Sweet's syndrome and malignancy.

Acute febrile neutrophilic dermatosis (Sweet's syndrome) is characterized by pyrexia, neutrophilia, and the abrupt appearance of erythematous, painful, cutaneous plaques, primarily on the upper extremities, head, and neck. Histologically, the salient feature is a dense dermal infiltrate of neutrophils. Approximately 10 to 15 percent of published cases of Sweet's syndrome occurred in patients with cancer. This report reviews the 39 patients with malignancy-associated Sweet's syndrome described in the world literature and compares Sweet's syndrome in cancer patients with the idiopathic form of the disease. The most common associated malignancy was acute myelogenous leukemia. However, other myeloproliferative disorders, lymphoproliferative disorders, myelodysplastic syndrome, and carcinomas have been observed. Importantly, the diagnosis of Sweet's syndrome was often the presenting sign of a new or recurrent tumor. The presence of anemia, abnormal platelet counts, immature cells in the differential, and/or severe vesiculobullous or ulcerative cutaneous lesions is infrequent in idiopathic Sweet's syndrome and should alert physicians to the possibility of a more serious underlying disease. Extracutaneous manifestations may occur and most often involve the musculoskeletal system. Response to systemic steroids is dramatic in virtually all patients, regardless of the presence of malignancy.