Triad of myasthenia gravis, myositis, and myocarditis after nivolumab administration in a patient with cholangiocarcinoma

Immune checkpoint inhibitors, including anti-programmed death receptor-1/ligand-1 drugs and anticytotoxic T lymphocyte-associated antigens, are novel drugs for the treatment of many cancers. However, they may rarely cause neurological immune-related adverse effects, including immune-related myasthenia gravis (MG). This condition leads to poorer clinical outcomes, especially when coexisting with myositis or myocarditis. We report a case of a patient with advanced cholangiocarcinoma along with a history of thymoma in whom a triad of MG, myositis, and myocarditis developed after nivolumab administration. Early recognition of neuromuscular symptoms remains critical to successful management.