ABSTRACT
Pulmonary Langerhans’ cell histiocytosis (LCH) is an important consideration in
the differential diagnosis of patients with diffuse lung disease, particularly in
cigarette smokers. Pulmonary LCH refers to the same disease that was formerly
known as eosinophilic granuloma or histiocytosis X, and is characterized by
proliferation and infiltration of the lungs, and occasionally other organs, by spe-
cific dendritic cells of the Langerhans’ type (1).
