Acute cardiac tamponade due to a bleeding pericardial cyst in a 3-year-old child

We report a case of a pericardial cyst complicated with acute cardiac tamponade in a 3-year-old child with no previous cardiac history who was transferred to our university hospital because of hemodynamic shock. A chest roentgenogram revealed marked cardiac enlargement, and transthoracic echocardiography showed massive pericardial effusion with a moving cystic structure. Percutaneous needle aspiration yielded bloody pericardial fluid. Emergency drainage of the pericardial effusion and resection of the cyst were performed through a median sternotomy. We found a blood-containing cyst that was attached to the right atrium near the sinus node and to the inferior wall of the pericardial cavity.