[Clinicopathological features of primary EB virus positive nodal T/NK cell lymphoma]

Objective: To investigate the clinicopathological features of primary Epstein-Barrvirus (EBV) positive nodal T/NK-cell lymphomas (EBV+nodal TNKL). Methods: The clinicopathological features of 7 cases of EBV+nodal TNKL diagnosed between November 2015 and May 2019 at the First Affiliated Hospital of Zhengzhou University were analyzed using immunohistochemistry, PCR gene rearrangement and in situ hybridization.Follow-up data were also collected. Results: There were 5 males and 2 females with a median age of 54 years (ranged from 41 to 75 years). All patients presented with multiple lymphadenopathies and common B symptoms (5/7) and at an advanced Ann Arbor stage Ⅲ/Ⅳ(6/7). Bone marrow involvementwas detected in 1 patient.Six cases of T-cell origin had monomorphic patterns, and the tumor cells showed CD56 negativity and TCRαβ⁺/TCRγδ^－ with T-cell clonality. One case of NK-cell origin had polymorphic pattern, and the tumor cells showed CD56 positivity and TCRαβ^-/TCRγδ^-without T-cell clonality. All cases were positive for the cytotoxic markers, but showed various CD4/CD8 expression. All 7 cases were diffusely positive for EBV (>100 cell/high power field). Six of the patients received chemotherapy, and 1 patient declined the treatments. During the follow-up period ranging from 3 to 48 months, 5 of the 7 patients died of the disease. Conclusions: EBV+nodal TNKL is a rare entity and is characterized by cytotoxic molecule expression, T/NK-cell derivation, and a predominance of nodal involvement at an advanced stage. It should be differentiated from other EBV+T/NK cell lymphoproliferative disorders, especially extranodal NK/T cell lymphoma.