Management of Refractory Thymoma‐Associated Myasthenia Gravis With Sequential FcRn Antagonist and Complement Inhibition Combined With Resection of Pleural Dissemination

Myasthenia gravis (MG) associated with disseminated thymoma is often refractory to conventional treatments due to continuous autoantibody production. The optimal treatment strategy, particularly the combination of complement component 5 (C5) inhibitor, neonatal Fc receptor (FcRn) antagonist, and surgical resection in thymoma‐associated myasthenic crisis, remains to be established. A 48‐year‐old man with Masaoka stage IVa thymoma developed an immunotherapy‐resistant myasthenic crisis. He was treated with a neonatal Fc receptor (FcRn) antagonist followed by a complement component 5 inhibitor, alongside repeated surgical resections of pleural implants. This strategy facilitated a persistent decline in anti‐acetylcholine receptor antibody titers and clinical remission despite the persistence of residual tumor. This case suggests that in MG associated with Masaoka stage IVa thymoma and pleural dissemination, the combination of FcRn antagonists, C5 inhibitors, and repeated surgical resection when feasible may contribute to providing an avenue from crisis to long‐term disease control.