Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cutaneous T-cell lymphoma that mimics panniculitis clinically and displays a lobular panniculitis with neoplastic T-cell infiltration microscopically. It represents less than 1% of all cutaneous lymphoma cases.

SPTCL is considered a prognostically favorable cutaneous T-cell lymphoma with an indolent course. Average age of onset is at 36 years, but it can present in both adults and children. There is a slight female predilection. Survival rate is excellent (5-year survival rate above 90%). It is generally confined to the subcutaneous tissue.

While extracutaneous involvement by lymphoma cells is typically absent, hemophagocytic syndrome (HPS) is a serious complication seen in 15%-37% of patients. HPS is characterized by uncontrolled activation and proliferation of normal lymphocytes and macrophages with multisystem involvement, and is associated with poor survival.

SPTCL may be associated with an autoimmune disease in around one-fifth of cases. Reported associations include systemic lupus erythematosus, juvenile rheumatoid arthritis, Sjögren syndrome, rheumatoid arthritis, diabetes mellitus type 1, idiopathic thrombocytopenic purpura, multiple sclerosis, Raynaud disease, and Kikuchi-Fujimoto disease.