lecture 7: pathology of lung cancer Flashcards Preview

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Flashcards in lecture 7: pathology of lung cancer Deck (39)
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1
Q

what are the initial clinical presentations?

A
  • most patients are asymptomatic
- the clear symptoms are
coughing  
coughing up blood (haemoptysis) 
lots of infections 
chest wall pain
2
Q

what is cytology?

what is shown in cytology?

A

cytology is looking at the individual cells

  • sputum
  • bronchial washings
  • pleural fluid
3
Q

what is histology ?

what does histology show?

A
  • histology is looking at the tissues
  • biopsy at bronchoscopy
  • lymph node biopsy
  • peripheral tumor biopsy
4
Q

what are the two types of tumour?

A
  • benign tumours
    do not metastasise
    cause local complications
  • malignant tumours
    have potential to metastasises
  • involves the adjacent tissues
5
Q

what are the two types of tumour of the lung?

A
  • non small cell
    adenocarcinoma
    squamous cell carcinoma
    large cell carcinoma
  • small cell
    much worse prognosis than the non small cell
    grow rapidly
    and metastasise
6
Q

what types of lung cancer are increasing and what is decreasing?

A
  • the incidence of squamous cell carcinomas is decreasing
    (due to a decreasing in the rates of smoking)
    ( also due to a change in the type of cigarettes smoked)
  • the proportion of lung cancer due to incidence of adenocarcinomas is inreasing
7
Q

what is the most common malignant lung tumour?

A
  • epithelial tissues
8
Q

what is the most common type of lung cancer of non smokers?

A

adenocarcinoma

9
Q

where are squamous cell carcinomas located ?

where are adenocarcinomas located?

A
  • squamous cell carcinomas are located near the mediastinum

- adenocarcinomas are located in the periphery

10
Q

what is the main cause of lung cancer?

A
  • smoking
    both passive and direct smoking
  • asbestos
  • radiation
11
Q

example of

  • tumour initiator
  • tumour promoter
  • complete carcinogens
A
  • hydrocarbons
  • nicotine
  • nickel
12
Q

how might a genetic predisposition arise?

A
  • familial lung cancer is really rare
  • there are some susceptible genes:
  • nicotine addiction
  • susceptibility to chromosome breaks and DNA damage
13
Q

what are the stages of development of a carcinoma?

A
  • metaplasia
  • dysplasia
  • carcinoma in situ
  • invasive carcinoma

a tumour is basically an accumulation of mutations

14
Q

what is the pathway of development of squamous cell carcinoma?

A
  • squamous cell carcinomas arise in the airways
  • the airway reacts to the chronic irritation of the cigarette smoke
  • the epithelium changes to a tougher epithelium
  • if there are no cilia on the epithelium the mucus will stay in the lungs so you acquire smokers cough
  • the squamous cells will acquire mutations so the normal pattern of growth is disrupted
  • the dysplasia becomes more and more disordered
    therefore becoming a carcinoma in situ
  • a further mutation will make it invasive
15
Q

what is the cytology of squamous cell carcinoma?

A
  • large nuclei

- keratin in the cytoplasm

16
Q

what is the histology of squamous cell carcinomas?

A
  • keratinisation
  • intracellular prickles
  • lots of subtypes
17
Q

what is the development of adenocarcinomas?

A
  • forms from glandular epithelium
  • they develop in the periphery
  • the pre cursor lesion is atypical adenomatous hyperplasia
  • this is when the atypical cells lining the alveolar walls proliferate and eventually become invasive
18
Q

what is the progression of an atypical adenomatous hyperplasia?

A
  • alveolar walls are thickened
  • and lined by atypical cells
  • over time some of these cells will grow larger and larger
  • at some point the cells mutate to produce enzymes that break down the stroma
  • this forms fibrous scars and is accompanies by inflammation
  • once the adenocarcinoma is invasive it might spread round the body
19
Q

what is the cytology of adenocarcinomas?

A
  • shows glandular differentiation
  • produces mucin
  • a typical nuclei
  • mucin globules present
20
Q

what is the histology of adenocarcinomas?

A
  • peripheral
  • glandular differentiation
  • extracthoracic differentiation
21
Q

what are the two pathways for development of adenocarcinomas?

A
  • smokers :
    k ras mutation
  • non smokers :
    EGFR mutation
22
Q

why is it important to identify the specific pathway?

A
  • k ras mutation does not respond to targeted therapy
  • EGFR mutation will respond to targeted therapy if it is a RESPONDER mutation
  • it will not work with resistance mutations

-

23
Q

what is large cell carcinoma?

A
  • poorly differentiated tumours consisting of large cells

- they are just poorly differentiated versions of adenocarcinomas or squamous cell carcinoma

24
Q

what is the cytology of small cell carcinomas?

A
  • this is the worst form of lung cancer

- just consists of nuclei and s tiny amount

25
Q

what is the histology of the small cell carcinoma?

A
  • often central near the bronchi
  • associated with smoking
  • lots of mitosis
  • tumour often outgrows its blood supply and becomes necrotic
26
Q

what is the importance of the histological tumour type?

small cell or non small cell?

A
  • small cell = use chemoradiotherapy

- non small cell = use surgery as it has not spread yet

27
Q

what are some predictors of response to conventional chemotherapy ?

eg ERCC1

A
  • this marker responds to cisplatin
  • ERCC1 positive tumours have a poor response to cisplatin therapy
  • so this can help us choose what drug to use
28
Q

how does the epidermal growth factor receptor help as a target of treatment?

A
  • EGFR
  • makes the cells divide
  • you can get a mutation of the EGFR
  • EGFR is a type of membrane receptor tyrosine kinase
  • it regulates angiotensin
  • proliferation
  • apoptosis
  • migration
  • EGFR is also the target of a tyrosine kinase inhibitor
29
Q

what are the local effects of a bronchogenic carcinoma ?

A
  • causes bronchial obstruction
  • leads to collapse of the distal lung
  • impaired drainage of the bronchus
30
Q

what happens when the lung cancer invades local structures?

A
invasion of local airways 
- haemoptysis 
invasion around large vessels 
- oedema due to superior vena cava syndrome 
-
31
Q

what happens when the lung cancer invades the oesophagus

A

dysphagia

32
Q

what happens when the lung cancer invades the chest wall?

A

pain

33
Q

what happens when the lung cancer invades nerves?

A

horners syndrome

34
Q

what happens when the lung cancer extends through pleua or pericardium?

A
  • breathlessness

- poor prognostic

35
Q

what are the systemic effects of bronchogenic carcinoma?

A
  • brain (fits)
  • skin ( lumps)
  • liver ( liver pain)
  • bone ( bone pain and fracture)
36
Q

what is the paraneoplastic syndrome?

A
  • it is the systemic effect of the tumour due to abnormal expression by tumour cells of factors (like hormones)
37
Q

what are paraneoplasmic syndromes that are endocrine?

A
  • ADH - extra ADH = hyponatremia (low sodium)
  • ACTH = cushings
  • parathyroid issues = hypercalcemia
38
Q

what is the aetiology of malignant pleural tumours?

A
  • due to asbestos
39
Q

what is the prognosis for malignant pleural tumours?

A
  • very fatal
  • more common in men
  • long lag time