Abstract: Objective To study the clinicopathologic features and immunophenotype of cutaneous NK/T cell lymphoma and the association with Esptein-Barr virus (EBV) infection. Methods Five cases of cutaneous NK/T cell lymphoma were studied. Histologic sections of embedded tissues were immunohistochemically stained with CD45RO, CD3ε, TIA-1, CD20, Ki-B5, CD68 and LMP1 antibodies, and in situ hybridization for EBV-encoded small nuclear RNAs-EBER1/2 was also carried out. Results Cutaneous NK/T cell lymphoma accounted for 5.68% in the cutaneous malignant lymphoma in the same period of observation. There were 4 male and 1 female patients, and the mean age was 34 years. The main clinical manifestations were asymptomatic nodules and masses, which were accompanied by ulcers in 2 cases. Histologically, the tumors were mainly located in the dermis and subcutaneous adipose tissue, the infiltrated lymphoid cells were pleomorphic, and angiocentricity and angiodestruction were found in almost all cases. Immunohistochemical stain showed that five cases were T cell phenotype and the expression rate of TIA-1 was 100% (4/4). The EBV was present in three of four cases by in situ hybridization. Conclusions Cutaneous NK/T cell lymphoma presents with unique and diagnostic clinicopathologic features, and is strongly associated with EBV.

Key words: Skin neoplasms, Lymphoma, NK/T-cell, Herpesvirus 4, human