Diffuse Tracheobronchial Wall Thickening

Jeffrey P. Kanne, MD

DIFFERENTIAL DIAGNOSIS

Common

Tracheal Neoplasms
Acute Bronchitis
Chronic Bronchitis

Less Common

Relapsing Polychondritis
Wegener Granulomatosis
Amyloidosis
Sarcoidosis

Rare but Important

Laryngeal Papillomatosis
Tracheopathia Osteochondroplastica
Rhinoscleroma

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Diffuse or focal abnormality
Involvement or sparing of posterior tracheal membrane
Expiratory CT useful for detecting tracheomalacia

Helpful Clues for Common Diagnoses

Tracheal Neoplasms
- Uncommon
  - < 1% of all lower respiratory tract neoplasms
  - Squamous cell carcinoma and adenoid cystic carcinoma account for > 80%
  - Other tumor types rare
- Polypoid intraluminal mass most common appearance
  - Squamous cell carcinomas often large at presentation (up to 4 cm)
- Eccentric nodular wall thickening or diffuse tracheal wall infiltrating uncommon
- Frequently extend into mediastinum and adjacent structures
  - Tracheoesophageal fistula in 15%
  - Main bronchial invasion in 25%
  - Regional lymph node metastases common
- Adenoid cystic carcinomas most commonly occur near tracheal carina
Acute Bronchitis
- Viral most common cause
- Bronchial wall thickening
  - Retained secretions
- Patchy atelectasis
- Peribronchial consolidation may indicate bronchopneumonia
- Acute bacterial tracheitis
  - Most common in children
  - Less commonly immunocompromised adults
  - Diffuse tracheal wall edema
  - Edema of surrounding mediastinal tissues
Chronic Bronchitis
- Related to cigarette smoking
- Clinical diagnosis
- Tracheobronchial wall thickening
  - No significant stenosis
  - Retained secretions
- Centrilobular pulmonary emphysema may be present

Helpful Clues for Less Common Diagnoses

Relapsing Polychondritis
- Involves only cartilaginous portions of trachea and main bronchi
- Spares posterior membrane
- Increased attenuation of tracheal wall
  - May become diffusely calcified
- Smooth tracheal wall thickening
- Tracheal stenosis
  - Occurs in 33-89% of patients
  - Diffuse or focal
  - Associated with bronchial narrowing
- Tracheomalacia
  - Result of cartilaginous inflammation and destruction
  - Suggested by > 70% reduction of cross-sectional area on expiration
Wegener Granulomatosis
- Tracheal wall thickening in 15%
- Bronchial wall thickening in 50-60%
- Focal > diffuse
  - Subglottic narrowing most common
- Tracheobronchial narrowing smooth or irregular
- Associated lung findings may be present
  - Nodules and masses
  - Cavitary lesions
  - Consolidation
  - Ground-glass opacity
Amyloidosis
- Tracheobronchial tree most commonly affected
- Smooth or nodular calcification in up to 50%
- Circumferential tracheal or tracheobronchial wall thickening
- Associated lung findings (from airway obstruction)
  - Atelectasis or obstructive pneumonitis
  - Pulmonary amyloid
Sarcoidosis
- Tracheal involvement very uncommon
- Larynx often affected
- Stenosis smooth, irregular, nodular, or mass-like
- Other typical findings usually present
  - Lymphadenopathy
  - Perilymphatic nodules

Helpful Clues for Rare Diagnoses

Laryngeal Papillomatosis
- Tracheobronchial involvement in 5-10%
- Usually develops 10 years after laryngeal disease
- May affect lungs
  - Nodules
  - Cavitary lesions
- Degeneration into squamous cell carcinoma rare
Tracheopathia Osteochondroplastica
- Mild diffuse tracheobronchial stenosis with nodularity
- Calcified nodules arising from tracheal cartilage protruding into lumen
  - Range in size from 3-8 mm
- Lower trachea most commonly involved
- May extend into bronchi to segmental level
  - Can cause atelectasis
- Sparing of posterior tracheal membrane characteristic
- Often associated with “saber-sheath” tracheal deformity
- Slowly progressive
- Older men with chronic obstructive lung disease most commonly affected
Rhinoscleroma
- Slowly progressive granulomatous infection caused by Klebsiella rhinoscleromatis
- Endemic in tropical and subtropical regions
- Upper respiratory tract most commonly involved
  - Especially nose, upper lip, hard palate, and maxillary sinuses
  - Trachea and proximal bronchi affected in up to 10%
- Thickening of trachea and main bronchi with luminal stenosis
  - Stenoses usually concentric
  - Smooth or nodular
  - Diffuse uniform narrowing uncommon
  - Occasional mediastinal and hilar lymphadenopathy
  - Atelectasis and obstructive pneumonitis may develop

Image Gallery

Axial NECT shows a polypoid carinal mass

extending into the tracheal lumen at the carina. Note the extension into the mediastinum anteriorly

. Biopsy confirmed squamous cell carcinoma.

Axial CECT shows a heterogeneous mass

protruding into the tracheal lumen at the level of the cricoid cartilage. Biopsy confirmed squamous cell carcinoma.

(Left) Axial CECT shows nodular thickening of the tracheal wall

in this patient with adenoid cystic carcinoma. Following resection, adenoid cystic carcinomas, while lower grade than squamous cell carcinoma, often recur because of submucosal growth. (Right) Coronal oblique CT reconstruction shows tracheal wall thickening