pulmonary disorders
Pulmonary Langerhans Cell Histiocytosis
Introduction
Pulmonary Langerhans cell histiocytosis (PLCH) is proliferation of monoclonal Langerhans cells in lung interstitium and airspaces. Etiology is unknown, but cigarette smoking plays a primary role. Symptoms are dyspnea, cough, fatigue, and pleuritic chest pain. Diagnosis is based on history and imaging tests and sometimes on bronchoalveolar lavage and biopsy findings. Treatment is smoking cessation. Corticosteroids are given in many cases, but efficacy is unknown. Lung transplantation is usually curative when combined with smoking cessation. Five-year survival is about 74%. Patients are at increased risk of cancer. (See also Overview of Interstitial Lung Disease and Pulmonary Langerhans cell histiocytosis is a disease in which monoclonal CD1a-positive Langerhans cells (a type of histiocyte) infiltrate the bronchioles and alveolar interstitium, accompanied by lymphocytes, plasma cells, neutrophils, and eosinophils. PLCH is one manifestation of Langerhans Cell Histiocytosis , which can affect many organs (most notably the lungs, skin, bones, pituitary, and lymph nodes) in isolation or simultaneously. PLCH occurs in isolation The etiology of PLCH is unknown, but the disease occurs almost exclusively in White people age 20 to 40 years who smoke. Men and women are affected equally. Women develop disease later, but differences in age at onset by sex may represent differences in smoking behavior. Pathophysiology may involve recruitment and proliferation of Langerhans cells in response to cytokines and growth factors secreted by alveolar macrophages in response to cigarette smoke. 