RESUMEN
The hemophagocytic syndrome is a benign systemic histiocytic proliferation which may be caused by several etiologies: infections, autoimmune diseases, hemopathy; << solid >> cancers, immunity deficits. The inadequatee activation of the loop << macrophage - lymphocyte >> with hypercytokinemia explain in the large proportion the physiopathological, clinical and biological features. This syndrome includes: fever, organomegaly, cytopenia, hypertriglyceridemia, hyperferritinemia and clotting disorders. The diagnosis is based on clinical, biological and especially histopathological criteria: with tissue and/or medullary histiocytic infiltration. We report two cases of hemophagocytic syndrome in which the etiology had remained undetermined and the evolution had been fatal