This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oncology, Subject name: Medicine
Treatment of choice for hairy cell leukaemia is 
Select and explain. 
A. Steroids, B. Cladribine, C. Splenectomy, D. Pentostatin
B: Cladribine
Answer: B: Cladribine 
Explanation: The first-line therapy for hairy cell leukemia is cladribine, 0.1 mg/kg/d 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