Uterine Fibroids
Uterine fibroids are the most common solid tumors of the female pelvis, affecting up to 70% of women. The highest incidence occurs during the fifth decade of life. They are symptomatic in approximately 25% of cases and are the direct cause of 30% of hysterectomies (removal of the uterus).
Causes
Race is a significant risk factor, as fibroids are 3 to 9 times more common in Black women than in Asian or White women. A family history of fibroids also increases risk, being 2.5 times more frequent in patients with three or more affected relatives.
Early menarche, obesity, hypertension, diabetes, and a diet high in red meat and vitamin A also appear to increase the risk of developing uterine fibroids.
On the other hand, smoking (more than 10 cigarettes per day), early childbirth, and multiparity are factors associated with a reduced risk of developing this condition.
Symptoms
Uterine fibroids are classified according to their location and can be divided into three main groups: submucosal, intramural, and subserosal.
Submucosal fibroids account for 5–10% of all fibroids but are the most symptomatic. They develop near the endometrium and deform the uterine cavity. The most common symptoms include heavy menstrual bleeding (menorrhagia), prolonged periods (polymenorrhea), and painful menstruation (dysmenorrhea). They are also associated with infertility, miscarriage risk, increased cesarean section rates, breech presentation, premature rupture of membranes, preterm delivery, and placental abruption. These complications are likely related to distortion of the uterine cavity and abnormalities in endometrial and placental vascularization.
Intramural fibroids represent about 80% of all fibroids. They develop within the thickness of the myometrium and usually do not cause symptoms unless they grow large, since they do not initially affect the endometrial lining or the uterine serosa. When their growth affects either layer, they are referred to as transmural fibroids and may produce symptoms similar to submucosal or subserosal fibroids.
Subserosal fibroids account for 10–15% of uterine fibroids. They develop beneath the uterine serosa and typically do not cause symptoms unless they reach a large size. In such cases, they may compress nearby organs such as the rectum, bladder, or ureters, leading to pelvic pain, constipation, dyspareunia (pain during sexual intercourse), or urinary discomfort.
Diagnosis
Diagnosis of uterine fibroids is mainly based on gynecological examination, ultrasound (abdominal and transvaginal), and diagnostic hysteroscopy. Hysteroscopy is performed on an outpatient basis and allows direct visualization of the submucosal component of the fibroid and helps determine the most appropriate treatment.
Fibroids rarely become malignant. However, it can be very difficult to distinguish them from leiomyosarcomas during routine examination. Leiomyosarcoma is a malignant tumor affecting approximately 0.7 per 100,000 women per year. If there is diagnostic uncertainty due to rapid tumor growth or suspicious imaging findings (Doppler ultrasound or MRI), surgical removal is recommended, as no diagnostic test can definitively establish the differential diagnosis.
Treatment
Treatment of uterine fibroids depends on several factors, including the patient’s age, number of children, number and size of fibroids, their location, and the symptoms they cause.
Medical treatments are indicated in few cases because, although they may reduce fibroid size, they do not eliminate them and often cause side effects that are poorly tolerated. Their use is generally limited to patients for whom surgery is contraindicated or those close to menopause who may soon become asymptomatic. They may also be used as preoperative therapy to reduce fibroid size and facilitate surgery.
Therefore, treatment is most often surgical. Hysteroscopic surgery is the treatment of choice for submucosal fibroids, as it is minimally invasive and usually performed on an outpatient basis.
For intramural and subserosal fibroids, the surgical approach depends on the patient’s age, reproductive wishes, and the number and size of the fibroids. Options include myomectomy (removal of the fibroids) or hysterectomy (removal of the uterus), which may be performed via abdominal, laparoscopic, or vaginal approaches depending on the individual case.