What is the most likely diagnosis? 
              
- 36 year-old male smoker with shortness of breath

                  
              Frontal Chest Radiograph
            
              - Asthma
- Lymphangiomyomatosis
-  Eosinophilic granuloma
- Metastatic osteosarcoma
- Chronic bronchitis
Additional Image - Axial CT scan of Upper Lobes
             
              
             
            
               
              Additional Images
               
              
              Axial CT scan of Upper Lobes
              
             
            
              
                  Answer:
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                3. Eosinophilic granuloma
              
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              More (Click Discussion Tab) 
             
            
              
              
              Eosinophilic Granuloma
              General Considerations
              
                - Upper lobe predominance in lung
- Small nodules which may contain cavities
- Cystic lesions of varying size, first thick walled, then thinner
- 25% pneumothorax
 
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