Pathology of pulmonary infection Oct20 M1

Question 1

4 categories of pulmonary infections

Answer 1

diffuse parenchymal (lobar)
patchy parenchymal (bronchopneumonia)
interstitial
nodular (granulomatous)

Question 2

location of lobar (airspace) pneumonia

Answer 2

lower lobe, peripherally

Question 3

mechanism of diffuse parenchymal (lobar) infection

Answer 3

aspirate organism, grows near resp bronchiole, acute inflammation causes outouring of fluid in airspace

Question 4

mechanism of diffuse parenchymal (lobar) infection: what happens after outpouring of fluid in airspace

Answer 4

fluid flows between alveoli, bacteria displaces, fluid in airways increases, consolidation of the lung. cells replace fluid with time

Question 5

lobar (airspace or diffuse parenchymal) pneumonia prognosis and why

Answer 5

can heal completely (no necrosis, lung itself not injured)

Question 6

bronchopneumonia (patchy disease) location

Answer 6

at primary site of infection and can affect both lungs and the bronchi

Question 7

bronchopneumonia (patchy disease) pathogenesis (where starts, etc.)

Answer 7

start at terminal bronchiole, pluggs airways, distant atelectasis, collapsed areas are surrounded by congestion, collapse and emphysema

Question 8

bronchopneumonia (patchy disease) how resolves

Answer 8

• resolution of exudate solves problem
• may have fibrosis (if organisation occurs)
• may cause abcesses (necrosis) if aggressive

Question 9

empyema def

Answer 9

greenish pus lining pleural surface (neutrophilic)

Question 10

when can see empyema

Answer 10

as complication of bronchopneumonia

Question 11

interstitial pneumonia location

Answer 11

mostly basal and peripheral

Question 12

what is affected in interstitial pneumonia

Answer 12

interstitium but may also affect airspace

Question 13

least severe interstitial pneumonia findings

Answer 13

diffuse parenchymal interstitium inflammation with normal airspaces

Question 14

mild interstitial pneumonia findings

Answer 14

lymphocyte infiltrate in parenchymal IS. normal septum but mild thickening in IS

Question 15

diffuse alveolar damage in interstitial pneumonia def

Answer 15

inflammation, tissue necrosis, esoinophilic exudate (proteins, neutrophils, necrotic tissue, hyaline membranes), fluid can leak to adjacent capillaries, consolidation of alveolar space

Question 16

what causes diffuse alveolar damage

Answer 16

measles pneumonia

Question 17

what causes diffuse parenchymal (lobar) pneumonia

Answer 17

viruses, bacteria, fungi

Question 18

what causes bronchopneumonia (patchy disease)

Answer 18

toxins, bacteria and viruses

Question 19

what causes interstitial pneumonia

Answer 19

infectious agents, viruses (cytomegalovirus)

Question 20

nodular (granulomatous) pulmonary infection example

Answer 20

TB

Question 21

initial TB

Answer 21

inflammation with neutrophils and fibrinous exudate

Question 22

TB as advances

Answer 22

necrosis center surrounded by epitheloid histiocytes

Question 23

advanced TB findings

Answer 23

expanding necrosis, walled off by fibrosis, multinucleated giant cells + lymphocyte + fibrosis in healing granuloma

Question 24

healed TB finding

Answer 24

Ghon focus (caseous), necrosis completely surrounded by fibrosis

Question 25

TB lung region affected

Answer 25

parenchyma of middle-lobe

Question 26

TB: what happens after mycobacteria reaches parenchyma

Answer 26

mycobacteria drains to lymph nodes and triggers inflamm there

Question 27

what happens in lymph nodes when see TB

Answer 27

T cells activate macrophages

Question 28

most frequent site for secondary TB (TB reactivation) and why

Answer 28

apex bc TB survives more there

Question 29

what secondary TB may look like on CXR

Answer 29

cavitation in upper lobe (grey space)

Question 30

miliary TB def

Answer 30

diff nodules spread of TB in the lung

Question 31

miliary TB how happens

Answer 31

TB spreads to other places in the lung using the pulmonary vasculature

Question 32

when see miliary TB

Answer 32

cancer therapy, immunosuppression