An unusual case of hairy cell leukemia: death due to leukostasis and intracerebral hemorrhage.

Hairy cell leukemia (HCL) was diagnosed in a 71-year-old Chinese man. His clinical presentation and the characteristics of the hairy cells were typical of classic HCL. However, extreme leukocytosis (195 to 323 x 10(9) cells/L) in peripheral blood was in striking contrast. This leukocytosis, which was much more pronounced than any of the reported cases of HCL with leukocytosis, was associated with leukostasis in the cerebral vasculature and was causally related to a massive intracerebral hemorrhage and death. This mode of death in HCL has not been reported previously.