pathology Flashcards
1
Q
what is pneumonia?
A
- infection involving the distal airspaces, usually with inflammatory exudation
- fluid filled spaces lead to consolidation
2
Q
what is community acquired pneumoina?
A
getting it by clinical setting
3
Q
what organisms cause pneumonia?
A
- mycoplasma
- pneumococcal
4
Q
what morphology classes pneumonia?
A
- lobar pneumonia
- bronchopneumonia
5
Q
what is lobar pneumonia?
A
- confluent consolidatio involving a compete lung lobe
- casued by streptococcus pneumoniae
- can be seen with other organisms eg klebsiella, legionella
6
Q
who gets lobar pneumonia?
A
- community acquired
- otherwise healthy young adults
7
Q
what is the pathology of lobar pneumoina?
A
- acute inflammatory response
- exudation of fibrin-rich fluid
- neutrophil infiltration
- macrophage infiltration
- resolution
- antibodies lead to opsonisation and phagocytosis of bacteria
8
Q
what are the complications of lobar pneumonia?
A
- organisation (fibrous scarring)
- abscess
- bronchiectasis
- empyema
9
Q
what in bronchopneumonia?
A
- infection starting in the airways and spreading to adjacent alveolar lung
- most often seen in the context of pre-existing disease eg COPD, cardiac failure, complication of viral infection and aspiration of gastric contents
10
Q
what organisms are involved in bronchopneumoina?
A
- strep. pnuemoniae, haemophilus influenza, staphylococcus, anaerobes, coliforms
11
Q
what organisms are seen in aspiration?
A
- staph
- anaerobes
- coliforms
12
Q
what are the complications of bronchopneumoina?
A
- organisatoin
- abscess
- beonchiectasis
- empyema
13
Q
what is a lung abscess?
A
- localised collection of pus
- tumour-like
- chronic malaise and fever
- context = aspiration
14
Q
what is bronchiectasis?
A
- abnormal fixed dilation of the bronchi
- usually due to fibrous scarring following infection eg pneumoina, TB, CF
- also seen with chronic obstruction (tumour)
- dilated airways accumulate purulent secretions
15
Q
what is tuberculosis?
A
- mycobacterial infection
- chronic infection in many site eg lungs, gut, kidneys etc
- pathology is charactersed by delayed type IV hypersensitivity (granulomas with necrosis)
16
Q
what organisms are associated with TB?
A
- M. tuberculosis/M. bovis
- others cause atypical infections in immunocompromised hosts. pathogenicity due to ability to avoid phagocytosis and to stimulate a host T cell response
17
Q
what is immunity and hypersensitivity of TB?
A
- T-cell response to organism enhances macrophage ability to kill mycobacteria - this ability constitutes immunity
- T-cell response causes granulomatous inflammation, tissue necrosis and scarring, this is hypersensitivity type IV
- commonly both processes occur together
18
Q
what is the pathology of primary TB?
A
- first exposure and up to 5 years afterwards
- inhaled organism phagocytosed and carried to hilar lymph nodes. immune activation leads to granulomatous response in nodes, usually with killing of organism
- in a few cases infection is overwhelming and spreads
19
Q
what is the pathology of secondary TB?
A
- reinfection or reactivation of disease in a person with some immunity
- disease tends to initially remain localise as, often in apices of lung
- can progress to spread by airways and/or bloodstream
20
Q
what tissue changes occur in primary TB?
A
- small focus (ghon focus) in periohery of mid zone of lung
- large hilar nodes (granulomatous)
21
Q
what are the tissue changes in secondary TB?
A
- fibrosing and cavitating apical lesion (cancer important differential diagnosis)
22
Q
why does disease reactivate?
A
- decreased T-cell function due to age, coincident disease (HIV), immunosuppressive therapy (steroid, cancer chemotherapy)
- reinfection at high dose or with more virulent organism
23
Q
what is the pulmonary interstitial?
A
- thin-elastic rich connective component containing capillary blood vessels
- alveolar lining calles (types 1&2)
24
Q
what is interstitial lung disease?
A
- early stage = alveolitits
- late stage = fibrosis
- clinical effects due to hypoxia and cardiac fail
25
what are the causes of interstitial lung diseases?
- environmental eg minerals, drugs, radiation, postARDS
| - idiopathic
26
what biopsys can you carry out for interstitial lung disease?
- transbronchial biopsy = special forceps used at bronchoscopy
- thoracoscopic biospy = more invasive but more reliable and generates far more tissue
27
what is idiopathic pulmonary fibrosis?
- progressive interstitial fibrosis of unknown cause
- variable associated inflammation
- finger clubbing
28
what is the pathology of idiopathic pulmonary fibrosis?
- sub-pleural and basal fibrosis
- inflammatory component variable
- terminally lung structure replaced by dilated spaces surrounded by fibrous walls
- as it progressises you get bigger white spaces and gas exchange gets worse and lungs cant expant because they have shrunk due to the fibrosis (honeycombing)
29
what is extrinsic allergic alveolitis (hypersensitivity pneumonitis)?
chronic inflammatory disease = small airways, interstitium, occasional granulomas
allergic origin = type 3 hypersensitivity, type 4 hypersensitivity
30
what are the causes of EAA?
- thermophilic bacteria - farmers lung
- avian proteins - bird fanciers lung
- fungi - malt workers lung
precipitins (antibodies) can often be detected in the serum , unusual cases come to a biopsy
31
what is sarcoidosis?
- multi system granulomatous disorder of unknown cause
- pulmonary involvement is common but it isnt a lung disease
- most cases mild and self-limiting
32
what are some manifestations of sarcoidosis?
- uveitis
- erythema nodosum
- lymphadenopathy
- hypercalcaemina
33
what is pneumoconiosis?
- lung disease caused by mineral dust exposure
- asbestosis
- coal workers lung
- silicosis (silica)
34
what is asbestos associate with?
- parietal pleural plaques
- interstitial fibrosis (asbestosis)
- bronchial carcinoma
- mesothelioma
- straight (amphibole) asbestos highly dangerous
