Case 121. 
JC virus infection (progressive multifocal leukoencephalopathy) (35 y-o F)
    Progressive deterioration of brain functions in case of SLE receiving corticosteroid    
Key words : 
progressive multifocal leukoencephalopathy, demyelination, JC virus, steroid    
opportunistic infection
Multifocal demyelinated foci are seen in the white matter of the cerebral hemisphere (LFB-HE, low power). PML, caused by papova virus reactivation, is a representative CNS lesion in AIDS.   Oligodendroglial cells contain pyknotic nuclei and nuclear inclusion bodies. Reactive astroglial cells are seen (LFB-HE, high power).
JC viral antigen is demonstrated in the nuclear inclusions and in some glial fibers (immunostaining).