Fibroids

Fibroids, benign tumours of the smooth muscle of the uterus which are more correctly known as leiomyomas. Fibroids are among the most common tumours found in the human body and are present in 5 per cent of women. They increase in frequency with age, and are more common in non-Caucasians. They are often multiple and vary in size from large tumours occupying a significant proportion of the pelvis and abdomen to microscopic lumps. The cause of fibroids is unknown but they are oestrogen dependent, increasing in pregnancy and regressing when the ovaries cease to function. Hormone replacement therapy only rarely causes regrowth of fibroids.

Fibroids are usually uncomplicated but they may affect menstruation, break down, undergo torsion (twisting), or calcify. Fibroids are associated with infertility and recurrent miscarriage. Occasionally, if large, fibroids may interfere with pregnancy; very rarely (less than 0.5 per cent), fibroids can undergo malignant change and become cancerous.

Fibroids vary in size and severity, and even when of a considerable size, may not be obvious to the patient, who may suffer no symptoms. They may be discovered during routine examination or may produce heavy periods and pelvic pain. Acute pelvic or abdominal pain is usually experienced if fibroids burst or break down during pregnancy. If large, fibroids can physically interfere with urination or defecation, leading to urinary retention (or increased frequency), or constipation. Fibroids can be diagnosed by routine examination, and a high-resolution ultrasound scan of the pelvis and abdomen helps to distinguish them from ovarian cysts or other tumours.

Treatment is usually only recommended when the woman suffers symptoms, which is usually the case. Treatment may involve surgical removal of the fibroids together with the uterus (a hysterectomy) or, in some cases, fibroids may be removed leaving the uterus intact (a myomectomy). Myomectomy can be a difficult operation and is associated with heavy bleeding; for this reason it is generally restricted to women who wish to have children. Alternatively, the control of symptoms can sometimes be achieved with medicines that reduce the pain and heavy menstrual blood loss caused by the fibroids, but these treatments have no effect on the size or the number of fibroids. Newer medicines, known as gonadotrophin-releasing hormone analogues, can shrink fibroids temporarily, but the fibroids will grow back to the original size once the medication is stopped, usually after three to four months. Their main use in fibroids is to make surgical treatments easier. Fibroids may recur unless the uterus is removed, but they usually regress after the menopause, thereby reducing the need for treatment.