Tracheal Narrowing and Tracheomalacia

The etiologies of tracheal narrowing and stenosis are myriad. An important first step in formulating an imaging differential diagnosis is to divide tracheal narrowing into the following categories: neoplastic (benign and malignant), idiopathic, traumatic, inflammatory/infiltrative, and that caused by underlying pulmonary disease. Lesion location along the tracheobronchial wall, the presence or absence of calcifications, and evidence of extension through the tracheal wall are important characteristics that may help to further narrow the differential diagnosis. Post-intubation or post-traumatic tracheal stenosis is often treated by serial balloon dilatation, stenting, or segmental resection with re-anastamosis. Evaluation of both the length and degree of stenosis is important. Tracheomalacia is a dynamic process that is best evaluated with inspiratory and forced expiratory CT images to demonstrate tracheal collapse. Like other tracheal diseases, tracheomalacia may mimic asthma, or affected patient may present with non-specific symptoms. Significant respiratory dysfunction may result if tracheomalacia goes untreated. In the adult population, most tracheal tumors are malignant, and squamous cell carcinoma is the most common tumor detected.