Infratentorial progressive multifocal leucoencephalopathy (PML) in a patient with SLE (2008: 4b).

Progressive multifocal leucoencephalopathy (PML) is a viral infection occurring in immunocompromised patients. The typical magnetic resonance imaging (MRI) findings include supratentorial asymmetric nonenhancing white matter lesions without mass effect. We present a patient with progressive cerebellar and brain stem lesions, emphasizing the fact that the diagnosis of PML should be considered also in cases with selective infratentorial involvement.