Therapeutic leukapheresis in a patient with hairy cell leukemia presenting with a white cell count greater than 500,000 /microliter.

A 49-year-old man presented with anemia, thrombocytopenia, and white cell count over 500,000 /microliters. Studies were diagnostic of hairy cell leukemia. Splenectomy was considered hazardous because of his general poor condition and the danger of leukostasis from the high white cell count. He was managed with leukapheresis with reduction in the white cell count from 556,000 /microliters to 20,000 /microliters followed by an uneventful splenectomy. Leukapheresis should be considered for patients with hairy cell leukemia and extremely elevated white cell counts.