Normal Pulmonary Vascular Anatomy (see Pulmonary Anatomy)

• Lung has Two Arterial Blood Supplies
  • Bronchial Arteries: arising from aorta and intercostal arteries
    • Form plexus in the bronchial wall
    • Uncommonly affected by pulmonary vasculitis
  • Pulmonary Arteries: arising from RV
    • Pulmonary capillaries are located in the alveolar septa (where they participate in gas exchange)
• Lung has Two Venous Drainage Systems
  • Bronchial Veins: uncommonly affected by pulmonary vasculitis
  • Pulmonary Veins: typically located in the intralobular septa

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Diagnosis of Pulmonary Vasculitis

• Chest CT
  • May be abnormal even in the absence of symptoms
  • Ndoules: with or without cavtation
  • Ground-glass infiltrates: due to DAH
  • Airway Stenosis: may be seen in vasculitis syndromes with airway involvement (ie: Wegener’s Granulomatosis)
  • Mediastinal Lymphadenopathy: uncommon -> usually indicative of malignancy or infecton, instead of vasculitis as the etiology [MEDLINE]
• FOB
  • Useful to rule out infection
  • Serially bloody BAL is indicative of diffuse alveolar hemorrhage
  • TBB: rarely useful in making the diagnosis of pulmonary vasculitis
• Upper Airway Fiberoptic Exam with Biopsy of Suspicious Lesions
  • Especially useful in the diagnosis of Wegener’s Granulomatosis
• OLB
  • Usually necessary to make the diagnosis
• Renal Biopsy
  • Diagnostic features of granulomatous inflammation or vasculitis are rarely found, but the presence of focal, segmental necrotizing glomeronephritis without immune deposits (ie: pauci-immune) is strongly suggestive of a systemic vasculitis syndrome

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Clinical Presentations Suggestive of Pulmonary Vasculitis

• Diffuse Alveolar Hemorrhage (see Diffuse Alveolar Hemorrhage)
  • Example: Microscopic Polyangiitis
• Destructive Upper Airway Soft Tissue or Bony Lesions
  • Example: Wegener’s Granulomatosis
  • Example: Relapsing Polychondritis
• Nodular or Cavitary Infiltrates (see Cystic-Cavitary Lung Lesions)
  • Example: Wegener’s Granulomatosis -> cavities are present in 35-50% of cases, nodules are found in 55-70% of cases
• Pulmonary-Renal Syndrome (see Organ Syndromes): with presence of acute or rapidly progressive glomerulonephritis
  • Example: Idiopathic Pauci-Immune Glomerulonephritis
  • Example: SLE
  • Example: Goodpasture’s Syndrome
• Palpable Purpura (see Purpura): indicates the presence of a small-vessel, cutaneous vasculitis
  • Example: Mixed Cryoglobulinemia
• Mononeuritis Multiplex (see Peripheral Neuropathy)
• Unexplained Multisystem Disease

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References

• Wegener’s granulomatosis in the chest: high-resolution CT findings. AJR Am J Roentgenol. 2009 Mar;192(3):676-82 [MEDLINE]