- 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
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