What is uterine calcification and how is it managed?

Uterine Calcification: Explanation and Management

Uterine calcification is primarily seen in two distinct patterns: peripheral rim calcification of fibroids (especially after uterine artery embolization) or endometrial calcifications that may be associated with infertility and menstrual abnormalities. The management depends on the type, location, and associated symptoms.

Types and Causes of Uterine Calcification

1. Fibroid-Related Calcifications

• Post-Embolization Calcification: Following uterine artery embolization (UAE), fibroids often develop a characteristic peripheral rim calcification ("fetal head sign") that differs from the central dystrophic calcification seen in natural fibroid degeneration 1
• Pathophysiology: Peripheral calcification after UAE results from aggregation of polyvinyl alcohol particles in peripheral fibroid arteries, followed by giant cell inflammatory reaction and eventual calcification 2
• Imaging Appearance: Appears as symmetric, hyperechoic foci with acoustic shadowing in the periphery of the uterine myometrium on ultrasound 3

2. Endometrial Calcifications

• Prevalence: Uncommon finding (0.4% in one study) 4
• Associations:
  • Infertility (found in 72.9% of reported cases) 5
  • Menstrual abnormalities (30.3% of cases) 5
  • Prior abortion history (76.5% of cases) 5
  • Endometrial polyps, chronic endometritis, or endometrial hyperplasia 4

3. Vascular Calcifications

• Arcuate Artery Calcification: Calcification of the arcuate branches of the uterine artery, often associated with severe underlying systemic disease 3

Diagnostic Approach

Imaging Studies

1. Transvaginal Ultrasound (TVUS):

   • First-line imaging modality (88.5% of reported cases) 5
   • Should be combined with transabdominal ultrasound (TAUS) when evaluating fibroids 1
   • Color Doppler helps evaluate internal vascularity and differentiate vascular from nonvascular tissue 1

2. Computed Tomography (CT):

   • Can confirm calcifications when ultrasound findings are equivocal
   • Better sensitivity for detecting calcifications than MRI 1

3. Magnetic Resonance Imaging (MRI):

   • Less sensitive than CT for detecting calcifications (69% vs 100%) 1
   • Better for evaluating soft tissue characteristics and distinguishing between different types of uterine pathology

Hysteroscopy

• Gold standard for direct visualization and diagnosis of endometrial calcifications (used in 85.7% of reported cases) 5
• Allows for simultaneous diagnosis and treatment

Management Approaches

For Fibroid-Related Calcifications

1. Observation:

   • Appropriate for asymptomatic calcified fibroids
   • Calcification after UAE often indicates successful treatment with 70-85% reduction in fibroid volume 2

2. Surgical Options (for symptomatic cases):

   • Myomectomy: For patients desiring fertility preservation
   • Hysterectomy: Definitive treatment for symptomatic calcified fibroids in patients who have completed childbearing

For Endometrial Calcifications

1. Hysteroscopic Removal:

   • Treatment of choice (used in 70.6% of reported cases) 5
   • Complete removal of calcifications can restore fertility in many cases (55.6% of infertile patients achieved pregnancy after removal) 5

2. Dilation and Curettage:

   • Alternative approach (27.1% of cases) 5
   • Less effective than hysteroscopic removal

Special Considerations

Malignancy Risk

• Curvilinear calcifications have been reported in endometrial stromal sarcoma 6
• Endometrial biopsy should be considered when calcifications are associated with abnormal uterine bleeding, especially in postmenopausal women

Differential Diagnosis

• Endometrial osseous metaplasia
• Retained fetal bone fragments after abortion
• Intrauterine contraceptive device
• Malignancy with calcification
• Arcuate artery calcification

Follow-up Recommendations

• For patients with calcified fibroids after UAE: ultrasound follow-up at 6 months to assess size reduction and symptom improvement 1
• For patients with endometrial calcifications who desire fertility: follow-up after removal to assess for restoration of normal endometrial cavity

Clinical Pearls

• Peripheral rim calcification after UAE is a normal finding and often indicates successful treatment
• Endometrial calcifications are an underrecognized cause of infertility that can be effectively treated with hysteroscopic removal
• Arcuate artery calcification may indicate underlying systemic disease and warrants appropriate workup