Environmental

Question 1

describe the occupations most at risk for the condition seen in the image

Answer 1

• inhalation of asbestos fibers common in:
  
  • mining, shipyard worker, ship builders, construction workers, home insulation, mining

Question 2

describe gross changes that occur from the condition seen in the image

Answer 2

• gross:
  
  • honeycomb lung → fibrosis
  • thickening of the pleura
  • see thickening of RV → hypertrophy → cor pulmonale
  • asbestos in the lymph nodes → bilateral hilar lymphadenopathy → carcinoma
  • large pleural mass in the recess → obliteration of pleural space
  • all indications of mesothelioma

Question 3

describe the microscopic changes that occur from the condition seen in the image

Answer 3

• microscopic
  
  • asbestos body → ferruginous body → macrophages + asbestos fiber
    
    • macrophages attempt to phagocytize asbestos fiber → macrophages coat fiber w/ iron → ferric state → beaded-structures w/ translucent center
      
      • H&E = golden-brown
      • Prussian blue = blue

Question 4

describe complications of the condition seen in the image

Answer 4

• complications:
  
  • honeycomb lung → fibrosis → contraction atelectasis
  • increased risk of cancer:
    
    • bronchogenic carcinoma = most common
    • mesothelioma
      
      • pleural cancer due to asbestos
  • pleural plaques = well-circumscribed plaques of dense collagen and Ca2+ → dystrophic calcification
    
    • found on anterior and posterolateral parietal pleura (NOT visceral) & domes of the diaphragm
    • flat or nodular; does not contain asbestos fiber

Question 5

describe the image

Answer 5

Question 6

describe the occupations associated with the condition seen in the image

Answer 6

• commonly due to sandblasting/stone cutting/hard rock mining
  
  • seen in miners, glass manufacturers, quarry workers, stone cutters

Question 7

describe the pathogenesis of the condition seen in the image

Answer 7

• macrophages engulf crystalline silica → H-bonds w/ proteins & phospholipids of macrophages → damage cell membrane and kills macrophages
  
  • release TGF-B → produce collagen → whorls of collagen nodules surrounded by lymphocytes and macrophages

Question 8

describe investigations for the condition seen in the image and what would be seen

Answer 8

• investigation:
  
  • CXR → eggshell calcification in hilar LM (thin rims of calcification in hilar LN)
  • stain w/ polarized microscopy → weakly birefringent
    
    • birefringent particles in polarized light → white particles of silica glowing
  • spirometry → restrictive → FEV1/FVC normal, TLC low

Question 9

describe complications of the condition seen in the image

Answer 9

• complications:
  
  • fibrosis w/ dystrophic Ca2+ → contraction atelectasis
  • resp. failure
  • cor pulmonale
  • increase risk of pulm. TB due to increase use of macrophages to digest silica → none available to form granulomatous inflammation response (poor granuloma formation)
    
    • depressed cell-mediated immunity