What is the investigation for axillary lymphadenopathy (enlargement of lymph nodes in the axilla)?

From the Guidelines

Investigation for axillary lymphadenopathy should begin with a thorough history and physical examination, followed by ultrasound of the axilla as the initial imaging modality, as recommended by the most recent and highest quality study 1. The initial assessment should include detailed questioning about duration of the swelling, associated symptoms like fever, weight loss, night sweats, recent infections, travel history, medication use, and any history of malignancy. Physical examination should document the size, consistency, tenderness, mobility, and distribution of the lymph nodes, along with examination of the ipsilateral breast and arm for potential sources of infection or malignancy. Some key points to consider in the investigation of axillary lymphadenopathy include:

• Laboratory investigations should include complete blood count, inflammatory markers (ESR, CRP), and liver function tests.
• Imaging studies typically start with ultrasound of the axilla, which can characterize the nodes and guide further management, as supported by 1.
• If concerning features are present (nodes >1 cm, irregular borders, loss of fatty hilum), a fine needle aspiration or core biopsy should be performed.
• Additional imaging such as mammography, chest X-ray, CT, MRI, or PET scan may be indicated based on clinical suspicion, as suggested by 1 and 1. The diagnostic approach should be tailored to the patient's age and risk factors, with a lower threshold for biopsy in older patients or those with risk factors for malignancy, as recommended by 1. Bilateral axillary lymphadenopathy often suggests systemic disease, while unilateral involvement more commonly indicates local pathology or malignancy. It is essential to note that the most recent and highest quality study 1 provides the most up-to-date guidance on the investigation of axillary lymphadenopathy.

From the Research

Investigation for Axillary Lymphadenopathy

The investigation for axillary lymphadenopathy involves several techniques, including:

• Ultrasonography-guided needle biopsy techniques 2
• Radio-guided lymph node biopsy, which uses Tc-99m-labelled human serum albumin macroagregate in saline injected under ultrasonographic guidance for the localization of the lymph nodes 2
• Sentinel lymph node biopsy (SLNB), which is considered the gold standard for axillary staging in early breast cancer patients with clinically negative lymph nodes (cN0) 3
• Imaging-based approach to axillary lymph node staging, which includes the use of computed tomography and magnetic resonance imaging 4

Techniques for Sentinel Lymph Node Biopsy

The techniques for SLNB include:

• Radiopharmaceutical, technetium sulfur colloid, and isosulfan blue dye (used in the United States) 5
• Technetium-labeled albumin and patent blue dye (used in Europe) 5
• Imprint cytology or frozen sections, followed by additional sections for light microscopy 5
• Immunochemical staining with cytokeratin or other techniques to identify "submicroscopic" metastasis 5

Considerations for Axillary Lymphadenopathy Investigation

The investigation for axillary lymphadenopathy should be performed by surgeons and patient management teams with appropriate training and experience 5

• The success rates of SLNB after neoadjuvant chemotherapy mainly depend on the clinical lymph node status pre-NAC 3
• A personalized multidisciplinary path in specialized breast centers should ensure an accurate clinical counselling and refined patient selection for SLNB post-NAC 3