Saber sheath trachea: A radiological sign of severe airway obstruction

A middle-aged man, chronic smoker, presented with complaints of productive cough & exertional breathlessness (mMRC grade III) for 3 years with frequent episodes of exacerbation in the past. There was no other comorbidity or significant past history. His chest radiograph showed narrowing of trachea. Evaluation with computerized tomography of thorax showed normal extra-thoracic trachea with narrowing of the coronal diameter with increase in the sagittal diameter of the trachea along with thickening and calcification of the tracheal wall seen in saber sheath trachea.