The Hypereosinophilic Syndromes

Abstract

This report concerns three individuals with a similar illness characterized by the following: a striking leukocytosis due primarily to increased numbers of mature eosinophils; cardiac or pulmonary symptoms, or both; and hepatosplenomegaly. Two of the patients died; the third remains in clinical good health. Distinctive morphologic abnormalities were found in the heart, bone marrow, liver, and spleen. Similar cases have often been reported as examples of eosinophilic leukemia. However, review of the pertinent evidence is not thought to support this concept; rather, it suggests an association with Löffler's syndrome and Löffler's endocarditis parietalis fibroplastica. To emphasize that such patients are part of a continuum, we propose the term "hypereosinophilic syndromes" to encompass the entire group.