RESUMO
Sézary syndrome is a form of cutaneous T-cell lymphoma and, like mycosis fungoides, results from the malignant proliferation of mature post-thymic T-cell lymphocytes. The main features are the presence of abnormal mononuclear cells (Sezary cells) in the peripheral blood and exfoliative erythroderma. The authors present of a 70-year-old woman admitted to our clinic due to the case pruriginous and exfoliative erythroderma, subcutaneous nodes and lymphadenopathy. The clinical diagnosis of Sézary syndrome was confirmed through the identification of Sézary cells in the peripheral blood by cytochemistry and membrane marker studies and by lymph node histopathology. Genotypic studies excluded the presence of HTLV-I and HTLV-II sequences in DNA samples and confirmed the monoclonal nature and T-cell origin of this lymphoproliferative disease.