A rare cardiac tumor: Bronchogenic cyst of interatrial septum.

Intracardiac bronchogenic cysts are uncommon congenital tumors, which rarely become symptomatic. We describe a rare case of bronchogenic cyst in the atrioventricular node. A 36-year-old man with third-degree atrioventricular block was referred to our hospital. Transthoracic echocardiography revealed a cystic mass at the right atrial aspect of the low interatrial septum. He underwent surgical resection of the mass, and a permanent epicardium pacemaker was implanted. His postoperative course was uneventful. Microscopic examination showed a cyst surrounded by ciliated columnar epithelium and partially smooth muscle, and the histopathological diagnosis was bronchogenic cyst.