Interesting Image: PDF OnlyFeatures of Systemic Immune Response From COVID-19 Vaccination on 18F-FDG PET/CTNawwar, Ayah Adel MSc*,†; Searle, Julie FRCR*,‡; Lyburn, Iain Douglas FRCR*,‡Author Information From the *Cobalt Medical Charity, Cheltenham, United Kingdom †Clinical Oncology and Nuclear Medicine Department, Cairo University, Cairo, Egypt ‡Gloucestershire Hospitals NHS Foundation Trust, Gloucestershire §Cranfield University, Bedford, United Kingdom. Received for publication April 12, 2021; revision accepted June 13, 2021. Conflicts of interest and sources of funding: none declared. Correspondence to: Ayah Adel Nawwar, MSc, Cobalt Medical Charity, Linton House, Thirlestaine Rd, Cheltenham, GL53 7AS, United Kingdom. E-mail: [email protected]. 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. Clinical Nuclear Medicine: July 14, 2021 - Volume - Issue - doi: 10.1097/RLU.0000000000003859 Buy PAP Metrics Abstract The rapid rollout of COVID-19 vaccination is accompanied by incidental findings on 18F-FDG PET/CT. Most cases describe reactive axillary lymphadenopathy. A 46-year-old woman with previous history of stage 3A breast cancer underwent follow-up 18F-FDG PET/CT, which demonstrated avid left axillary nodes and intense diffuse splenic uptake and moderate diffuse bone marrow uptake. She had been administered COVID-19 vaccination in the left deltoid 1 week earlier and required hospitalization for 24 hours due to fever. Symptoms settled with supportive treatment. One month after the PET/CT scan, she remained well. Sites of uptake were taken to relate to a systemic immune response. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.