Cerebellar-onset Progressive Multifocal Leukoencephalopathy (PML) Associated with Hepatitis B-related Liver Cirrhosis.

We herein report a case of progressive multifocal leukoencephalopathy (PML) in a woman in her 70s with hepatitis B-related liver cirrhosis. She presented with cerebellar onset symptoms, including ataxia and dysarthria. The diagnosis was delayed despite the initial magnetic resonance imaging (MRI) findings of an asymmetric cerebellar white matter lesion. PML was ultimately diagnosed based on a re-evaluation of a brain biopsy specimen and a retrospective JC virus (JCV) PCR analysis of the cerebrospinal fluid. Treatment with mefloquine and mirtazapine resulted in viral clearance from the cerebrospinal fluid (CSF) and clinical stabilization. This case highlights that crescent-shaped cerebellar lesions should raise suspicion of PML, even in patients without severe immunodeficiency.