Radiologists across the country are seeing a potential side effect of the COVID-19 vaccine: swollen lymph nodes under the armpit that appear on mammograms.
Lymph nodes exist in several regions of the body, including the neck, groin and armpits, and swell in the presence of bacteria, infections or sometimes cancer, according to the Mayo Clinic.
Normally, an enlarged lymph node in the armpit region would justify a biopsy of the breast tissue, as it may be an indicator of breast cancer that is beginning to spread, according to the Susan G. Komen Foundation; however, radiologists say that these occurrences after receiving the COVID-19 vaccine are expected and are not normally a cause for concern.
In most patients, evidence of swollen lymph nodes after vaccination does not normally warrant further action, unless swelling persists or other health problems are at stake, Massachusetts General Hospital said in a recent statement.
The Centers for Disease Control and Prevention noted in their vaccine reports Moderna and Pfizer that swollen lymph nodes were “plausibly related to the vaccine” and were most often seen in the arm and neck regions two to four days after vaccination. The swelling tended to last an average of one to two days at Moderna and about 10 days at Pfizer.
Massachusetts General Hospital warned that radiologists would likely see an increase in the number of enlarged lymph nodes during mammograms, as vaccination efforts across the country increased.
Constance Lehman, head of breast exams at Massachusetts General Hospital, told The New York Times that she is happy with the news of this occurrence to help put people at ease.
“I am particularly eager to get the word out to all patients under surveillance after successful previous cancer treatment,” she said.