Regional Lymph Node Evaluation

Haydee Ojeda-Fournier, MD

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Lymph Node Evaluation Talk


In this talk, we are going to discuss a lymph node evaluation.


At the end of this presentation, we will review the auxiliary anatomy and know how to classify the auxiliary lymph node levels. We're going to evaluate normal, benign, and malignant auxiliary findings. I will also demonstrate a couple of image-guided procedures that can be performed for the management of auxiliary lymph nodes.


1. Importance of Axilla Evaluation

The evaluation of the axilla is crucial because both benign and malignant processes can occur there. We must be aware of this, especially considering recent changes due to COVID vaccinations causing inflammation.

  • Auxiliary lymphadenopathy is about 1% in the screening setting.
  • It is important for radiologists to know the anatomy, processes, and evaluation methods of the axilla.

2. Classification of Axillary Lymph Nodes

The axillary lymph nodes are classified into three levels based on their relationship to the pectoralis minor muscle.

  • Level 1: Lateral to the pectoralis minor muscle.
  • Level 2: Behind the pectoralis minor muscle.
  • Level 3: Medial to the pectoralis minor muscle.

3. Characteristics of Lymph Nodes

Several characteristics of lymph nodes must be described to assess whether they are normal or abnormal.

  • Morphology: Normal lymph nodes are oval with circumscribed margins, large fatty hilum, and a thin homogeneous cortex.
  • Number: Describe the number of lymph nodes, as it impacts radiation therapy decisions.
  • Unilateral or Bilateral: Bilateral lymph nodes often indicate a systemic process.
  • Appearance: Matted, fixed, or indistinct lymph nodes are significant for surgical planning.

4. Imaging Modalities

Various imaging modalities are used to evaluate lymph nodes.

  • Ultrasound: The primary modality for evaluating the axilla, allowing real-time assessment and image guidance.
  • Mammography: Limited to the lower axilla; special views are required for higher evaluation.
  • MRI: Effective for staging and assessing all levels of the axilla, internal mammary, and supraclavicular lymph nodes.
  • PET/CT: Used for evaluating local, regional, and widespread metastatic disease.

5. Image-Guided Interventions

Ultrasound-guided procedures are preferred for performing interventions.

  • FNAs and Core Biopsies: Safe and well-tolerated methods for sampling lymph nodes.
  • Wireless Localization: Helps surgeons perform selective lymph node biopsies.

6. Non-Lymph Node Abnormalities

Several other conditions can affect the axilla that are not necessarily lymph nodes or malignancies.

  • Skin molds, keloids, and scars can mimic lymph nodes.
  • Pigment from tattoos and auxiliary gold therapy can deposit in lymph nodes.
  • Auxiliary breast tissue, silicone deposition, and various diseases can also cause abnormalities.

7. COVID-19 Considerations

Adjustments are necessary for managing axillary findings in the era of COVID-19 vaccinations.

  • Vaccinations can cause lymphadenopathy, and patient history is crucial.
  • Short interval follow-ups are recommended to document lymph node resolution.

8. Management Algorithm

An algorithm for managing auxiliary findings based on clinical and imaging evaluations.

  • Start with ultrasound for abnormal findings.
  • For known breast cancer patients, abnormal lymph nodes require biopsy and potentially change management to neoadjuvant chemotherapy.
  • For patients with normal ultrasound evaluation, proceed with sentinel lymph node biopsy.


In summary, we reviewed the anatomy and evaluation of axillary lymph nodes, characteristics of normal and abnormal lymph nodes, imaging modalities, image-guided interventions, non-lymph node abnormalities, COVID-19 considerations, and the management algorithm. Understanding these aspects is crucial for effective diagnosis and treatment of axillary conditions.

Thank you for your attention.