Cutaneous histiocytoid Sweet syndrome and its relationship to hematological diseases.

Sweet syndrome (SS) was described over 50 years ago as a distinctive form of neutrophilic dermatosis. It may be idiopathic, drug-induced or paraneoplastic, and in the last of those subtypes, myeloproliferative diseases are prominently represented. A peculiar variant of SS is termed 'histiocytoid' SS (HSS), and early accounts of that condition asserted that it showed no linkage to hematological disorders. We herein report two additional cases of HSS--both of which were associated with myeloid dyscrasias--together with a review of the pertinent literature. Along with our observations, the latter process appears to contradict the contention that HSS has no relationship to hematopoietic diseases; between 35 and 55% of reported cases have indeed shown such an association, usually with myelogenous leukemia or myelodysplastic syndromes.