Peribronchovascular Region: Anatomy, Pathology & Imaging Significance

Peribronchovascular = "around the bronchi and blood vessels." Refers to the connective tissue sheath surrounding bronchi and pulmonary vessels as they branch through the lung.

Anatomic Basis

• Bronchi and pulmonary arteries/veins travel together in bronchovascular bundles.
• Surrounded by loose connective tissue (peribronchovascular interstitium) containing lymphatics, nerves, fibroblasts.
• Continuous with perihilar interstitium centrally and peripheral interlobular septa peripherally.

Key Pathologic Patterns

Pattern	Description	Common Causes
Peribronchovascular thickening/cuffing	Smooth/irregular widening of bundle sheath on imaging	Heart failure (Kerley B lines), lymphangitic spread, sarcoidosis, edema
Peribronchovascular nodules	Discrete nodules along bundles	Sarcoidosis (perilymphatic), metastases, lymphoma, silicosis
Peribronchovascular ground-glass/consolidation	Infiltration of interstitial space	Organizing pneumonia (COP), alveolar proteinosis, hemorrhage, vasculitis
Peribronchovascular fibrosis	Irregular thickening, traction bronchiectasis	Fibrotic ILD (IPF, chronic HP), radiation, post-transplant

Imaging Features (CT)

• Thickened bronchial walls with peribronchovascular extension.
• Vascular convergence toward fibrotic areas.
• Centrilobular nodules (if small airways involved).
• Lymph node enlargement along bundles (sarcoid, lymphoma, metastases).

Clinical Significance

Peribronchovascular distribution narrows differential: favors lymphangitic, sarcoid, edema, organizing pneumonia, fibrotic ILD. Distribution pattern (upper vs. lower lobe, symmetry) further refines diagnosis. Biopsy often targets this region (transbronchial, surgical).