Abstract： Objective To investigate the expressions of survivin and Ki67 in cutaneous extranodal NK/T-cell lymphoma,nasal type and their significance.Methods Clinical data and laboratory test results were collected from 15 cases of cutaneous extranodal NK/T-cell lymphoma,nasal type with skin lesions as the initial manifestation.Immunohistochemical SP method was used to measure the expression of survivin and Ki67 in tissue sections from the lesions of these patients.To determine the percentage of survivin-or Ki67-positive cells,200 tumor cells were counted in a high power field (HPF) and 5 HPFs were observed in 1 section.Results There were 10 males and 5 females among the 15 patients,with the median age at diagnosis being 28.7 (range:9-62) years.Immunohistochemical study showed that the lesional tissue was positive for CD56 in 9 cases,CD3ε in 13 cases,T cell intracellular antigen (TIA)-1 in 15 cases,granzyme B in 10 cases,CD3 in 2 cases,βF1 in 1 case,but negative for CD4,CD5,CD8,CD20,and CD79α.All the 15 cases were positive for 1 or 2 T-cell associated antigens (CD2,CD7 or CD45RO).CD30 was observed in large tumor cells in 3 of the 15 cases.Monoclonal TCR-γ gene rearrangement was found in 3 of 14 cases.In situ hybridization for EBER1/2 was positive in all of the 15 cases.Survivin and Ki67 were expressed in 73.3％ (11/15) and 100％ (14/14,note:a tissue section was unavailable because of the detachment of tissue from the slide) of the specimens respectively,with the average percentage of positive cells being 23.97％ ± 18.35％ and 41.20％ ± 19.52％ for survivin and Ki67,respectively.Statistical differences were observed in the percentage of Ki67-expressing cells between the specimens with 0-2 mitotic figures per high power field from 9 cases and those with more than 2 mitotic figures from 6 cases (25.27％ ± 12.96％ vs.58.23％ ± 16.02％,F =19.14,P =0.001).No correlation was found between the expression of survivin and Ki67 in cutaneous extranodal NK/T-cell lymphoma,nasal type.Conclusion The high expressions of survivin and Ki67 may play a role in the occurrence and development of cutaneous extranodal NK/T-cell lymphoma,nasal type.