Radiologists report COVID-19 vaccine causing swelling on mammograms | TheHill - The Hill

Radiologists around the country are noting a potential aftereffect of the COVID-19 vaccine: swelling in lymph nodes under the armpit that are showing up on mammograms.

Lymph nodes exist in various regions around 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 armpit region would warrant a biopsy of the breast tissue, as it can be an indicator of breast cancer that is beginning to spread, according to the Susan G.