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Can the COVID-19 vaccine affect my mammogram?

June 1, 2021

Ask the doctors

161e2a67-1ebb-426c-99d3-b34faada940aQ. I heard that getting the COVID-19 vaccine might affect my mammography results. Is this true?

A. Yes. At least two of the approved COVID-19 vaccines may cause lymph nodes in the armpit (or other spots in the body) to swell as they prime your immune system to recognize and fight the virus. It’s a harmless temporary reaction, but one that might cause some confusion on a mammogram. Swollen lymph nodes in the armpit or other nearby locations are in rare cases a sign of cancer. To avoid unnecessary tests and needless anxiety, experts are now advising radiologists to use caution when interpreting the significance of swollen lymph nodes seen on a woman’s mammogram if she has recently gotten the COVID-19 vaccine. If your breast imaging center hasn’t asked about it, be sure to let them know. If your mammogram shows that you have swollen lymph nodes, your radiologist may want you to undergo follow-up ultrasound testing or return in a few weeks for a repeat ultrasound to see if the swelling has gone away. If the swelling persists, further testing may be warranted. To avoid problems try to schedule your mammogram before you get your first dose or schedule your appointment for four to six weeks after your second dose. But don’t skip either the test or your COVID-19 vaccination.

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