Subcutaneous Panniculitis-Like T-cell Lymphoma

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare primary cutaneous lymphoma composed of cytotoxic alpha-beta T-cells that mimics panniculitis. Distinction from the more aggressive primary cutaneous gamma delta T-cell lymphoma was made in the 2008 revision of the World Health Organization (WHO) Classification of Tumours of Hematopoietic and Lymphoid Tissues. Autoimmune diseases occur in approximately 20% of cases, and lupus erythematosus panniculitis (LEP) is usually part of the differential diagnosis due to similar clinical and histologic features. Histologically, the neoplastic CD8+, beta F1 expressing cytotoxic T-cells characteristically surround and disrupt individual adipocyte membranes (see Subcutaneous Panniculitis). Most cases have a good prognosis and follow an indolent clinical course; however, 15% to 20% of cases are complicated by hemophagocytic syndrome (HPS).