COVID-19 Vaccination Manifesting as Incidental Lymph Nodal Uptake on 18F-FDG PET/CT

Benign uptake on F-18-FDG PET can be seen with inflammatory conditions. We report a case of an 86-year-old woman with successfully treated nasal melanoma who underwent routine follow-up F-18-FDG PET, day 6 after the second dose of Pfizer-BioNTech COVID-19 vaccine inoculated in the left deltoid muscle. F-18-FDG PET showed increase tracer uptake in the left deltoid muscle and in 2 normal-sized left subpectoral nodes. These findings were considered secondary to vaccination. With the current drive of global COVID-19 immunization, this case highlights the importance of documenting vaccination history at the time of scanning to avoid false-positive results.

Automated summary

A case of abnormal uptake on F-18-FDG PET scan after COVID-19 vaccination in an 86-year-old female patient was reported. This highlights the importance of documenting vaccination history during PET scans to prevent false positive results.