| • The white arrows point to the cut edges of the pulmonary artery and its branches.
• The yellow arrows point to the large obstructing pulmonary embolus. |
| • The white arrows point to the cut edges of the pulmonary artery and its branches.
• The yellow arrows point to the large obstructing pulmonary embolus. |
| Pulmonary Embolism |
| Etiology |
• Most pulmonary emboli are from deep leg vein thrombi • Unclear what causes the thrombi to break loose and travel to the heart |
| Pathogenesis |
• Conditions which promote deep vein stasis such as immobility,
hypercoagulable states, and endothelial damage lead to thrombosis |
| Epidemiology |
•
Causes death in approximately 10% of adults dying in the hospital • 50,000 U.S. deaths/annum |
| Clinical |
• Large emboli obstructing more than 1/2 pulmonary circulation may cause
sudden death • Smaller emboli may result in nothing more severe than hemorrhage if
sufficient bronchial vascular or collateral supply to distal parenchyma • If no other supply to the distal lung or underlying chronic pulmonary
disease infarct results |
| General Gross Description |
• Large or medium sized pulmonary artery involved • Deep reddish purple firm material containing some fibrin strands or lines
of Zahn (alternating platelet and red cell layers) • May be quite adherent to vessel wall if organization has begun • Smaller strands of thrombus may extend into smaller vessels |
| General Micro Description |
• Mixture of red blood cells, platelets and fibrin • Over a few days capillaries, smooth muscle cells and fibroblasts grow into
the embolus from the pulmonary
vessel wall • Surface of the embolus will become endothelialized • Recanalization may occur |
| Reference |
• Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th edition. Philadelphia, W.B. Saunders, 1994, pp. 105-109, 111-112, 679.
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