[A case report of huge bronchogenic cyst originated in the atrial septum].

Bronchogenic cysts of the heart are extremely rare neoplasma comprising only 1.3% of all the primary cardiac and pericardial tumors. We experienced a case of bronchogenic cyst originated in the interatrial septum that caused the marked swelling of the septum. An asymptomatic woman of 43 years of age was evaluated because of cardiac enlargement on the chest X-ray film. The examinations including cardiac catheterization indicated a left atrial tumor broadly based on the atrial septum. Surgical removal was attempted, and the tumor was revealed to be a cyst involving the whole atrial septum. The histological diagnosis was bronchogenic cyst. The surgery included resection of the cyst together with the septum that was reconstructed with Dacron patch. Postoperative course was smooth, and the patient has returned to normal daily life without any sign of recurrence for two years.