Primary progressive multifocal leukoencephalopathy: report of a case.

The authors describe a case of primary progressive multifocal leukoencephalopathy (pPML). Unlike previous similar reports, our patient underwent up-to-date and extensive in vivo and post-mortem investigations that established beyond doubt the competence of his immune system and the absence of underlying predisposing disorders. The various implications of this case, both clinical and related to the possible pathogenetic mechanisms of JC virus infection, are discussed.