Pericardial Cyst

Introduction Pericardial cysts are an uncommon benign congenital anomaly in the middle mediastinum. They represent 6% of mediastinal masses, and 33% of mediastinal cysts. Other cysts in the mediastinum are bronchogenic - 34%, enteric - 12%, thymic and others - 21% [1]. In the middle mediastinum 61% of presenting masses are cysts [1]. Pericardial and bronchogenic cysts share the second most common etiology after lymphomas [1]. The presented case is of a symptomatic pericardial cyst. Case Presentation Patient is a twenty-nine-year-old female, who was diagnosed with a pericardial cyst when she was seventeen years old during a work-up of asthma. Recently, the patient presented with a persistent cough, and a repeat CT scan revealed increase in size of the cyst to approximately 6x6 cm (Figure 1 and 2). Her past medical history was significant for Wolff-Parkinson-White syndrome. On examination no abnormalities were found. Since the cyst was enlarging, causing significant anxiety, and possibly contributing to her persistent cough, resection was recommended. Her cardiologists felt that her WPW Syndrome was not a contraindication to surgery. In the operating room, under general anesthesia and one lung ventilation, the thoracoscope was introduced at the right midaxillary line and the 7th intercostal space (Video 1 below). The cyst was readily visualized at the anterolateral aspect of the right pericardium, measuring approximately 9x6 cm (Figure 3). The phrenic nerve was seen posterior to the cyst. The second incision was made at the anterior axillary line in the 4th intercostal space. A ring clamp was used to grasp the cyst (Figure 4). The third incision was made at the scapula line in the 5th intercostal space. Thoracoscopic scissors and cautery (at a low setting to minimize the chance of cardiac arrhythmias) were used through that port to dissect the cyst from the pericardium (Figure 5). The connection between the cyst and the pericardial space was identified. It was small, and was divided with the scissors. The dissection of the posterior aspect of the cyst completed the removal. The phrenic nerve was clearly visualized at all times. The pathology report confirmed the diagnosis of a benign mesothelial-lined cyst (Figure 6). Patient had an uneventful post-surgical course, and was discharged home on post-operative day number two. Discussion Pericardial cysts occur at the rate of 1 person per 100,000 [2]. They are thought to result from failure of fusion of one of th