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.