Management of Axillary Lump with Hyperemia
For a patient presenting with an axillary lump with hyperemia (suggesting inflammation or infection), perform axillary ultrasound as the initial imaging modality, followed by ultrasound-guided core needle biopsy if the mass appears suspicious, to differentiate between infectious/inflammatory causes and malignancy. 1
Initial Clinical Assessment
The presence of hyperemia (redness/inflammation) significantly narrows the differential diagnosis compared to a simple axillary mass. Key considerations include:
- Infectious causes: Mastitis with associated lymphadenitis, skin wound infections, or granulomatous inflammation 2, 3
- Inflammatory conditions: Autoimmune disease-related adenopathy 2
- Malignancy with inflammatory features: Though less common, metastatic breast cancer or lymphoma can occasionally present with overlying skin changes 1, 2
The hyperemic presentation suggests an acute process requiring prompt evaluation to prevent progression and guide appropriate treatment. 1
Imaging Strategy
Ultrasound as First-Line Imaging
Axillary ultrasound is the most appropriate initial imaging modality for any palpable axillary lump, including those with hyperemia. 1 This recommendation applies regardless of whether the patient has known breast cancer or presents with an isolated axillary finding.
Ultrasound allows assessment of:
- Whether the mass is solid or cystic (abscess formation) 2
- Lymph node morphology including cortical thickness (>0.3 cm suggests malignancy) and presence/absence of fatty hilum 1
- Surrounding soft tissue inflammation 3, 4
- Vascular flow patterns that may help distinguish inflammatory from malignant processes 3
Complementary Mammography
For patients ≥30 years of age, diagnostic mammography and/or digital breast tomosynthesis should complement axillary ultrasound to evaluate for an occult breast primary lesion. 1, 2 This is critical because breast cancer is the most common malignant cause of axillary adenopathy, and approximately 5 of 17 cancer cases presenting as isolated axillary masses have occult breast cancer. 1
For patients <30 years of age, ultrasound alone is typically sufficient unless clinical suspicion for breast malignancy is high. 1
Tissue Diagnosis
Core Needle Biopsy Preferred
If the ultrasound demonstrates suspicious features or if clinical concern persists despite benign-appearing imaging, perform ultrasound-guided core needle biopsy rather than fine needle aspiration. 1
The evidence strongly supports core biopsy superiority:
Core biopsy provides architectural information crucial for distinguishing reactive lymphadenopathy from lymphoma and allows for immunohistochemical studies. 1
Exception for Anticoagulation
FNA remains appropriate for patients unable to discontinue anticoagulation, though inadequate sampling occurs in 5-10% of cases. 1 On-site cytopathology assessment, when available, can reduce inadequate sampling rates. 1
Management Based on Biopsy Results
If Benign/Reactive Lymphadenopathy
- Treat underlying infection or inflammatory condition appropriately 1, 2
- Consider short-interval follow-up ultrasound (4-6 weeks) to document resolution 1
- If the mass persists or enlarges despite treatment, repeat biopsy or excisional biopsy may be warranted 1
If Malignancy of Breast Origin
- Proceed with breast MRI if mammography/ultrasound shows no breast primary (MRI identifies occult primary in ~70% of cases) 2
- Follow NCCN Guidelines for Breast Cancer management 1
- Staging workup as clinically indicated 1
If Lymphoma Suspected
Special pathologic evaluation and/or surgical excision may be required rather than core biopsy alone, as lymphoma diagnosis often requires flow cytometry and extensive immunohistochemistry. 1
Critical Pitfalls to Avoid
Do not assume hyperemia automatically indicates benign disease. While infectious/inflammatory causes are more common, malignancy can present with overlying skin changes, particularly inflammatory breast cancer or aggressive lymphomas. 1, 2
Do not rely on negative ultrasound alone to exclude malignancy. Axillary ultrasound has relatively low negative predictive value and sensitivity (26-94% sensitivity range), and a negative ultrasound does not rule out nodal disease. 1 Clinical correlation and tissue diagnosis remain essential when suspicion is high.
Do not perform mammography alone without ultrasound. Mammography has a high false-negative rate for detecting axillary lymphadenopathy and is not optimal for axillary evaluation. 1
Do not delay biopsy if imaging shows suspicious features (cortical thickness >0.3 cm, absent fatty hilum, short-axis diameter >1 cm), as the absence of fatty hilum has 90-93% positive predictive value for malignancy. 1