Reactive Axillary Lymphadenopathy to COVID-19 Vaccination on 18F-FDG PET/CT.

In this report, we present 18F-FDG PET/CT findings of reactive left axillary and supraclavicular hypermetabolic lymphadenopathy, as well as ipsilateral deltoid muscle injection site radiotracer uptake, related to recent coronavirus disease 2019 (COVID-19) vaccination in a patient with osteosarcoma. With the growing number of patients receiving COVID-19 vaccine, recognition of benign characteristic 18F-FDG PET/CT image findings will ensure staging and restaging accuracy and avoid unnecessary biopsy.