Key Features of Idiopathic Interstitial Pneumonias*
Disorder | People Most Often Affected | Prodrome | Chest X-ray Findings | High-Resolution CT Findings | CT Differential Diagnosis | Histologic Pattern |
|---|---|---|---|---|---|---|
More frequently men > 50 (> 60% smoke) | Chronic (> 12 months) | Basal-predominant reticular abnormality with volume loss and honeycombing | Peripheral, subpleural, and basal reticular honeycombing Traction bronchiectasis or bronchiolectasis Architectural distortion | Systemic rheumatic disorders, particularly rheumatoid arthritis | Usual interstitial pneumonia | |
More frequently men, aged 30–50 (> 90% smoke) | Subacute to chronic (weeks to years) | Ground-glass opacification | Lower zone, peripheral predominance in most cases Ground-glass opacification Reticular lines | Hypersensitivity pneumonitis Pneumocystis jirovecii pneumonia Respiratory bronchiolitis–associated interstitial lung disease | Desquamative interstitial pneumonia | |
More frequently women, usually age 40–60 (< 40% smoke) | Subacute to chronic (months to years) | Ground-glass and reticular opacity | Peripheral, basal, symmetric Reticular opacities Variable ground-glass opacification Irregular lines | Cryptogenic organizing pneumonia Desquamative interstitial pneumonia Hypersensitivity pneumonitis Idiopathic pulmonary fibrosis | Nonspecific interstitial pneumonia | |
People of any age, usually aged 40–50 (< 50% smoke) | Subacute (< 3 months) | Patchy bilateral consolidation | Peribronchial Patchy consolidation, nodules, or both | Alveolar cell carcinoma Chronic eosinophilic pneumonia Infection Nonspecific interstitial pneumonia Sarcoidosis | Organizing pneumonia | |
Respiratory bronchiolitis–associated interstitial lung disease | Slightly more men, aged 30–50 (> 90% smoke) | Subacute (weeks to months) | Bronchial wall thickening Ground-glass opacification | Diffuse pattern Bronchial wall thickening Centrilobular nodules Patchy ground-glass opacification | Desquamative interstitial pneumonia Hypersensitivity pneumonitis Infection Nonspecific interstitial pneumonia | Respiratory bronchiolitis–associated interstitial lung disease |
People of any age† | Abrupt (1–2 weeks) | Progressive, diffuse ground-glass opacification | Diffuse consolidation, ground-glass opacification, often with lobular sparing Traction bronchiectasis later | Acute respiratory distress syndrome Hydrostatic edema | Diffuse alveolar damage | |
Mostly women, of any age† | Chronic (> 12 months) | Reticular opacities Nodules | Diffuse pattern Centrilobular nodules Ground-glass opacification Septal and bronchovascular thickening Thin-walled cysts | Lymphangitic carcinoma Sarcoidosis Systemic rheumatic disorders | Lymphocytic interstitial pneumonia | |
No sex predilection, median age of 57 years | Chronic (> 12 months) | Bilateral apical irregular pleural thickening | Dense subpleural consolidation Traction bronchiectasis Architectural distortion Upper lobe volume loss | Asbestosis Hypersensitivity pneumonitis Nonspecific interstitial pneumonia Radiation-induced lung disease Sarcoidosis Systemic rheumatic disorders | Pleuroparenchymal fibroelastosis | |
* Disorders listed in order of decreasing frequency. | ||||||
† History of smoking unknown. | ||||||