ABSTRACT
While ipsilateral lymphadenopathy following COVID-19 vaccination is a relatively common finding on mammography and breast ultrasound transient ipsilateral breast edema is rare with only a few published case reports. Radiologists should be aware of this potential imaging appearance of the breast and axilla following COVID-19 vaccination given the imaging features of edema such as trabecular thickening, skin thickening, and increased echogenicity can overlap with benign and malignant breast conditions such as mastitis and inflammatory breast cancer. We describe a case of transient ipsilateral breast edema after COVID-19 vaccination followed by a discussion summarizing the current understanding and management of transient ipsilateral breast edema following COVID-19 vaccination.