10/12/2018
Algorithmic Approach to Lung Opacities
Brett M. Elicker, MD University of California, San Francisco
Approach to lung opacities
• This is hard! • You will not be an expert today • Approach • Practice • Think like a pathologist
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Categories of lung opacities
• 1. Consolidation
• 2. Interstitial (diffuse lines or nodules)
• 3. Airways
• 4. One or a few nodules
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Alveolar
Interstitial
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Airways
Not applicable
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Consolidation
• Confluent opacity • Fluffy around periphery • Air bronchograms • Lack of volume loss
Confluent opacity, no volume loss
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Air bronchograms
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Well-defined: Ill-defined: interstitial alveolar
Consolidation
• Acute vs. chronic symptoms • Distribution • Acuity of changes • Differential diagnosis in acute setting – Focal: pneumonia/aspiration, hemorrhage – Diffuse: edema, acute lung injury, pneumonia, hemorrhage
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2 month f/u
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Invasive mucinous adenocarinoma
4 month f/u
Chronic alveolar disease
• Tumor – Invasive mucinous adenocarinoma (aka multifocal bronchoalveolar CA) – Lymphoma (recurrent or 1° pulmonary) • Inflammatory – Organizing pneumonia – Chronic eosinophilic pneumonia – Sarcoidosis • Other – Lipoid pneumonia – Alveolar proteinosis
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Comparison
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Signs of atelectasis: volume loss
Fissure displacement Deviation of mediastinal structures Elevated diaphragm
Rapid change
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? atelectasis or an alveolar process
Atelectasis (types)
• Obstructive/resorptive (obstruction of bronchus)
• Passive (compression of lungs)
• Cicatricial (related to scarring)
• Adhesive (surfactant deficiency)
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Lung cancer (Golden S sign)
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Lower lobe atelectasis
Combined RML/RLL atelectasis
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Left upper lobe collapse
• 1. Veil-like density • 2. Volume loss – Elevated diaphragm – Elevated left PA • Luftsichel sign
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Interstitial opacities
Nodules Lines
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Nodules: diff dx
• Hematogenous spread – Miliary tuberculosis – Miliary fungal infection (e.g. cocci) – Metastases • Lymphatic spread – Sarcoidosis – Lymphangitic spread of tumor – Pneumoconioses (e.g. silica)
Histoplasmosis
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Miliary tuberculosis
Interstitial: lines
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Causes of interstitial lines
• Edema
Kerley-b lines may be present
• Malignancy
• Fibrotic lung diseases (this These lines are typically is a long list) thick, wavy and irregular
Linear opacities
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Pulmonary edema (kerley-b lines)
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Reticular opacities (distribution)
• Lower lobe predominant – Idiopathic pulmonary fibrosis – Connective tissue disease – Drugs – Asbestosis – Hypersensitivity pneumonitis • Upper lobe predominant – Sarcoidosis – Prior TB/fungus – Pneumoconioses
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Idiopathic pulmonary fibrosis
Hypersensitivity pneumonitis
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Tuberculosis
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Airways disease
• Circular
• Tubular
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Differential diagnosis of airways disease
• Mild: • Severe: – Asthma – Bronchiolitis obliterans – Viral infection – Immunodeficiency – Chronic bronchitis – Ciliary dyskinesia – Etc. – Cystic fibrosis – ABPA – Tuberculosis – Cartilage diseases
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Cystic fibrosis
Which compartment of lung is affected?
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Solitary pulmonary nodule: differential diagnosis
• Granuloma
• Hamartoma
• Primary bronchogenic carcinoma
• Lots of others
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Which one is malignant?
Nodules: benign vs. malignant
Benign Malignant Small size Large size Smooth border Spiculated border No or irregular Diffuse calcification calcification Stability over time Growth over time
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Nodule: size
Nodule: calcification
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Nodule borders
So you see a nodule on CXR…
• 1. Is it actually a nodule?
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? nodule
Shallow obliques
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? nodule
Apical lordotic
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So you see a nodule on CXR…
• 1. Is it actually a nodule?
• 2. Look for prior films?
• 3. Is diffuse calcification present?
Dual energy subtraction x-ray
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So you see a nodule on CXR…
• 1. Is it actually a nodule?
• 2. Look for prior films?
• 3. Is diffuse calcification present?
• 4. Get a CT scan or a follow-up CXR
Category Subcategory CXR features Common causes •Confluent opacities •Edema Alveolar •Air bronchograms •Acute lung injury •Fluffy edges •Infection •Tuberculosis •Small, well‐defined nodules •Fungal infection Nodules •Opacities not confluent •Metastases •Normal lung between nodules •Sarcoidosis Interstitial •Thin, fine, delicate lines Lines •Pulmonary edema •Lines at periphery of lung (kerley‐b) •Cancer (kerley‐b) Lines •Fibrotic lung •Thick, wavy, irregular lines (reticular) disease •Circular or tubular Airways •Numerous causes •Thin or thick walled •Lung cancer Not in a single •One or afew nodules (≤3 cm) or •Metastasis compartment masses (>3 cm) •Granuloma •Hamartoma
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Algorithmic Approach to Lung Opacities
On to the cases…
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