Progressive multifocal leukoencephalopathy--a case report and review of the literature.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system which affects the white matter and is caused by reactivation of the JC polyomavirus. CASE REPORT: We report the case of a 63-year-old man with chronic lymphocytic leukemia who was treated with fludarabine; rituximab and fludarabine; fludarabine, cyclophsphamide and rituximab; and lenalidomide. While he underwent chemotherapy, the patient was diagnosed with PML. After stabilization of PML, the patient underwent non-myeloablative allogeneic bone marrow transplantation as a treatment for chronic lymphocytic leukemia. Unfortunately, after several opportunistic infections, the patient died. DISCUSSION: The patient underwent allogeneic bone marrow transplantation with the expectation that donor-derived competent immunological cells would migrate into the cerebral lesions, maintaining immunological response. The effect of bone marrow transplantation in patients with PML requires investigation in larger patient series.