Pocket ObGyn – Uterine Fibroids
See Abbreviations
Definition
- Benign smooth muscle tumors, originating from myometrial tissue (leiomyoma).
- Uterine fibroids can be classified based on their anatomical
Epidemiology (Obstet Gynecol Clin N Am 2011;38:703)
- By 50 yo, fibroids are found in ~70% of whites & >80% of Indication for 30–40% of hysterectomies. Risks: >40 yo, black, FHx, nulliparity, obesity.
Figure 5.1 Fibroid location & nomenclature
| Pedunculated serosal
Submucosal
Intramural Subserosal
Pedunculated submucosal Cervical |
Pathology
- Gross: Pearly, round, well Size & location vary. Relatively avascular but surrounded by rich vasculature system ® signif bleeding.
- Histology: Smooth muscle cells aggregated in
- Degenerating leiomyoma types: Hyaline (65%), myxomatous (15%), calcific (10%, mainly older women), cystic (4%, hylanized areas ® liquefaction), fatty (rare), carneous (red) necrosis (esp pregnant pts, acute d/t outgrowing bld supply ® acute musc infarction ® sev pain & local peritoneal irritation).
- Leiomyomas do not transform into leiomyosarcoma. Likely represents a de novo neoplasm & is NOT a result of malig transformation of a benign
Pathophysiology
- Fibroids are estrogen- (& progesterone-) sensitive Fibroids create estrogen environment ® growth & size maint. estrogen conditions (obesity, early menarche) ® fibroid risk.
Clinical Manifestations
- Mostly Sx depend on size, location, & number. In general, the larger the fibroid, the larger the chance of sx.
- Vaginal bleeding = most common symptom; usually presents as
- Other sx: Pelvic pain & pres, urinary frequency, incontinence, constip, infertility
- Evid sugg that myomas are the primary cause of infertility in a small # of Myomas that distort the uterine cavity & larger intramural myomas may have adverse effects on fertility (Fertil Steril 2008;90:S125).
Physical Exam & Diagnostic Studies
- Findings: Uterine enlargement, irreg uterine
- Must r/o other causes of abn Postmenopausal bleeding w/ fibroids should be evaluated the same way as women w/o fibroids.
- Imaging:
US: Defines pelvic anatomy & effective in locating fibroids.
SIS: Allows eval of uterine cavity, particularly if infertility or menorrhagia is a concern. Good for submucosal type.
MRI: Very accurate.Very expensive. Not practical depending on the clinical setting.
Hysteroscopy: Gold std for submucosal fibroid.
Treatment & Medications
- Observation: Asx fibroids do not require intervention, no matter their
- Medical mgmt (Obstet Gynecol Clin N Am 2011;38:703): Should be tailored to alleviating Cost & s/e of rx may limit long-term use.
NSAIDs: No data to support use as sole agent for therapy. Good for dysmenor- rhea based on role of PGs as pain mediators.
OC: 1st line. Combined OCs may control bleeding & pain, but progestin-only OCs w/ mixed results.
Levonorgestrel IUD: Beneficial for menorrhagia. rate expulsion & vaginal spotting.
GnRH agonist (Leuprolide 3.75–11.25 mg/m IM): Reversible amenorrhea in most, & 35–65% ¯ in size w/i 3 mo. Most useful in women w/ large fibroids.
Induces menopause sx + ¯ bone density. Consider add-back therapy for pro- longed use (>6 mo) or symptomatic pts. Use preop ® ¯ uterine size before Surg.
Aromatase inhibs: Block ovarian & periph estrogen production ® ¯ estradiol level after 1 d of rx. ¯ s/e compared to GnRH w/ rapid results. Little data.
Antiprogestins (Mifepristone 5 or 10 mg/d ¥ 6 mo): 26–74% ¯ in uterine vol & ¯ recurrent growth after cessation. S/e: Endometrial hyperplasia (dose- dependent) & transient in transaminase (monit LFTs).
• Nonsurgical mgmt:
UAE: IR injects PVA spheres into bilateral uterine artery ® ¯ bld flow ® ischemia & necrosis ® ¯ size & sx. Postembolization syn may require hospitalization postop for pain control. Successful pregnancies occur after UAE, but long-term data lim- ited.
US ablation under magnetic resonant guidance:
- Surgical Mgmt:
Hysteroscopic myomectomy: 1st line for symptomatic submucosal fibroids.
Myomectomy: Option for those desiring fertility or decline hysterectomy. Goal to remove visible & accessible fibroids, & reconstruct uterus.Via laparotomy or laparoscopy. Fibroids may recur. When myomectomy invades endometrial cavity (complete wall resxn) consider CS deliv @ 37–38 w gest (Obstet Gynecol 2011;118:323).
Hysterectomy: Definitive surgical rx. Satisfaction rate >90%.