Cause: Mechanical stress?; estrogen stimulation?, eg, from bcp's
Pathophys:Intramyometrial stress causes localized smooth muscle proliferation? Estrogens increase rate of formation. Bleeding is from overlying endometrium stretched (?) and/or poor uterine contractions during menses, hence spiral arteries bleed. Pain due to contractions against mass during menses
Premenopausal women primarily affected, usually appear age 30-50 yr. 70+ incidence by age 50 yr; fibroids shrink in postmenopausal women and rarely cause sx. Increased prevalence and incidence in blacks
Sx: Menorrhagia; pain; sense of fullness; urinary frequency; obstipation; but often asx
Si: Anemia, pelvic mass
Infertility; anemia from menorrhagia; ureteral compression and blockage; sudden bleed into fibroid with pain and enlargement; necrosis and calcification (10%); benign metastasizing type (Nejm 1981;305:204); leiomyosarcomas (<1%)
Lab:
Hem:Iron deficiency anemia
Path: Intramural, 90% in fundus, 8% in cx, rarely in round or broad ligaments
Xray:
Incidental fining on KUB, calcified in 10%, esp in older women
Ultrasound usually diagnostic, though can't r/o cancer
Rx:
Wait for sx; cyclic bcp's low in estradiol to decrease bleeding, though still may stimulate growth; gonadotropin-releasing hormone agonists like leuprolide (Nejm 1991;324:97) (Prostatic Carcinoma) decrease estradiol by feedback inhibition, shrink fibroids and cause medical menopause, may be used presurgically
Surgical hysteroscopic resection of submucous types; or myomectomy ("shelling out") may allow future pregnancies; hysterectomy, or subtotal hysterectomy (Nejm 2002;347:1318)
Uterine artery embolization, 90% effective (Nejm 2007;356:368, 411; Med Let 2005;47:31), painful for a week postop; increases subsequent miscarriages more than myomectomy (Nejm 2009;361:690)
Ultrasonic beam destruction, MRI-guided (ExAblate)