Massive Cervical Lymphadenopathy Post-COVID-19 Vaccination.

The coronavirus disease 2019 (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus 2. Rapid spread with rampant growth of cases and deaths brought forth an urgent need for novel therapies including vaccinations. The mRNA vaccines for COVID-19 disease have been implemented at an unprecedented scale in an effort to combat the unrelenting pandemic. Such a massive scale vaccination program is bound to coincide with adverse events related to treatment. We present a case of massive cervical lymphadenopathy in a 58-year-old male patient post-Moderna COVID-19 vaccination. Additional investigations did not identify malignancy and he was diagnosed with vaccine-related lymphadenopathy. Patient significantly improved with corticosteroid treatment within 2 days of admission. Lymphadenopathy is reported as the second most common local reaction to the Moderna vaccine. Promoting knowledge of this side effect, particularly in the setting widespread vaccination efforts, would allow for better management of cases, especially in relation to oncologic patients.