False-Positive Axillary Lymph Nodes on FDG PET/CT Resulting From COVID-19 Immunization

Abstract

World-wide mass COVID-19 vaccination has been deployed starting with those most vulnerable, including the elderly and cancer patients. A 70-year-old man with right lung cancer underwent staging FDG PET/CT, which demonstrated an avid right lung mass with avid hilar and mediastinal nodes. Avid left axillary nodes of benign configuration were also noted. The patient had the Oxford-AstraZeneca COVID-19 vaccination in the left arm a week earlier. On reflection, the axillary nodes were concluded to be reactive related to this. This is a potential COVID-19 vaccination associated pitfall on PET/CT that should be considered when interpreting FDG PET/CT images.