Epicardial mesothelial cyst located over the left anterior descending coronary artery.

We report the 5th case of pericardial cyst found to originate from epicardium. A 30-year-old woman with a history of rheumatic fever underwent open-heart surgery for severe aortic and mitral insufficiency. A cyst located over the left anterior descending coronary artery was detected during surgery. Excision of the cyst was performed with the patient on cardiopulmonary bypass, to avoid injury to the artery. Histologic examination showed the cyst to be lined by a single layer of benign mesothelial cells, which was consistent with a diagnosis of epicardial mesothelial cyst.