Progressive multifocal leukoencephalopathy and peripheral neuropathy in a patient with Good's syndrome

Good's syndrome (GS) is an immunodeficiency characterized by thymoma, hypogammaglobulinemia, and impaired T-cell function. Progressive multifocal encephalopathy (PML), an infection caused by JC virus (JCV), usually occurs in patients infected with human immunodeficiency virus (HIV), or in patients on treatment with immunosuppressive or immunomodulatory drugs. There were few reports of PML due to GS, especially with the comorbidity of peripheral neuropathy. We describe a case of an uncommon presentation of PML and peripheral neuropathy in a male who presented with blurred vision, cognitive changes, limb weakness, and numbness over a 4-month period due to GS. To the best of our knowledge, this is the first report of PML and peripheral neuropathy due to GS. This case aims to highlight that it is necessary to consider the possibility of PML due to GS in patients with thymoma and intracranial lesions, and we should focus not only on opportunistic infections of the central nervous system, such as PML, but also on peripheral neuropathy.