<prompt> Treatment of choice for hairy cell leukaemia isSteroidsCladribineSplenectomyPentostatin  <response>: The first-line therapy for hairy cell leukemia is cladribine, 0.1 mgkgd by continuous intravenous infusion for 7 days. The drug can be administered on an outpatient basis with a pump, after placement of a percutaneous intravenous central catheter PICC. Ref Harrison 20th edition pg 544 