ABSTRACT
This chapter reviews the changes in bronchoalveolar lavage (BAL) cytology and cell differentials in drug-induced lung disease. Sometimes even a normal BAL may be useful to exclude some disorders with high probability and to focus attention in other directions. Alveolar macrophages are the predominant cell population of the BAL fluid obtained from healthy, non-smoking adults without lung disease. BAL is broadly indicated in every patient with unclear pulmonary shadowing or interstitial lung disease, no matter what cause is suspected. The underlying disorders may be of infectious, non-infectious, immunological or malignant aetiology. Many disorders in which BAL can directly confirm a particular diagnosis, replacing lung biopsy, are included in the group of the alveolar filling syndromes. Many drugs can induce an interstitial lung reaction, either toxic or immune-mediated. BAL can significantly contribute to a diagnosis in diffuse pulmonary malignancies: for metastatic carcinoma and lymphoma the sensitivity reaches 80 and 50 per cent, respectively.
