Progressive multifocal leukoencephalopathy (PML) was first considered a distinct neurological entity in 1958. Its neuropathology is represented by multifocal demyelinating lesions accompanying oligodendroglia-like cells with markedly enlarged nuclei. Electron microscopy in 1965 showed polyomavirus-like structures in the enlarged nuclei. The causative JC virus was isolated from autopsied human brains in 1971. Investigators subsequently focused on its neurotropism and oncogenicity. The pathology of this virus-induced demyelinating disease is better understood now, including the intranuclear target for JC virus infection, promyelocytic leukemia nuclear bodies (PML-NBs).
Shishido-Hara, Y. (2014). Progressive Multifocal Leukoencephalopathy (PML). In Encyclopedia of the Neurological Sciences (pp. 982–986). Elsevier Inc. https://doi.org/10.1016/B978-0-12-385157-4.00385-7