The first autopsy case of Epstein-Barr virus-positive marginal zone lymphoma that deteriorated after COVID-19 vaccination.

This is the first autopsy case of Epstein-Barr virus-positive marginal zone lymphoma (EBV + MZL) with an other iatrogenic immunodeficiency-associated lymphoproliferative disorders (LPD) (methotrexate [MTX]-associated LPD) that deteriorated after the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. This case had a unique immunophenotype. A 71-year-old female patient with rheumatoid arthritis receiving MTX presented with fatigue 1 week after the SARS-CoV-2 vaccination. She was hospitalized due to hepatorenal dysfunction and pancytopenia. Computed tomography revealed systemic lymphadenopathy. Her physical condition deteriorated, and the patient died. The autopsy revealed systemic lymphadenopathy comprising medium-sized atypical lymphocytes and scattered Hodgkin/Reed-Sternberg (H/RS)-like cells. An immunohistochemical examination showed that atypical lymphocytes were positive for CD79a and MUM-1 and some were positive for CD20 and IRTA-1. H/RS-like cells were immunoreactive for CD30 and CD15 and ringed by T cells. Both cell types were positive for EBV-encoded small RNA. The majority of H/RS-like cells were positive for CD20, whereas a small number of CD3-positive cells were admixed. We herein presented the first autopsy case of EBV + MZL that deteriorated after the SARS-CoV-2 vaccination.