Abstract
Bronchoalveolar lavage (BAL) is a simple and safe procedure performed during flexible bronchoscopy. BAL provides an important diagnostic tool in the diagnosis of various diffuse lung diseases. BAL fluid analysis for cell count and differential, bacteriology and cytology may suggest specific disease or give alternative diagnosis. Nevertheless, BAL is seldom useful as a “stand-alone” diagnostic test for various diffuse pulmonary diseases. Confident diagnoses can be obtained when clinical evaluation and high-resolution computed tomography of the chest (HRCT) findings are combined with BAL fluid analysis and/or transbronchial lung biopsy. BAL may also be helpful in determining the response to treatment and prognosis of interstitial pulmonary disease. This review is about the role of BAL in approaching patients with interstitial lung diseases (ILDs) and will describe the value of different cell patterns found.