Lymph nodes in the armpit area can become swollen after a COVID-19 vaccination, and this is a normal reaction that typically goes away with time. Radiologists at Massachusetts General Hospital (MGH) who recently published an approach to managing this situation in women who receive mammograms for breast cancer screening in the American Journal of Roentgenology have now expanded their recommendations to include care for patients who undergo other imaging tests for diverse medical reasons. Their guidance is published in the Journal of the American College of Radiology.

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"Our practical management plan extends the impact of our recommendations to the full spectrum of patients having imaging tests after vaccination," says lead author Constance Lehman, MD, PhD, chief of Breast Imaging, co-director of the Avon Comprehensive Breast Evaluation Center at MGH, and professor at Harvard Medical School.

Lehman and her colleagues—from multiple subspecialties in radiology—note that as COVID-19 vaccination programs ramp up, radiologists should expect to see increasing numbers of patients who show swollen lymph nodes on imaging exams. They recommend that imaging centers document COVID-19 vaccination information—including the date(s) of vaccination, the location of the injection site, and the type of vaccine—on all patient forms and ensure that this information is easily available to radiologists at the time the image is interpreted.

In most cases, no additional imaging tests are needed for swollen lymph nodes after recent vaccinations unless the swelling persists or if the patient has other health issues. Additional tests may be warranted in cases where there was a heightened concern for cancer in the lymph nodes before the imaging test was performed. "In a patient with a recent cancer diagnosis, the patient's full care team and the radiologist can work together to determine how best to manage nodes that appear abnormal on imaging after a recent vaccination. That way, they can tailor care to the individual patient," says Leslie Lamb, MD, breast imaging specialist at MGH and co-author of the study.

Radiologists' communication with clinicians and patients should stress the importance of avoiding delays in either vaccinations or recommended imaging tests to ensure their optimal care throughout the pandemic. "Advanced planning can support our patients to feel confident and safe to receive their vaccinations as well as undergo recommended imaging in their usual care," says Lehman.

The team's management recommendations will continue to be updated as more data are available to guide best practice.