PERICARDIAL DIVERTICULUM IN THE RIGHT MIDDLE MEDIASTINUM : Report of two cases

We recently experienced two patients who underwent surgical resection of pericardial diverticulum in the right middle mediastinum. The diagnosis was obtained during surgery.Fifty-nine percent of reported pericardial diverticula in Japan were located in the right upper or the right middle mediastinum ; the majority were in “cephalad recess of azygos vein” which is between the superior vena cava and the azygos vein. This seems to be the noteworthy position for pericardial diverticulum. Therefore, the frequency of a cystic tumor in the right upper or right middle mediastinum being a pericardial diverticulum may be high.