Axillary Lymphadenopathy Associated With COVID-19 Vaccination: Updates and Recommendations

Lymphadenopathy (LAD) associated with vaccination has been documented as complicating the evaluation of metastatic malignancy. In the past this was a limited finding, primarily documented in association with smallpox and H1N1 vaccination.The advent of the novel mRNA vaccine for COVID-19 in December of 2021, and subsequent large scale vaccination effort, has resulted in a marked increase in the identification of LAD associated with vaccination. Because axillary LAD is a concerning sign of metastatic disease in breast cancer, identifying the difference between benign inflammatory reaction and concerning LAD and avoiding unnecessary additional imaging and biopsy is an essential skill. This article describes the current literature, recommendations for follow-up, and interventions to improve diagnostics.