Progressive Multifocal Leukoencephalopathy in a Patient with Good Syndrome 11 Years after Thymectomy

Progressive multifocal leukoencephalopathy (PML) occurs in immunocompromised patients. We report a 60-year-old woman with rapidly progressive aphasia and cognitive decline 11 years after thymectomy. Brain magnetic resonance imaging revealed asymmetric, non-enhancing confluent white matter lesions. Laboratory tests showed hypogammaglobulinemia, reduced B cells, and a reversed CD4/CD8 ratio, consistent with Good syndrome. John Cunningham virus DNA was detected in cerebrospinal fluid, confirming PML. This case highlights that PML can occur in patients with Good syndrome even years after remote thymectomy.