Leiomyoma of the uterus (Fibroid Tumor)

Introduction

Essentials of Diagnosis

     
  • Irregular enlargement of the uterus (may be asymptomatic).  
  • Heavy or irregular vaginal bleeding, dysmenorrhea.  
  • Acute and recurrent pelvic pain if the tumor becomes twisted on its pedicle or infarcted.  
  • Symptoms due to pressure on neighboring organs (large tumors).

General Considerations

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. A submucous myoma may become pedunculated and descend through the cervix into the vagina.

Clinical Findings

A. Symptoms and Signs
In nonpregnant women, myomas are frequently asymptomatic. However, they can cause urinary frequency, dysmenorrhea, heavy bleeding (often with anemia), or other complications due to the presence of an abdominal mass. Occasionally, degeneration occurs, causing intense pain. Infertility may be due to a myoma that significantly distorts the uterine cavity.

B. Laboratory Findings
Hemoglobin levels may be decreased as a result of blood loss, but in rare cases polycythemia is present, presumably as a result of the production of erythropoietin by the myomas.

C. Imaging
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. Hysterography or hysteroscopy can also confirm cervical or submucous myomas.

Differential Diagnosis

Irregular myomatous enlargement of the uterus must be differentiated from the similar but symmetric enlargement that may occur with pregnancy or adenomyosis (the presence of endometrial glands and stroma in the myometrium). 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.

Treatment

A. Emergency Measures
If the patient is markedly anemic as a result of long, heavy menstrual periods, preoperative treatment with depot medroxyprogesterone acetate, 150 mg intramuscularly every 28 days, or danazol, 400-800 mg orally daily, will slow or stop bleeding, and medical treatment of anemia can be given prior to surgery. Emergency surgery is required for acute torsion of a pedunculated myoma. The only emergency indication for myomectomy during pregnancy is torsion; abortion is not an inevitable result.

B. Specific Measures
Women who have small asymptomatic myomas should be examined at 6-month intervals. If necessary, elective myomectomy can be done to preserve the uterus. Myomas do not require surgery on an urgent basis unless they cause significant pressure on the ureters, bladder, or bowel or severe bleeding leading to anemia or unless they are undergoing rapid growth. Cervical myomas larger than 3-4 cm in diameter or pedunculated myomas that protrude through the cervix must be removed. Submucous myomas can be removed using a hysteroscope and laser or resection instruments.

Because the risk of surgical complications increases with the increasing size of the myoma, preoperative reduction of myoma size is desirable. GnRH analogs such as depot leuprolide, 3.75 mg intramuscularly monthly, or nafarelin, 0.2-0.4 mg intranasally twice a day, are used preoperatively for 3- to 4-month periods to induce reversible hypogonadism, which temporarily reduces the size of myomas, suppresses their further growth, and reduces surrounding vascularity.

C. Surgical Measures
Surgical measures available for the treatment of myoma are laparoscopic or abdominal myomectomy and total or subtotal abdominal, vaginal, or laparoscopy-assisted vaginal hysterectomy. Myomectomy is the treatment of choice during the childbearing years. Recent developments include transcatheter bilateral uterine artery embolization and myolysis with cryotherapy or cauterization. While these approaches are promising and potentially cost-effective alternatives, randomized clinical trials to compare long-term outcomes with these new methods with conventional therapy are needed.

Prognosis

Surgical therapy is curative. Future pregnancies are not endangered by myomectomy, although cesarean delivery may be necessary after wide dissection with entry into the uterine cavity.

Preferences:
Beinfeld MT et al: Cost-effectiveness of uterine artery embolization and hysterectomy for uterine fibroids. Radiology 2004;230:207.

Myers ER et al: Management of uterine leiomyomata: what do we really know? Obstet Gynecol 2002;100:8.

Provided by ArmMed Media
Revision date: June 20, 2011
Last revised: by Amalia K. Gagarina, M.S., R.D.