[Progressive multifocal leukoencephalopathy in a child with acute lymphocytic leukemia].
D002675:Child, Preschool; D006801:Humans; D007945:Leukemia, Lymphoid / Q000150:complications*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000209:etiology*; D008297:Male; D013539:Simian virus 40; D014412:Tumor Virus Infections / Q000209:etiology*