[Drug-resistant B cell chronic lymphocytic leukemia safely treated with rituximab to control leukemic cell increment and platelet transfusion dependence].

A 61-year-old man was found to have mild lymphocytosis during a medical checkup and was referred to our hospital in 1993. Physical examination showed a mild hepatomegaly, and bone marrow examination revealed the proliferation of monoclonal mature B cells. He was diagnosed with B-CLL. Chlorambucil and then fludarabine were effective initially. However, large transformed cells started to increase in 2000, and the increment became uncontrollable and platelet transfusion dependence developed. He was admitted to our hospital in October 2001. He intermittently received a total of 32 administrations of rituximab. The total dose was 15, 500 mg. The toxicity was tolerable and he became transfusion independent for 6 months. However, systemic lymphoadenopathy and hepatomegaly did not respond to the drug. We conclude that rituximab treatment is useful for refractory B-CLL because of its excellent safety.