Epstein-Barr virus–positive, primary cutaneous marginal zone lymphoma, with transformation: Case report and review of the literature

Epstein-Barr Virus (EBV) positive primary cutaneous marginal zone lymphoma (PCMZL) is uncommon and subsequent transformation is rare. Methods: We report a patient with EBV positive PCMZL with subsequent transformation to plasmablastic lymphoma and review the literature for transformed PCMZL to assess clinical and pathologic characteristics. In the case we describe, the patient presented with multifocal PCMZL, developed large B cell transformation with plasmacytic differentiation, followed by plasmablastic transformation (PBL), and ultimately died of disease progression despite multiple lines of therapy. Past history was significant for psoriatic arthritis (multiple prior lines of immunomodulatory therapy). The lymphomas and non-involved bone marrow share the same somatic DNMT3A and TET2 mutations, suggesting clonal relatedness and an association with clonal hematopoiesis (CH). Results: Eighteen cases complied the cohort (seventeen cases from the literature and the case reported herein). Nearly half of the eighteen cases of PCMZL with transformation died of progressive disease (44%). Transformed cases were more commonly seen in patients with >2 sites at initial diagnosis. EBV was assessed in 5 patients, 3 were positive (all died of disease). Two patients with NGS studies demonstrated TET2 and DNMT3A mutations. Conclusions: Transformation of EBV positive PCMZL appears to be a poor prognostic indicator, with our reported case being the first well defined case transformed to PBL, suspected to arise from myeloid-CH.