An Unusual Case of Nonneutropenic Fever Associated With Myelodysplasia and Sweet's Syndrome.

Sweet's syndrome (SS) is a rare paraneoplastic condition characterized by skin lesions, fever, and leukocytosis. It is typically associated with hematological malignancies but is also linked to solid tumors, medications, and inflammatory diseases. The onset of SS can precede or coincide with the discovery of an undiagnosed cancer. Here, we present the case of a 72-year-old woman with neutropenic fever and an incidental nodule in the right breast. Skin biopsy revealed a neutrophilic infiltrate within the deeper dermis and likely subcutis, which is diagnostic for SS. Successful treatment with systemic steroids was administered, while the concurrent diagnosis of myelodysplastic syndrome led to the initiation of decitabine therapy following a bone marrow biopsy.