<unk>  <unk> , also known as<unk>  (British spelling), and<unk>  or<unk>  syndrome, is an uncommon hematologic disorder seen more often in children than in adults. It is a life-threatening disease of severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and macrophages, characterised by proliferation of morphologically benign lymphocytes and macrophages that secrete high amounts of inflammatory cytokines. It is classified as one of the cytokine storm syndromes. There are inherited and non-inherited (acquired) causes of<unk>  <unk> .
Hemophagocytic lymphohistiocytosis
Diffuse infiltrative lymphocytosis syndrome
Congenital self-healing reticulohistiocytosis
Thymoma with immunodeficiency
Langerhans cell histiocytosis
Blastic plasmacytoid dendritic cell neoplasm
Hereditary pyropoikilocytosis
Angioimmunoblastic T-cell lymphoma