Atypically located pericardial cyst in a patient who underwent off-pump myocardial revascularization.

Pericardial cysts are rare benign mediastinal lesions and most commonly located at the cardiophrenic angle. We present a case of an atypically located pericardial cyst in a patient who underwent myocardial revascularization. A 61-year-old man with acute myocardial infarction was scheduled for coronary artery bypass grafting (CABG). Preoperative chest computed tomography revealed a homogenous cystic lesion in the superior mediastinum. The mass was located between the ascending aorta, the superior vena cava, and the left innominate vein. It was growing to the anterior of the aorta and to the right anterior paratracheal area. The density of the mass was close to that of water; thus, the contrast medium failed to enhance its visualization. A concomitant resection of the mass and the CABG was scheduled. After a medial sternotomy and bypass graft harvest, a median pericardectomy was performed. The surgeon found the cystic mass along the roof of the pericardium and located between the ascending aorta and superior vena cava. There was no adhesion between the mass and cardiovascular components. The mass was resected en bloc; therefore, off-pump CABG was completed. Histopathological examination of the resected specimen confirmed diagnosis of a pericardial cyst.