Cytophagic histiocytic panniculitis and subcutaneous panniculitis-like T-cell lymphoma: Report of 7 cases

Background: Cytophagic histiocytic panniculitis (CHP) is a rare subtype of panniculitis that usually follows a fatal course, with a terminal hemophagocytic syndrome. Recent reports on a subset of peripheral T-cell lymphoma named subcutaneous panniculitis-like T-cell lymphoma (SPTL) raised the question about the relationship between these entities. Observations: We describe 7 patients in the study: 1 with fatal CHP, 4 with SPTL, and 2 with long-term CHP. The 3 patients with fatal CHP and SPTL died of complications of hemophagocytic syndrome, with a disease duration ranging from 8 to 74 months. The other 2 patients were still alive 6 and 41 years after disease onset. Immunohistochemical results proved that 2 of the SPTL cases were type α/β and expressed the cytotoxic/suppressor antigen CD8, while the other 2 were type γ/δ and were positive for the natural killer-associated antigen CD56. In these 4 cases, molecular biology studies by polymerase chain reaction detected T-cell receptor γ gene rearrangement, indicating a clonal process. In contrast, in the 2 patients who had long-term CHP, the polymerase chain reaction results failed to disclose clonality. In the subject with fatal CHP, genotypic analysis was not performed. Conclusion: Our observations suggest that CHP and SPTL may span a clinicopathologic spectrum in which there is a natural disease progression from CHP to SPTL.