Wegener Granulomatosis, Airways

Wegener Granulomatosis, Airways
Melissa L. Rosado-de-Christenson, MD, FACR
Key Facts
Terminology
  • Systemic necrotizing granulomatous vasculitis of small to medium-sized vessels
  • May produce tracheobronchial stenosis
Imaging Findings
  • Tracheal wall thickening/stenosis
    • Frequent subglottic involvement
    • Typically 2-4 cm in length
    • Circumferential or asymmetric involvement
  • Bronchial wall thickening/stenosis
    • Focal or long segment
    • Associated atelectasis &/or consolidation
  • Distal airway involvement
    • Peribronchovascular thickening
    • Bronchiectasis
  • Laryngeal/supraglottic stenosis
Top Differential Diagnoses
  • Tracheobronchial Neoplasm
  • Amyloidosis
  • Relapsing Polychondritis
  • Acquired Tracheal Stenosis
Pathology
  • Necrotizing vasculitis and granulomatosis
  • Subglottic stenosis, tracheobronchial stenosis, and ulcerating tracheobronchitis
Clinical Issues
  • Dyspnea, wheezing, and stridor
  • Asymptomatic, incidental diagnosis at bronchoscopy
Diagnostic Checklist
  • Airway involvement may be presenting manifestation of WG and may occur without other features of WG
Axial NECT shows the typical features of subglottic stenosis secondary to Wegener granulomatosis. Asymmetric circumferential soft tissue image produces smooth stenosis of the tracheal lumen.
Coronal NECT shows the length of tracheal involvement by Wegener granulomatosis and smooth circumferential stenosis extending from the subglottic airway image to the proximal intrathoracic trachea image.
TERMINOLOGY
Abbreviations and Synonyms
  • Wegener granulomatosis (WG)
Definitions
  • Wegener granulomatosis = systemic necrotizing granulomatous vasculitis of small to medium-sized vessels
  • Classic WG = triad of upper respiratory tract, lung, and renal vasculitis; other organs may be affected
  • Limited WG = pulmonary vasculitis without upper respiratory tract or renal involvement; other organs may be affected
  • American College of Rheumatology criteria distinguishes WG from other vasculitides
    • ≥ 2 abnormal urinary sediments (red cell casts)
    • Oral ulcers or nasal discharge, hemoptysis
    • Granulomatous inflammation on lung biopsy
  • Anti-neutrophil cytoplasmic antibodies (ANCA)
    • Antibodies present in serum of patients with WG
  • Cytoplasmic staining pattern of antineutrophil cytoplasmic antibodies (c-ANCA)
    • Diffuse granular staining pattern; ANCA binds to antigenic targets in neutrophil cytoplasm
    • Proteinase 3 (PR3); most common cytoplasmic antigenic target
    • PR3-ANCA; 80-90% sensitivity and 95% specificity in generalized active WG
  • Perinuclear-staining pattern of antineutrophil cytoplasmic antibodies (p-ANCA)
    • Staining of antigen targets aberrantly positioned around cell nucleus
    • Associated with vasculitis; may be seen in active WG
IMAGING FINDINGS
General Features
  • Best diagnostic clue
    • Large airway focal or diffuse stenosis
    • Association with multifocal bilateral lung nodules &/or consolidations that may exhibit cavitation
  • Patient position/location: Subglottic trachea, bronchi
  • Size: Length of airway stenosis, typically 2-4 cm
  • Morphology: Circumferential soft tissue thickening of airway wall
CT Findings
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Sep 20, 2016 | Posted by in RESPIRATORY IMAGING | Comments Off on Wegener Granulomatosis, Airways

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