摘要Objective:The aim was to study the features and clinical significance of cell apoptosis and proliferation of NK/T cell lymphoma. Methods:TdT-mediated dUTP nick end labeling and immunohistochemical Streptavidin-peroxidase method were used to study cell apoptosis and the expression of proliferation cell nuclear antigen in 25 NK/T cell lymphoma and 10reactive lymphoid tissues. Results:Apoptotic index (AI) and proliferative index (PI) averaged (1.92% ± 0.86%) and (41.48%± 5.10%) respectively in the 25 NK/T cell lymphomas and (6.70% ± 1.89%) and (20.10% ± 2.77%) in the 10 reactive lymphoid tissues. Compared with reactive lymphoid tissues, AI was significantly reduced in NK/T cell lymphoma (t = 10.80, P < 0.01)while PI significantly increased (t = 12.39, P < 0.01). In addition, in NK/T cell lymphoma, AI and PI were positively related (r = 0.69, P < 0.01). Conclusion:In NK/T cell lymphoma, cell apoptosis is reduced while cell proliferation increased. The imbalance between cell apoptosis and cell proliferation is closely related to the development and progression of NK/T cell lymphoma.