Langerhans Cell Histiocytosis and Other Histiocytic Diseases of the Lung.

Several histiocytic disorders may affect the thoracic cavity. Pulmonary Langerhans cell histiocytosis (LCH) is the histiocytic disorder that most frequently manifests with thoracic involvement in adults and is associated with cigarette smoking. The histiocytic disorders follow variable clinical courses ranging from benign disease to life-threatening aggressive disorders. Although the pathogenesis is not fully understood, it is now apparent that some of these disorders are associated with activating mutations in cell proliferative/regulatory pathways. Management of these rare disorders must be individualized. Pharmacologic treatment may include the use of chemotherapeutic agents. Smoking cessation is imperative in the management of pulmonary LCH.