PLCH is "a unique form of LCH".
"In adults, pulmonary involvement with Langerhans' cell histiocytosis usually occurs as a single-system disease and is characterised by focal Langerhans' cell granulomas infiltrating and destroying distal bronchioles. High-resolution computed tomography (HRCT) of the chest is essential to the diagnosis, typically showing a combination of nodules, cavitated nodules, and thick-and thin-walled cysts."
"The definite diagnosis of Pulmonary Langerhans' Cell Histioicytosis requires identification of Langerhans' cell granulomas, which is usually achieved by surgical lung biopsy t a site selected by chest HRCT. In practice, however, lung biopsy is performed on a case-by-case basis."
"No effective treatment is available to date, and improved understanding of the mechanisms involved in the pathogenesis of Pulmonary Langerhans' Cell Histiocytosis is urgently needed, and should help in the development of specific therapeutic strategies for patients with this orphan disease."
Resource: Tazi A. Eur Respir J. 2006 Jun:27(6):1272-85. Pulmonolgy Dept. Saint Louis Teaching Hospital, ... PMID 16772390 [PubMed-indexed for MEDLINE]