[A case of complete absence of the left pericardium coexisting with straight back syndrome].

A case of complete absence of the left pericardium coexisting with straight back syndrome in a 30-year-old female is presented. She had been asymptomatic, but was referred to our hospital because of an abnormal finding on a chest X-ray obtained during a routine physical examination. The posteroanterior view of the chest X-ray showed displacement of the right and left cardiac border to the left and bulging of the left cardiac border. The lateral view showed loss of normal thoracic curvature and also demonstrated the straight back syndrome. Echocardiography showed paradoxical movement of the ventricle septum, hyperkinetic movement of the free wall of the left ventricle and enlargement of the right ventricle. Computed tomography and magnetic resonance imaging with an artificial pneumomediastinum clearly showed rotation of the heart into the left hemithorax, prominence of the pulmonary trunk and pneumopericardium. Hence the diagnosis of the complete absence of the left pericardium coexisting with straight back syndrome was made. Congenital defect or absence of the pericardium are rarely reported. Only about 120 cases have been described in Japan. Only a few cases have been diagnosed antemortem. Most of them were found by chance during operations or on installation of an artificial pneumothorax. We suggest that an artificial pneumomediastinum as well as a pneumothorax is useful for the diagnosis of the absence of the pericardium. This is the first reported case of a complete absence of the left pericardium coexisting with straight back syndrome.