18F-FDG–Avid Lymph Nodes After COVID-19 Vaccination on 18F-FDG PET/CT

A 68-year-old man with right cheek melanoma after resection underwent 18 F-FDG PET/CT, which was unremarkable except for multiple FDG-avid subcentimeter but rounded lymph nodes in the left axilla. The patient had undergone a COVID-19 vaccination in the left arm 3 weeks prior. As under vaccinations have been documented to cause reactive FDG-avid lymph nodes, the nodes in our patient were considered benign, reactive to the COVID-19 vaccination....