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A. Characteristics

  1. Solid, benign tumors of uterine smooth muscle
  2. Also called fibroids, myomas, or fibromyomas
  3. Most common masses of uterine origin
  4. Usually multiple nodules of different sizes

B. Occurrence

  1. Extremely common
    1. Over 20% of white females >30 years
    2. About 50% of black females >30 years
  2. Timing
    1. Rare before puberty
    2. Very common during childbearing years
    3. Rarely grow following menopause
  3. Organ Involvement
    1. Uterus most common
    2. Fallopian Tubes
    3. Vagina
    4. Ligaments (uterosacral, round)
    5. Vulva, gastrointestinal Tract
  4. ~30% of hysterectomies are performed due to symptomatic uterine fibroids
  5. Cowden Disease [1]
    1. Hamartomatous polyposis syndrome with colon cancer
    2. Uterine leiomyomas are common
    3. Due to mutations in PTEN gene on chromosome 10q

C. Pathology

  1. Initially, these are localized proliferations of smooth muscle
  2. With progression of growth, fibrous material is added
  3. These more advanced growths are called fibromyoma (fibroid)
  4. Growth is nearly always dependent on estrogens
  5. Distinct proliferative zones lead to differential growth rates causing multinodular uterus
  6. Frequently associated with polyps and endometrial hyperplasia
  7. Stromal Leiomyomatosis
    1. Global or symmetric enlargement of entire uterus
    2. Collagenous infiltration with whirling bundles of smooth muscle cells
    3. Multinodular studded uterus (both macro- and micronodular bundles)
  8. Degenerative Changes
    1. Occur frequently within the myoma
    2. Alterations in circulation - arterial or venous
    3. Infection - most comon with submucous fibroids, overlying endometrial tissue
    4. Malignant transformation (sarcomatous degeneration) is very rare
    5. Cystic and Hyaline Degeneration very common
    6. Necrosis - secondary to infection, infarction, or torsion
    7. Calcific Degeneration is usually end stage

D. Symptoms

  1. Most common is disturbance in menstrual period
  2. Initially, increase in amount of flow with normal cycle length maintained
  3. Late Changes
    1. Prolongation of Blood Flow (menorrhagia or hypermenorrhea)
    2. Appearance of Intramenstrual Bleeding (Usually with submucous myoma)
  4. Anemia (with increased bleeding)
  5. Pain
    1. Usually with menstrual cycle (dysmenorrhea)
    2. Acute pain with fibroids usually due to either torsion or infarction
    3. Feeling of pelvic heaviness with large myomas
  6. Infertility
  7. Pregnancy Loss - often second trimester loss (spontaneous abortion)

E. Diagnosis

  1. Clinical Symptoms Suggestive of Fibroids (very common)
  2. Pelvic Ultrasound

F. Treatment

  1. Highly Dependent on symptoms
  2. Progesterones (usually with birth control pills)
  3. GnRH Agonist
    1. "Chemical" oopherectomy
    2. Leads to reduction in estrogen and progesterone levels
    3. Agents are used in the treatment of endometriosis as well
  4. Uterine Artery Embolization (UAE) [2]
    1. Alternative invasive technique for treating uterine fibroids
    2. Embolic agent of 500-700 µm in diameter is placed in the artery feeding the fibroid
    3. Hospitalization typically 1 day
    4. Repeat procedure in ~10% of patients within 1 year
    5. Major adverse events ~5%
    6. Improved short term but similar long term outcomes versus hysterectomy/myomectomy
    7. Increased need for repeat procedures versus surgery
  5. Surgical Resection
    1. Often preceded by dilatation and curatage to rule out occult endometrial lesions
    2. Indications for surgery are discussed below
    3. UAE is often chosen initially for treatment of symptomatic fibroids
    4. Surgery is more definitive treatment for fibroids, requiring less repeat procedures [2]

G. Indications For Surgery

  1. Pain -Degeneration, Torsion, Dysmenorrhea
  2. Bleeding - Increased blood loss (menorrhagia), anemia
  3. Size ->12 gestational weeks equivalent
  4. Pressure - Bladder (Urgency), Ureters (Hydronephrosis)
  5. Location - Submucous, Intraligamentous, Pedunculated
  6. Reproductive Disorders - Sterility, Recurrent Abortion or Prematurity
  7. Evidence of Malignant Transformation - abnormal "complex" ultrasound appearance
  8. May be removed alone without a hysterectomy to preserve fertility
  9. About 30% of hysterectomies are performed due to uterine fibroids

References

  1. Ivanovich JL, Read TE, Ciske DJ, et al. 1999. Am J Med. 107(1):68 abstract
  2. REST Investigators. 2007. NEJM. 356(4):360 abstract