Metastatic Lung Disease

Pathophysiology:  By far the commonest lung cancer. Almost any sarcoma or carcinoma can metastasize to lung. Lympho-hematogenous spread to lungs.  Commonest cancers to spread to lungs are:

1.      Lung

2.      Breast

3.      GI and pancreas

4.      Renal

5.      Melanoma

6.      Sarcomas of bone and lymphoma

7.      Choriocarcinoma

8.      Squamous cell cancers, head and neck, and cervix

9.      Thyroid

CXR Findings: usually, pattern is pretty typical

1.      multiple nodules of varying sizes

2.      tend to have a lower 2/3 lung predominance because of increased perfusion

3.      often seen with adenopathy, pleural effusions

4.      may be calcified if primary bone or cartilaginous producer.  May rarely calcify by necrosis and dystrophic calcification 

Clues:

1.      rapid increase in size (days; hemorrhage ± necrosis)

2.      may calcify after chemo or radiation therapy

3.      sterile metastases may persist as lung nodules

“Aunt Sophies”:  

1.      Granulomatous lung infections

2.      Vasculitis

3.      Pulmonary amyloidosis

4.      Multiple arteriovenous malformations

5.      Septic emboli

6.      Multiple pulmonary emboli

7.      Post-inflammatory scarring