Hemophagocytic syndrome (HPS) in children and adults.

Hemophagocytic' syndrome (HPS) is a clinicopathologic entity characterized by systemic proliferation of benign hemophagocytic cells of the monocyte-macrophage-histiocyte lineage, associated with fever, cytopenias, hepatosplenomegaly, lymphadenopathy, and coagulopathy. Two forms of the syndrome have been well characterized; familial hemophagocytic lymphohistiocytosis (FHL) of infants and reactive hemophagocytic syndrome (RHS) encountered at any age. Although the clinical features and pathophysiology of HPS have been reported, the differences in the clinical characteristics of HPS in children and adults have not been studied extensively. In this article the latest concepts and clinical features of HPS are reviewed, focusing on the differences in features depending on the age of onset.