Myasthenia gravis that has developed long after radical resection of lung cancer: A case report

Myasthenia gravis (MG) is the most common disorder of neuromuscular transmission and is a heterogeneous disorder generally caused by auto-antibody to the nicotinic acetylcholine receptor. The current study presented a rare case of MG that occurred a long time after surgical resection of lung cancer. A 58-year-old man with lung adenocarcinoma underwent upper lobectomy and mediastinal lymph node dissection. Severe myasthenic symptoms began 7 years after the operation, and emergent mechanical ventilation was needed because of myasthenic crises. Levels of serum anti-acetylcholine receptor antibody were high and typical decremental responses to repetitive stimulation on electromyography were observed. Appropriate therapies for a severe acute condition were performed, and MG has been controlled for 6 years since then. There is no recurrence of lung cancer or appearance of thymoma. In conclusion, although very rare, physicians should be aware of MG as a potential comorbidity developing in patients with a history of lung cancer.