INTRODUCTION: Hemophagocytic syndrome is a rare clinicopathological condition characterized by the activation of the mononuclear phagocyte system, resulting in hemophagocytosis in the reticuloendothelial systems. The pathogenesis of HPS remains unclear. CASE PRESENTATION: We report the case of a 20-year-old soldier suffering from HPS. Because of long history fever and no reasons being found, his left groin lymph node and left neck lymph node biopsy were done with two weeks interval. We found a marked increase in plasma cells in left neck lymph node during the course of the disease. CONCLUSION: Our result provides a new thought for the researchers to understand the mechanisms responsible for the phagocytosis in HPS.