Pulmonary Vasculitis

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

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

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

References

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