Lung Pathology

Question 1

Pathogenesis of asthma

Answer 1

 Sensitisation to allergen; followed by…
 Immediate phase = mast cell degranulation  mediator release  inc. vascular permeability, eosinophil and mast cell recruitment and bronchospasm
 Late phase = tissue damage, increased mucous production, muscle hypertrophy

Question 2

Histology of asthma

Answer 2

Hyperaemia
 [Top right] Eosinophils and goblet cell hyperplasia
 Hypertrophic constricted muscle
 Mucus plugging and inflammation

Question 3

Histology of COPD

Answer 3

 Dilatation of airways
 Hypertrophy of mucous glands
 Goblet cell hyperplasia

Question 4

Causes of bronchiectasis

Answer 4

 Congenital (CF, ciliary dyskinesia

 Inflammatory (post-infectious, obstruction, 2nd to bronchiolar disease and interstitial fibrosis, asthma)

Question 5

Histoogy of pulmonary oedema

Answer 5

 Intra-alveolar fluid on histology

 “Heart failure cells” = iron-laden macrophages (right)

Question 6

Pathology of ARDS

Answer 6

1. Capillary congestion
2. Exudative phase
3. Hyaline membranes
4. Organising phase

Question 7

Bronchopneumonia pathology

Answer 7

Patchy bronchial and peribronchial distribution, lower lobes, inflammation surrounding the airways themselves and is within the alveoli

Question 8

Lobar pneumonia pathology

Answer 8

• (1) Congestion Hyperaemia, Intra-alveolar fluid
• (2) Red hepatization Hyperaemia, Intra-alveolar neutrophils (non-atypical)
• (3) Grey hepatization (looks like liver) Intra-alveolar connective tissue
• (4) Resolution Restoration normal architecture

90-95% pneumococci (i.e. strep)

Question 9

Inflammation in atypical pneumonias

Answer 9

 Interstitial inflammation without the accumulation of intra-alveolar inflammatory cells

Question 10

Pathogenesis of emphysema

Answer 10

Cigarette smoke inhibits A1AT- causes proteases to degrade the tissue causing permanent loss of alveolar parenchyma distal to terminal bronchiole

Question 11

Causes of granuloma

Answer 11

TB, sarcoidosis, FB aspiration

Question 12

Sarcoidosis lung involvement

Answer 12

 discrete epithelioid and giant cell granulomas, preferential distribution in upper zones with a tendency to peri-lymphatic and peri-bronchial  advanced disease becomes fibrocystic

Question 13

Diagnosis of sarcoidosis

Answer 13

non-caseating granuloma, elevated serum ACE, hypercalcaemia (1a-hydroxylase)

Question 14

Types of fibrosis interstitial lung disease

Answer 14

Idiopathathic pulmonary fibrosis
Extrinsic allergic alveolitis
Pneumoconiosis

Question 15

IPF pathology

Answer 15

• Macro = basal and peripheral fibrosis and cyst formation

* Micro = interstitial fibrosis (varying stages)

Question 16

Diagnosis of IPF

Answer 16

 HR-CT ± biopsy diagnosis

Question 17

Which lung cancers are associated with smoking

Answer 17

Squamous cell carcinoma
Small cell carcinoma
Large cell

Question 18

Which lung cancer is not associated with smoking

Answer 18

Adenocarcnioma

Question 19

Features of Squamous CC

Answer 19

 Centrally located arising from bronchial epithelium  spread locally  metastasise late

Question 20

Features of adenocarcinoma

Answer 20

o	Peripheral (terminal airways) with multi-centric pattern 
o	Precursor lesion: atypical adenomatous hyperplasia 

 In smokers, the main mutations are K-ras, issues with DNA methylation and p53
 In non-smokers, EGFR mutations are very important (these are drug targets)

o Extra-thoracic metastases are COMMON and occur EARLY (80% present with metastases

Question 21

Histology of adenocarcinoma

Answer 21

 Gland formation
 Papillae formation
 Mucin

Question 22

Histology of large cell carcinoma

Answer 22

o Poorly differentiated tumours composed of large cells

Question 23

Features of small cell carcinoma

Answer 23

 Often CENTRAL and near the bronchi
 80% will present with advanced disease  very chemosensitive but VERY POOR PROGNOSIS
 May cause paraneoplastic syndromes (i.e. SIADH)

Question 24

Histology of small CC

Answer 24

	Small poorly differentiated cells 
	Common mutations: p53, RB1
o	Cytology:
	Small cells
	Ciliated normal respiratory cell

Question 25

Adenocarcinoma molecular targets

Answer 25

• EGFR mutation (responder or resistance)
• ALK translocation responds to Crizotinib
• Ros1 translocatio

Question 26

Paraneoplastic conditions associated with lung cancer

Answer 26

ADH, ACTH, PTH