Subcutaneous Panniculitis-Like T-Cell Lymphoma Revealed By Immunophenotyping of Necrosis

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare but well-defined entity, often associated with autoimmune manifestations, generally with a good prognosis unless associated with hemophagocytic syndrome. Typically, the lymphoma cells rim the adipocytes and are characterized by a CD8 + cytotoxic phenotype. We report 2 cases of SPTCL where the first biopsies only showed subcutaneous fat necrosis without any lymphoma cell visible. The diagnoses were allowed by immunophenotypic markers which characterized necrotic neoplastic T cells and confirmed on further biopsies with a typical pattern of SPTCL. These observations should prompt dermatologists to perform as large biopsies as possible, and pathologists to perform immunophenotyping in all suspected cases even if only lobular necrosis is seen morphologically.