A Rare Case of Overlapping Durvalumab-induced Myositis, Takotsubo-like Morphological Changes Caused by Myocarditis, and Myasthenia Gravis.

Immune checkpoint inhibitors can cause a range of immune-related adverse events, including myositis, Takotsubo cardiomyopathy, and myasthenia gravis. We herein report a rare case of a 78-year-old man with concurrent durvalumab-induced myositis, Takotsubo-like morphological changes caused by myocarditis, and myasthenia gravis. The patient initially required invasive ventilation and exhibited symptoms of myasthenia gravis after treatment with high-dose steroids. However, he subsequently achieved successful recovery after the administration of intravenous immunoglobulin, plasmapheresis, and high-dose steroids. We advocate vigilant neurological monitoring of patients with immune checkpoint inhibitor-induced myositis, including the assessment of ptosis and other relevant signs, so that prompt treatment can be initiated at the time of emergence or progression of immune checkpoint inhibitor-induced myasthenia gravis.