Sweet syndrome (SS) associated with myeloproliferative disorders has been considered an inflammatory process mediated by neutrophils in which immunologic mechanisms are operative. The authors report the case of a 68-year-old man suffering from a myelodysplastic syndrome, who presented with a relapsing skin eruption resembling SS. Histopathologically, the skin infiltrates showed prominent neutrophilic features masking the underlying malignant process. Extensive immunophenotypic studies of skin revealed the presence of a few immature myeloid cells intermingled with an overwhelming infiltrate of neutrophils. The atypical cells in the skin had a phenotype identical to that of leukemic cells in the peripheral blood and bone marrow. Whether or not immature myeloid cell precursors constitute a specific infiltrate of leukemia cutis or are a result of recruitment of circulating leukemic cells to this area of inflammation is discussed.