Langerhans’ cell histiocytosis (LCH) is a group of disorders characterized by infiltration of multiple systems by Langerhans’ cell. The exact pathophysiology of this idiopathic disorder is unknown. Reticulo-micronodular infiltration is the commonest pattern observed by CXR, although the abnormalities vary with the stage of the disease 1.
CT, especially the HRCT plays an important role in the diagnosis of of PLCH 2 . The typical HRCT pattern of PLCH is thick- and thin-walled cysts combination with small poorly limited nodules, cavitated nodules, which affect both the peripheral and the central parts of the lung fields 1.