What is the management of non-palpable (not palpable) lymph nodes found on imaging in breast cancer?

Management of Non-Palpable Lymph Nodes Found on Imaging in Breast Cancer

For non-palpable suspicious lymph nodes detected on imaging in breast cancer patients, ultrasound-guided biopsy is recommended as the standard approach to determine nodal status before deciding on appropriate surgical management. 1

Evaluation of Non-Palpable Axillary Lymph Nodes

Initial Assessment

• Ultrasound is the preferred imaging modality for evaluating axillary lymph nodes detected on other imaging 1, 2
• Suspicious features on ultrasound include:
  • Cortical thickness >3mm
  • Loss of fatty hilum
  • Round shape (rather than reniform/kidney-shaped)
  • Abnormal morphology or irregular margins 2

Biopsy Approach

• For suspicious non-palpable nodes, ultrasound-guided core needle biopsy is preferred over fine-needle aspiration (FNA) 1, 3
• Core needle biopsy advantages:
  • Higher accuracy for non-palpable lesions 1, 4
  • Provides sufficient tissue for definitive diagnosis 1
  • Allows assessment of histologic type and grade 4
  • Better concordance with surgical specimens for biomarkers (ER/PR) 4

Management Algorithm Based on Biopsy Results

If Biopsy is Negative:

• Proceed with sentinel lymph node biopsy (SLNB) as the standard nodal staging procedure 1
• SLNB has replaced axillary lymph node dissection (ALND) as the standard for clinically node-negative patients 1

If Biopsy is Positive:

1. For patients receiving upfront surgery:

   • Historically, ALND was performed, but current guidelines have evolved
   • For patients with T1-T2 tumors with 1-2 positive sentinel nodes, SLNB alone may be sufficient without ALND 1
   • This approach is based on the Z0011 trial showing no difference in 10-year overall survival between SLNB alone versus ALND 1

2. For patients receiving neoadjuvant chemotherapy (NAC):

   • Place a clip in the biopsy-proven positive node before starting NAC 1
   • After NAC, options include:
     • Targeted axillary lymph node dissection (removing the clipped node plus sentinel nodes)
     • SLNB with removal of at least 3 nodes including the clipped node 1
   • These approaches reduce false-negative rates compared to standard SLNB alone 1

Important Considerations and Pitfalls

• Avoid overtreatment: The Z0011 trial demonstrated that ALND can be safely omitted in select patients with limited nodal disease, reducing morbidity (particularly lymphedema) 1

• Biopsy technique matters: Core needle biopsy is more accurate than FNA for non-palpable lesions 1, 4

  • FNA has higher rates of insufficient sampling and cannot determine invasiveness 4
  • If FNA is performed, ensure cytology expertise is available for interpretation 5

• Marker clip placement: Always place a marker clip during biopsy of suspicious nodes, especially if neoadjuvant therapy is planned, to allow for targeted removal later 1

• Dual tracer technique: When performing SLNB after neoadjuvant therapy, using dual tracer techniques improves sentinel node identification rates (87.6-92.7%) and reduces false-negative rates 1

By following this evidence-based approach to non-palpable lymph nodes detected on imaging, clinicians can optimize nodal staging while minimizing unnecessary axillary surgery and its associated morbidity.