Atlas of pathophysiology, 2 Edition

Part II - Disorders

Genital Diseases

Fibroid Disease of Uterus

Uterine leiomyomas, also known as myomas, fibromyomas, or fibroids, are the most common benign tumors in women. They're most common in the uterine corpus, although they may appear on the cervix or on the round or broad ligament.

The tumors become malignant (leiomyosarcoma) in less than 0.1% of patients, which should serve to comfort women concerned with the possibility of a uterine malignancy in association with a fibroid.

Age Alert

Fibroids of the uterus may be present in 15% to 20% of reproductive age women and 30% to 40% of women over age 30.

Causes

Primary cause unknown

Implicated regulators of leiomyoma growth

·   Several growth factors, including epidermal growth factor

·   Steroid hormones, including estrogen and progesterone

Pathophysiology

Leiomyomas are masses of smooth muscle and fibrous connective tissue. They're classified according to location: in the uterine wall (intramural), protruding into the endometrial cavity (submucous), or protruding from the serosal surface of the uterus (subserous). Their size varies greatly. They're usually firm and surrounded by a pseudocapsule composed of compressed but otherwise normal uterine myometrium. The uterine cavity may become larger, increasing the endometrial surface area and causing increased uterine bleeding.

Signs and symptoms

·   Mostly asymptomatic

·   Abnormal bleeding, typically menorrhagia with disrupted submucosal vessels (most common symptom)

·   Pain only with:

§  torsion of a pedunculated (stemmed) subserous tumor

§  degenerating leiomyomas (fibroid outgrows its blood supply and shrinks down in size; after myolysis, a laparoscopic procedure to shrink fibroids; after uterine artery embolization)

·   Pelvic pressure and impingement on adjacent viscera leads to mild hydronephrosis

Diagnostic test results

·   Blood studies show anemia from abnormal bleeding.

·   Bimanual examination reveals enlarged, firm, nontender, and irregularly contoured uterus.

·   Ultrasound and magnetic resonance imaging accurately assess the dimension, number, and location of tumors.

Treatment

Nonsurgical

·   Gonadotropin-releasing hormone agonists (not a cure, as tumors increase in size after cessation of therapy)

·   Nonsteroidal anti-inflammatory drugs

Surgical

·   Hysteroscopic resection of fibroids

·   Abdominal, laparoscopic, or hysteroscopic myomectomy (removal of tumors in the uterine muscle)

·   Myolysis (a laparoscopic procedure, performed on an outpatient basis); contraindicated in women who desire fertility

·   Uterine artery embolization (a promising alternative to surgery, but no existing long-term studies confirm effect on fertility or establish long-term success)

·   Hysterectomy (usually isn't the only available option)

·   Blood transfusions for severe anemia due to excessive bleeding

P.321

UTERINE FIBROIDS

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