Uterine fibroids are the most common solid tumours of the female pelvis, reaching an incidence of up to 70% of women. The highest incidence occurs in the age range of 40-50. They are symptomatic in 25% of cases and the direct cause of 30% of hysterectomies (removal of the uterus).
Risk factors include race, with them being between 3 and 9 times more common in black women than in Asian and white women, and a family history of fibroids, with them being 2.5 times more common in patients with three or more affected family members. Early menarche, obesity, high blood pressure, diabetes and the consumption of a diet containing red meat and vitamin A also seem to increase the risk of onset of uterine fibroids. On the other hand, smoking (more than 10 cigarettes a day), giving birth at a young age and having more than one child are factors that decrease the risk of suffering from this condition.
Uterine fibroids are classified according to their location, and they can be subdivided into three large groups which are submucosal, intramural and subserosal.
Submucosal fibroids represent 5 to 10% of all fibroids, but are those which produce the most symptoms. They develop in the area close to the endometrium and they deform the uterine cavity displacing it and producing as the most common symptoms, very heavy (hypermenorrhoea), long (polymenorrhoea) and painful (dysmenorrhoea) periods. They are also related to infertility, risk of abortion, higher incidence of Caesarean sections, breech delivery, premature rupture of membranes, preterm birth and premature separation of the placenta. All of this is possibly related to the deformity of the uterine cavity and anomalies in the endometrial and placental vascularisation that they may cause.
Intramural fibroids account for 80% of all fibroids. They are produced in the thickness of the myometrium and do not usually cause symptoms unless they reach a large size, since they do not affect the endometrial mucosa or the uterine serous membrane. When, due to growth, they affect the endometrial mucosa or the uterine serous membrane, they are considered transmural fibroids and they produce symptoms similar to the submucosal or subserosal fibroids.
Subserosal fibroids represent between 10-15% of uterine fibroids. They are those which develop under the uterine serous membrane and do not usually produce symptoms, except when they become large, when they may produce symptoms due to the compression of neighbouring organs, such as the rectum, the bladder or the ureters, including pelvic pain, constipation, dyspareunia (painful intercourse) or painful urination.
The diagnosis of uterine fibroids is based mainly on a gynaecological examination, in the ultrasound scan (abdominal and vaginal) and in a diagnostic hysteroscopy, a test that is performed on an outpatient basis and allows the submucosal component of the fibroid to be assessed through direct vision and to assess which is the most appropriate treatment.
Uterine fibroids rarely become malignant, although in the routine examination it is very difficult to differentiate from leiomyosarcoma, which is a malignant tumour affecting 0.7 out of 100,000 women per year. In the case of diagnostic uncertainty due to rapid growth of the tumour or suspicion from the imaging tests (Doppler ultrasound and magnetic resonance scan) it should be removed, since there is no diagnostic test that allows the differential diagnosis to be made with certainty.
Treatment of uterine fibroids will depend on many factors, such as the age of the patient, the number of children, the number and size of the fibroids, their location and the symptoms that they produce.
Medical treatments are indicated in few cases as, although they decrease their size, they do not remove them and they have side effects, which in the majority of cases are poorly tolerated by the patient. Their use is restricted to patients in whom surgery is contraindicated or who will probably stop being symptomatic in a short period of time, as they are of an age close to the menopause. They are also used as a pre-surgical treatment to reduce their size and to facilitate the surgery.
Treatment is therefore almost always surgical, with the surgical hysteroscopy being the technique of choice in submucosal fibroids, since it is minimally invasive and it allows for an outpatient treatment in most cases. In intramural and subserosal fibroids, the technique of choice varies according to the age of the patient, her reproductive desires and the number and size of the fibroids. It may be a myomectomy (removal of the fibroids) or a hysterectomy (removal of the uterus) whether it is via the abdominal or laparoscopic route.