Chronic aneurysm of the descending thoracic aorta presenting with right pleural effusion and left phrenic paralysis

A 62-year-old man was admitted to the emergency department with chronic dysphagia and lower back pain. Chest radiography revealed a wide mediastinal shadow and an elevated left diaphragm, which proved to be secondary to left phrenic paralysis. The patient was diagnosed with an aneurysm of the descending thoracic aorta and was admitted to the hospital. After the patient was admitted, the aneurysm ruptured into the right chest. The patient underwent an emergency operation to replace the ruptured segment with a synthetic graft. Postoperative recovery and follow-up were uneventful. This report describes an unusual presentation of a thoracic aortic aneurysm. Hemidiaphragmatic paralysis caused by compression of the phrenic nerve is an unusual complication that, to our knowledge, has not been previously reported.