Relapsing Polychondritis

Aqeel A. Chowdhry, MD

Tan-Lucien H. Mohammed, MD, FCCP

Key Facts

Terminology

Rare autoimmune episodic disorder that destroys cartilage, especially of ear, nose, and laryngotracheobronchial tree

Imaging Findings

Malacia earliest finding, probably secondary to edema and cartilage inflammation
Airway wall then becomes thickened and cartilaginous portions start to calcify
Stenosis late finding with scarring
Increased attenuation of airway wall on noncontrast CT classic, up to 100%
- Spares posterior tracheal membrane (no cartilage)
- Calcification is smudgy or putty-like

Top Differential Diagnoses

Clinical Issues

Diagnostic Checklist

Sparing of posterior membrane tracheal wall key to differentiate from other causes of diffuse tracheal disease

Frontal radiograph shows diffuse thickening of the tracheal wall

in a patient with relapsing polychondritis. Tracheal pathology is often overlooked on chest radiography.

Axial CECT shows smooth thickening of the trachea

. The airway wall is slightly increased in attenuation, but the posterior trachea

is normal.

TERMINOLOGY

Definitions

Rare autoimmune episodic disorder that destroys cartilage, especially of ear, nose, and laryngotracheobronchial tree

IMAGING FINDINGS

General Features

Best diagnostic clue: Increased thickness and attenuation of tracheal wall
Patient position/location: Trachea and main bronchi most common
Morphology: Diffuse thickening of tracheal wall, sparing of posterior tracheal membrane

CT Findings

Central airways
- Airway wall thickening
  - Distribution: Trachea & bronchi > trachea only > bronchi only
  - Diffuse with smooth external and internal contours (90%)
  - Focal and nodular uncommon
- Increased attenuation of airway wall (100%)
  - Ranges from subtle increase in attenuation to calcification
  - Calcification is often smudgy or putty-like
  - Involves cartilaginous portions of airway only
- Dimensions
  - Diffuse narrowing (50%)
  - Focal (50%), usually subglottic location
- Distribution
  - Involves cartilaginous airway wall only
  - Spares posterior tracheal membrane (no cartilage)
- Evolution
  - Malacia earliest finding, probably secondary to edema and cartilage inflammation
  - Airway wall then becomes thickened, and cartilaginous portions start to calcify
  - Stenosis late finding with scarring
Lung
- Air-trapping and bronchomalacia (50%)
  - Lobular air-trapping > segmental air-trapping > lobar air-trapping
- Mild cylindrical bronchiectasis (25%) due either to recurrent infections or direct destruction of cartilage
- Diffuse alveolar hemorrhage associated with glomerulonephritis
Cardiovascular
- Aneurysmal dilatation of aorta, especially ascending aorta root
- Aortic wall thickening if aortitis
- Cardiac enlargement: Aortic or mitral valve regurgitation or from pericarditis