[Spontaneous pneumopericardium. Apropos of a case report].

A patient operated for carcinoma of the bladder complicated by infection by anaerobic organisms developed pneumopericardium. Spontaneous pneumopericardium may or may not follow effraction of the pericardium. The following causes have been described: fistula with a tuberculous cavernoma, parenchymatous or pleural infection, carcinoma of the bronchus; oesophageal or gastro-pericardial fistulae arising from carcinoma or ulceration of the stomach or oesophagus; rupture of a mediastinal, hepatic or subphrenic abscess and, exceptionally, pericarditis complicated by fistulisation to the tracheo-bronchial tree. Pneumopericardium without effraction is caused by in situ gas production, a complication of pericarditis caused by anaerobic organisms; this may be a primary or a metastatic infection. Idiopathic pneumopericardium is included in this variety whilst "alveolar rupture" is usually considered in the group of pneumopericardial fistulae: air under pressure passes from the mediastinum into the pericardium by microscopic dissection (bronchitis, asthma, obstructive laryngitis, childbirth). The outcome and prognosis depends on the cause and type of effusion: pneumopericardium rarely contains air alone; serous fluid, blood or pus, are usually associated.