Abstract
Nivolumab, a monoclonal antibody approved in 2014 as an immune checkpoint inhibitor, offers benefits in cancer treatment but can cause serious neurological complications, including multifocal disseminated necrotizing leukoencephalopathy. We report a case of severe central nervous system toxicity in a 13-year-old boy with Hodgkin lymphoma who was treated with nivolumab following an inadequate response to multiple lines of chemotherapy. After six cycles of nivolumab, the patient developed multifocal disseminated necrotizing leukoencephalopathy, presenting with altered mental status, seizures, and neurological deficits with magnetic resonance imaging (MRI) findings of extensive white matter involvement, rendering him completely disabled. This case highlights the potential for disabling neurological complications associated with immune checkpoint inhibitors, emphasizing the importance of early detection through regular neurological assessment and MRI surveillance. The case also underscores the need for careful patient selection and monitoring when using nivolumab to mitigate the risk of severe central nervous system toxicity.