Bone marrow eosinophil cytoreduction with imatinib therapy (case 6).

Hematoxylin-eosin (H&E)–stained bone marrow biopsy tissue (A), showing markedly hypercellular marrow with left-shifted granulopoiesis and eosinophilia before treatment with imatinib. (B) Shows the dramatic reduction in marrow cellularity with normal trilineage hematopoiesis after imatinib therapy (at 16 weeks). Original magnification for both panels, × 160.