Progressive Multifocal Leukoencephalopathy with Detection of JC Virus in a Patient with Chronic Lymphocytic Leukemia Parallel to Onset of Fludarabine Therapy. - Kiewe, Philipp; Seyfert, Sepp; Korper, Sixten; Rieger, Kathrin; Thiel, Eckhard; Knauf, Wolfgang (Leukemia & Lymphoma, 2003)