Overview
Uterine Fibroids (Leiomyomas)
1. Overview
Fibroids are benign smooth muscle tumors of the uterus (myometrium). They are the most common tumor in women (present in 40-60% of women by age 45).
They are Estrogen and Progesterone dependent (grow during pregnancy/reproductive years, shrink after menopause).
Classification by Location (FIGO System)
The FIGO PALM-COEIN system classifies fibroids by position (0-8):
- 0-2 (Submucosal): Inside the cavity. Cause HMB.
- 0: Pedunculated intracavitary.
- 1: <50% intramural.
- 2: >50% intramural. // ...
- Only for Submucosal fibroids (<3cm). Shaved off from inside. // ...
- Anemia: Iron deficiency from HMB. Can be severe (HB < 50g/L). // ...
- Rare (<0.2%).
- 3-4 (Intramural): Within the wall. Cause Bulk/Pain.
- 5-7 (Subserosal): On the outside.
- 8 (Cervical/Parasitic).
Image: Fibroid Locations
Image: Ultrasound Appearance
2. Pathophysiology
- Monoclonal proliferation of smooth muscle cells.
- Hormonal Drive: Contain more Estrogen/Progesterone receptors than normal muscle.
- Genetics: More common in Afro-Caribbean women (3x risk).
Red Degeneration
- Occurs during PREGNANCY.
- Fibroid grows too fast -> outstrips blood supply -> Necrosis.
- Present with acute severe pain.
3. Clinical Features
50% are Asymptomatic.
Symptoms
- Heavy Menstrual Bleeding (HMB): Menorrhagia. Commonest symptom.
- Pressure Effects: Urinary frequency (pressing on bladder), Constipation (rectum).
- Pain: Dysmenorrhea.
- Fertility issues: Recurrent miscarriage or failure of implantation (Submucosal).
Examination
- Abdomen: Palpable firm, irregular mass arising from pelvis.
- Bimanual: Enlarged, knobbly uterus.
4. Diagnosis
- Pelvic Ultrasound (TVUSS/TA):
- First line.
- Diagnostic. Maps size and location.
- Hysteroscopy:
- Gold standard for Submucosal fibroids (to assess for resection).
- MRI Pelvis:
- For surgical planning (Myomectomy) or UAE. Differentiates adenomyosis.
5. Management Algorithm
Treat SYMPTOMS, not the fibroids. (If asymptomatic -> Leave alone).
Image: Management Algorithm
(See ASCII below for detailed decision making).
┌─────────────────────────────────────────────────────────────────────────────┐
│ FIBROID MANAGEMENT PROTOCOL │
├─────────────────────────────────────────────────────────────────────────────┤
│ │
│ 1. MEDICAL (Symptom Control - NOT Curative) │
│ • **Mirena Coil (LNG-IUS)**: First line for HMB. Shrinks fibroids slightly.│
│ • **Tranexamic Acid / Mefenamic Acid**: For bleeding/pain. │
│ • **GnRH Analogues (Goserelin)**: "Medical Menopause". │
│ - Shrinks fibroids by 50% in 3 months. │
│ - Used pre-operatively to make surgery easier/safer. │
│ - Not for long term (bone loss). │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ ↓ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ 2. NON-HYSTERECTOMY SURGERY │ │
│ │ **A. Uterine Artery Embolization (UAE)** │ │
│ │ • Interventional Radiology. Inject beads to block blood supply. │ │
│ │ • Fibroids shrink/die. Uterus preserved. │ │
│ │ • *Not recommended if wanting future pregnancy* (risk of failure). │ │
│ │ │ │
│ │ **B. Myomectomy (Open or Laparoscopic)** │ │
│ │ • Shelling out the fibroids. Repairing the uterus. │ │
│ │ • Gold Standard for Fertility Preservation. │ │
│ │ • Risk: High bleeding (Tourniquet used). │ │
│ │ │ │
│ │ **C. Hysteroscopic Resection (TCRF)** │ │
│ │ • Only for Submucosal fibroids (<3cm). Shaved off from inside. │ │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ ↓ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ 3. HYSTERECTOMY (Definitive) │ │
│ │ • Only cure. No recurrence. │ │
│ │ • For women with family complete. │ │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ │
└─────────────────────────────────────────────────────────────────────────────┘
Management Debate: UAE vs Myomectomy
| Feature | Uterine Artery Embolization (UAE) | Myomectomy |
|---|---|---|
| Invasiveness | Minimally Invasive (Groin puncture). | Surgical (Open or Laparoscopic). |
| Recovery | 1-2 weeks. | 4-6 weeks (Open). |
| Fertility | Not advised (risk of ovarian failure/miscarriage). | Standard of Care for fertility. |
| Recurrence | Low (treats all fibroids at once). | Common (new ones grow). |
| Pain | Severe pain for 24h post-procedure (ischemia). | Post-op surgical pain. |
Image: Uterine Artery Embolization
6. Complications
- Anemia: Iron deficiency from HMB. Can be severe (HB < 50g/L).
- Pressure:
- Hydronephrosis: Large fibroids compressing ureters (silent renal failure).
- DVT: Compression of pelvic veins.
- Malignancy: Leiomyosarcoma.
- Rare (<0.2%).
- Suspect if: Rapid growth post-menopause, severe pain, solitary mass.
- Avoid Morcellation (grinding up fibroid in laparoscopic surgery) if cancer suspected -> spreads it everywhere.
7. Prognosis
- Benign.
- Shrink after menopause (no estrogen).
- Recurrence: 15-30% recurrence rate after Myomectomy.
8. Special Considerations
Fibroids in Pregnancy
Fibroids grow in the first trimester (hCG/Estrogen) then stabilize.
- Risks:
- Pain: Red Degeneration (Second Trimester). Treatment is Rest + Opiates.
- Malpresentation: Breech/Transverse lie (fibroid blocks the head).
- Obstructed Labour: Cervical fibroids block the exit.
- PPH: Uterus cannot contract down over the fibroid.
- Management:
- DO NOT REMOVE during C-Section.
- Why? The pregnant uterus is incredibly vascular. Myomectomy during CS causes massive, uncontrollable haemorrhage.
Fertility
- Submucosal: Definitely reduce fertility (act like a Coil) -> Resect them.
- Intramural/Subserosal: Controversy. Generally only removed if >4cm or multiple IVF failures.
9. Key Clinical Pearls
Exam-Focused Points
- Red Degeneration: Pregnant woman + Acute fibroid pain. Treat with Analgesia & Rest.
- Submucosal: The ones that cause the heavy bleeding (disrupt endometrium).
- Subserosal: Can be massive but asymptomatic (grow outwards).
- GnRH Agonists: Shrink fibroids pre-op. Can't use long term.
- Calcification: Old fibroids calcify ("Popcorn" appearance on X-ray).
Common Exam Scenarios
- 30yo Afro-Caribbean woman with heavy periods and 14-week size firm uterus. Dx? (Fibroids).
- Pregnant woman in pain, tender lump on uterus. (Red Degeneration).
- Patient wants to keep uterus but avoid major surgery. (Offer Uterine Artery Embolisation).
10. Patient Explanation
What are they?
"They are balls of muscle that grow in the wall of the womb. They are extremely common - like knots in a piece of wood. They are NOT cancer."
Do I need them out?
"Only if they bother you. If your periods are manageable and you don't have pressure symptoms, we leave them alone. They will naturally shrink after the menopause."
11. Evidence & Guidelines
Key Guidelines
| Guideline | Organization | Year | Key Points |
|---|---|---|---|
| Heavy Menstrual Bleeding | NICE (NG88) | 2018 | Hysteroscopy first line investigation. |
| UAE vs Surgery | FEMME Trial | 2020 | UAE allows quicker recovery but higher re-intervention. |
Evidence-Based Recommendations
| Recommendation | Evidence Level |
|---|---|
| Mirena Coil for symptoms | High |
| Myomectomy for fertility | High |
| UAE for uterine preservation | High |
13. References
- NICE Guideline [NG88]. Heavy menstrual bleeding: assessment and management. 2018.
- Manyonda I, et al. Uterine-Artery Embolization or Myomectomy for Uterine Fibroids (FEMME). N Engl J Med. 2020.