FIP1L1-PDGFRA fusion-negative hypereosinophilic syndrome with uncommon cardiac involvement responding to imatinib treatment: A case report.

Hypereosinophilic syndrome is a rare, chronic hematological disease characterized by a persistently elevated eosinophil count exceeding 1.5×10/l, following the exclusion of other potential etiologies. The systemic involvement of the disease causes tissue damage through eosinophil infiltration, and may affect various organs; cardiac complications are observed in 50-60% of cases, which are predominately attributed to endomyocardial fibrosis.