Those who have received the COVID-19 vaccine may experience mild, temporary swelling of lymph nodes in the armpit and neck. This is known as unilateral axillary lymphadenopathy (LAD), and is a good thing when related to a recent vaccine – it means the body is showing the desired immune response. LAD occurred in a small population of people who participated in the Pfizer and Moderna vaccine trials, and generally presented a few days post vaccination. It may appear longer when detected by mammography.
Screening mammography is intended to detect changes in breast and surrounding tissue, including LAD. Therefore, we suggest patients schedule their annual screening mammogram either prior to receiving a COVID-19 vaccine or 4 weeks after their second dose to avoid a potential complication in the screening process. If an LAD finding is present on a screening exam for any reason, we will schedule a follow up exam for further investigation.