Reports of some patients developing enlarged lymph nodes after a COVID-19 vaccination have raised questions about whether screening mammograms should be delayed following the vaccination. This stems from concerns that finding enlarged axillary lymph nodes following a vaccination could lead to unnecessary testing.
However, when health-care providers know a patient was recently vaccinated along with the location of the injection site, enlarged axillary lymph nodes can be safely attributed to the vaccination.
The American College of Radiology quality assurance program developed a process to evaluate enlarged axillary lymph nodes caused by an inflammatory response to a vaccination and safely avoid unnecessary further diagnostic testing. Radiology Associates of Ithaca radiologists and Cayuga Health use this evaluation process and do not advise delaying screening mammography or diagnostic imaging for a new breast lump or other breast concern following a COVID-19 vaccination. When a radiologist has a patient’s medical history to review, the risk of a false positive mammogram finding due to a vaccination is far outweighed by the risk of delayed breast cancer diagnosis.
What prompted the concerns related to COVID-19 vaccinations and mammograms?
As the COVID-19 vaccination rate increased, radiologists saw more recently immunized people had enlarged axillary nodes. The bean-shape nodes are in the armpit, and about 15% of patients receiving the Pfizer or Moderna vaccine get enlarged axillary lymph nodes. The lymph node enlargement caused by the vaccinations is a normal reaction by the immune system to the vaccine. It occurs in the same arm where the shot was given and usually resolves within a few weeks.
How does lymph node enlargement from the vaccination affect the mammogram image?
Enlarged lymph nodes may be visible in the axillary portion of your mammogram. If enlarged nodes appear on the image, your radiologist will review your medical history to determine if a COVID-19 vaccination had recently been administered.
How can I help avoid a false positive mammography result following a COVID-19 vaccination?
To lessen the chance of a false positive test, let the mammography technologist know if you recently had a COVID-19 vaccination and in which arm. Cayuga Health mammography technologists will also ask you about recent vaccinations.
What happens if I had a recent COVID-19 vaccination and enlarged lymph nodes appear on my mammogram?
If your mammogram reveals enlarged axillary lymph nodes only in the arm where you were vaccinated, Cayuga Health radiologists will advise you to have your primary care physician examine the lymph nodes in your armpit about six weeks after your mammogram. This protocol follows the American College of Radiology quality assurance guidelines.
The radiologist will give you a written recommendation for this follow-up exam, and a copy will be sent to your physician. Enlarged lymph nodes resulting from a vaccination usually resolve in a few weeks. If the enlargement persists at the follow-up exam, additional testing would be needed to determine the cause.
Why not just delay my mammogram following COVID-19 vaccination or delay my vaccination until after a scheduled mammogram?
Unfortunately, breast cancer doesn’t stop for COVID-19, so it’s important not to put off your screening mammogram. Regular screening mammograms ensure that breast cancer can be detected as early as possible and allow for the most effective treatment options.
It is equally important to get the COVID-19 vaccine when it is available to you. The vaccine is a critical measure to help prevent infection. You should get your COVID-19 vaccination at the earliest possible date, even if you are scheduled to have your mammogram soon afterwards.
Walter Silbert, MD, is a board certified Diagnostic Radiologist at Cayuga Medical Center. Diana Hewitt, RN, is a certified Breast Cancer Nurse Navigator at Cayuga Medical Center.