Abstract
While cladribine is a highly effective therapy for patients with symptomatic hairy cell leukemia (HCL), up to 37% of patients ultimately relapse and incompletely responding patients relapse more frequently. Rituximab is a monoclonal antibody against CD20 that has been shown to be effective in patients with relapsed HCL. We present an unusual case of successful multiple re-treatments with rituximab in a patient with heavily pre-treated HCL and briefly review the relevant literature.