[Hemophagocytic syndrome. Current concepts].

Hemophagocytic lymphohistiocytosis is a syndrome characterized by pathological immune activation that may occur as either a primary a familial disorder (associated with genetic mutations), or as a sporadic condition, associated to infections, malignancies or autoimmune diseases. The clinical picture is characterized by a disproportionate inflammation that causes fever, cytopenias, splenomegaly, bone marrow hemophagocytosis, hypertriglyceridemia and hypofibrinogenemia. Syndrome-related mortality is high, so it is important to maintain a high index of suspicion and start early treatment with immunochemotherapy and bone marrow transplantation in primary and refractory cases. In this article, we review the clinical manifestations, pathology, diagnosis and treatment of these patients.