Radiologists across the country are noticing a possible aftereffect of the COVID-19 vaccine: swelling in underarm lymph nodes seen on mammograms.
Lymph nodes exist in various parts of the body, including the neck, groin, and armpits, and swell in the presence of bacteria, infection, or sometimes cancer, according to the Mayo Clinic.
Typically, an enlarged lymph node in the axilla region would warrant a biopsy of the breast tissue, as it may be an indicator of breast cancer that is starting to spread, according to the Susan G. Komen Foundation; However, radiologists say these events are to be expected after receiving the COVID-19 vaccine and are not normally of concern.
In most patients, evidence of swollen lymph nodes after vaccination does not typically warrant further action unless the swelling persists or other health concerns are at play, Massachusetts General Hospital said in a recent release.
The Centers for Disease Control and Prevention noted in their Moderna and Pfizer vaccine reports that lymph node swelling was “plausibly related to the vaccine” and was most commonly observed in the arm and neck regions two to four days after vaccination. The swelling lasted an average of one to two days for Moderna and about 10 days for Pfizer.
Massachusetts General Hospital warned that radiologists would likely see an increase in the number of enlarged lymph nodes appearing on mammograms as nationwide vaccination efforts increase.
Constance Lehman, chief of chest imaging at Massachusetts General Hospital, told The New York Times that she is pleased that this incident is spreading to put people at ease.
“I am particularly excited to give the floor to all patients who are being monitored after successful previous cancer treatment,” she said.