Chronic Myelogenous Leukemia with Mild Basophilia as the Predominant Manifestation at Presentation

Chronic myelogenous leukemia (CML) is a clonal hematological malignancy typically presenting with basophilia and massive proliferation of differentiating myeloid cells. We report an atypical case of CML in which mild basophilia was the sole manifestation at presentation, and the condition persisted for 27 months with no sign of progression. This case reconfirms the importance of basophilia as a clinical manifestation of CML, and BCR-ABL FISH analysis should always be applied to cases of basophilia, even when the basophilia is modest and no other features of CML are present.