| Abstract: | A 57-year-old woman with chronic myelogenous leukemia developed neurological abnormalities. Brain biopsy revealed enlarged and basophilic nuclear cells with bizarre astrocytes on the background of demyelination, which are the characteristic histological findings of progressive multifocal leukoencephalopathy (PML). Immuno-histochemical analysis confirmed JC virus infection. Analysis of the viral regulatory regions demonstrated two different clones. DNA sequences of both clones showed a constant rearrangement of duplication and deletion, which was characteristic of the PML type of JC virus. |
