Primary tracheal lymphoepithelioma-like carcinoma in a young non-smoking male: a case report highlighting the diagnostic value of flow-volume loop

Background Primary tracheal lymphoepithelioma-like carcinoma (LELC) is an extremely rare malignancy (<2% of tracheal tumors) strongly associated with Epstein–Barr virus. Tracheal tumors can mimic asthma due to dynamic airway obstruction, often leading to diagnostic delay. The flow-volume loop provides critical clues to central airway obstruction but is frequently overlooked. Case Presentation We report a 30-year-old non-smoking male initially misdiagnosed with asthma, whose refractoriness to inhaled corticosteroids prompted spirometry. The flow-volume loop revealed a plateau pattern in both inspiratory and expiratory limbs, consistent with fixed upper airway obstruction which guided chest computed tomography (CT) and bronchoscopy to identify a tracheal polypoid mass. Pathological examination confirmed LELC with positive EBV-encoded small RNAs (EBER) in situ hybridization. The patient underwent endoscopic resection followed by video-assisted thoracoscopic surgery (VATS) tracheal resection-anastomosis with lymphadenectomy. Postoperative pulmonary function testing at 1-year follow-up demonstrated complete normalization of the flow-volume loop morphology, with FEV 1 (Forced expiratory volume in 1 s) improved from 0.91L to 3.62L(+298%) and PEF (peak expiratory flow) from 2.03L/s to 6.76 L/s (+233%). The patient remained asymptomatic without recurrence at 1-year follow-up. Conclusion This case underscores that, in young patients with asthma-like symptoms refractory to conventional therapy, flow-volume loop analysis should not be deferred, as it can unmask central airway obstruction and expedite the diagnosis of rare tracheal malignancies.