Subcutaneous T-cell lymphoma with associated hemophagocytic syndrome and terminal leukemic transformation

We report a case of subcutaneous T-cell lymphoma that presented as recurrent subcutaneous nodules, pancytopenia, and fever. Histopathologic examination revealed a dense infiltrate of markedly atypical lymphoid cells localized to the panniculus. These cells were identified as T cells by immunohistochemistry. There was associated karyorrhexis and fat necrosis. Hemophagocytosis was present both in the panniculus and in the bone marrow, with no tumor evident outside the subcutaneous tissue. Despite chemotherapy in conjunction with an autologous bone marrow transplant, the patient died after metastases, including explosive leukemic transformation, developed. Review of the literature shows subcutaneous T-cell lymphoma to be a rare peripheral T-cell lymphoma, often mistaken initially as a benign panniculitis, that manifests an aggressive, fulminant presentation in approximately one half of the patients; the remainder transform into a high-grade malignancy after months to years. The hemophagocytic syndrome, thought to be a reactive T-cell process mediated by cytokines, is a frequent complication of this lymphoma and is responsible for its poor prognosis. Our patient uniquely demonstrated fatal leukemic transformation.