[Chronic hypereosinophilia and hematologic malignancies]

Peripheral blood and/(or) marrow hypereosinophilia may be associated to various subtypes of myeloid or lymphoid hematological malignancies. Eosinophilia is frequently paraclonal, due to the recruitment of eosinophilic polymorphonuclear cells by cytokines secreted by lymphomatous or leukemic cells. In some myeloid disorders, eosinophilia may also be clonal, due to the involvement of the eosinophilic lineage within the leukemic clone. Generally, hypereosinophilia is only a side-symptom and eosinophilic visceral damages are rare.