Pulmonary Langerhans cell histiocytosis in a young adult with a history of vaping and smoking: A case report

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare interstitial lung disease characterized by the proliferation of Langerhans cells, typically associated with smoking. It accounts for 3%-5% of adult diffuse lung diseases, although the true prevalence may be higher due to asymptomatic cases and diagnostic challenges. Recently, e-cigarette use (vaping) has emerged as a potential contributing factor in PLCH. We report the case of an 18-year-old male with a history of heavy nicotine vaping and prior light smoking who presented with pneumothorax and diffuse cystic lung lesions. Lung biopsy confirmed PLCH through CD1a and S100 positivity. Smoking cessation led to symptomatic and functional improvement, although long-term outcomes remain uncertain. This case highlights vaping as a possible risk factor for PLCH, distinct from traditional smoking, and underscores the need for further research into vaping-related pulmonary diseases. A multidisciplinary approach is essential for the diagnosis and management of PLCH.