Löffler's Endomyocardial Fibrosis With Eosinophilia in Association With Acute Lymphoblastic Leukemia

The association of eosinophilia and Löffler's endomyocardial fibrosis with acute lymphoblastic leukemia in a 9-yr-old boy is reported. During the illness, there were three leukemic relapses, each preceded by eosinophilia which subsided upon induction of remission. It is suggested that the eosinophilia in this case was not “eosinophilic leukemia,” but more likely a non-neoplastic response to an antigenic stimulus from the leukemic process.