[Hypereosinophilic syndrome. Case report of the differential diagnosis of eosinophilic leukemia].

We report on a 48 years old patient with chronic eosinophilic leukemia. The diagnosis is based on changes of the blood picture with leukocytosis, deviation to the left to promyelocytes and sometimes normoblasts in the differential smear in with eosinophilia of up to 90%. A hepatosplenomegaly with an extensive extramedullary blood formation could be observed. Endocarditis parietalis fibroplastica was found on autopsy. The problem whether the organ changes observed are due to the eosinophilia existing for more than two years is discussed.