Abstract: XU Jiao-sheng*, LIU Yuan-xiang, XU Zhe, ZHANG Li-xin, XU Zi-gang, GAO Zi-fen, MA Lin. *Department of Dermatology, Beijing Children′s Hospital, Capital Medical University, Beijing 100045, China Corresponding author: ZHANG Li-xin, Email: zhanglixinpifuke@aliyun.com 【Abstract】 A 13-year-old girl presented with multiple recurrent cutaneous plaques for more than six months, which had been aggravated with intermittent fever for five months. No obvious systemic abnormality was found. Dermatological examination revealed multiple, non-ulcerative, painless, infiltrative, indurated, poorly marginated, purple subcutaneous plaques measuring 3 － 11 cm in diameter with slight squamation in bilateral buttocks and lower limbs. Laboratory investigations showed bicytopenia with the white blood cell count being （0.03 - 3.7） × 109/L and red blood cell count being （2.8 - 4.4） × 1012/L, a normal platelet count, hypofibrinogenemia （1.79 g/L） and low proportion of natural killer cells （4.6%）. Bone marrow smear showed active proliferation of cells, decreased proportion of granulocytes, presence of a few indefinitely classified cells, and phagocytosis. Reticulocytes were easily seen in the bone marrow smear. Pathologically, no obvious abnormality was observed in the epidermis or dermis, while the subcutaneous adipose tissue, especially fat lobules and some interlobular septa, was extensively infiltrated by large- to medium-sized lymphoid cells with pleomorphic and twisted nuclei as well as a small amount of cytoplasm; necrosis and phagocytosis of nuclear debris and lymphocytes were visible. The atypical lymphoid cells stained positive for CD3, T-cell intracellular antigen-1, granzyme B and TCRγδ with partial loss of CD5 and CD7, but negative for CD56, CD4, CD8 and TCRαβ. No Epstein-Barr virus-encoded RNA （EBER） was detected by in situ hybridization. Based on these findings, a diagnosis of primary cutaneous γδ-T cell lymphoma with hemophagocytic syndrome was made. 【Key words】 Lymphoma, T-cell, cutaneous; Lymphohistiocytosis, hemophagocytic