FDG PET Findings Post-COVID Vaccinations: Signs of the Times?

ABSTRACT: Vaccinations can cause hypermetabolic axillary lymphadenopathy on FDG PET. We present the case of a 71-year-old man who underwent FDG PET/CT for melanoma staging 6 days following a COVID (coronavirus disease) vaccination. Imaging showed a prominent intramuscular mass at the vaccination site, in addition to extensive axillary lymphadenopathy. The mass was compatible with a hematoma at the vaccination site, and the lymphadenopathy was most likely reactive. This case demonstrates unconventional findings in response to a routine vaccination event-findings that, in light of current world events, are likely to be routinely encountered on PET imaging and that should be recognized reactive rather malignant.

FDG PET/CT Findings in an Asymptomatic Case of Confirmed COVID-19

In the current and rapidly worsening pandemic, patients with COVID-19 may undergo imaging with FDG PET/CT. Because a significant proportion of infected patients may be asymptomatic, incidental discovery on a PET/CT scan performed for unrelated reasons can occur. Because of the highly infectious nature of this agent, it is important that interpreting physicians be aware of the typical imaging findings to identify potentially affected patients. We present the case of an asymptomatic patient referred for FDG PET/CT imaging of a lung nodule who demonstrated the typical CT findings of COVID-19 infection and was subsequently found to be positive on testing. Received for publication April 2, 2020;revision accepted April 27, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Patrick Martineau, MDCM, PhD, Health Sciences Centre, 820 Sherbrook St GC321, Winnipeg, Manitoba, Canada, R3A 1R9. E-mail: pmartineau@manitoba-physicians.ca. This article is made available via the PMC Open Access Subset for unrestricted re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the COVID-19 pandemic or until permissions are revoked in writing. Upon expiration of these permissions, PMC is granted a perpetual license to make this article available via PMC and Europe PMC, consistent with existing copyright protections. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.