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Uterine Myomas

BASICS

DESCRIPTION

Uterine leiomyomas are well-circumscribed, pseudoencapsulated, benign monoclonal tumors composed mainly of smooth muscle with varying amounts of connective tissue. Subtypes: - Subserous: external; may become pedunculated - Intramural: within myometrium; may enlarge the uterus - Submucous: ~5% of cases; internal; causes abnormal bleeding/infection - Rare sites: broad, round, and uterosacral ligaments

EPIDEMIOLOGY

  • Cumulative incidence: up to 80%
  • By age 35: 60% (African American women), 40% (Caucasian women)
  • By age 50: 80% (African American), 70% (Caucasian)
  • Rare in premenarchal females

ETIOLOGY AND PATHOPHYSIOLOGY

  • Hormonal influence:
    • Estrogen and progesterone stimulate myoma growth
    • Myomas have increased estrogen receptor density
  • Growth factors involved:
    • TGF-ฮฒ, bFGF, EGF, PDGF, IGF, VEGF
  • Genetic factors:
    • 40% show somatic chromosomal rearrangements
    • 70% have MED12 mutations
    • High aromatase levels in African American women

RISK FACTORS

  • African American heritage (2.9x risk)
  • Early menarche (<10 years)
  • Nulliparity
  • OCP use before age 16
  • Hypertension
  • Obesity (21% increase per 10 kg)
  • Positive family history
  • Alcohol use
  • Protective: parity, progestin-only contraception, healthy diet

COMMONLY ASSOCIATED CONDITIONS

- Endometrial and breast cancers (due to unopposed estrogen)

DIAGNOSIS

HISTORY

  • Often asymptomatic
  • When symptomatic:
    • Heavy/prolonged menstruation
    • Pain (torsion, degeneration)
    • Urinary frequency/obstruction
    • Constipation/low back pain
    • Infertility (rare) ALERT: Rapid growth postmenopause may indicate sarcoma (0.1โ€“0.3%)

PHYSICAL EXAM

  • Firm, smooth, mobile uterine masses

DIFFERENTIAL DIAGNOSIS

  • Pregnancy, ovarian/uterine cancer, diverticulitis, pelvic kidney, urachal cyst

TESTS

  • Initial:
    • Pregnancy test
    • Hemoglobin
    • Pelvic ultrasound
    • Saline infusion sonography (submucosal fibroids)
    • Hysterosalpingogram
    • CT/MRI (for embolization planning or atypical cases)
  • Follow-up:
    • CA-125 (limited utility)
    • IVP or barium enema (if mass effect on ureters or bowel)
  • Procedures:
    • D&C
    • Hysteroscopy
    • Laparoscopy Histology:
  • Smooth muscle bundles with fibrous tissue
  • Hyaline degeneration (most common)
  • Others: calcification, necrosis (in pedunculated/twisted myomas)

TREATMENT

GENERAL PRINCIPLES

  • Tailored to symptoms, fertility desire, proximity to menopause
  • Asymptomatic: observation, iron supplements if anemic

NON-SURGICAL OPTIONS

  • Uterine artery embolization (UAE): 50% shrinkage, but possible ovarian failure, amenorrhea
  • MRgFUS: noninvasive thermal ablation, limited by location/type

MEDICATIONS

  • Progestins:
    • Norethindrone, Medroxyprogesterone, LNG-IUD
  • OCPs: reduce bleeding, prevent new myomas
  • GnRH agonists: Nafarelin, Goserelin, Leuprolide
    • Rapid shrinkage, pre-op use, not >6 months
  • Mifepristone: reduces size and bleeding
  • SPRM: Ulipristal acetate

SURGERY

  • Indications:
    • Rapid growth, symptomatic submucosal, torsion, pressure symptoms, infertility
  • Options:
    • Hysterectomy (vaginal/laparoscopic/robotic/abdominal)
    • Myomectomy: abdominal, laparoscopic, hysteroscopic
    • Endometrial ablation (small submucosal)

FOLLOW-UP

  • Pelvic US every 2โ€“3 months initially, then 6โ€“12 months
  • Monitor Hb/Hct if bleeding

PATIENT EDUCATION

PROGNOSIS

  • Most regress post-menopause
  • 10% recurrence post-myomectomy; only 25% need repeat treatment

COMPLICATIONS

  • Rare: uterine sarcoma
  • May prolapse through cervix
  • Degeneration = pain/bleeding

PREGNANCY CONSIDERATIONS

  • Common rapid growth
  • Risks: miscarriage, malpresentation, labor dystocia
  • C-section advised if cavity entered during prior myomectomy

GERIATRIC CONSIDERATIONS

- Postmenopausal fibroid growth raises concern for malignancy

ICD-10 CODES

  • D25.9: Leiomyoma, unspecified
  • D25.2: Subserosal leiomyoma
  • D25.1: Intramural leiomyoma

CLINICAL PEARLS

  • Benign smooth muscle tumors
  • Frequently asymptomatic
  • May cause bleeding, mass effect, or infertility
  • Management ranges from observation to advanced surgery