07 Respiratory Pathology

Question 1

How does lung cancer arise

Answer 1

Genetic predisposition
Smoking
Asbestos
Radiation
Heavy metals

Question 2

Describe the multistep process of carcinoma development

Answer 2

Disordered growth
Loss of cell adhesion
Invasion of tissue by tumour
Angiogenesis

Question 3

State common malignant epithelial tumours of lung

Answer 3

Non-cell carcinoma - 80%
- squamous cells carcinoma (20-40%)
- adenocarcinoma (20-40%)
- large cell carcinoma (uncommon)
Small cell carcinoma - 20%

Question 4

Describe the development process in squamous cell carcinoma

Answer 4

Normal -> hyperplasia -> metaplasia -> dysplasia -> carcinoma in situ -> invasive carcinoma

Question 5

Describe the cytology of squamous cell carcinoma

Answer 5

Large nucleus

Keratin cytoplasm

Question 6

What is the origin of adenomatous development

Answer 6

Atypical adenomatous hyperplasia

Question 7

What are the two different molecular pathways associated with adenocarcinoma

Answer 7

Smoker: Kras

Non-smoker: EGFR

Question 8

Compare squamous cell carcinoma and adenocarcinoma in terms of the 1) target population, 2) trend of incidences, 3) location of origin, 4) cytological characteristics, 5) metastasis

Answer 8

Squamous cell carcinoma vs adenocarcinoma

1) smokers vs non-smokers
2) decreasing vs increasing
3) central (mediastinal) vs peripheral
4) large nucleus and keratin cytoplasm vs atypical adenomatous hyperplasia
5) Local spread before metastasis vs metastasise early with elastases to degrade basement membrane and elastin

Question 9

What is the prognosis of large cell carcinoma

Answer 9

Poor

Question 10

Where does small cell carcinoma normally arise. What is its prognosis and why.

Answer 10

Central - usually near bronchi

Poor prognosis because they divide very fast

Question 11

What is the characteristics of small cell carcinoma

Answer 11

Small cell with virtually only a nucleus (cytoplasm cannot be seen)

Question 12

Why is chemoradiotherapy usually not used for patients with small cell carcinoma

Answer 12

Although patients with small cell carcinoma are chemosensitive, patients diagnosed with it usually have spread

Question 13

True or false: non-small cell carcinoma is usually chemosensitive

Answer 13

False

Question 14

What does EGFR do and what drug can target it

Answer 14

It’s a tyrosine kinase and responsible for:

1) angiogenesis
2) apoptosis
3) proliferation
4) migration

Gefitinib

Question 15

Where can samples be extracted to assess cytological features of lung cancer

Answer 15

Sputum
Bronchial lavage
Pleural fluid

Question 16

Describe TNM staging system

Answer 16

It is a measure of how advanced a tumour is

• Tumour: 1-4, is a measure of location, size and proximity to other orans
• Lymph node metastasis: 0-3, number of lymph nodes involved in this tumour
• Metastasis: 0-1, whether the tumour has metastasised or not

Question 17

What is the cytological features of adenocarcinoma

Answer 17

Glandular differentiation and have big atypical nuclei and mucin granules