Limited data are available regarding the role of bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBB) as diagnostic tools in pulmonary Langerhans’ Cell Histiocytosis (LCH) and lymphangioleiomyomatosis (LAM).

The aim of this study was to review our experience regarding the value of these two techniques in the diagnosis of these cystic lung diseases.

Records of 452 patients with the presumptive diagnosis of interstitial lung disease were reviewed; 67 had a clinical-radiological diagnosis of either LCH (n = 27) or LAM (n = 40). Of 16 patients with LCH who underwent BAL, four specimens (25%) contained cells which had positive immunoreactivity for CD1a. Of three patients with negative BAL fluid who had TBB, only one had a positive tissue diagnosis. Ten LCH patients were diagnosed by surgical lung biopsy of which five had negative BAL fluid. The remaining 12 patients were diagnosed by clinical and radiologic features. Standard examination of BAL fluid was of no diagnostic value in LAM. TBB was performed in seven patients and was diagnostic in six, not resulting in complications. All 13 patients who underwent surgical lung biopsies had a positive histopathologic diagnosis The remaining 21 patients were diagnosed by clinical and radiologic features. We suggest that BAL may assist in the diagnosis of LCH whereas TBB may be useful in the diagnosis of LAM, thus avoiding the need for surgical biopsy.