Objective: To investigate the clinical features including history, radiology, pulmonary function and histological pathology of adult pulmonary Langerhans' cell histiocytosis (PLCH).
Method: Clinical data of 5 PLCH patients were reviewed from June 2006 to October 2007.
Results: All 5 patients were smokers with lung involvements. Spontaneous pneumothorax was the initial manifestation in 2 patients. One end-stage patient presented with severe pulmonary arterial hypertension. High-resolution CT scans of the lungs showed multifocal nodules and cysts that predominantly affected the upper and middle lung zones. At microscopic analysis, lung specimen showed discrete bronchiolocentric stellate lesions separated by uninvolved lung with air-space enlargement. Langerhans' cells expressed cell surface CD1a and cytoplasmic S-100 protein. Cessation of smoking led to stabilization of the disease. The decrease of V50 (53.6%-77.6% pred) and V25 (38.5%-70.5% pred) was consistent with small airway damages of lung histology.
Conclusion: PLCH is an isolated form of Langerhans' cell histiocytosis that primarily affects a single-system in smokers.