Background: Pulmonary Langerhans cell histiocytosis (PLCH) is an interstitial lung disease characterized by bilateral nodular and cystic lesions. Clinically it seems to be a reactive process related to cigarette smoking.
Cases: In 2 cases of PLCH, cytologic and immunocytochemical evaluation of bronchoalveolar lavage (BAL) fluid was successfully used for the diagnosis of PLCH.