ABSTRACT
Background: Myasthenia gravis is an autoimmune neuromuscular junction disorder characterized by fatigable muscle weakness and autoantibodies. Frequent associations exist between myasthenia gravis and thymic abnormalities, including hyperplasia and thymoma. Several autoimmune illnesses have been identified to be associated with thymoma; however, a few case reports have linked thymoma and achalasia, and the underlying mechanism is unknown. Case report: A 43-year-old man with thymoma-associated myasthenia gravis presented with dysphagia that was refractory to conventional treatment of myasthenia gravis. This dysphagia was challenging to diagnose even after multiple gastroenterology consults and upper endoscopy. The diagnosis of achalasia type II was established after a comprehensive evaluation, including upper endoscopy, barium swallow, and high-resolution esophageal manometry. The patient underwent elective pneumatic balloon dilatation, which successfully alleviated his dysphagia. Conclusion: This case confirmed the association between myasthenia gravis secondary to thymoma and achalasia and showed how the diagnosis of achalasia was challenging. Awareness of this association is crucial for early diagnosis and treatment, improving affected patients' quality of life.