[Biopsy of the pericardium. Diagnostic value in subacute and chronic pericarditis, apropos of 70 cases].

The aetiology of pericarditis is often difficult to assess. To try to clear up this problem, a pericardial biopsy through a left lateral thoracotomy was performed in 70 cases in which the cause could not be established by the usual means (including pericardial paracenthesis in 32 cases). They included either subacute pericarditis, dry or with effusion (biopsy being undertaken as an average 45 days after the clinical onset), or chronic pericarditis with effusion. Tuberculosis was thus demonstrated in 14 cases (8 of which were aged more than 60 years), inaugural pericardial tumours in 8 and suppuration in 3 cases. Microscopical examination gave support to pathogenic hypotheses concerning cholesterol pericarditis (5 cases) and multi-recurrent pericartitides (6 cases). By elimination with a high probability) of tuberculosis and tumours, it demonstrated definitely the diagnosis of post-radiotherapy pericarditis with effusion (4 cases) pericarditis with normal serous membrane (4 cases) and "idiopathic" forms (23 cases of common sclerogenous subacute inflammation). The inocuity of this method, its more accurate results than those obtained by cytological and bacteriological examination of the pericardial fluid obtained by paracenthesis, should induce to consider this procedure more often in the cases of pericarditis when the aetiology remains doubtful; not to mention the benefit derived from surgical drainage which results in a quicker and more complete cure than repeated paracentheses of chronic and subacute pericardial effusions.