Immune checkpoint inhibitor-associated polyneuropathy in malignant pleural mesothelioma: A case report

Immune checkpoint inhibitors (ICIs), such as nivolumab and ipilimumab, have revolutionized treatment for malignant pleural mesothelioma (MPM) but may cause rare, immune-related neurological adverse events. A 71-year-old man with recurrent MPM developed rapidly progressive weakness, sensory loss, and neuropathic pain following his second cycle of nivolumab/ipilimumab. Workup ultimately revealed inflammatory demyelinating and axonal polyradiculoneuropathy. Cerebrospinal fluid analysis supported an autoimmune process. High-dose corticosteroids and intravenous immunoglobulin (IVIG) were initiated, resulting in functional improvement. He was discharged on a steroid taper with outpatient follow-up. Why should an emergency physician be aware of this? This case highlights the importance of recognizing immune-mediated polyneuropathy as a potential complication of ICI therapy. Timely diagnosis, multidisciplinary care, and early immunosuppressive treatment can lead to meaningful recovery.