1. Chest p66-77 (Diseases of Interstitial Lung (Cystic lung disease, Pneumoconioses, ILDs))

Question 1

Pulmonary LCH (Langerhans Cell Histiocytosis) - progression (3)

Answer 1

Starts with centrilobular nodules w/upper lobe predominance,
Nodules cavitate into cysts, from thin to thick walled.
“Bizzare shaped cysts” when multiple cysts merge together.

Question 2

Pulmonary LCH - Trivia (3)

Answer 2

Half of cases resolve spontaneously (if you stop smoking).
Spares costophrenic angles.
Affects smokers in 20s-30s.

Question 3

What spares the costophrenic angles? (2)

Answer 3

LCH
Hypersensitivity Pneumonitis

Question 4

Lymphangiomyomatosis (LAM) - trivia (2)

Answer 4

Seen in women of child-bearing age (oestrogen dependent)
Associated with tuberous sclerosis.

Question 5

LAM - anatomy (2)

Answer 5

Thin walled cysts, uniform distribution.
Association with chylothorax.

Question 6

LAM - Rx/prognosis

Answer 6

Usually progressive, despite hormonal therapy (tamoxifen)

Question 7

Birt Hogg Dube - features

Answer 7

Thin walled, oval cysts.

Question 8

Birt Hogg Dube - trivia (2)

Answer 8

Associated with renal findings (bilateral oncocytomas, chromophobe RCCs).
Associated with skin findings.

Question 9

Lung cysts - comparison (3)

Answer 9

LCH: Bizzare shape, thick walled
LAM: Round, thin walled
BHD: Oval, thin walled

Question 10

Lymphocytic Interstitial Pneumonitis (LIP) - Features (3)

Answer 10

Benign lymphoproliferative disorder with lung infiltration.
Cysts usually thin walled, deep within the lung parenchyma, predominantly Sjogrens.
Other causes have ground glass or nodules

Question 11

LIP - trivia (2)

Answer 11

Associated with autoimmune diseases (Sjogrens, SLE, RA).
Associated with HIV (kids)

Question 12

PCP - trivia

Answer 12

Commonest opportunistic infection in AIDS

Question 13

PCP - imaging (4)

Answer 13

Ground glass appearance, predominantly hilar and mid-lung zones.
Pneumatoceles present in 30%.
Cystic form is more common when receiving aerosolized prophylaxis (b/l thin walled cysts, predominantly upper lung).
Gallium positive (diffuse uptake), Thallium negative.

Question 14

AIDS + Ground Glass Lungs

Answer 14

PCP

Question 15

Emphysema - definition (3)

Answer 15

Permanent enlargement of airspaces distal to terminal bronchioles,
accompanied by alveolar wall destruction,
without clear fibrosis

Question 16

Emphysema - Imaging (CXR) (5)

Answer 16

Often only indirect signs on CXR until very bad.
Flattening of hemidiaphragm considered most reliable sign.
AP diameter increases.
Retrosternal clear space becomes larger.
Paucity of, or pruning of blood vessels

Question 17

Emphysema - Types

Answer 17

Centrilobular.
Pan-lobular.
Para-septal.

Question 18

Centrilobular emphysema - trivia (3)

Answer 18

By far most common.
Common in asymptomatic elderly.
Associated with smoking.

Question 19

Centrilobular emphysema - imaging (3)

Answer 19

Apical to basal gradient (favour upper zones).
Focal lucency centrally within secondary pulmonary lobule, with central dot representing bronchovascular bundle (Central Dot Sign is buzzword).

Question 20

Pan-lobular emphysema - imaging (2)

Answer 20

Favours lower lobes.
More uniform distribution through the secondary pulmonary lobule.

Question 21

Pan-lobular emphysema - trivia (3)

Answer 21

Associated with alpha-1 antitrypsin deficiency.
Associated with Ritalin.
Patients present in 60s-70s (earlier if smoker)

Question 22

Para-septal emphysema - imaging (4)

Answer 22

Adjacent to pleura and septal lines.
Peripheral distribution within the secondary lobule.
Small focal lucencies up to 10mm.
Looks like honeycombing but less than 3 layers.

Question 23

Saber sheath trachea (2)

Answer 23

Diffuse coronal narrowing of the trachea, sparing extrathoracic portion.
Pathognomonic for COPD.

Question 24

Main PA larger than Aorta associated with.. (2)

Answer 24

Associated with worse outcomes in COPD.
Pulmonary HTN caused by emphysema.

Question 25

Vanishing lung syndrome - features (4)

Answer 25

Idiopathic cause of giant bullous emphysema. Results from avascular necrosis of lung parenchyma and hyperinflation. Defined as bullous disease occupying at least 1/3 hemithorax. Favours upper lobes

Question 26

Vanishing Lung syndrome - trivia (2)

Answer 26

Commonest in younger men. 20% have alpha-1-antitrypsin deficiency.

Question 27

Compensatory emphysema (3)

Answer 27

aka pneumonectomy syndrome Expansion of one lung to compensate for absence of other. No destructive process

Question 28

Honeycomb lung (3)

Answer 28

Most commonly associated with UIP. Other end stage fibrotic diseases can cause it. Subpleural thick walled cysts, tightly clustered (2-3 rows thick).

Question 29

Asbestosis - definition

Answer 29

Refers to changes of pulmonary fibrosis.

Question 30

Asbestosis - features (4)

Answer 30

Looks similar to UIP. Parietal pleural thickening (most important differentiator from IPF. 20 year lag between expsure and lung cancer or mesothelioma. Benign pleural effusions are earliest feature, still 5 year lag

Question 31

Asbestosis - associations (5)

Answer 31

Associated with extrapulmonary cancer including: - Peritoneal mesothelioma - GI cancer - Renal cancer - Laryngeal cancer - Leukaemia

Question 32

Benign asbestos related changes (4)

Answer 32

Pleural effusion is earliest and most common (5 years). Pleural plaques after 20-30 years, calcified at 40. Plaques tend to spare apices and costophrenic angles. Round atelectasis, associated with pleural findings, a.k.a. asbestos pseudotumor.

Question 33

Malignant mesothelioma - trivia (3)

Answer 33

Commonest pleural cancer. 80% had asbestos exposure. NOT dose dependent. 30-40 year lag time.

Question 34

Malignant mesothelioma - features (2)

Answer 34

Buzzword "Pleural Rind". Tendency for direct invasion. Extension into fissure is highly suggestive.

Question 35

Silicosis - association (2)

Answer 35

Seen in miners and quarry workers. Triples risk of TB (consider if cavitations)

Question 36

Silicosis - types (2)

Answer 36

Simple. PMF - Progressive Massive Fibrosis

Question 37

Simple silicosis - features (3)

Answer 37

Multiple nodular opacities, favouring upper lobes. Egg shell calcifications of hilar nodes. Perilymphatic nodules.

Question 38

PMF - features (4)

Answer 38

Large masses in upper lobes with radiating strands. Masses are T2 dark (T2 bright suggests cancer) Also seen in coal workers pneumoconiosis. Masses can cavitate - consider TB

Question 39

Coal workers pneumoconiosis - association

Answer 39

Exposure to washed coal.

Question 40

Coal workers pneumoconiosis - features (3)

Answer 40

Simple and complex forms, like silicosis. Simple: multiple nodular opacities, with calcifications showing a central nodular dot. Small nodules tend to be perilymphatic. Complex: Complicated: PMF similar to silicosis.

Question 41

Berryliosis - cause/features (4)

Answer 41

Caused by metal used in aircraft/space industries. - Generalised granulomatous disease - hilar adenopathy - upper lobe predominant reticular opacities

Question 42

Silo Filler's disease - cause/features (2)

Answer 42

Caused by Nitrogen Dioxide - Pulmonary oedema pattern, typically recovers within 5 weeks.

Question 43

Talcosis - cause/features (3)

Answer 43

Filler in tablets, sometimes injected (along with drugs) in IVDU. - Hyperdense micronodules, with conglomerate masses (similar to PMF). - Ground glass opacities.

Question 44

Consolidation - definition

Answer 44

Density that obscured underlying vessels

Question 45

Ground glass opacity - definition

Answer 45

Density NOT obscuring underlying vessels

Question 46

Secondary pulmonary lobule - definition (4)

Answer 46

- Basic unit of pulmonary structure and function. - Smallest part of lung surrounded by connective tissue. - Centre contains terminal bronchiole and accompanying artery. - Periphery contains vein and lymphatics.

Question 47

Nodule distribution types (3)

Answer 47

- Pleural nodules w/subpleural and peribronchovascular predominance = perilymphatic - Pleural nodules with no predominance = random - No pleural nodules = centrilobular

Question 48

Perilymphatic nodules DDx (3)

Answer 48

Sarcoid (90%) Lymphangitis spread of Ca Silicosis

Question 49

Random nodules DDx (3)

Answer 49

Miliary TB Mets Fungal

Question 50

Centrilobular nodules DDx (3)

Answer 50

Infection RB-ILD Hypersensitivity pneumonitis (ground glass)

Question 51

Interlobular septal thickening - definition (3)

Answer 51

Reticular abnormality outlining the lobules, characteristic shape and size (~2cm). Can be due to pulmonary oedema (smooth, symmetric) or lymphangitis spread of neoplasm (asymmetric and nodular). Kerley B lines are plain film equivalent.

Question 52

Honeycombing - definition (3)

Answer 52

Cystic areas of lung destruction, subpleural. Hallmark of UIP. Paraseptal emphysema can mimic, but consists of only 1 row of bubbles. 2-3 rows = honeycombing.

Question 53

Idiopathic interstitial pneumonitis - features (3)

Answer 53

Not diseases, but lung reactions to lung injury. Variety of patterns and degrees of inflammation and fibrosis. Many causes, for exam purposes, either UIP or not UIP.

Question 54

UIP vs other ILDs (prognosis/Rx)

Answer 54

Not UIP will get better with steroids. often does OK. UIP won't improve with steroids, terrible prognosis.

Question 55

UIP - trivia (2)

Answer 55

Commonest ILD. When cause is idiopathic, termed IPF.

Question 56

UIP - imaging (2)

Answer 56

Reduced lung volume. Reticular pattern in posterior costophrenic angle is first finding on CXR.

Question 57

UIP - buzzwords (4)

Answer 57

Apical to Basal gradient (worse in lower lobes). Traction bronchiectasis (and honeycombing). Honeycombing seen 70% of the time. Histology is Heterogenous

Question 58

End stage lung disease

Answer 58

All look the same once disease has ruined the lungs, except honeycombing is rare in end stage sarcoid.

Question 59

NSIP (Non-specific Interstitial Pneumonia) - trivia (4)

Answer 59

Less common than UIP. Commonest ILD in scleroderma. A specific entity, not actually non-specific. Homogenous inflammation or fibrosis on histology (UIP is heterogenous). Associated with collagen vascular disease & drug reactions.

Question 60

NSIP - types/DDx (4)

Answer 60

Cellular or Fibrotic. Ground glass alone = Cellular Ground glass + reticulation = Cellular or Fibrotic Reticulation and traction bronchiectasis = Fibrotic

Question 61

NSIP - features (3)

Answer 61

Predominance for lower lobe, posterior and peripheral. Sparing of subpleural lung in up to 50%. Ground glass is the NSIP equivalent of honeycombing in UIP.

Question 62

RB-ILD - features (4)

Answer 62

Respiratory Bronchiolitis + symptoms = RB-ILD. Apical centrilobular ground glass nodules. Tends to involve entire cross section of lung. Associated with smoking.

Question 63

DIP - features

Answer 63

Thought of as end-spectrum RB-ILD. Peripheral lower lobe predominant ground glass, with small cystic spaces. More diffuse GGO with patchy or subpleural distribution.