What is the recommended diagnostic procedure for patients with suspicious breast lesions identified on imaging, specifically regarding stereotactic breast biopsy?

Stereotactic Breast Biopsy for Suspicious Breast Lesions

Stereotactic core needle biopsy is the preferred initial diagnostic procedure for suspicious nonpalpable breast lesions, particularly microcalcifications, due to its high diagnostic accuracy (95-100% sensitivity, 90-100% specificity) compared to surgical biopsy, while being less invasive and more cost-effective. 1

Indications for Stereotactic Breast Biopsy

• Primary indication: Suspicious nonpalpable mammographic abnormalities, especially microcalcifications
• Secondary indications:
  • Architectural distortions visible on mammography
  • Asymmetric densities not visible on ultrasound
  • Suspicious findings on digital breast tomosynthesis (DBT)

Patient Selection Considerations

Not all patients are ideal candidates for stereotactic biopsy. Consider the following limitations:

• Breast size too small to accommodate the biopsy probe
• Insufficient breast thickness for the full throw of the biopsy device
• Lesions in technically challenging locations:
  • Just beneath the skin
  • Far posterior/close to chest wall
  • Widely separated calcifications
  • Axillary region
• Poor patient cooperation 2

In these cases, image-directed open surgical biopsy is the preferred approach.

Technical Procedure

1. Pre-procedure imaging: Complete diagnostic mammography or DBT to characterize the lesion
2. Positioning: Either prone stereotactic table or upright add-on stereotactic device
3. Needle selection: Vacuum-assisted biopsy devices (9-11G) are preferred for microcalcifications
4. Sampling technique:
   • Multiple cores (recommended average: 8-13 cores)
   • Specimen radiography to confirm adequate sampling of microcalcifications
   • Leave marker clip at biopsy site if:
     • All microcalcifications are removed
     • Small lesion likely to be completely removed
     • No other landmark near biopsy site 2, 3, 4

Advantages Over Surgical Biopsy

• Less invasive procedure
• No general anesthesia required
• Minimal scarring and tissue distortion
• Lower cost
• Faster recovery
• Comparable diagnostic accuracy to surgical biopsy 5, 6

Important Caveats and Pitfalls

1. Underestimation of disease: Areas of invasive carcinoma will be found in approximately 20% of cases initially diagnosed as DCIS on stereotactic biopsy 2

2. Atypical findings: Diagnosis of atypical ductal hyperplasia on core biopsy requires surgical excision due to high risk of upgrade to malignancy 7

3. Specimen handling: Always perform specimen radiography to confirm adequate sampling of calcifications 2

4. Post-biopsy considerations:

   • Minor complications: ecchymosis, tenderness
   • Major complications (rare): hemorrhage, infection
   • Scar formation may occur (17% of cases) and can occasionally resemble malignancy on follow-up imaging 4

Diagnostic Algorithm for Suspicious Breast Lesions

1. Initial imaging:

   • Women <30 years: Ultrasound first
   • Women 30-39 years: Either ultrasound or diagnostic mammography/DBT
   • Women ≥40 years: Diagnostic mammography/DBT with targeted ultrasound 2

2. Tissue sampling based on imaging findings:

   • Solid mass visible on ultrasound: Ultrasound-guided core biopsy
   • Microcalcifications or lesion only visible on mammography/DBT: Stereotactic core biopsy
   • Complex cystic lesions: Core biopsy (due to higher risk of malignancy) 2, 1

3. Post-biopsy management:

   • Benign concordant: Follow-up imaging at 6-12 months
   • Atypical findings: Surgical excision
   • Malignant: Definitive surgical management 1

By following this systematic approach to stereotactic breast biopsy, clinicians can achieve high diagnostic accuracy while minimizing patient discomfort and unnecessary surgical procedures.