Endotracheal hamartoma mimicking a mucus plug in an asymptomatic young never-smoker: a case report

Primary endotracheal hamartoma is an exceedingly rare benign neoplasm. Owing to the substantial functional reserve of the trachea, most patients remain asymptomatic in early stages, and these lesions are frequently overlooked or misdiagnosed as asthma, chronic obstructive pulmonary disease, or mucus plugs. This diagnostic pitfall is particularly common in young, never-smoker patients in whom the pretest probability for primary airway neoplasms is extremely low. We report a case of endotracheal hamartoma in a 32-year-old asymptomatic never-smoker woman that was incidentally discovered during routine screening and initially misinterpreted as a mucus plug. A 32-year-old asymptomatic never-smoker woman presented with a fixed intraluminal tracheal nodule incidentally discovered on routine chest computed tomography (CT), which was initially misinterpreted as a mucus plug (retained airway secretion). Prompted by a pulmonologist’s clinical suspicion, contrast-enhanced CT, ¹⁸F-FDG PET/CT, and bronchoscopic evaluation were performed. Rigid bronchoscopy with electrocautery snare and argon plasma coagulation achieved complete bronchoscopic removal with no visible residual lesion. Histopathology confirmed cartilaginous hamartoma. The patient recovered uneventfully and remained asymptomatic at follow-up. Despite the absence of respiratory symptoms, pulmonary function testing revealed a severe obstructive ventilatory defect with reduced diffusing capacity for carbon monoxide. Bronchoscopy at postoperative week 7 confirmed complete bronchoscopic removal with no visible residual lesion, and surveillance chest CT at 11 months post-procedure showed a patent trachea and major bronchi with no evidence of recurrence. This case highlights the diagnostic challenges associated with primary endotracheal hamartoma in young, asymptomatic, low-risk patients. The initial misinterpretation of a fixed intraluminal nodule as a benign secretion underscores the necessity of bronchoscopic verification before accepting a presumptive non-neoplastic diagnosis. Early bronchoscopic evaluation enables effective endoscopic removal and prevents diagnostic delay. Notably, severe pulmonary function abnormalities preceded any respiratory symptom in this patient. This case demonstrates that maintaining clinical suspicion and pursuing early bronchoscopic evaluation are essential for the accurate diagnosis and effective endoscopic management of endotracheal hamartoma in young, asymptomatic patients. Objective pulmonary function abnormalities, such as an unexplained obstructive ventilatory defect, may precede symptoms and should prompt airway evaluation in patients with a fixed intraluminal nodule.