A 46-year-old patient with a strong family history of breast cancer had a screening ultrasound prior to COVID-19 vaccination demonstrating a morphologically normal left axillary lymph node. (B) 25 days following the second dose of the COVID-19 vaccination, the patient presented with a palpable lump in the left axilla and ultrasound demonstrated enlarged lymph nodes with cortex measuring up to 6 mm in thickness (arrow). (C) A follow-up ultrasound 21 weeks following demonstrated stable axillary lymphadenopathy. (D) An ultrasound-guided core biopsy was then recommended and pathology demonstrated lymphoid cells negative for carcinoma. Image courtesy of RSNA