[A case of cyclosporin responsive myasthenia gravis with an invasive thymoma]

We report a patient with myasthenia gravis (MG) accompanied by invasive thymoma which we treated with cyclosporin. The patient was a 42-year-old woman who was admitted to our hospital because of diplopia and left blepharoptosis. Thymectomy was undertaken but it was incomplete because the thymoma had already invaded other tissues. Following thymectomy, the antibody level for acetylcholine receptors (AChR) gradually increased and generalized weakness and dyspnea emerged. The symptoms did not improve with ADOC chemotherapy and steroid pulse. Treatment with cyclosporin (200 mg/day) was initiated after plasmapheresis and the symptoms improved and AChR antibody levels subsided. There has not been a recurrence of the thymoma after 28 months. In conclusion, treatment with cyclosporin may be more effective than other treatments in patients with inveterate MG that is accompanied by thymoma.