Fibroids (uterine leiomyomas) are benign tumours of the smooth muscle cells of the uterus, with a thin capsular covering. They start as multiple, single cell seedlings distributed throughout the uterine wall. These then increase in size very slowly over many years, stimulated by oestrogens. As the fibroid grows, the central areas may not receive an adequate blood supply and undergo benign degeneration often followed by calcification.
Fibroids are classified according to their position within the uterine wall:
- Intramural (the majority).
- Growing into the uterine cavity; either submucosal, pedunculated submucosal or pedunculated vaginal.
- Growing outwards from the uterus - can be:
- Pedunculated subserous (abdominal)
Most uterine fibroids are asymptomatic but they can cause significant morbidity, including prolonged or heavy menstrual bleeding, pelvic pressure or pain and reproductive dysfunction. Fibroids almost certainly don't undergo malignant change to a sarcoma but tumours assumed to be benign fibroids are very occasionally later found to be uterine sarcomas.
- Uterine fibroids are the most common noncancerous tumours in women of childbearing age.
- Uterine fibroids are the single most common indication for hysterectomy. They are clinically apparent in up to 25% of women.
- Fibroids are more common in women with a higher body mass index and in nonsmokers.
- Fibroids are three times more common in black American women than in white women. Black women tend to be younger at the time of diagnosis and at hysterectomy. Asian women have a lower incidence of symptomatic uterine fibroids.
- Although they have been reported occasionally in adolescents, most women are in their 30s or 40s when the myomas become symptomatic. The incidence increases with age up to the menopause.
- Pregnancy and the use of oral contraceptives decrease the risk of fibroids.
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- Up to half of women with fibroids have no symptoms. The presence of symptoms depends on their size, position and condition.
- They usually present between the ages of 30 and 50 years.
- They may cause excessive or prolonged heavy periods, leading to iron deficiency anaemia and therefore lethargy and pallor. Submucosal fibroids are more likely to cause menorrhagia.
- Pedunculated submucosal fibroids can cause persistent intermenstrual bleeding.
- They can cause dysmenorrhoea and dyspareunia; acute pain occurs when a fibroid degenerates or there is torsion of a pedunculated fibroid.
- An enlarging uterus may cause lower abdominal cramps, discomfort, and heaviness. Pressure on the bowel may cause constipation and pressure on the bladder may cause urinary frequency.
- They may present with recurrent miscarriage or infertility.
- Palpable abdominal mass arising from the pelvis.
- Enlarged, often irregular uterus palpable on bimanual pelvic examination.
- Signs of anaemia due to menorrhagia.
Fibroids are so common that other more serious causes of abnormal bleeding or pelvic mass can often co-exist and need to be excluded. The differential diagnosis for fibroids depends on the symptoms they are causing but includes:
- Dysfunctional uterine bleeding.
- Endometrial polyps, endometrial carcinoma.
- Chronic pelvic inflammatory disease.
- Tubo-ovarian abscess.
- Uterine sarcoma.
- Ovarian tumour.
- Pelvic masses (other causes of a pelvic mass include tumour of the large bowel, appendix abscess, and diverticular abscess).
- Pregnancy test may be indicated.
- FBC (anaemia), iron studies.
- Pelvic ultrasound: to confirm the presence and size of a fibroid, exclude other causes of a pelvic mass, and exclude possible complications such as urinary tract obstruction causing hydronephrosis. Transvaginal ultrasound is more accurate.
- MRI: this is occasionally required if ultrasound is not definitive in assessing depth when hysteroscopic removal is being considered.
- Endometrial sampling: for histology in the assessment of abnormal uterine bleeding.
- Hysteroscopy: with biopsies.
Treatment is only required if symptomatic, as long as other causes of pelvic masses and abnormal bleeding have been excluded.
- Non-steroidal anti-inflammatory agents, eg mefenamic acid, reduce menstrual blood loss and dysmenorrhoea.
- Antifibrinolytic agents, eg tranexamic acid, also reduce menorrhagia.
- The combined oral contraceptive pill is also effective if the patient requires contraception.
- Danazol reduces menorrhagia, by suppressing gonadotrophin secretion and abolishing cyclical ovarian function.
- Gonadotrophin-releasing hormone (GnRH) agonists:
- Produce reduction in the size of fibroids, in the region of 50% within three months but, once discontinued, fibroids regrow to their former size within about two months; therefore, they are mainly useful preoperatively.
- They are associated with significant side-effects, including amenorrhoea, menopausal symptoms and bone loss which can lead to osteoporosis in long-term use.
Surgery is indicated when:
- There is excessively enlarged uterine size.
- Pressure symptoms are present.
- Medical management is not sufficient to control symptoms.
- Subfertility is also a factor.
Surgical options include:
- This is used in patients who wish to maintain their reproductive potential or keep their uterus. However, during surgery this may be revealed as an unrealistic option and women should be consented appropriately with this in mind.
- Laparoscopic myomectomy is the best treatment option for symptomatic women with subserous fibroids, who wish to maintain their fertility.
- Hysteroscopic myomectomy is an established surgical procedure for women with submucosal fibroids and excessive uterine bleeding, infertility or repeated miscarriages.
- There is a risk of excessive bleeding and a risk of requiring hysterectomy at the time of the operation. Therefore, blood should be cross-matched preoperatively and the patient should consent (on the consent form) to hysterectomy should the need arise.
- Myomectomy carries an annual recurrence rate of 2-3%.
- Pedunculated vaginal fibroids may be removed vaginally but biopsy is essential to exclude a sarcoma in women aged over 60 years.
- Hysteroscopic endometrial ablation - for women presenting with menorrhagia.
- MRI-guided transcutaneous focused ultrasound is safe and effective. High power pulses of ultrasound are used to ablate the fibroid - there may be skin burns as a result. Long-term outcomes (fertility and need for further treatments) is uncertain as yet.
- Total hysterectomy:
- This has been the mainstay of treatment for many years, eliminating both symptoms and the possibility of recurrence.
- In women who have completed their family, hysterectomy remains the most effective treatment for excessive uterine bleeding.
- It is also indicated when there are many fibroids.
- If these are small then the vaginal route is appropriate but if they are large (especially if intraligamentous) then laparotomy is indicated with preservation of ovaries if possible.
- The National Institute for Health and Clinical Excellence (NICE) recommends that laparoscopic techniques for hysterectomy (eg laparoscopically-assisted vaginal hysterectomy, laparoscopic hysterectomy, laparoscopic supracervical hysterectomy and total laparoscopic hysterectomy) appear to be sufficiently safe and effective to support their use. There is, however, a higher risk of urinary tract injury and of severe bleeding in comparison with open surgery.
- Uterine artery embolisation (UAE):
- This procedure has been shown to be both effective (for short- and medium-term symptom relief) and safe for women who may wish to have children at some time in the future. A register of 1,387 patients showed 84% and 83% had improvement in their symptoms at 6 and 24 months.
- If patients are considering pregnancy, there is a theoretical risk of placental insufficiency leading to small-for-gestational-age babies, increased Caesarean section and prematurity.
- Ensuring the tumour is a benign fibroid and not a malignant sarcoma is essential prior to UAE.
- Women should be informed during consenting that symptom relief may not be achieved for some women and that symptoms may return.
- Compared with UAE, hysterectomy is associated with better improvement in pelvic pain. However, UAE is a good alternative to hysterectomy.
- Iron-deficiency anaemia.
- Bladder frequency, constipation (due to increased pelvic pressure).
- Hyaline degeneration (asymptomatic).
- Torsion of pedunculated fibroid.
- Ureteral obstruction causing hydronephrosis.
- Infertility; this may occur as a result of narrowing of the isthmic portion of the Fallopian tube or as a consequence of interference with implantation (especially with submucosal fibroids).
- In pregnancy:
- Recurrent miscarriage.
- Fetal malpresentation.
- Red degeneration: presents with fever, pain and vomiting.
- Intrauterine growth restriction.
- Premature labour.
- Postpartum haemorrhage.
Typically, fibroids regress with the menopause and symptoms resolve; however, they will continue if the patient is on hormone replacement therapy.
Further reading & references
- Heavy menstrual bleeding, NICE Clinical Guideline (January 2007)
- Fibroids, Prodigy (December 2009)
- Thomason P, Uterine Leiomyoma (Fibroid) Imaging, Medscape, May 2011
- Stewart EA; Uterine fibroids. Lancet. 2001 Jan 27;357(9252):293-8.
- Buzaglo K, Bruchim I, Lau SK, et al; Sarcoma post-embolization for presumed uterine fibroids. Gynecol Oncol. 2008 Jan;108(1):244-7. Epub 2007 Oct 22.
- Agdi M, Tulandi T; Endoscopic management of uterine fibroids. Best Pract Res Clin Obstet Gynaecol. 2008 Mar 4;.
- Olufowobi O, Sharif K, Papaionnou S, et al; Are the anticipated benefits of myomectomy achieved in women of reproductive age? A 5-year review of the results at a UK tertiary hospital.; J Obstet Gynaecol. 2004 Jun;24(4):434-40.
- Magnetic resonance image-guided transcutaneous focused ultrasound for uterine fibroids, NICE Interventional Procedure Guideline (November 2011)
- Al-Mahrizi S, Tulandi T; Treatment of uterine fibroids for abnormal uterine bleeding: myomectomy and uterine artery embolization. Best Pract Res Clin Obstet Gynaecol. 2007 Dec;21(6):995-1005. Epub 2007 May 2.
- McPherson K, Metcalfe MA, Herbert A, et al; Severe complications of hysterectomy: the VALUE study. BJOG. 2004 Jul;111(7):688-94.
- Laparoscopic techniques for hysterectomy, NICE Technology Appraisal (2007)
- Uterine artery embolisation for fibroids, NICE Interventional Procedure Guideline (November 2010)
- Uterine Artery Embolisation in the Management of Fibroids, Royal College of Obstetricians and Gynaecologists (Jan 2009)
- Laparoscopic laser myomectomy, NICE Technology Appraisal (2003)
- Magnetic resonance image-guided percutaneous laser ablation of uterine fibroids, NICE Technology Appraisal (2003)
- Reed SD, Cushing-Haugen KL, Daling JR, et al; Postmenopausal estrogen and progestogen therapy and the risk of uterine leiomyomas.; Menopause. 2004 Mar-Apr;11(2):214-22.
|Original Author: Dr Colin Tidy||Current Version: Dr Hayley Willacy||Peer Reviewer: Dr John Cox|
|Last Checked: 19/01/2012||Document ID: 1236 Version: 25||© EMIS|
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