Lung Pathology 2

Question 1

What are examples of occupational lung diseases?

Answer 1

occupational asthma 
pneumonitis with an ARDS
hypersensitivity pnuemonititis
emphysema 
pulmonary or pleural fibrosis 
malignancy - lung or pleura

Question 2

What are examples of fibrogenic dusts?

Answer 2

capable of lung fibrosis

• silicosis
• asbestosis
• hard metal disease - tungsten and cobalt

Question 3

How does silicosis present?

Answer 3

collagenous nodules within the lungs and in mediastinal lymph nodes
irreversible and tends to have a low mortality
if severe = respiratory incapacity
long latency
many cases are asymptomatic

Question 4

What is the pathology of silicosis?

Answer 4

well defined nodular opacities in the upper and posterior lung zones
lung nodules may coalesce to form confluent complicated nodules

Question 5

What is seen microscopically in silicosis?

Answer 5

whorled, laminated well-circumscribed nodules of collagen (onion skin)
anthracotic pigment may be present and they may be found anywhere in the lung

Question 6

What immune dysfunction can silicosis cause?

Answer 6

promotes development of mycobacterial infection (TB and atypical forms) - 5% complicated by TB
increased risk of connective tissue disorders e.g. scleroderma
increased levels of autoantibodies in the blood - likely due to depressed cell immunity and macrophage function

Question 7

What is coal worker’s pneumoconiosis like?

Answer 7

may be asymptomatic
coal dust is not as fibrogenic as silica
pathologically can see coal dust macule
upper lobe predominance
histologically see an accumulation of coal dust around respiratory bronchioles
nodular lesions with silicotic morphology may be found
emphysema invariably present

Question 8

What is progressive massive fibrosis likely associated with?

Answer 8

related to the quartz.silica content of inspired particles and is not related to cigarette smoking

Question 9

What is the pathology of PMF?

Answer 9

Upper zone predominant and related to poor lymphatic drainage
mass like areas of lung opacification associated with radiating strands
cavitation may occur so its important to exclude tb

Question 10

What is PMF like histologically?

Answer 10

black lipid debris, deposition of cholesterol clefts, necrosis and giant cells

Question 11

What is asbestos?

Answer 11

group of minerals made of microscopic fibre - of these there are 2 types = amphiboles (straight) and serpentine (curvy)

cause both ling and pleura pathologies - benign or malignant

Question 12

What are amphibole fibre like?

Answer 12

needle like (crocidolite and amosite) - stiff, straight and brittle 
fibre are less prevalent but more pathogenic

Question 13

What are serpentine fibre like?

Answer 13

white asbestos - cleared reasonably effectively

less pathogenic

Question 14

What is the pathology of benign asbestos?

Answer 14

pleura plaques = fairly common, non-neoplastic and invariably asymptomatic - irreversible and composed of hyaline collagen - may show as calcification
benign pleural thickening
pleural effusion
interstitial fibrosis

Question 15

What is the pathology of malignant asbestos?

Answer 15

mesothelioma - 90% cases associate with prior asbestos exposure
bronchogenic carcinoma = invariably associated with accompanying asbestosis
all forms of lung cancer may occur but particular adenocarcinoma
other cancers = laryngeal, potentially colon
if individual smokes as well risk increases dramatically

Question 16

How is asbestos inhalation assessed?

Answer 16

inspection for presence of asbestos bodies
characteristic beaded rod shaped structures coated with iron salts
only few asbestos fibers become coated in this way becoming visible = significant asbestos inhalation
digestion of tissue and manually counting asbestos fibers

Question 17

What is pulmonary hypertension?

Answer 17

mean pulmonary arterial pressure >25mmHg at rest or 30mmHg during exercise

Question 18

Which group is pulmonary hypertension more common?

Answer 18

rare and happens in females more than males - often occurs in young adults and has a very poor prognosis

Question 19

Why does secondary pulmonary hypertension occur?

Answer 19

left to right cardiac shunts 
venous back pressure - occur due to mitral stenosis 
hypoxaemic lung disease - COPD
drugs 
vascular obstruction

Question 20

What are the causes of pulmonary hypertension?

Answer 20

pre-pulmonary causes = increased pressure and flow in blood system = congenital heart disease

pulmonary causes = disruption of the lungs (loss of lung parenchyma - emphysema), vascular obstruction (chronic thromboembolism), hypoxemia
post-pulmonary causes = mitral stenosis

Question 21

What is the morphology of pulmonary hypertension?

Answer 21

muscularisation of the arterioles and medial thickening of the muscular arteries
as it gets worse we see intimal thickening, plexiform lesions (vascular formations originating from remodeled pulmonary arteries) and fibrinoid necrosis
end stage = aneurysm