Mammogram & COVID Vaccines

Lymph node swelling a common immune response

Lymph nodes in your armpits and breast tissue might swell as part of the normal immune response to the COVID vaccine. If you are due for a regular screening mammogram, pay attention to how you schedule it in relation to vaccination.

The Society of Breast Imaging (SBI) recommends :

If possible, and when it does not unduly delay care, consider scheduling screening exams prior to the first dose of a COVID-19 vaccination or 4–6 weeks following the second dose of a COVID-19 vaccination.

The journals Radiology and Clinical Imaging have both published case studies of unclear mammogram readings following COVID-19 vaccinations. Some of those cases included follow-up imaging tests or biopsies that showed no cancer indications.

I learned about this problem today at my annual “well woman” exam with my gynecologist. As the nurse took my history, I rather jubilantly let her know that I received the J&J vaccine this morning.

I had planned to make an appointment for a mammogram during this office visit. Last year at this time, I canceled the exam, saying that I would reschedule “when this COVID thing gets figured out.” Since I am at low risk for breast cancer, it is not a big deal for me to delay for a bit longer.

Women who are at higher risk should pay careful attention to how they schedule their vaccines and mammograms to avoid such a delay.

All of the COVID-19 vaccines can produce a strong immune response, which swells lymph nodes on the side of the vaccination. This “unilateral axillary adenopathy” is what throws up red flags on breast screenings. My nurse explained that other vaccines, like the flu shot, don’t cause as strong a reaction, so this is a new issue.

Elemental has also reported on the side effect:

Discovering a breast lump or having a “call-back” based on irregular results of breast imaging is an emotional roller-coaster.

Since about 80% of breast biopsies are not cancerous, even before vaccination-induced swelling, following the SBI’s recommendations can help women avoid that additional stress of an initial false positive.

That is not to say that you should put off having a regular mammogram as long as I have. If you are due for your regular screening now, try to schedule it before you are eligible to get the vaccine. However, if you are at high risk or you have diagnostic screenings scheduled, consult with your doctor about the implications of this research before you adjust diagnostic or preventative appointments.

Librarian. Curious human. Writing about psychology, science, and messy productivity. I believe in the Oxford comma. (She/Her/Hers)

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