Fibroid uterus (leiomyoma) 

• Epidemiology
  • diagnosed in approximately 40-50% of pre-menopausal women >35 yr
  • common indication for major surgery in females
  • minimal malignant potential (1:1000)
  • typically regress after menopause
• Pathogenesis
  • estrogen stimulates monoclonal smooth muscle proliferation
  • progesterone stimulates production of proteins that inhibit apoptosis
  • degenerative changes (occur when tumour outgrows blood supply)
  • fibroids can degenerate, become calcified, develop sarcomatous component, or obtain parasitic blood supply  

• Classification
  • intramural: most common, grow within the muscular wall of the uterus
  • submucosal: grow within myometrium, can grow into endometrial cavity
  • subserosal: grow from the serosa
  • fibroids can also grow in the cervix and vagina

• Clinical Features
  • majority asymptomatic (60%), often discovered as incidental finding on pelvic exam or U/S
  • abnormal uterine bleeding (30%): dysmenorrhea, heavy menstrual bleeding
  • pressure/bulk symptoms (20-50%)
    • pelvic pressure/heaviness
    • increased abdominal girth
    • urinary frequency and urgency
    • constipation, bloating (rare)
    • acute urinary retention (extremely rare, but surgical emergency!)
  • acute pelvic pain
    • fibroid degeneration
    • fibroid torsion (if pedunculated subserosal)
  • infertility, recurrent pregnancy loss
  • pregnancy complications (potential enlargement and increased pain, obstructed labour, difficult cesarean delivery)

• Investigations
  • bimanual exam: uterus asymmetrically enlarged, usually mobile
  • CBC: anemia
  • U/S: to confirm diagnosis and assess location of fibroids
  • sonohysterogram: useful for differentiating endometrial polyps from submucosal fibroids or for assessing intracavitary growth
  • endometrial biopsy to rule out uterine cancer for abnormal uterine bleeding (especially if age >40 yr) occasionally MRI is used for preoperative planning (e.g. before myomectomy)

• Treatment
  • only if symptomatic (heavy menstrual bleeding, menometrorrhagia, bulk symptoms), rapidly enlarging or intracavitary
  • treat anemia if present
  • conservative approach (watch and wait) if:
    • symptoms absent or minimal
    • fibroids <6-8 cm or stable in size
    • not submucosal (submucosal fibroids are more likely to be symptomatic)
    • currently pregnant due to increased risk of bleeding (follow-up U/S if symptoms progress)
  • medical approach to treat AUB-L
    • antiprostaglandins (ibuprofen, other NSAIDs)
    • tranexamic acid (Cyklokapron®)
    • CHC, IUS, or Depo-Provera®
    • GnRH agonist: leuprolide (Lupron®)
  • interventional radiology approach
    • UAE occludes both uterine arteries, shrinks fibroids by 50% at 6 mo; improves heavy bleeding in 90% of patients within 1-2 mo
    • not an option in women considering childbearing
    • higher risk of surgical re-intervention than with surgical approaches
  • surgical approach
    • myomectomy (hysteroscopic, transabdominal, or laparoscopic)
    • hysteroscopic resection of fibroid and endometrial ablation for AUB-Lsm
    • hysterectomy (see Hysterectomy, GY6)
    • note: avoid operating on fibroids during pregnancy (due to vascularity and potential pregnancy loss); expectant management usually best