A 47-year-old woman was admitted with a history of dyspnea on mild exertion as her only symptom. Clinical exam, laboratory tests, and electrocardiography were normal. Chest X-ray demonstrated right hemithorax base mass, and CT scan revealed a well-defined cystic mass measuring approximately 11.3 x 10.6 x 10.9 cm, suggesting the diagnosis of pericardial cyst. The patient underwent right thoracotomy for resection of the cyst. The patient's progress- was uneventful. The result of histopathological examination, contrary to expectations, revealed thymic cyst.
Mediastinal cyst; Thymus gland; Thoracotomy
