Subcutaneous Panniculitis-Like T-cell Lymphoma: A Clinical and Pathologic Study of 14 Korean Patients

BACKGROUND Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is a distinctive skin lymphoma characterized by neoplastic T-cell infiltration of the subcutaneous tissue, mimicking panniculitis. OBJECTIVE To describe the clinical and pathologic features of SPTL in Korean patients. METHODS Fourteen SPTL patients evaluated over 15 years were retrospectively reviewed. RESULTS The mean patient age was 35 years (range: 7~73 years), with male predominance (2.5:1). Most patients presented with either nodules or plaques, occurring most commonly on the trunk, with two patients (14%) having hemophagocytic syndrome. Histopathologically, all patients showed infiltrates of small-to-medium pleomorphic cells mimicking panniculitis, with some also showing rimming, bean-bag cells, and fat necrosis. Most patients were positive for CD3 (14/14), CD8 (12/13), TIA-1 (9/9) and βf1 (5/5), but were negative for CD4 (11/12), CD20 (8/8), CD56 (14/14) and Epstein-Barr virus (8/8). Ten patients (71%) received chemotherapy and 2 (14%) died due to the disease, with an average survival time of 4 months. Survival analysis did not reveal any significant prognostic factors. CONCLUSION This is the first series of patients with SPTL in Korea. Due to its indolent clinical course and relatively high survival rate, SPTL should be differentiated from cutaneous γδ T-cell lymphoma.