Uterine Fibroids (Leiomyoma)
Uterine fibroids, also called leiomyomas, are benign smooth muscle tumours of the myometrium and are the most common benign uterine tumours in women of reproductive age.
Updated UKMLA guide to uterine fibroids based on NICE NG88 and NICE CKS covers: types, signs and symptoms, complications, diagnosis, and management.
Definition
Uterine fibroids (leiomyomas) are benign tumours arising from the smooth muscle cells and fibroblasts of the myometrium.
Types and Location
Fibroids may develop anywhere within the myometrium. They can be categorised into 3 types depending on their locations:
| Type | Description |
|---|---|
| Subserosal fibroid | Fibroids develop near the outer serosal surface of the uterus and extend outwards into the peritoneal cavity |
| Intramural fibroid | Fibroids develop near the central myometrium without extending significantly into the uterine cavity or peritoneal cavity |
| Submucosal fibroid | Fibroids develop near the inner mucosal surface of the uterus and extend into the uterine cavity |
Epidemiology
Fibroids are the most common benign uterine tumours in women of reproductive age.
The incidence of fibroids increases with age during the reproductive years:
- Peaks in the perimenopausal years, and
- Decline after menopause
The true prevalence of fibroids is likely to be underestimated, as they are frequently asymptomatic and under- or unreported to healthcare professionals.
Causes and Risk Factors
Fibroids typically develop in women of reproductive age, as their growth and maintenance are thought to be oestrogen and progesterone-dependent. However, the exact underlying cause remains unclear.
Risk factors include:
- Family history (affected 1st degree relative)
- Increasing age during reproductive years (peaks in perimenopausal years and decline after menopause)
- Early menarche (<11 y/o)
- Nulliparity
- Older age at first pregnancy
- Comorbidities
- Obesity
- Diabetes
- Hypertension
- Black and Asian women (compared to white women)
- Fibroids are also more likely to be symptomatic, occur at an earlier age, be larger and multiple in these ethnic groups
Clinical Features
Fibroids are commonly asymptomatic.
If symptomatic:
| Menstrual-related symptoms |
|
| Bulk / pressure symptoms |
|
| Examination findings |
Large fibroids → central irregular abdominal mass |
Infertility may be a concurrent presentation, in addition to those above.
Clinical presentations largely depend on the type of fibroid:
| Type | Clinical presentation |
|---|---|
| Subserosal fibroids | Commonly asymptomatic or minimally symptomatic, even when relatively large
When symptomatic, bulk / pressure symptoms predominate Minimal effects on menstrual bleeding and fertility |
| Intramural fibroids | Causes a mixed symptom profile of menstrual-related and/or bulk symptoms |
| Submucosal fibroids | Even relatively small ones can cause significant menstrual-related symptoms and infertility |
Complications
General complications include:
- Iron deficiency anaemia (from heavy menstrual bleeding)
- Pressure on the bladder may cause
- Recurrent UTIs
- Urinary retention
- Hydronephrosis (if the ureter is compressed)
- Infertility / subfertility (mainly seen in submucosal or deep intramural fibroids)
Possible complications when a woman with fibroids becomes pregnant:
- Miscarriage (esp. with submucosal and deep intramural fibroids)
- Fibroid vascular infarction (red degeneration)
- Presents as acute pain
- High levels of sex hormones in pregnancy causes rapid growth of a fibroid, which outgrow its blood supply
- Preterm delivery and fetal malpresentation
Investigation and Diagnosis
1st line investigation: pelvic ultrasound (transabdominal +/- transvaginal)
Particularly if ANY of the following:
- Uterus is palpable abdominally
- History / exam suggest a pelvic mass
- Examination is inconclusive / difficult (e.g. woman is obese)
If submucosal fibroids are suspected:
- 1st line: outpatient hysteroscopy
- 2nd line: hysteroscopy under anaesthesia
- 3rd line: consider pelvic ultrasound
Management
Primary care management is suitable if:
- Fibroid <3 cm, and
- Not distorting the uterine cavity
Refer to secondary care if any of the following:
- Fibroid ≥3cm
- Fibroids distorting the uterine cavity
- Suspected submucosal fibroid
- Severe symptoms (inc. compressive symptoms)
- Suspected fertility issues associated with fibroids
Primary Care Management
This is essentially the same as the primary care management of heavy menstrual bleeding outlined in the Heavy Menstrual Bleeding (HMB) article.
Choice of management is largely determined by whether the patient is planning to conceive (at the moment or in the near future).
| Patient’s conceiving wish | Recommended management |
|---|---|
| NOT planning to conceive |
|
| PLANNING to conceive | Offer non-hormonal treatment:
|
Key contraindications to LNG-IUS:
- History / current breast / cervical / endometrial cancer
- Unexplained, uninvestigated vaginal bleeding (due to possible endometrial cancer)
- Distorted uterine cavity (e.g. due to submucosal fibroids, intrauterine adhesions, large endometrial polyps, congenital uterine anomalies)
- Current PID
It is important not to mix up the role of copper IUD and LNG-IUS in HMB:
- Copper IUD can worsen or cause HMB
- LNG-IUS often causes oligomenorrhoea / amenorrhoea, thus used to treat HMB
Secondary Care Management
Primary care management should also be considered and continued if effective.
Medical Therapy
Consider short-term GnRH agonist (e.g. leuprolide, nafarelin, goserelin) therapy:
- Prior to interventional therapy, if the fibroids are causing an enlarged/distorted uterus (to shrink the fibroids), OR
- In women approaching menopause
GnRH is the only medical option that can significantly shrink fibroid size. However, this effect is only transient, with fibroids generally regrowing to their original size after treatment is discontinued.
They are therefore useful as bridging therapy to surgery/interventions OR as short-term therapy in women approaching menopause, where symptoms tend to improve thereafter.
GnRH agonists are only used short-term due to their prominent hypoestrogenic side effects with prolonged therapy (>3-6 months), which include:
- Bone mineral density loss (→ osteoporosis)
- Vasomotor symptoms (e.g. hot flushes, night sweats)
Interventional Options
NICE states that pharmacological treatments for ≥3cm fibroids have limited effectiveness. Therefore ≥3cm is generally considered the cut-off for considering interventional management.
Pre-procedural ultrasound (+/- MRI) should be offered before uterine artery embolisation and myomectomy.
Interventional options include: [Ref]
| Intervention / procedure | Indications / rationale |
|---|---|
| Hysteroscopic removal | Submucosal fibroids |
| Endometrial ablation |
NOT to be performed if fertility is desired |
| Uterine artery embolisation |
NOT to be performed if fertility is desired |
| Myomectomy | 1st line to improve fertility
|
| Hysterectomy | Definitive management – eliminates symptoms completely
Usually indicated if
|
If interventional options are not appropriate / failed → consider ulipristal acetate
- For intermittent treatment of moderate to severe symptoms
- Note that ulipristal acetate is rarely associated with serious liver injury (hence, its limited use in fibroid management)
Do not offer dilatation and curettage as a treatment option for HMB.
References