1. Chest p66-77 (Diseases of Interstitial Lung (Cystic lung disease, Pneumoconioses, ILDs)) Flashcards
Pulmonary LCH (Langerhans Cell Histiocytosis) - progression (3)
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.
Pulmonary LCH - Trivia (3)
Half of cases resolve spontaneously (if you stop smoking).
Spares costophrenic angles.
Affects smokers in 20s-30s.
What spares the costophrenic angles? (2)
LCH
Hypersensitivity Pneumonitis
Lymphangiomyomatosis (LAM) - trivia (2)
Seen in women of child-bearing age (oestrogen dependent)
Associated with tuberous sclerosis.
LAM - anatomy (2)
Thin walled cysts, uniform distribution.
Association with chylothorax.
LAM - Rx/prognosis
Usually progressive, despite hormonal therapy (tamoxifen)
Birt Hogg Dube - features
Thin walled, oval cysts.
Birt Hogg Dube - trivia (2)
Associated with renal findings (bilateral oncocytomas, chromophobe RCCs).
Associated with skin findings.
Lung cysts - comparison (3)
LCH: Bizzare shape, thick walled
LAM: Round, thin walled
BHD: Oval, thin walled
Lymphocytic Interstitial Pneumonitis (LIP) - Features (3)
Benign lymphoproliferative disorder with lung infiltration.
Cysts usually thin walled, deep within the lung parenchyma, predominantly Sjogrens.
Other causes have ground glass or nodules
LIP - trivia (2)
Associated with autoimmune diseases (Sjogrens, SLE, RA).
Associated with HIV (kids)
PCP - trivia
Commonest opportunistic infection in AIDS
PCP - imaging (4)
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.
AIDS + Ground Glass Lungs
PCP
Emphysema - definition (3)
Permanent enlargement of airspaces distal to terminal bronchioles,
accompanied by alveolar wall destruction,
without clear fibrosis
Emphysema - Imaging (CXR) (5)
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
Emphysema - Types
Centrilobular.
Pan-lobular.
Para-septal.
Centrilobular emphysema - trivia (3)
By far most common.
Common in asymptomatic elderly.
Associated with smoking.
Centrilobular emphysema - imaging (3)
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).
Pan-lobular emphysema - imaging (2)
Favours lower lobes.
More uniform distribution through the secondary pulmonary lobule.
Pan-lobular emphysema - trivia (3)
Associated with alpha-1 antitrypsin deficiency.
Associated with Ritalin.
Patients present in 60s-70s (earlier if smoker)
Para-septal emphysema - imaging (4)
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.
Saber sheath trachea (2)
Diffuse coronal narrowing of the trachea, sparing extrathoracic portion.
Pathognomonic for COPD.
Main PA larger than Aorta associated with.. (2)
Associated with worse outcomes in COPD.
Pulmonary HTN caused by emphysema.
Vanishing lung syndrome - features (4)
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
Vanishing Lung syndrome - trivia (2)
Commonest in younger men.
20% have alpha-1-antitrypsin deficiency.
Compensatory emphysema (3)
aka pneumonectomy syndrome
Expansion of one lung to compensate for absence of other.
No destructive process
Honeycomb lung (3)
Most commonly associated with UIP.
Other end stage fibrotic diseases can cause it.
Subpleural thick walled cysts, tightly clustered (2-3 rows thick).
Asbestosis - definition
Refers to changes of pulmonary fibrosis.
Asbestosis - features (4)
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
Asbestosis - associations (5)
Associated with extrapulmonary cancer including:
- Peritoneal mesothelioma
- GI cancer
- Renal cancer
- Laryngeal cancer
- Leukaemia
Benign asbestos related changes (4)
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.
Malignant mesothelioma - trivia (3)
Commonest pleural cancer.
80% had asbestos exposure. NOT dose dependent.
30-40 year lag time.
Malignant mesothelioma - features (2)
Buzzword “Pleural Rind”.
Tendency for direct invasion. Extension into fissure is highly suggestive.
Silicosis - association (2)
Seen in miners and quarry workers.
Triples risk of TB (consider if cavitations)
Silicosis - types (2)
Simple.
PMF - Progressive Massive Fibrosis
Simple silicosis - features (3)
Multiple nodular opacities, favouring upper lobes.
Egg shell calcifications of hilar nodes.
Perilymphatic nodules.
PMF - features (4)
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
Coal workers pneumoconiosis - association
Exposure to washed coal.
Coal workers pneumoconiosis - features (3)
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.
Berryliosis - cause/features (4)
Caused by metal used in aircraft/space industries.
- Generalised granulomatous disease
- hilar adenopathy
- upper lobe predominant reticular opacities
Silo Filler’s disease - cause/features (2)
Caused by Nitrogen Dioxide
- Pulmonary oedema pattern, typically recovers within 5 weeks.
Talcosis - cause/features (3)
Filler in tablets, sometimes injected (along with drugs) in IVDU.
- Hyperdense micronodules, with conglomerate masses (similar to PMF).
- Ground glass opacities.
Consolidation - definition
Density that obscured underlying vessels
Ground glass opacity - definition
Density NOT obscuring underlying vessels
Secondary pulmonary lobule - definition (4)
- 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.
Nodule distribution types (3)
- Pleural nodules w/subpleural and peribronchovascular predominance = perilymphatic
- Pleural nodules with no predominance = random
- No pleural nodules = centrilobular
Perilymphatic nodules DDx (3)
Sarcoid (90%)
Lymphangitis spread of Ca
Silicosis
Random nodules DDx (3)
Miliary TB
Mets
Fungal
Centrilobular nodules DDx (3)
Infection
RB-ILD
Hypersensitivity pneumonitis (ground glass)
Interlobular septal thickening - definition (3)
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.
Honeycombing - definition (3)
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.
Idiopathic interstitial pneumonitis - features (3)
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.
UIP vs other ILDs (prognosis/Rx)
Not UIP will get better with steroids. often does OK.
UIP won’t improve with steroids, terrible prognosis.
UIP - trivia (2)
Commonest ILD.
When cause is idiopathic, termed IPF.
UIP - imaging (2)
Reduced lung volume.
Reticular pattern in posterior costophrenic angle is first finding on CXR.
UIP - buzzwords (4)
Apical to Basal gradient (worse in lower lobes).
Traction bronchiectasis (and honeycombing).
Honeycombing seen 70% of the time.
Histology is Heterogenous
End stage lung disease
All look the same once disease has ruined the lungs, except honeycombing is rare in end stage sarcoid.
NSIP (Non-specific Interstitial Pneumonia) - trivia (4)
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.
NSIP - types/DDx (4)
Cellular or Fibrotic.
Ground glass alone = Cellular
Ground glass + reticulation = Cellular or Fibrotic
Reticulation and traction bronchiectasis = Fibrotic
NSIP - features (3)
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.
RB-ILD - features (4)
Respiratory Bronchiolitis + symptoms = RB-ILD.
Apical centrilobular ground glass nodules.
Tends to involve entire cross section of lung.
Associated with smoking.
DIP - features
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.
