Diagnostic Approach to Focal Unilateral Breast Pain with Axillary Lymphadenopathy

Immediate Diagnostic Approach

The National Comprehensive Cancer Network recommends urgent age-appropriate diagnostic imaging (diagnostic mammogram with ultrasound if ≥30 years, ultrasound alone if <30 years) followed by core needle biopsy of the axillary lymph nodes to exclude malignancy in patients with focal unilateral breast pain and palpable axillary adenopathy 1
This presentation is clinically significant and requires immediate workup because it combines focal unilateral pain with swollen lymph nodes, which distinguishes it from benign cyclical mastalgia 2, 3
The cancer detection rate for focal breast pain alone is 2.3-4.6%, but the addition of axillary lymphadenopathy substantially increases malignancy risk 4, 5

Breast cancer with axillary metastases, such as invasive lobular carcinoma and anaplastic carcinoma, can present with pain as a primary symptom 2, 5
Occult breast cancer can occur in patients with isolated axillary masses, with 9 of 17 cancer cases having occult breast cancer 1

If imaging shows suspicious findings (BI-RADS 4 or 5), immediate core needle biopsy is mandatory 1
For patients with BI-RADS 1 (Negative) or 2 (Benign) imaging results, but with high clinical suspicion, do not rely on negative imaging alone—proceed to biopsy 1

The National Comprehensive Cancer Network recommends over-the-counter NSAIDs (ibuprofen) for pain control in patients with excluded malignancy 1