Cutaneous T-cell lymphomas: the Sézary syndrome, mycosis fungoides, and related disorders.

Substantial evidence has accumulated to indicate not only that mycosis fungoides and the Sézary syndrome are closely related malignancies, but to suggest that they are part of a larger spectrum of cutaneous lymphomas. The neoplastic cells of these disorders have membrane features of thymus-derived (T) lymphocytes, a characteristic tissue distribution (skin infiltration, marrow sparing, localization in T-cell regions of lymphoid tissue), and distinctive morphology. For these reasons, we suggest that these lymphoproliferative disorders be grouped together as "cutaneous T-cell lymphomas". The anergy noted in patients of this group with leukemia probably is related to both decreased percentages of normal T cells and presence in the serum of macrophage migration inhibitory activity. Leukapheresis has been particularly effective in the management of selected patients. The homogeneous T-cell populations in the patients with leukemia also provide important opportunities to study many aspects of lymphocyte physiology that are of broad biologic significance.