Case Presentation:
A 58‐year‐old woman presented with a 4‐month history of dysphagia. The dysphagia was to solids and liquids, and was associated with regurgitation and loss of appetite. On further questioning, it was discovered that during this time period she had also been experiencing right eye ptosis, diplopia, 40 pound weight loss, fatigue, and intermittent urticaria and angioedema. She denied shortness of breath, cough, and chest pain. Previous outpatient evaluation included abdominal ultrasound and CT abdomen which showed mild splenomegaly. She had been diagnosed with Helicobacter pylori infection; when her symptoms did not improve on triple therapy, she presented to the hospital for further evaluation. On admission, chest x‐ray showed a large left hemithorax mass. CT chest revealed a 12 x 9 x 12 cm heterogeneous mass in the anterior left hemithorax, causing compression of the left upper lobe pulmonary artery and atelectasis of the left lung. CT‐guided biopsy revealed numerous T‐cell precursors, immunochemically and morphologically consistent with a thymoma. Although the acetylcholine receptor binding antibody was negative, the history of fluctuating ptosis, dysphagia, and diplopia was consistent with paraneoplastic myasthenia gravis (MG) in the setting of thymoma. Pulmonary function tests were normal. Single fiber electromyography was suggestive of MG, and the patient was started on pyridostigmine. Upper endoscopy revealed grade C reflux esophagitis, and she was treated with a proton pump inhibitor. The etiology of her dysphagia was likely multifactorial, including extrinsic compression by the mass, esophageal dysmotility due to MG, and reflux esophagitis. The patient received neoadjuvant therapy with two cycles of cisplatin, doxorubicin, and cyclophosphamide, resulting in significant reduction of mass size and improvement in dysphagia, ptosis, and urticaria. She is currently scheduled for surgical thymectomy.
Discussion:
Dysphagia is commonly encountered by primary care providers and hospitalists. The differential diagnosis is broad and requires a detailed history and physical examination. Upper endoscopy may identify intraluminal and intrinsic causes including esophageal webs, eosinophilic esophagitis, stricture, and esophageal or gastric carcinoma. If extrinsic compression is suspected, a barium swallow may aid in diagnosis. In patients with negative upper endoscopies, motility testing may reveal achalasia or diffuse esophageal spasm. While evaluation of the gastrointestinal tract alone may correctly diagnose many causes of dysphagia, a history of paraneoplastic symptoms should broaden the differential. 40‐53% of patients with thymoma may present with symptoms of MG, including dysphagia, diplopia, ptosis, and fatigue. In contrast, 10‐15% of patients with MG have an underlying thymoma. Dysphagia in these patients may be due to oropharyngeal muscle weakness or esophageal dysmotility. In this case, a careful history revealed significant weight loss and concerning paraneoplastic symptoms including ptosis and angioedema, thus leading to the diagnosis.
Conclusions:
Myasthenia gravis is commonly seen in patients with thymoma and can cause dysphagia through a variety of mechanisms. For effective and expeditious management of dysphagia, it is imperative to maintain a broad differential diagnosis. Thymoma should be suspected in patients presenting with dysphagia, ptosis, and weight loss.