Abstract: Objective:To study the clinicopathologic features,diagnosis and differential diagnosis of subcutaneous panniculitis-like T-cell lymphoma(SPTCL).Methods:One case of SPTCL was examined by HE stainning and immunohistochemistry study.The antibodies which be used were CD3,CD45RO,CD20,CD79a,CD4,CD8,CD30,CD56,CD68 and TIA-1.Results:The case presented as fever,redness,swelling and skin ulcers in left midabdomen and the left inguinal region.Laboratory abnormalities mainly included anemia,leucopenia,thrombocytopenia,elevated liver function tests and hepatosplenomegaly.The histopathology showed a predominant subcutaneous lobular infiltrate with pleomorphic T cells of variable size with irregular and often hyperchromatic nuclei,predominantly with small to medium-sized cells with only scattered large lymphoid cells and rimming of individual adipocytes by atypical lymphocytes.Mitotic figure and karyorrhexis were present.Fat necrosis,hemorrhage,tumor-like necrosis and other cellular responses were also present in the tumor.Immunohistochemistry results showed the tumor cells were positive for CD3,CD45RO,CD8,CD30 and TIA-1,and negative for CD4,CD20,CD79a,CD56 and CD68.The patient died in two months after the onset of the disease.Conclusions:SPTCL is a rare cytotoxic T-cell lymphoma involving primarily in subcutaneous fatty tissues,it has a good prognosis commonly.But if a haemophagocytic syndrome and other syndrome is present,the prognosis maybe be poor.