Hypereosinophilic syndrome (HES) is a heterogeneous group of rare disorders
characterized by peripheral blood and tissue eosinophilia leading to end-organ damage.
Hypereosinophilic syndrome can be fatal, particularly in patients with endomyocardial
fibrosis, and treatment has traditionally been palliative or preventive. The disease shares
features with myeloproliferative disorders, such as chronic myeloid leukemia, including
responsiveness to hydroxyurea and interferon. The tyrosine kinase inhibitor imatinib, a …