Pathology of Lung Cancer Flashcards
What are common symptoms of lung cancer?
Haemoptysis
Cough
Chest/Shoulder Pain
How can samples be acquired for cytological analysis?
Bronchial brushing, lavage, pleural fluid
What are some features of benign tumours?
Grow more slowly
Do NOT metastasis
Do NOT invade adjacent tissues
What are the three types of non-small cell carcinoma? What percentage of lung cancers are non-small cell?
Non-Small Cell = 80%
Squamous cell carcinoma
Adenocarcinoma
Large cell carcinoma
How are the incidences of squamous cell carcinoma and adenocarcinoma changing?
Squamous cell carcinoma incidence is decreasing
Adenocarcinoma incidence is increasing
Where do squamous cell carcinomas and adenocarcinomas tend to arise?
Squamous cell carcinoma tends to arise near the mediastinum
Adenocarcinoma tends to arise near the periphery
State three major risk factors for lung cancer.
Smoking, Radiation, Asbestos Exposure
What are the four stages in the pathway to carcinoma?
Metaplasia - Dysplasia - Carcinoma in situ - Invasive Carcinoma
Why has a precursor lesion for small cell lung carcinoma not been found?
Because small cell carcinoma grows too quickly and it metastasises early
How do the cells lining the airways change in squamous cell carcinoma?
The ciliated cells undergo metaplasia due to the chronic stimulation by cigarette smoke to become squamous cells
Which type of lung cancer is common in non-smokers?
Adenocarcinoma
Which types of lung caner are strongly associated with smoking?
Small cell carcinoma
Squamous cell carcinoma
Describe the cytological features of squamous cell carcinoma.
Large Nuclei
Keratin in cytoplasm
What is the precursor lesion for adenocarcinoma?
Atypical Adenomatous Hyperplasia
At what point does adenocarcinoma in situ become invasive adenocarcinoma?
When the cells develop a mutation so that they can break down the stroma and become invasive. The breaking down of the stroma causes inflammation and leads to the formation of fibrous tissue.
Describe the cytological features of adenocarcinoma.
Adenocarcinoma shows glandular differentiation. They have big atypical nuclei with mucin globules
Where does adenocarcinoma usually develop and are they usually multi-focal?
Adenocarcinoma normally develops near the periphery and they ARE usually multi-focal
What are the two molecular pathways for adenocarcinoma and which one is associated with smoking?
K ras - associated with smoking
EGFR - responder or resistance mutations
Why is it important to differentiate between the different pathways?
K ras mutation means that it is unlikely to respond to targeted therapies
EGFR responder mutation could mean that the patient has an almost complete regression even in very advanced disease.
What is large cell carcinoma?
POORLY differentiated carcinoma - has a poor prognosis
Electron microscopy shows some evidence of squamous/neuroendocrine differentiation suggesting that they could be very poorly differentiated squamous cell carcinoma or adenocarcinoma
What are the cytological features of small cell carcinoma?
They look like lymphocytes. Large nucleus and little cytoplasm.
Where does small cell carcinoma tend to arise?
Often arise central near the bronchi
What does the ERCC1 marker determine?
ERCC1 positive means that advanced non-small cell lung cancer is unlikely to respond to cisplatin
What type of receptor is EGFR and what is used to block this receptor?
Tyrosine kinase receptor - tyrosine kinase inhibitors work against this
What are paraneoplastic syndromes?
Systemic effect of tumour due to abnormal expression by tumour cells of factors (e.g. hormones) NOT normally expressed by the tissue from which the tumour arose
State some endocrine paraneoplastic syndromes.
SIADH (inappropriate ADH)
Cushing’s Syndrome (producing ectopic ACTH)
What is strongly associated with mesothelioma?
Asbestos
