LEIOMYOMA OF THE UTERUS (Fibroid Tumor)
Uterine leiomyoma is the most common benign neoplasm of the female genital tract. It is a discrete, round, firm, often multiple uterine tumor composed of smooth muscle and connective tissue. The most convenient classification is by anatomic location: (1) intramural, (2) submucous, (3) subserous, (4) intraligamentous, (5) parasitic (ie, deriving its blood supply from an organ to which it becomes attached), and (6) cervical. Submucous myomas may become pedunculated and descend through the cervix into the vagina.
Signs and symptoms
In nonpregnant women, myomas are frequently asymptomatic. The two most common symptoms of uterine leiomyomas for which women seek treatment are AUB and pelvic pain or pressure.
Occasionally, degeneration occurs, causing intense pain.
The risk of miscarriage is increased if the myoma significantly distorts the uterine cavity and interferes with implantation.
Fibroids rarely cause infertility by leading to bilateral tubal blockage; they more commonly cause miscarriage and pregnancy complications such as preterm labor, preterm delivery, and malpresentation.
Ultrasonography will confirm the presence of uterine myomas and can be used sequentially to monitor growth. When multiple subserous or pedunculated myomas are being followed, ultrasonography is important to exclude ovarian masses. MRI can delineate intramural and submucous myomas accurately and is necessary prior to uterine artery embolization to assess blood flow to the fibroids. Hysterography or hysteroscopy can also confirm cervical or submucous myomas.
Irregular myomatous enlargement of the uterus must be differentiated from the similar, but symmetric enlargement that may occur with pregnancy or adenomyosis. Subserous myomas must be distinguished from ovarian tumors. Leiomyosarcoma is an unusual tumor occurring in 0.5% of women operated on for symptomatic myoma. It is very rare under the age of 40 and increases in incidence thereafter.
A. Emergency Measures
Emergency surgery may be required for acute torsion of a pedunculated myoma. If the patient is markedly anemic as a result of long, heavy menstrual periods, preoperative treatment with DMPA, 150 mg intramuscularly every 3 months, or use of a GnRH agonist, such as depot leuprolide, 3.75 mg intramuscularly monthly, will slow or stop bleeding, and medical treatment of anemia can be given prior to surgery. Levonorgestrel-containing IUDs have also been used to decrease the bleeding associated with fibroids; however, IUD placement can be more technically challenging in patients with fibroids. The only emergency indication for myomectomy during pregnancy is torsion of a pedunculated fibroid.
B. Specific Measures
Women who have small asymptomatic myomas can be managed expectantly and evaluated annually. In patients wishing to defer surgical management, nonhormonal therapies (such as NSAIDs and tranexamic acid) have been shown to decrease menstrual blood loss. Hormonal therapies such as GnRH agonists and selective progesterone receptor modulators (SPRMs), such as low-dose mifepristone (5–10 mg/day) have been shown to reduce myoma volume, uterine size, and menstrual blood loss. Surgical intervention is based on the patient’s symptoms and desire for future fertility. Uterine size alone is not an indication for surgery. Cervical myomas larger than 3–4 cm in diameter or pedunculated myomas that protrude through the cervix can cause bleeding, infection, degeneration, pain, or urinary retention and often require removal. Submucous myomas can be removed by hysteroscopic resection.
Because the risk of surgical complications increases with the increasing size of the myoma, preoperative reduction of myoma size is sometimes desirable prior to hysterectomy. GnRH analogs such as depot leuprolide, 3.75 mg intramuscularly monthly, can be used preoperatively for 3- to 4-month periods to induce reversible hypogonadism, to temporarily reduce the size of myomas, and reduce surrounding vascularity.
C. Surgical Measures
A variety of surgical measures are available for the treatment of myomas: myomectomy (hysteroscopic, laparoscopic, or abdominal) and hysterectomy (vaginal, laparoscopy-assisted vaginal, laparoscopic, abdominal, or robotic). Myomectomy is the treatment of choice for women who wish to preserve fertility. Uterine artery embolization is a minimally invasive treatment for uterine fibroids. In uterine artery embolization, the goal is to block the blood vessels supplying the fibroids, causing them to shrink. Magnetic resonance–guided high-intensity focused ultrasound, myolysis/radiofrequency ablation, and laparoscopic or vaginal occlusion of uterine vessels are newer interventions, with a smaller body of evidence.