An unusual cause of pneumothorax during percutaneous pleural biopsy.

blood. Similar results in the pleural fluid have been reported by Groman et al;i however, in this report BAL cell analysis was not available. In our patients, the lymphocyte profile found in pkural effusion was closer to that seen in BAL. Lymphocyte subpopulation findings in the pleural fluid seem to be representative ofthe pleural histologic involvement, as BAL is of alveolitis. By contrast, in another granulomatosis, an amiodarone-induced pleuropulmonary hypersensitivity pneumonitis,a cell profile in BAL was quite different from that found in blood and pleural fluid. That would indicate a pathogenetic mechanism in sarcoidosis distinct from that involved in hypersensitivity granulomatosis.