SUBCUTANEOUS T-CELL LYMPHOMA - A CLINICAL, HISTOPATHOLOGIC, AND IMMUNOHISTOCHEMICAL STUDY OF 6 CASES

Recently, T-cell lymphoma localized to the subcutaneous tissue has bee n reported. We report the clinical, histologic, immunohistochemical, a nd molecular genetic findings in 6 patients who we believe had this pe culiar T-cell lymphoma with its unique morphologic and clinical featur es. All patients presented with deep-seated nodules, most frequently o n the extremities, and with systemic complaints of low-grade fever, fa tigue, myalgias, and weight loss. In all cases, the neoplastic lymphoc ytic infiltrate was confined to the subcutaneous tissue, predominantly in a lobular pattern. Hemorrhage, necrosis, and rare erythrophagocyto sis were also seen. Immunohistochemical staining was predominantly T-c ell reactive (CD43, CD3, and CD45RO). Clonal rearrangements of the bet a and gamma chains of the T-cell antigen receptor genes were found in 1 case. Three of the 6 patients died within 22 months of the diagnosis of lymphoma. We believe that subcutaneous T-cell lymphomas are a dist inctive group of peripheral T-cell lymphomas with unusual clinical and morphologic features and that they should be distinguished from other types of lymphoma.