What are the diagnosis and treatment options for swollen lymph nodes under the left axilla and sharp pain on the left side of the chest at the bottom of the ribs?

Evaluation and Management of Left Axillary Lymphadenopathy with Left-Sided Chest Pain

Start with axillary ultrasound immediately to characterize the lymph node morphology, looking for cortical thickness, size, shape, and vascularity patterns, as this is the primary diagnostic tool for axillary lymphadenopathy. 1, 2, 3

Initial Diagnostic Workup

Imaging Strategy

• Perform diagnostic mammography or digital breast tomosynthesis if you are ≥30 years old, as this can identify occult breast cancer that has metastasized to the axilla 3
• If you are <30 years old, ultrasound is the primary examination without mammography 3
• The ultrasound should specifically assess:
  • Cortical thickness and uniformity 2, 3
  • Size and shape (round vs. oval) 2
  • Vascularity pattern 2, 3
  • Look for "snowstorm" appearance if you have breast implants, which indicates silicone adenitis 1, 3

Clinical History to Obtain

• Recent infections, vaccinations, or trauma 3
• Presence of breast implants (can cause benign lymphadenopathy) 1, 3
• Other sites of adenopathy 3
• Fever, night sweats, unintentional weight loss (suggests lymphoma or systemic disease) 4
• Occupational exposures and animal contacts 5
• Duration of symptoms (lymphadenopathy persisting >4 weeks requires more aggressive workup) 4

Differential Diagnosis

Most Common Causes

• Reactive lymphadenopathy from infections is the most common benign cause 1
• Metastatic breast cancer is the most common malignant cause when cancer is identified in axillary nodes 1
• Non-Hodgkin's lymphoma should be considered, especially with bilateral involvement 1

Chest Pain Considerations

The sharp left-sided chest pain at the rib margin is likely unrelated to the lymphadenopathy itself but requires evaluation for:

• Musculoskeletal causes (costochondritis)
• Pleuritic processes
• Cardiac causes (though less likely with this description)

The lymphadenopathy and chest pain may represent two separate processes unless there is evidence of systemic disease or malignancy.

Management Based on Imaging Results

If Ultrasound Shows Morphologically Abnormal Nodes

Proceed directly to ultrasound-guided core needle biopsy for definitive diagnosis 2, 3

• Core needle biopsy is preferred over fine needle aspiration 3
• This is mandatory if ultrasound reveals suspicious features (thick cortex, round shape, abnormal vascularity) 2

If Imaging is Negative/Benign

• Observe with clinical follow-up or repeat imaging in 4-6 weeks if symptoms persist or worsen 3
• If benign appearance but symptoms persist, perform ultrasound monitoring every 6 months for 1-2 years to ensure stability 2
• Re-biopsy if there are changes in size, morphology, or cortical features during follow-up 2

Additional Imaging Considerations

When to Order Advanced Imaging

• Consider PET/CT if there is concern for lymphoma or other non-breast malignancy 2, 3
• CT chest/abdomen/pelvis may be warranted if metastatic disease from an unknown primary is suspected 2, 3
• MRI has limited value for isolated axillary adenopathy evaluation 3

Red Flags Requiring Immediate Biopsy

• Lymph nodes larger than 2 cm 4
• Hard or matted/fused nodes 4
• Supraclavicular location (though yours is axillary) 4
• Persistence beyond 4 weeks with systemic symptoms 4

Common Pitfalls to Avoid

• Do not start antibiotics empirically without tissue diagnosis if the node appears suspicious on ultrasound, as this can delay diagnosis of malignancy 4
• Avoid corticosteroids entirely, as they can mask the histologic diagnosis of lymphoma or other malignancy 4
• Do not assume bilateral lymphadenopathy is always benign—it can represent lymphoma or systemic disease requiring biopsy 1
• Do not rely on mammography alone to exclude malignancy—ultrasound is essential for lymph node characterization 3