Neurologic Complications of Hairy Cell Leukemia

Involvement of the nervous system in some forms of leukemia is a common, well-recognized problem. To our knowledge, no study has investigated hairy cell leukemia (HCL) with this question in mind, so we reviewed the records of 108 patients with HCL seen during a sevenyear period. Neurologic complications developed in roughly 5% of these patients. Direct infiltration of the nervous system in cases of HCL has rarely been reported in the literature, and the clinicopathologic appearance is insufficiently documented. We found no cases of direct invasion of the nervous system and only one case of vertebral-body invasion and radicular compression, indicating that epidural spread is also rare. Infection was the most frequent cause of neurologic problems in this series of patients with HCL.