[Hemophagocytic syndromes. A series of 23 cases].

Inappropriate macrophage activation is responsible for clinical, biological and histological features characterized by diffuse non malignant histiocytic tissue infiltration called "reactive hemophagocytic syndrome" (RHS). We report here 23 new cases. Immunodepression (10 cases), hematologic malignancies (13 cases) and infection (10 cases) are the most favorable conditions associated with RHS. In many cases, several conditions were present at time of diagnosis of RHS and increased its severity. Mechanisms of RHS remains unclear, but cytokine may play a role. Outcome is variable, but death is the most common issue (17 deaths in our series related to RHS). Corticosteroids, etoposide can improve some situations. Further study is needed to establish the role of cyclosporine A or allogenic bone marrow transplantation.