Spontaneous pneumothorax with pulmonary Langerhans cell histiocytosis (PLCH) in an adult heavy cigarette smoker-A case report.

Pulmonary Langerhans cell histiocytosis is a rare disease caused by the proliferation of CD1a-positive histiocyte-like cells infiltrating the lung's interstitial layer. Most cases affect young to middle-aged persons, especially adult heavy cigarette smokers. A 49-year-old male heavy smoker (40 pack-year), with non-productive cough, dyspnoea and desaturation, presented with a right-sided pneumothorax on chest x-ray with total atelectasis. Chest computed tomography (CT) revealed bilateral multiple thick-walled infiltrated cysts and multiple ground-glass nodules throughout the entire lung. Surgery with minimal invasive thoracoscopic lung biopsy and pleurodesis was performed. Pathology showed histiocyte-like cells aggregates in the pulmonary parenchyma. Immunohistochemical stain demonstrated CD1a(+), S100(+) and CD68(+). After 3 months of smoking cessation, clear improvement was evidenced with a chest CT showing bilateral multiple thin-walled rounded cysts and multiple ground-glass nodules that are smaller in size and decreased in numbers. Early minimal invasive thoracoscopic lung biopsy and pleurodesis can also be a choice if the development of secondary spontaneous pneumothorax occurs.