Evolving Bilateral Hypermetabolic Axillary Lymphadenopathy on FDG PET/CT Following 2-Dose COVID-19 Vaccination

Clin Nucl Med. 2021 Dec 1;46(12):1011-1012. doi: 10.1097/RLU.0000000000003711.


A 50-year-old woman with stage IV sigmoid adenocarcinoma presented for restaging FDG PET/CT status post neoadjuvant chemotherapy/immunotherapy and diverting sigmoid colostomy. FDG PET/CT demonstrated FDG uptake in the known sigmoid mass and in abdominopelvic lymph node metastases. Bilateral, asymmetric, hypermetabolic axillary lymphadenopathy was also observed, an atypical pattern of spread for colon cancer. Further investigation revealed the patient had received both doses of COVID-19 vaccine in the 2 months prior to presentation. The authors discuss immunogenic nodal hypermetabolism following vaccination against COVID-19 and incorporating vaccination history to aid in PET/CT interpretation, especially in malignancies involving the axillae.

Publication types

  • Case Reports

MeSH terms

  • COVID-19 Vaccines
  • COVID-19*
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Lymphadenopathy* / diagnostic imaging
  • Lymphatic Metastasis
  • Middle Aged
  • Positron Emission Tomography Computed Tomography
  • SARS-CoV-2
  • Vaccination


  • COVID-19 Vaccines
  • Fluorodeoxyglucose F18