Fibroids are benign (non-cancerous) tumours of muscle and fibrous tissue that grow in or around the uterus (womb). They are common and vary in size. They usually occur in women of childbearing age and their growth is stimulated by oestrogen. Once menopause starts they start shrinking in size and become less troublesome.
Fibroids are sometimes known as uterine myomas fibromas or leiomyomas.
In very rare circumstances, fibroids become cancerous, a condition known as leiomyosarcoma.
- The type of fibroid depends on the part of the uterus in which they grow. The main types of fibroid are:
- Intramural fibroids: these develop in the muscle wall of the uterus and are the most common type of fibroid.
- Subserosal fibroids: these grow outside the wall of the uterus into the pelvis.
- Submucosal fibroids: these develop in the muscle beneath the inner lining of the uterine wall and grow into the cavity of the womb. They are more likely to cause menstrual problems or difficulty with conception.
- Pedunculated fibroids: these grow from the outside wall of the womb and are attached to the uterine wall by a narrow stalk.
Most women with fibroids do not have symptoms. Problems, when they do occur, can range from mild to severe, and can include:
- Heavy, painful and/or prolonged periods
- Bleeding between menstrual cycles
- Abdominal pain or discomfort
- Back pain
- Pelvic pain (caused by the tumour pressing on the pelvic organs)
- Frequent urination or difficulty passing urine
- Pain during sex
- A firm mass, often located near the middle of the pelvis, which can be felt by a doctor
Although fibroids do not interfere with conception, if they displace the cavity of uterus (submucosal fibroids) then they can affect the implantation of the embryo and result in recurrent miscarriage or reduced fertility.
In such cases, the removal of the fibroid is recommended. In some cases this can be done with a telescopic technique.
Fibroids are commonly found as an irregular mass during a pelvic and abdominal examination. The following diagnostic procedures may also be used:
- Pelvic ultrasound: this can be performed with a probe either vaginally or abdominally. Apart from confirming the diagnosis, the ultrasound can also help to find the number, size and position of the fibroids.
- Magnetic resonance imaging (MRI): this is a non-radiating imaging technique that creates picture slices of the pelvis and uterus. This is used to further evaluate the size and location of the fibroids in order to help determine the appropriate form of treatment.
- Hysteroscopy: a small telescope called a hysteroscope is inserted through the vagina. It provides a visual examination of the cervix canal and the uterus. It is the gold standard investigation for the diagnosis (and treatment) of submucosal fibroids. It can be performed either under local or general anaesthetic.
Not all fibroids need treatment, as they are most commonly benign and eventually shrink with the arrival of the menopause. Treatments are dependent on the type and severity of symptoms. The type of treatment may also depend on a woman’s plans for future pregnancies.
- Medication: drugs cannot eliminate fibroids but they can reduce their size or slow down their speed of growth. They work by affecting the hormones that regulate the menstrual cycle, and reduce heavy periods. They can, however, be less effective for larger fibroids.
- Levonorgestrel intrauterine system (LNG-IUS): this is a small plastic T-shaped device placed inside the womb. It slowly releases the progesterone hormone Levonorgestrel to stop the uterus lining growing too quickly. It helps it to become thinner and bleeding becomes noticeably lighter.
- Gonadotropin-releasing hormone (Gn-RH) agonists: these, prescribed on a short-term basis (3–6 months) block the production of oestrogen and progesterone to create an artificial and temporary menopausal state. This effectively stops periods to allow the fibroids to shrink. Sometimes we may prescribe a Gn-RH agonist to reduce the size of a woman’s fibroids before elective surgery. Menopausal symptoms (hot flushes, sweating, muscle stiffness, vaginal dryness) are a side-effect of this treatment so a low dose of hormone replacement therapy (HRT) is often offered alongside Gn-RH. Fibroids may also start growing again and the symptoms gradually return after the medication is stopped.
- Ulipristal acetate (Esamya): this is a daily tablet approach to treating fibroids that cause moderate to severe symptoms. After the initial course of treatment, two periods are monitored and if they are still heavy, another three-month course of Ulipristal acetate may be given.
- Contraceptive pill: this is a popular option to make bleeding lighter and help reduce menstrual pain.
- Intra-uterine system (Mirena coil): this progesterone-releasing coil is implanted inside the womb to reduce heavy bleeding caused by fibroids. It can improve the symptoms but doesn’t affect the size of the fibroids.
If medical management has failed or significantly large fibroid is found, then we may advise surgical intervention.