Bronchoalveolar lavage in drug-induced lung disease.

Given the varying histologic reactions and differ-ent mechanisms of action, it is not surprising that no uniform constellation of BAL changes is seen in drug-induced lung disease. BAL findings are not specific for any drug-induced lung disease and the definitive diagnosis cannot rely solely on the BAL findings. BAL findings can, however, contribute to the expected clinicopathologic pattern of a given drug-induced lung disease. BAL also is helpful in the differential diagnosis, primarily in the exclusion of an infective cause and of involvement of the lungs by the underlying disease (eg, metastatic cancer or malignant lymphoma).