成人肺部蘭格罕氏組織細胞增生症(adult pulmonary Langerhans’ cell histiocytosis)是罕見的間質性肺部疾病，好發在年輕有抽菸的族群。主要的致病機轉為吸菸促使肺部產生細胞激素(cytokines)，造成蘭格罕氏細胞增生聚集，進而生成發炎性結節，導致臨床上一些不具特異性的症狀，例如咳嗽、呼吸喘。肺部電腦斷層檢查是可以提供疾病早期診斷的工具，影像上可見為數眾多的結節及囊腫分布在兩側的肺中葉及上葉。經外科手術切片的病理組織分析為黃金診斷方式，病理切片可見肺部細胞中混雜著大量細胞質染色淡且核仁摺疊的蘭格罕氏細胞，免疫染色CD1抗原及S-100蛋白質呈陽性。治療首重戒菸，單純戒菸即可獲得症狀上及影像上的改善。內科治療方面，類固醇的使用為最常見的治療方式，肺移植手術治療僅症狀嚴重影響存活或內科治療無效才考慮進行。

Pulmonary Langerhans’ cell histiocytosis (PLCH) is an uncommon interstitial lung disease of young adult smokers associated with a significant morbidity. Cigarette smoke causes proliferation and recruitment of Langerhans’ cells in the lung, forming of inflammatory nodules. The diagnosis of PLCH is usually established if the findings on high-resolution CT (HRCT) present. The typical CT features of the lung are mixed cystic spaces and nodular opacities in the middle and upper lobes. Surgical lung biopsy has the highest diagnostic yield. Microscopically, the lung tissue infiltrated in Langerhans’ cells with pale cytoplasm and folded nuclei which are positive for CD1a and S-100. The most important part of treatment is smoking cessation, which leads to stabilization of symptoms in most patients. Corticosteroids have been the mainstay of medical therapy. Lung transplantation should be considered for patients with severe respiratory impairment and limited life expectancy. (J Intern Med Taiwan 2014; 25: 288-294)