Tracheal Stenosis

Short Segment:

• Iatrogenic: Endotracheal intubation, tracheostomy.
• Wegener granulomatosis: Irregularity and thickening. Subglottic involvement common. Circumferential involvement.
• Sarcoid: Irregularity and thickening.
• Amyloidosis: Localized tumor-like nodules, causing irregular narrowing and stenosis of the lumen. May have calcifications.
• Infection: Tuberculosis or histoplasmosis. Irregularity and thickening.
• Extrinsic compression: Tumor, lymph node.

Long Segment:

• Relapsing polychondritis: Thickening of the cartilaginous part of the wall (posterior wall spared). Collapse on expiratory images.
• Amyloidosis: Diffuse or multifocal submucosal infiltration, causing irregular narrowing and stenosis of the lumen. May have calcifications. May be circumferential.
• Tracheobronchopathia osteochondroplastica (TPO): Very rare. Multiple submucosal nodules of bone and cartilage protrude into the lumen of the distal trachea and central bronchi. Posterior wall spared. Presence of calcification/ossification may give an appearance similar to amyloidosis and relapsing polychondritis.

Tracheal neoplasms:

• Primary Tumor: Squamous cell carcinoma (most common primary tracheobronchial malignancy), adenoid cystic carcinoma, mucoepidermoid carcinoma, and carcinoid.
• Metastases: Renal cell carcinoma, breast cancer, colon cancer, hepatocellular carcinoma, and melanoma.
• Papillomatosis: Associated with HPV and increased risk of squamous cell carcinoma. Multiple irregular filling defects. Usually seen in young people, particularly children. Larynx most commonly affected with occasional extension into the trachea and proximal bronchi.

See the related post on Mounier-Kuhn Syndrome for a discussion of causes of tracheal widening.

References

Park CM, Goo JM, Lee HJ, Kim MA, Lee CH, Kang MJ. Tumors in the tracheobronchial tree: CT and FDG PET features. Radiographics. 2009 Jan-Feb;29(1):55-71.