[A case report of pericardial diverticulum in the upper mediastinum: surgical treatment of two cases].

Pericardial cyst and diverticulum are commonly found in areas of cardiophrenic angles. In this article, we reported on two operated cases (54-year-old female, 43-year-old male) with pericardial diverticula in upper mediastinum. On their chest CT films, well circumscribed cystic lesions were seen in the right (case 1) and left (case 2) upper mediastinum. Based on findings of imaging modalities such as CT, MRI and transesophageal ultrasonography, the lesions were suspected of benign cystic tumors such as bronchogenic cyst, lymphatic cyst, esophageal cyst and pericardial cyst. However, definite diagnoses were made by thoracotomy. Even though the cystic lesion is recognized in the upper mediastinum, pericardial diverticulum should be considered as its diagnosis as well as bronchogenic cyst, lymphatic cyst, esophageal cyst.