Transbronchial lung biopsy and bronchoalveolar lavage in diagnosis of diffuse infiltrative lung diseases.

We investigated 801 patients with lung infiltrates who underwent transbronchial lung biopsy (TBB) and performed cytologic studies of lavage fluid of 491 patients who also underwent bronchoalveolar lavage (BAL). A specific histopathological diagnosis was made in 232 cases (29%). Histopathological changes consistent with the clinical pattern were present in 296 cases (37%). The diagnostic yield of TBB was 66%. Routine evaluation of BAL fluid allowed us to make a specific diagnosis in 49 cases. The role of the pulmonary pathologist in the interpretation of TBB and BAL specimens is discussed.