Pathology of Restrictive Lung Diseases

Question 1

What is the interstitium of the lung?

Answer 1

The connective space around the airways and vessels. Also the space between the basement membranes of the alveolar walls

Question 2

What are the effects of interstitial lung disease on FEV1 and FVC?

Answer 2

Low FEV1
Low FVC
Ratio is normal

Question 3

What happens to lung compliance in restrictive lung disease?

Answer 3

Reduced so stiff lungs

Question 4

What happens to gas transfer in restrictive lung disease?

Answer 4

Reduced due to diffusion abnormality
Is the main cause of hypoxia

Question 5

What happens to ventilation/perfusion in restrictive lung disease?

Answer 5

There is a ventilation/perfusion imbalance when small airways affected by pathology

Question 6

What is the presentation of restrictive lung disease?

Answer 6

Dyspnoea on exertion and at rest when disease progresses
Discovery of abnormal CXR or CT scan

Question 7

What can restrictive lung disease lead to?

Answer 7

Respiratory failure type 1
Heart failure

Question 8

What is the signs of restrictive lung disease on CXR?

Answer 8

Reduced lung volume and increased lung markings

Question 9

What is the acute response to parenchymal lung injury?

Answer 9

Diffuse Alveolar Damage (DAD) or known as ARDS or shock lung

Question 10

What is diffuse alveolar damage associated to?

Answer 10

Major trauma, chemical injury, circulatory shock, drugs, infection, autoimmune disease and radiation
Idiopathic

Question 11

What viruses is diffuse alveolar damage associated to?

Answer 11

Influenza
SARS Cov1
SARS Cov2

Question 12

Explain the evolution of DADs

Answer 12

It is a modified acute inflammatory response
There is involvement of immune tissue damage
Has exudative and proliferation stage

Question 13

What are the histological features of DADs?

Answer 13

Protein rich oedema, fibrin, hyaline membranes and denuded basement membranes
Alveoli is filled with fluid and surrounded by proteins with fibrin making gas exchange harder

Question 14

What type of proliferation occurs in DADs?

Answer 14

Epithelial and fibroblast

Question 15

What is the result of DADs histologically?

Answer 15

Scarring of interstitium and airspaces so gives solid lung

Question 16

What are some chronic responses to parenchymal lung injury?

Answer 16

Usual interstitial pneumonitis (UIP), granulomatous responses and other patterns

Question 17

What is sarcoidosis?

Answer 17

A multisystem granulomatous disorder of unknow aetiology

Question 18

What is the histopathology of sarcoidosis?

Answer 18

Epithelioid and giant cell granulomas
Necrosis/ caseation is very unusual
Little lymphoid infiltrate and variable associated fibrosis

Question 19

What is the presentation of sarcoidosis?

Answer 19

Young adult - acute arthralgia, erythema nodosum and bilateral hilar lymphadenopathy
SOB, cough and abnormal CXR

Question 20

What is the treatment for sarcoidosis?

Answer 20

Most resolve after 2 years
Some may resolve, persist or progress so may need corticosteroids

Question 21

What is used to diagnose a patient with sarcoidosis?

Answer 21

Clinical findings, imaging findings, serum Ca++ and ACE, and biopsy

Question 22

What is hypersensitivity pneumonitis?

Answer 22

Patient is exposed to sensitive antigen by inhalation
Is due to immunological makeup

Question 23

What can cause hypersensitivity pneumonitis?

Answer 23

Thermophilic actinomycetes, bird/ animal proteins, fungi, chemical and others

Question 24

What is the presentation of acute hypersensitivity pneumonitis?

Answer 24

Fever, dry cough and myalgia
Chills after exposure
Crackles, tachypnoea and wheeze

Question 25

What are the presentation for chronic hypersensitivity pneumonitis?

Answer 25

Insidious - not aware of antigen exposure
Malaise, SOB and cough
Low grade illness
Crackles and wheeze

Question 26

Explain the histopathology of hypersensitivity pneumonitis?

Answer 26

Soft centriacinar epithelioid granulomata
Foamy histocytes, interstitial pneumonitis and lymphocytes around granuloma

Question 27

What immune complex mediated reactions happen in hypersensitivity pneumonitis?

Answer 27

Type 3 and 4
3 - chronic inflammation
4 - granulomas

Question 28

What zone does hypersensitivity pneumonitis usually effect?

Answer 28

Upper zone disease - where the fibrosis usually seen

Question 29

What is a usual interstitial pneumonitis UIP?

Answer 29

Idiopathic Pulmonary Fibrosis

Question 30

Which chronic response has the most chance of end stage honeycomb lung/ fibrosis?

Answer 30

Usual interstitial pneumonitis UIP

Question 31

When might usual interstitial pneumonitis be seen?

Answer 31

Connective tissue diseases, drug reaction, post infection and industrial exposure - asbestos
Most are idiopathic

Question 32

Explain the histopathology of UIP?

Answer 32

Patchy interstitial chronic inflammation and type 2 pneumocyte hyperplasia
Smooth muscle and vascular proliferation
Fibroblastic Foci

Question 33

What is temporal and spatial heterogenicity of UIP?

Answer 33

Temporal - can see all stages of lung in different places
Spatial - some affected and some of lung not

Question 34

What is the clinic presentation of idiopathic pulmonary fibrosis?

Answer 34

Dyspnoea, cough
Basal crackles, cyanosis and clubbing

Question 35

What is the prognosis for idiopathic pulmonary fibrosis?

Answer 35

Some are steroid responsive
Poor prognosis as irreversible

Question 36

What is seen on the lung when a patient has UIP?

Answer 36

Basal and posterior fibrosis with honeycombing

Question 37

What is the risk of fibrotic conditions?

Answer 37

Causing lung cancer