Single-system pulmonary langerhans cell histiocytosis with only tracheobronchial involvement: a case report

Pulmonary Langerhans cell histiocytosis (PLCH) only with airway involvement manifested as diffuse thickening of the tracheobronchial walls is rare.

A 26-year-old male was admitted to the hospital with progressive wheezing, cough, and a source of blood in sputum after activity. He had no history of smoking. Chest computed tomography showed airway stenosis of different degrees with tracheobronchial wall thickening, and fiberoptic bronchoscopy demonstrated multiple nodular neoplasms in tracheobronchial, while the pulmonary parenchyma was normal. The patient's condition partially improved after excision of partial lesions by fiberoptic bronchoscope. Histopathological results showed that CD1a and S-100 immunohistochemical staining was positive, and the molecular pathological results suggested that the BRAF V600E mutation, thus confirming the diagnosis of PLCH. The treatment of partial resection and systemic chemotherapy is effective.

The possibility of PLCH needs to be considered when diffuse tracheobronchial lesions without lung parenchyma involvement are encountered, which provides experience for early clinical diagnosis and adequate treatment.