Evaluation of PD1/PDL1 Expression and Their Clinicopathologic Association in EBV-associated Lymphoproliferative Disorders in Nonimmunosuppressed Patients

摘要

Epstein-Barr virus (EBV)-associated lymphoproliferative disorder (LPD)/lymphoma was originally described as a distinct clinicopathologic group in elderly Japanese patients.1 It was then listed as a provisional entity named "EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly" in the World Health Organization (WHO) 2008 classification2 and further modified to EBV-positive DLBCL, not otherwise specified in the updated 2016 WHO classification.3 It is thought to be related to immune senescence associated with the aging process, and usually has a poor prognosis.1'2 The spectrum of clinical and pathologic features of EBV-positive B-cell LPDs in the Western population with no other identifiable cause of immunosuppression has been further described to include reactive lymphoid hyperplasia, polymorphic ex-tranodal LPD, polymorphic nodal LPD, and DLBCL.4