Risk of Malignancy in Histiocytoid Sweet Syndrome: A Systematic Review and Reappraisal

The nature of the histiocytoid infiltrate in HSS has generated considerable controversy in the literature and, compared to classical SS, a higher risk of association with hematologic malignancies have been proposed by some authors and refuted by others. Compared to classical SS, we found that HSS lacks the clear female predominance, is associated with less extracutaneous manifestations and underlying inflammatory disorders and, very importantly, is related to a higher risk of underlying malignancy, particularly of the hematological type. Dermatologists should be aware of these distinctive features of HSS.