An 80-year-old female with fever, edema in the lower extremities, and marked eosinophilia was referred to our hospital. Based on the presence of the Philadelphia chromosome, she was diagnosed with chronic myeloid leukemia (CML). Although imatinib induced a complete cytogenetic response (CCyR), CML relapsed after 28 months of starting it. A CCyR was achieved again by nilotinib but was lost after about 14 months. Only transient response occurred to dasatinib, and the patient died. At relapse, neutrophilia was more predominant than eosinophilia. We reviewed 6 patients with CML whose eosinophil rate in the peripheral blood was >50%. Most patients were males with palpable splenomegaly and had cardiac disorders, peripheral vascular disease, or pleural effusion. Typically, CML causes neutrophil-predominant leukocytosis. However, a subgroup of CML with marked eosinophilia resembles chronic eosinophilic leukemia or idiopathic hypereosinophilic syndrome.
Keywords: BCR/ABL tyrosine kinase inhibitor; Chronic myeloid leukemia; Eosinophilia.