibroids. In some cases they may help with controlling symptoms by reducing bleeding or pain symptoms. However, there are no well conducted scientific studies testing those therapies and most of the evidence is anecdotal. We recommend speaking with a medical doctor or your surgeon before starting any alternative medicines or treatments.