Concomitant progressive multifocal leucoencephalopathy and primary centralnervous system lymphoma expressing JC virus oncogenic protein, large T antigen

This report describes the concomitant occurrence of the JC virus (JCV) indu ced demyelinating disease progressive multifocal leucoencephalopathy (PML) and a primary central nervous system lymphoma (PCNS-L) in a patient with AI DS. Postmortem neuropathological examination revealed characteristic featur es of PML including multiple lesions of demyelination, enlarged oligodendro cytes with hyperchromatic nuclei (many containing eosinophilic intranuclear inclusions), and enlarged astrocytes with bizarre hyperchromatic nuclei. I mmunohistochemical analysis demonstrated the expression of the JCV capsid p rotein VP-1 in the nuclei of infected oligodendrocytes and astrocytes. The PCNS-L lesion located in the basal ganglia was highly cellular, distributed perivascularly, and consisted of large atypical plasmacytoid lymphocytes. Immunohistochemical examination of this neoplasm identified it to be of B c ell origin. Moreover, expression of the JCV oncogenic protein, T antigen, w as detected in the nuclei of the neoplastic lymphocytes. This study provide s the first evidence for a possible association between JCV and PCNS-L.