Progressive multifocal leukoencephalopathy mimicking cerebral vasculitis in systemic granulomatosis.

We describe the case of a 69-year-old man with systemic granulomatosis who presented with left-sided hemiplegia. Initial diagnosis concerning the neurological troubles was cerebral vasculitis. Corticosteroids associated with antituberculosis therapy showed a rapid but transient amelioration followed by neurological aggravation. Two weeks later, JC virus was detected in cerebrospinal fluid by PCR and the diagnosis of progressive multifocal leukoencephalopathy (PML) was made. Treatment with cytarabine and cidofovir was initiated but the patient died three months after the first neurological signs. In the presence of central neurological symptoms occurring during systemic granulomatosis before specific therapy, PML should be evoked.