Respiratory Pathology

Question 1

What is bronchiectasis?

Answer 1

Chronic disorder characterised by permanent dilatation of the bronchi and inflammatory changes in their walls and in adjacent lung parenchyma

Question 2

Describe the pathogenesis of bronchiectasis

Answer 2

Recurrent inflammation of the bronchial walls combined with fibrosis in the surrounding parenchyma leads to traction on weakened walls causing irreversible dilatation

Question 3

List 4 post-inflammatory causes of bronchiectasis

Answer 3

Allergic bronchopulmonary aspergillosis Infection (pneumonia, measles, whooping cough) Congenital (congenital hypogammaglobulinaemia, CF, immotile cilia syndrome) Reactions to inhaled toxic fumes

Question 4

List 5 post-obstructive causes of bronchiectasis

Answer 4

Neoplasm Foreign body Inspissated mucus (in asthma) External compression (by e.g. hilar LNs, aortic aneurysm) Rarely bronchial webs or atresia

Question 5

What is the most common cause of lung abscess?

Answer 5

Aspiration

Question 6

What disease process is most often associated with lung abscess?

Answer 6

Bacterial pneumonia

Question 7

What 3 factors are associated with aspiration?

Answer 7

Altered consciousness (e.g. in alcoholics)

Poor dental hygiene

Immune suppression

Question 8

What bacteria are commonly found in lung abscesses?

Answer 8

Anaerobic

Question 9

List 5 other associations of lung abscess

Answer 9

Pulmonary infarcts

Malignancies

Penetrating trauma

Necrotising pneumonias

Bronchial obstruction

Question 10

Why does lung abscess occur mostly in the right lung?

Answer 10

Because the right bronchus is more vertical

Question 11

List 4 important risk factors for lung cancer

Answer 11

Smoking

Occupational hazards

Scarring

Question 12

What level of smoking places you at 20x risk of lung cancer?

Answer 12

>40 cigarettes/day for several years

Question 13

List 5 occupational hazards which may increase risk of lung cancer

Answer 13

Asbestos

Crystalline silica

Radon

Polycyclic aromatic hydrocarbons

Heavy metals

Question 14

Correlate the clinical presentation of lung cancers with their anatomical location

Answer 14

Centrally located: cough, dyspnoea, weakness

Question 15

Correlate the anatomical location of lung cancers with its probable type

Answer 15

Distal: more often adenoma

Proximal: more often squamous or small cell

Question 16

How can tissue sampling be achieved for a centrally located tumor?

Answer 16

Sputum

Bronchial washings/brushings

EBUS-TBNA (endobronchial U/S transbronchial needle aspirate)

Bronchial biopsy

Question 17

How can tissue sampling be achieved for a peripherally located tumour?

Answer 17

FNA (CT-guided, ENB - electromagnetic navigation bronchoscopy-guided)

Pleural biopsy

Question 18

List the 5 types of non-small cell carcinoma

Answer 18

Squamous cell carcinoma

Adenocarcinoma

Adenosquamous carcinoma

Large cell carcinoma

Sarcomatoid carcinoma

Question 19

Does squamous cell carcinoma tend to be central or peripheral?

Answer 19

Central with frequent involvement of large airways

Question 20

What are the histological criteria for diagnosis of a squamous cell carcinoma?

Answer 20

Intercellular bridges

Keratinisation

If features not obvious due to poor differentiation, immunohistochemical staining may be required

Question 21

How does squamous cell carcinoma usually appear macroscopically?

Answer 21

Grey-white to yellow, often with a dry flaky appearance that reflects keratinisation

Necrosis and haemorrhage common, may be cavitation

Question 22

What is the most common type of non-small cell carcinoma?

Answer 22

Adenocarcinoma

Question 23

Describe the typical anatomical location of adenocarcinoma

Answer 23

Generally peripheral and well-circumscribed

Most unrelated to bronchi

May have pleural involvement

Question 24

Describe the macroscopic appearance of adenocarcinoma

Answer 24

Grey-white with necrosis and haemorrhage

Mucoid appearance in tumours with extensive mucin production

Question 25

Can adenocarcinoma be diagnosed on cytology? What is the advantage of this? What is the disadvantage?

Answer 25

Yes, usually Cheap, low complications However often histo is done as this gives more reliable tissue for molecular testing, which most adenocarcinomas undergo

Question 26

What histological features are characteristic of adenocarcinoma?

Answer 26

Well to moderately differentiated tumour with glandular and/or papillary structures Cytoplasmic mucinous vacuoles or mucin extending into stroma

Question 27

What is adenocarcinoma-in-situ?

Answer 27

Adenocarcinoma showing growth of neoplastic cells along pre-existing alveolar structures (lepidic growth), with no evidence of stromal, vascular or pleural invasion

Question 28

What is the prognosis of adenocarcinoma-in-situ/bronchiolo-alveolar carcinoma (BAC)?

Answer 28

Solitary BAC

Question 29

Describe the typical anatomical presentation of adenocarcinoma-in-situ

Answer 29

Well-demarcated single or multiple nodules "Pneumonic" pattern with involvement of whole lobe

Question 30

In what clinical scenario should adenocarcinoma-in-situ be considered?

Answer 30

Non-resolving consolidation/pneumonia

Question 31

What are the 3 histo subtypes of adenocarcinoma-in-situ, in order from most to least common?

Answer 31

Non-mucinous Mucinous Mixed mucinous and non-mucinous

Question 32

What line of differentiation does small cell carcinoma show?

Answer 32

Neuroendocrine

Question 33

List 8 complications of lung cancer

Answer 33

Lipid pneumonia distal to obstructing tumour (due to build-up of surfactant) Atelectasis Bronchitis Bronchiectasis Cavitation and abscess formation Fistula formation Pleuritis, pleural effusion Vascular thrombosis

Question 34

What are the 4 most common sites of distal metastases for lung cancer (from most to least common)?

Answer 34

Adrenals Liver Brain Bone

Question 35

What are the 4 most common types of cancer metastasising to the lungs?

Answer 35

Breast Lower GIT Melanoma RCC

Question 36

Describe the typical anatomical presentation of small cell carcinoma

Answer 36

Rapidly growing mass often with local obstruction (e.g. major bronchi, SVC) Often regional LN or distant metastases at initial presentation