Axillary adenopathy detected on breast MRI following COVID-19 vaccination: outcomes and follow-up recommendations

This retrospective study presents 110 patients with suspected COVID-19 vaccine-related axillary adenopathy on breast MRI. Our study aimed to assess the outcomes of axillary adenopathy detected on breast MRI performed within one year after COVID-19 vaccination. The median time between the COVID-19 vaccine and breast MRI was shorter in patients with detected adenopathy compared to patients without detected adenopathy (6 weeks [2–17] versus 15 [7–24] weeks, p < 0.001). Unilateral axillary adenopathy detected on breast MRI had a low malignancy rate (3.3%), and no cases of malignant axillary adenopathy were diagnosed without a known breast cancer in the ipsilateral breast. Our findings suggest that unilateral axillary adenopathy identified on breast MRI ipsilateral to a recent COVID-19 vaccination can be considered benign in the absence of a suspicious breast finding or known breast cancer. Regardless of vaccine status and timing, unilateral axillary adenopathy detected on MRI evaluation with a known malignancy or suspicious breast finding should be considered suspicious. This will avoid unnecessary scheduling constraints, patient anxiety, and cost, without delaying diagnosis of metastatic breast cancer.