From diagnostic biopsy to bullectomy: A case of progressive complications in pulmonary langerhans cell histiocytosis.

A 38-year-old male smoker presented with a persistent dry cough lasting several weeks. Chest radiography showed bilateral reticulonodular opacities predominantly in the upper lung fields. Subsequent chest computed tomography revealed diffuse, thick-walled, irregular cystic lesions mainly involving the mid and upper lung zones with a centrilobular distribution. Histopathological examination obtained through video-assisted thoracoscopic surgery demonstrated bronchiolocentric nodules and cysts containing Langerhans cells with convoluted nuclei, confirmed by positive immunohistochemical staining for CD1a, S-100, and Langerin. These findings confirmed the diagnosis of pulmonary Langerhans Cell Histiocytosis (PLCH). The patient's symptoms improved initially following smoking cessation but were complicated by recurrent pneumothorax and the formation of giant bullae, ultimately requiring surgical intervention. This case emphasizes the association between PLCH and smoking, highlights potential complications following surgical biopsy, and underscores smoking cessation as a critical therapeutic measure, with targeted therapies reserved for refractory or mutation-specific cases.