Excellent response of chemotherapy-resistant B-cell-type chronic lymphocytic leukemia with meningeal involvement to rituximab.

A 70-year-old woman was diagnosed with B-cell-type chronic lymphocytic leukemia (B-CLL) in May 2001. Initial white blood cell (WBC) count was 37 x 10(9)/l and most of the cells were mature small lymphocytes. Surface antigen analysis of these lymphocytes revealed positive reactions for CD19, 20, 25, 5, and lambda-light chain. Despite her Rai stage-0 status, various treatments were ineffective, including cyclophosphamide; fludarabine; 6-mercaptopurine; a combination of vincristine, cyclophosphamide, prednisolone, and adriamycin; and etoposide. Her WBC count increased, ranging from 150 to 450 x 10(9)/l, with marked splenomegaly, and symptoms of meningitis, such as headache, ophthalmalgia, hearing disturbance, and abnormal behavior, being manifested. The WBC count in the cerebrospinal fluid was elevated to 134/microl. The surface phenotype of these cells was identical to that of circulating lymphocytes, indicating meningeal involvement of leukemia, a rare complication in B-CLL. At the time of this WBC elevation, 24% of circulating lymphocytes had prominent nucleoli, indicating progression of the disease to CLL/prolymphocytic leukemia. Her symptoms disappeared after repeated intrathecal injections of methotrexate and dexamethazone. After four courses of treatment of the refractory B-CLL with rituximab, an anti-CD20 monoclonal antibody, the WBC count returned to normal levels and the splenomegaly disappeared. She is currently well, with sustained remission, as of April 2004.