Tag: demyelinating

PML or PMLE. Viral disease in immunosuppressed. Demyelination -> Multifocal.

Etiology

JC Polyoma Virus.

Pathology

Infects Oligodendrocytes –> causes demyelination.

Clinical features

Asymptomatic in childhood. But serology positive.

Reactivates during immunosuppression.
Focal progressive neurological symptoms.
Imaging: Multifocal white matter lesions.

Morphology

Gross: Variably sized small to large irregular ill-defined white matter lesions in subcortical areas of cerebrum and cerebellum.

Microscopy: Central lipid laden macrophages, with paucity of axons. Surrounded by oligodendrocytes with viral nuclear inclusions -> Glassy amphophilic body within enlarged nucleus.
Bizarre giant astrocytes + (Reactive).