Also known as myoma and uterine fibroids, fibromyoma are benign (non-cancerous) tumours in the wall of uterus and its adjacent connective tissue. Oestrogen stimulates the growth of fibromyoma, which may appear after the commencement of menstruation grow rapidly during pregnancy and shrink on menopause. If a fibroid grows rapidly, it may outstrip its nutrition supply from nearby blood vessels, resulting in the degeneration and death of the oxygen-deprived tissue; severe abdominal pain may result. Some fibroids can enlarge beyond the size of a three-month pregnancy and may cause excessive bleeding, anaemia that does not respond to iron supplements, pelvic pain and pressure on urinary structures. However, most women have no symptoms at all. In women who do not wish to have more children, a large symptomatic fibroid is an accepted reason for hysterectomy. An increasingly popular alternative is a myomectomy, in which just the fibroid is removed.
Although fibromyoma are benign in their nature, they can undergo malignant (cancerous) change in approximately 0.1 - 0.5% of patients. Clinical symptoms depend on where in the uterus fibromyoma are located, their size and the physiological state of the patient, e.g. pregnancy. For example cervical fibroids may manifest with vaginal bleeding, dyspareunia (painful intercourse) and infertility.
Fibromyoma is probably the most appropriate name, since this benign tumour is composed from two elements: muscle cells from arterial vessels feeding uterus ("myoma" element), and the fibrous connective tissue ("fibro" element) which builds uterine wall. Fibroids are usually firm, spherical lumps that often occur in groups. On cut section fibromyoma reveal whorls of the two elements, fibrous and muscular, resembling an onion on a cross-section.
One in five women in the USA has at least some evidence of fibroids, with most occurring in women in their thirties and forties. Fibroids are much more common among black women than among white women, although the reason for this difference is not known. Uterine fibroids account for 30% of hysterectomies.