Respiratory Pathology Flashcards
what are the three factors that make up the COPD definition?
- persistant airflow obstruction
- poorly reversible
- progressive
what is the clinically definition of chronic bronchitis?
Cough productive of sputum for 3 consecutive months for 2 consecutive years which has no other cardiac or pulmonary cause
what is the pathological definition of emphysema?
permanent dilatation of the airways distal to the terminal bronchiole due to destruction of alveolour walls
why do COPD patients get increased sputum production?
There is hyperplasia of the mucus producing glands in the submucosa and hyperplasia of the goblet cells on the surface epithelium
In COPD there is destruction of the respiratory bronchiole walls, what is the consequence
- less pulmonary surface area for gas exchange leading to hypoxia
- loss of elastic tissue in terminal airways meaning less natural recoil leading to obstruction
what is the spirometry result in COPD?
obstructive
What are causes of IECOPD?
- infection
- pneumothorax
- PE
- LVF
- lung carcinoma
where is the infection site in IECOPD compared to pneumonia?
Pneumonia- alveoli
COPD- airways
what are the most common causes of IECOPD?
H.influenzae
M.catarrhalis
S.pneumonia
virus
what are the most common causes of pneumonia?
S.pneumoniae
H.influenzae
Viruses
atypicals
what is the most common cause of cor pulmonale?
COPD
what is pulmonary hypertension?
Increase in blood pressure in the pulmonary vasculature as resting pulmonary artery pressure above 25
what leads to pulmonary hypertension in COPD?
Chronic hypoxia leading to increased EPO leading to polycythaemia
Chronic hypoxia leading to pulmonary arterial vasoconstriction
what is pneumonia?
Inflammation of the lung parenchyma due to an infective agent
Pneumonia affects the parenchyma, what is this?
the alveolour spaces
What is the pathological classification of pneumonia?
Bronchopneumonia vs lobar
what are the characteristics of bronchopneumonia?
- normally bilateral
- ## widespread patchy inflammation
what are the characteristics of lobar pneumonia?
diffuse inflammation affecting the entire lobe or lobes
what is consolidation?
replacement of air by fluid or other material
in pneumonia this is exudate
what is the single most common cause of community acquired pneumonia?
Strep pneumonia (pneumococcus)
Other than the most common (strep pneumoniae) what are other causes of community acquired pneumonia?
Influenza, chlamydia pneumonia, mycoplasma pneumoniae, legionella pneumoniae, haemophilus influena
what are the three causes of more severe CAP?
S.Pneumoniae, legionella, S.aureus
what is used to assess severity of CAP?
curb 65
what does CURB 65 stand for?
confusion- AMT above 8 Urea above 7 Resp rate above 30 Blood pressure (90/60) 65 yrs or older
when does HAP Tend to occur?
2 days after admission
what is responsible for HAP?
gram negative pneumonia klebsiella E coli pseudomonas S.aureus S.pneumoniae
what patients are at risk of aspiration pneumonia?
Stroke, impaired swallowing, septic with reduced consciousness
what fungis can cause pneumonia in the immunocompromised?
pneumocystitis
Candida
Aspergillus
what characterises diffuse parenchymal lung diseases?
inflammation is centred on the instertitium of the alveolour walls
in diffuse parenchymal lung diseases one outcome possibility is that the inflammation is followed by scarring how does this happen?
macrophages release fibrogenic cytokines that stimulate fibroblasts in the interstitium to secrete collagen
what is CXR finding of severe parenchymal lung diseases where scarring takes place?
honeycomb lungs
what is pneumonitis?
inflammation of the lung parenchyma
what is pneumonia?
inflammation of the lung parenchyma due to an infective agent
what are the categories for causes of diffuse parenchymal lung diseases?
- unknown
- pneummoconioses
- extrinsic allergic alveolitis
- side effects of a treatment
- multisystem disese
what is pneumoconiosis?
A cause of diffuse parenchymal lung disease
inhaled inorganic material such as mineral dust
includes coal dust, silica and asbstososes
what is extrinsic allergic alveolitis?
A cause of DPLD
inhaled organic particles such as bird fancier lung and farmer lung
what spirometry result does DPLD show?
restrictive
what are possible long term complications of DPLD?
- can cause cor pulmonale
- pulmonary hypertension
- right ventricular hypertrophy
What are the four main groups of lung cancer?
- adenocarcinoma
- squamous cell carcinoma
- small cell carcinoma
- large cell carcinoma
where do squamous cell carcinomas arise?
In the larger airways near the hilum
what is the sequence of events leading to squamous cell carcinoma?
Metaplasia-dysplasia carcinoma
what is the most common type of lung cancer in non-smokers?
Adenocarcinoma
where does adenocarcinoma tend to arise?
Peripheral smaller airways
what is the precursor to adenocarcinoma?
atypical adenomatous hyperplasia
what lung cancer has the strongest association with smoking?
small cell carcinoma
where does small cell carcinoma normally arise?
A central location
what is the grading of small cell carcinoma?
Not graded. By definition is highly aggresive
what chromosome 2 mutation is associated with lung cancer?
inversion in the short arm of chromosome 2 causing fusion of EML4 gene with ALK gene.Responds to TKI crizotibin
why do some cancer cells express PD-L1?
PDL1 regulates T cell function. Expressing it stops T cells attacking them.
How do you obtain a biopsy for central lesions?
Bronchoscopy
how do you obtain a biopsy for peripheral lesions?
CT guided sampling
what imaging is good for the T part of staging in lung cancer?
CT
what imaging Is good for the N and M part of staging for lung cancer?
PET
what cancer tends to cause SVC obstruction?
right sided small cell carcinoma
what are signs of SVC obstruction?
SOB, facial swelling, head fullness, cough, arm swelling, chest pain, stridor
what is a pancoast tumour?
A cancer In the lung apex that involves the C8 nerve and T1 AND 2 nerves.
how can pancoasts tumour present?
- pancoasts syndrome (shoulder pain radiating in an ulner distribution
- horners syndrome
what is horners syndrome characterised by?
- endophthalmos (eyeball depression)
- ptosis (droop of upper eyelid)
- miosis (pupil constriction)
- anhidrosis
what causes horners syndrome?
sympathetic nerve infiltration especially T1
what is a paraneoplastic syndrome?
A syndrome caused by substances produced from the tumour cells which act remotely from the tumour
what cancer is hypercalcaemia as a paraneoplastic syndrome more common with?
squamous cell carcinoma
what causes the paraneoplastic effect of hypercalcaemia?
The production of PTH related peptide by tumour cells causing calcium release from bone
what cancer is SIADH commonly seen with?
Small cell carcinoma
what are the effects of SIADH?
low sodium, low serum osmolality, overhydration
what cancer is ectopic ACTH secretion by tumour cells?
small cell carcinoma
what are the main manifestations of ectopic ACTH secretion?
thirst
polyuria
what are lambert eaton myasthenic syndrome associated with?
small cell carcinoma
what happens in lambert eaton myasthenic syndrome?
autoantibodies block VG ca channels blocking Ach release
how do you manage small cell lung carcinomas?
- often has mets so surgery is of no help
- initial chemo
how do you manage non small cell lung carcinoma?
surgery is possible at low stage or chemo
what is mesothelioma?
A malignant tumour of the pleura associated with abstesos exposure
what is the presentation of mesothelioma?
breathlessness
chest pain
pleural effusion
what is asbestosis?
A DPLD where there is diffuse fibrosis of the lung parenchyma
