Myasthenia gravis posterior to thymectomy: Case report

The association between myasthenia gravis (MG) and thymoma is a frequent finding; however, the post-thymectomy MG is rare. The pathogenic mechanisms are poorly understood and include thymoma recurrence, surgical exposure and activation of peripheral lymphocytes after surgery.

39-year-old male patient who 6 months after surgical treatment of B1 thymoma presented a clinical picture, characterized by dysphagia, global weakness, diplopia and respiratory failure. The antibodies against acetylcholine receptor were positive (16.10 nmol/L). Electromyography was not performed due to technical problems. With these results, the patient’s clinic was attributed due to MG Osserman IV crisis. The patient had medical management with parasympathomimetics, ventilatory support and plasmapheresis, with favorable clinical evolution.

The late onset of MG and other autoimmune disorders should be considered as possible complications of the surgical treatment of thymomas. Therefore, after the resection of a thymoma, follow-up care with post-operative MG consideration is necessary.