Progressive multifocal leukoencephalopathy in a patient with pre-clinical primary biliary cirrhosis

•PML is rare and normally manifests in people with a compromised immune system.•We describe an apparently immunocompetent old patient who developed PML.•We identified a pre-clinical PBC as exclusive risk factor for PML manifestation.•We present this first description of a PML in association with a possible or early stage PBC.