Pulmonary Langerhans Cell Histiocytosis
Siwadol Sunhapanit, M.D.
Division of Respiratory Disease and Tuberculosis, Department of Medicine
Faculty of Medicine Siriraj Hospital
Langerhans’ cell was discovered by Paul Langerhans in 1868 and named after him. This cell was first described as an extracellular nerve cell from dendritic morphology.(1) Later, this cell was described as an immune cell from as part of the mononuclear phagocyte system in the skin (antigen-presenting cell) and can be found in the other tissue.(2) The unique of Langerhans’ cell which different from other dendritic cell are the present of Birbeck granules and CD1a antigen on their cell surface as well as their origin, yolk-sac progenitor cells, and fetal liver-derived monocytes instead of myeloid progenitor cells(2,3)
Langerhans’ cell histiocytosis (LCH) is one of the histiocytosis disorders, abnormal accumulation of monocyte, macrophage, or dendritic cell in organs. It is a rare disease of inconclusive etiology and has a broad spectrum of clinical manifestations and prognosis.(2–4)This disease was firstly described in 1893 and had many synonyms based on organ involvement.(5,6) LCH can affect all age groups and is divided into systemic LCH (Hand-Schuller-Christian disease, Letterer-Siwe disease) and localized LCH. The latter has a better prognosis.(7) Pulmonary Langerhans’ cell histiocytosis (PLCH) can be found either in isolated PLCH or systemic LCH(8)