A Case of Concurrent Antiacetylcholine Receptor-Positive Myasthenia Gravis and Anti-HMGCR–Positive Myositis Following Statin Exposure

Myasthenia gravis (MG) and inflammatory myopathy (IM) are distinct autoimmune diseases that rarely coexist. By 2020, fewer than 70 cases of MG-IM overlap had been reported, most with thymic abnormalities.1 MG-IM overlap has also been recognized as an immune-related adverse event from immune checkpoint inhibitor therapy.2