ABSTRACT
BACKGROUND: Erythroderma could be the first sign of a cutaneous T-cell lymphoma (CTCL), such as Sézary syndrome. Causes of erythroderma include inflammatory dermatosis, toxicoderma, paraneoplastic erytroderma, and CTCL. Hence, diagnosing Sézary syndrome can be difficult. Sézary syndrome is a rare, aggressive disease characterized by erythroderma, generalized lymphadenopathy and the presence of clonally related neoplastic T-cells in skin, peripheral blood, and lymph nodes. Treatment consists of photochemotherapy (PUVA), radiotherapy, immunomodulatory agents, low dose cytotoxic agents, and intensive chemotherapy. Immunotherapy directed against CCR4 and PD1 are new, promising developments. CASE DESCRIPTION: A 51-year-old man presented with a 1-year history of progressive, itchy erythroderma and lymphocytosis. After extensive cytomorphological, histopathological and molecular examination the diagnosis of Sézary syndrome could be established. Combination treatment of interferon and photochemotherapy (PUVA) was started. CONCLUSION: Diagnostic delay in Sézary syndrome is common. Integrated cytomorphological, immunological, and molecular evaluation of peripheral blood in patients with unexplained erythroderma non-responsive to (topical) treatment is warranted.