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]