Abstract
A 30-year-old male developed a PET-positive left-sided cervical lymphadenopathy that was suspected representing metastasis of a known right-sided papillary thyroid cancer. First-dose-application of Spikevax three weeks ago was neither reflected, nor reported to the pathologists. Diagnostic lymphadenectomy was performed showing extrafollicular proliferation of B-blasts, likely attributable to the vaccine application.