resp pathology Flashcards
What type of fluid is this and what is this condition called?
-sero-sanguinous transudate
hydrothorax
what can cause a hydrothorax?
CHF
What has hapenned to the dark areas of lung?
congested and deflation (atelectasis)
what diseases can cause congestion and atelectasis?
thoracic cavity tumour
pneumothorax
haemothorax
pyothorax
abscess
inhaled fb / food
What is the major abnormality present in image A?
emphysema - diffuse alveolar and interstitial
What major abnormality is seen in image B?
- flooding of alveoli with protein rich fluid
- widened interlobular septa with fibrin
what cattle disease can cause emphsema and alveoli flooding with protein rich fluid?
Acute bovine pulmonary oedema and emphysema (fog fever)
- lush autumn grass has tryptophan which converts to a pneumotoxin in the rumen
name 4 features of the upper and lower resp tract that protect the lung from airborne infections?
- mucociliary escalator
- mucus
- nasal cavity with turbulent air flow
- resident alveolar macrophages
what area of the resp tract is most vulnerable to infection?
where cilia end before alveoli
(bronchoalveolar junction)
What portion of the lung is affected and what has hapenned to it?
- Cranioventral distribution on each lobe
- dark bit = consolidation and congestion (chronic pneumonia)
what is the condition shown?
bronchiolectasis = permenant bronchiole dilation
What is illustrated in image B?
artery and bronchiole infiltrated in wall and lumen by inflammatory cells
neutrophils and purulent exudate stretch the bronchiole and fix it as dilated
How do the changes in image A develope from the changes in image B?
-damaged smooth muscle so stay dilated
what is the blue material that is asteriksed within the airway lumen?
thick mucous plugging the airways
can also see excess goblet cells and hyperplasia of the wall so reduced cilia so cant clear mucous
This is from a stabled horse with a chronic history of dyspnoea and coughing. What is the most likley diagnosis?
RAO
How can you alleviate the symptoms of RAO?
- soak hay
- good hay quality
- change bedding to mats
- turn horse out
- mucolytics
- bronchiodilators
- expectorants
- NSAIDs, steroids, anti-histamines
What is the obvious abnormality and what do we call this in neonates?
- light and dark patchy appearance
- primary partial atelectasis
- it has taken a few breaths as some areas inflated
What is the difference between the two images?
Top = normal
Bottom = pink protein rich exudate - oedema
What can cause pulmonary oedema?
LS HF
brain injury
symp stimulation
tryptophan
smoke
paraquat
iatrogenic - excess fluids
barbiturate euthanasia
A = normal
B and C = abnormal
c= more magnified
What is the difference in B and C?
- pink exudate and no air in alveoli
- neutrophils present
What two patterns of pneumonia are characterised by the changes in B and C?
bronchopneumonia - infl cells in air space, inhaled
Embolic - from blood
Describe the gross appearance of the lungs
Large variably sized cream - yellow nodules
Granuloma or abscess
what is the difference in cell type between a granuloma and abscess?
Granuloma - macrophage
Abscess - neutrophil
What does image A show?
necrotic centre with viable macrophages then lymphocytes then capsule
- a granuloma
- dark foci = dystrophic mineralisation due to necrosis
What cell is indicated by the asterisk in image B?
multinuclear giant cell
(fused macrophages)
How can you confirm Tb presence?
ziehl - neelson stain - see magenta bits in macrophages
What are the pathological changes with Tb?
giant cells
granulomas
What pigment do all these lesions have in common?
Melanosis
-flat nodule
what is the gross abnormality?
Mucopurulent exudate
diffuse redenning (hyperaemia / congestion / haemorrhage)
sulphur granules in exudate
what is the most likely undelrying cause?
Norcardia or actinomyces as make sulphur granules
- from environment from cat fight wound
What has hapenned and what is this condition called?
Atrophic rhinitis
- bilateral concha loss, smaller turbinates and wonky snouth
- tear staining
- more prone to secondary infection
What pathogens cause atrophic rhinitis and how do they work?
- pasturella multocida - activates osteoclast
- bordatella bronchiseptica - inhibits osteoblasts
Describe the macroscopic changes in the lung? What are 3 possible causes?
White nodules on very dark red lung - atelectasis
- neoplasia
- granuloma
- abscess
What is the underlying cause?
Glandular (cells stuck to neighbouring cells and forming lines) neoplasia
- adenocarcinoma
what is the most likely parasite causing this infection?
Dictycalus viviparus
what is the likley immune status of this calf to the parasite?
Been exposed before as formed a type 4 hypersensitivity granuloma
What defence function to the nasal chambers play?
remove particles
humidify and warm
sneeze with noxious stimulie
what defence function do the pharynx/larynx play?
cough if particles aspirated
epiglottis blocks off trachea
in what environment can resident alveolar macrophages increase in number
dusty environment
Where are lung mets common from?
mammary
haemangiosarcomas
osteosarcomas
what is hypertrophic pulmonary osteopathy?
paraneoplastic disease where space occupying lung lesions can cause periosteal thickening of long bones
What is primary atelectasis?
failure of lung tissue to expand at birth
what is secondary atelectaiss?
collapse of a previously ventilated lung
What is unusual about cattle lungs?
thick fibrous septae between lobes so lack collateral ventilation
what 2 things can cause secondary atelectasis?
1) Compression - mass, pneumothorax etc, recumbency
2) obstruction - exudate
what is emphysema?
excessive air in lungs
what is alveolar emphysema?
permenant abnormal enlargement of airspaces distal to the terminal bronchioles, often from alveolar wall destruction by neutrophil elastace (RAO eg)
what is interstitial emphysema?
septal lymphatic are dilated with air secondary to forced expiration (pneumonia eg)
what is compensatory emphysema?
adjacent to an area of consolidation
what to pigments can affect the lungs?
melanin
anthracosis - carbon in alveolar macrophages
What are 5 circulatory disorders affecting the lungs?
hyperaemia
congestion
oedema
haemorrhage
thrombosis/embolism/infarction
what is hyperaemia?
increase blood flow into tissue (acute infl eg)
what does dark red lung tissue indicate?
hyperaemia
what is congestion?
decreased blood flow from a tissue (cardiac failure eg)
what does grey/blue lung tissue indicate?
congestion
what are 4 causes of oedema?
cardiogenic (press overload)
neurogenic (brain damage)
excess fluid therapy
damage to endothelium/epithelium
How does oedema fluid appear with H and E?
pale pink as protein rich
what are normal factors resisting oedema?
- tight junction between alveolar ep and capillaries
- intra-alveolar pressure > interstitial pressure
- lymphatic drainage
What are the 3 things contributing to a thrombus?
endothelial injury
abnormal blood flow
hypercoagulation
What is thrombosis?
obstruction of vessels by blood during life
what is an embolism?
detachment of thrombi, lodged in small vessels
What are the 6 types of pneumonia?
broncho -
lobar -
broncho-interstial -
interstitial -
embolic -
granulomatus -
what causes broncho-pneumonia?
bacterial inf
aspiration pneumonia
*from airways
What is the normal distribution of broncho-pneumonia?
cranioventral lung
how does bronchopneumonia spread between lobes?
airway / necrosis of alveoli +septa
what are the possible sequelae of broncho-pneumonia?
resolution
abscess
pleuritis and adhesion
death from hypoxaemia
chronic and get bronchiectasis
what is bronchiectasis?
permenant dilation of some bronchi due to irreversible damage to bronchi wall
what causes lobal pneumonia?
highly toxic bacteria
aspiration
what does lobar pneumonia normally infect?
entire lobes
(common in cats as incomplete lobulation and septation)
what causes broncho-interstitial pneumonia?
mycoplasma
virus
what is the pathogenesis of broncho-interstitial pneumonia?
infl in bronchioles – lymphocytic proliferation – lymphoid cuffing of airways
What can cause interstitial pneumonia?
-haematogenous damage
what distribution does interstitial pneumonia have?
diffuse
what are 2 toxins that can cuase interstitial pneumonia?
- paraquat
- tryptophan
what can cause embolic pneumonia?
endocarditis, hepatic abscess, phlebitis
what is the distribution of embolic pneumonia?
focal
what can cause granulomatus pneumonia?
mycobacteria
funghi
What are A-F?
A = ciliated ep cell
B = type 1 ep cells (pneumocyte)
C= type 2 ep cells
D=alveolar capillary
E=alveolar macrophage
F=Clara cell
This is from a cat’s nose with persistent unilateral nasal discharge
What is the mass composed of? what is the diagnosis?
diffuse proliferation of subepithelial connective tissue overlain by an intact ep
inflammatory polyp
Lung from a horse with long term resp difficulty. Diagnosis?
RAO
chronic aggregation of plasma cells, lymphocytes and eosinophils around bronchioles with emphysema
Lung from a young intensively housed calf with unresolving pneumonia
How did the infection enter the lungs?
What is the difference in the damaged areas of each lung?
- entered by inhalation as accumulated in lower cranioventral lobes
- furthest left lung - chronic as pale and nodular. Will be firm and consolidated. Bronchiectasis and fibrosis cause the pallor and nodularity
Middle lobe - sub-acute = darker red due to blood leakage. Slightly undulating surface from infl cells filling and expanding alveoli and bronchioles
Right lobe = acute = dark red from hyperaemia. Surface is shiny and moist and smooth
Lung from a 6mo calf that died in resp distress.
What is S and is it what caused death? How was S formed?
S = bull of emphysema
- a secondary lesions to bronchopneumonia obstructing air outflow by accumulating exudate
- as cattle have fibrous interlobar septa trapped air can penetrate the alveolar walls and enter interstitial tissue forming air pockets
What pattern is this?
Nodular interstitial
What pathology is shown here?
Pleural effusion
- cardiac silhouette and diaphrgam not visible
- increased opacity
- fissure lines
- lung edges away from thoracic wall
What pathology is shown here?
Pneumothorax
- elevation of cardiac silhouette
- no vessel or bronchi
- area of lucency on left side if collapsed lung
What pathology is shown here?
cranial mediastinal mass
- trachea deviated to left
What are the 3 most common dog cranial mediastinal tumours?
thymoma
lymphoma
haemangiosarcoma
what pathology is present here?
Diaphragmatic hernia
What pathology is present here?
pneumomediastinum
- as two vessels below trachea re visible when they shouldnt be
- aorts appears better marginated than normal due to surrounding gas
What pathology is shown here? what else is abnormal?
Diaphragmatic hernia
Sternal fracture with some new bone formation
What pathology is shown here?
pleural effusion
- black anechoic area at location of lung on both sides of cranial mediastinum which is consistent with fluid
