What is the pathophysiology of metastatic spread secondary lung tumors?

Updated: Feb 08, 2019
  • Author: Daniel S Schwartz, MD, MBA, FACS; Chief Editor: John Geibel, MD, DSc, MSc, AGAF  more...
  • Print
Answer

True metastases occur via the pulmonary arteries or bronchial arteries, via the pulmonary lymphatics, across the pleural cavity, or, infrequently, via the airways.

Arterial

The pulmonary arteries are the most common route for metastases. Cancers most likely to metastasize to the lungs include those with a rich vascular supply draining directly into the systemic venous system. Spread via bronchial arteries may be responsible for some endobronchial metastases. (Other proposed modes of endobronchial spread include bronchial invasion from parenchymal lesions, spread via involved mediastinal or hilar lymph nodes, and extension along the proximal bronchus.)

Lymphatic

Lymphangitic spread can occur in association with hematogenous dissemination, which is subsequently followed by invasion of the adjacent interstitium and lymphatics, with subsequent tumor spread toward the hila or toward the periphery of the lung.

Lymphangitic spread can also occur via retrograde spread of a tumor from the originally affected mediastinal or hilar lymph nodes, with consequent obstruction of lymphatic flow.

Pleural

Pleural spread most frequently results in pleural metastases in the caudal and posterior parts of the pleural cavities.

Airway

Spread via airways is rare and difficult to prove, except in the case of bronchoalveolar carcinoma.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!