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 1 10/12/2018 Categories of lung opacities • 1. Consolidation • 2. Interstitial (diffuse lines or nodules) • 3. Airways • 4. One or a few nodules 2 10/12/2018 Alveolar Interstitial 3 10/12/2018 Airways Not applicable 4 10/12/2018 Consolidation • Confluent opacity • Fluffy around periphery • Air bronchograms • Lack of volume loss Confluent opacity, no volume loss 5 10/12/2018 Air bronchograms 6 10/12/2018 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 7 10/12/2018 2 month f/u 8 10/12/2018 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 9 10/12/2018 Comparison 10 10/12/2018 Signs of atelectasis: volume loss Fissure displacement Deviation of mediastinal structures Elevated diaphragm Rapid change 11 10/12/2018 ? atelectasis or an alveolar process Atelectasis (types) • Obstructive/resorptive (obstruction of bronchus) • Passive (compression of lungs) • Cicatricial (related to scarring) • Adhesive (surfactant deficiency) 12 10/12/2018 Lung cancer (Golden S sign) 13 10/12/2018 Lower lobe atelectasis Combined RML/RLL atelectasis 14 10/12/2018 Left upper lobe collapse • 1. Veil-like density • 2. Volume loss – Elevated diaphragm – Elevated left PA • Luftsichel sign 15 10/12/2018 Interstitial opacities Nodules Lines 16 10/12/2018 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 17 10/12/2018 Miliary tuberculosis Interstitial: lines 18 10/12/2018 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 19 10/12/2018 Pulmonary edema (kerley-b lines) 20 10/12/2018 Reticular opacities (distribution) • Lower lobe predominant – Idiopathic pulmonary fibrosis – Connective tissue disease – Drugs – Asbestosis – Hypersensitivity pneumonitis • Upper lobe predominant – Sarcoidosis – Prior TB/fungus – Pneumoconioses 21 10/12/2018 Idiopathic pulmonary fibrosis Hypersensitivity pneumonitis 22 10/12/2018 Tuberculosis 23 10/12/2018 Airways disease • Circular • Tubular 24 10/12/2018 Differential diagnosis of airways disease • Mild: • Severe: – Asthma – Bronchiolitis obliterans – Viral infection – Immunodeficiency – Chronic bronchitis – Ciliary dyskinesia – Etc. – Cystic fibrosis – ABPA – Tuberculosis – Cartilage diseases 25 10/12/2018 Cystic fibrosis Which compartment of lung is affected? 26 10/12/2018 Solitary pulmonary nodule: differential diagnosis • Granuloma • Hamartoma • Primary bronchogenic carcinoma • Metastasis • Lots of others 27 10/12/2018 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 28 10/12/2018 Nodule: size Nodule: calcification 29 10/12/2018 Nodule borders So you see a nodule on CXR… • 1. Is it actually a nodule? 30 10/12/2018 ? nodule Shallow obliques 31 10/12/2018 ? nodule Apical lordotic 32 10/12/2018 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 33 10/12/2018 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 34 10/12/2018 Algorithmic Approach to Lung Opacities On to the cases… 35 10/12/2018 36 10/12/2018 37 10/12/2018 38.