Wegener Granulomatosis, Lung

Wegener Granulomatosis, Lung

Helen T. Winer-Muram, MD

Coronal CECT shows right apical consolidation image and bilateral diffuse mixed ground-glass and interstitial opacities image due to necrotizing granulomatous vasculitis and hemorrhage.

Coronal CECT in same patient 2 weeks later shows complete clearing of the pulmonary hemorrhage. The right upper lobe consolidation has evolved into a cavitary nodule image. The diagnosis is Wegener granulomatosis.


Abbreviations and Synonyms

  • Classic Wegener granulomatosis (WG) triad: Sinus, lung, & renal disease


  • Multisystem disease of unknown etiology characterized by necrotizing granulomatous small-vessel vasculitis

    • Pulmonary involvement occurs at some stage in > 90% of patients (10% lung only)


General Features

  • Best diagnostic clue: Multiple cavitary lung nodules & large airway narrowing

  • Patient position/location: Lung nodules tend to be bronchocentric or subpleural & peripheral

  • Size: Nodules range up to 10 cm

CT Findings

  • Nodules: Most common manifestation (70%)

    • Morphology

      • Multiple (75%), usually < 10 in number, can coalesce into large masses

      • Usually 2-4 cm, rounded or oval

      • Margin: Sharp or ill-defined from surrounding hemorrhage

      • CT halo sign: Nodule with surrounding ground-glass due to hemorrhage

      • Nodules may be seen with consolidation or ground-glass opacities

    • Cavitation (50%)

      • Thick-walled > thin-walled (thin-walled usually chronic)

      • Inner margin irregular and shaggy; outer margin often spiculated

      • Air-fluid levels uncommon; however, may contain necrotic debris

      • Rapid enlargement or air-fluid levels suggest hemorrhage or superinfection

    • Distribution

      • Bilateral (85%)

      • No zonal predilection

  • Parenchymal: Ground-glass opacities or consolidation (50%)

    • Usually represents hemorrhage

    • ± Nodules

    • Various distribution and patterns

      • Wedge-shaped peripheral consolidation: Infarcts or airway involvement

      • Focal mass-like

      • Diffuse ground-glass opacities (“bat wing”) with subpleural sparing

      • May have “crazy-paving” pattern

      • May have reverse halo sign

      • Cavitation (5%)

  • Adenopathy (15%)

    • Always associated with parenchymal disease (< 2 cm short axis diameter)

    • Larger nodes should suggest superimposed infection or malignancy

  • Pleura (20%)

    • Thickening or effusion: 20%, pneumothorax rare

  • Evolution

    • Active disease correlated with nodules, masses, or parenchymal disease

  • Post-therapy

    • Parenchymal findings should start to clear within 1 week

    • If no improvement, suspect superinfection

    • Complete normalization averages 1 month (2-6 weeks)

      • 35% total clearance

      • 50% partial clearance

    • Larger masses and cavitated nodules more likely to resolve

  • Relapse

    • Frequently in areas of previous disease

    • Involves airways more often

    • Appearance of pulmonary relapse different in 25%

Radiographic Findings

  • Asymptomatic radiographic lung involvement (10-30%)

Echocardiographic Findings

  • Echocardiographic abnormalities related to WG (35%)

    • Pericardial effusion (20%)

Imaging Recommendations

  • Best imaging tool: CT more sensitive, particularly for evaluating possible airway involvement

  • Protocol advice

    • Usually performed without contrast because of renal insufficiency

    • Including glottis is helpful because of frequent subglottic involvement

    • Multiplanar reconstructions are particularly useful for evaluating airways


Pneumonia: Bacterial, Fungal

  • Radiographic findings can be identical

  • Differentiate by culture or special stains

Lung Cancer, Non-Small Cell

  • Squamous cell carcinoma most likely to cavitate

  • Usually solitary


  • Sharply marginated and variably sized

  • Squamous cell carcinoma or sarcoma histology more common

Septic Emboli

  • Nodules evolve rapidly and cavitate, blood culture positive

  • Source: Indwelling catheters, IV drug abuse

Rheumatoid Necrobiotic Nodules

  • History of joint disease

  • Usually small and subpleural

  • Spontaneous pneumothorax common (uncommon in WG)

Lymphomatoid Granulomatosis

  • Triad: Lung, skin, and nerve (central or peripheral)

  • Multiple cavitary lung nodules identical to WG

Pulmonary-Renal Syndromes

Sep 20, 2016 | Posted by in RESPIRATORY IMAGING | Comments Off on Wegener Granulomatosis, Lung

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