Hairy cell leukemia (HCL), comprising 2% of all leukemias, is a chronic disorder characterized by mononuclear cells with prominent cytoplasmic projections. For years, patients with HCL underwent splenectomies and then interferon alpha for treatment, which provided high response rates but low...

Imatinib mesylate (Gleevec®, Novartis Pharmaceuticals Corporation, East Hanover, NJ) has revolutionized the treatment of chronic myelogenous leukemia (CML) with marked improvement in survival in all three phases—chronic, accelerated, and blast. Most patients with CML now receive imatinib, which...