Lymphadenopathy with florid lymphoid and Langerhans cell hyperplasia and hemophagocytosis mimicking lymphoma after COVID‐19 mRNA vaccination

Abstract

Abbreviations Covid-19 coronavirus disease 2019 EBV Epstein-Barr virus HIV human immunodeficiency virus HLH hemophagocytic lymphohistiocytosis LCs Langerhans cells SARS-CoV-2 severe acute respiratory syndrome coronavirus 2 INTRODUCTION Vaccine campaigns are currently the most promising method to combat the COVID-19 pandemic. The differential diagnosis includes vaccination-induced (post-vaccinal) lymphadenitis and acute viral infection (particularly Epstein-Barr virus [EBV]-induced infectious mononucleosis, as well as rubella, human immunodeficiency virus [HIV], influenza, and herpes zoster), which can mimic malignant lymphomas [ 3,4]. Of the multiple epitopes on SARS-CoV-2, the spike (S) glycoprotein is the target commonly selected for COVID-19 vaccine development, since it is the major SARS-CoV-2 surface protein and mediates viral entry by binding to the angiotensin-converting enzyme 2 (ACE2) receptor in host cells.