Migratory Distribution



Migratory Distribution


Jonathan H. Chung, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Asthma


  • Recurrent Aspiration


  • Atelectasis


  • Pulmonary Infarct


Less Common



  • Septic Emboli


  • Organizing Pneumonia


  • Cystic Fibrosis


  • Allergic Bronchopulmonary Aspergillosis


  • Eosinophilic Pneumonia


Rare but Important



  • Pulmonary Vasculitis


ESSENTIAL INFORMATION ˜


Key Differential Diagnosis Issues



  • Migratory pulmonary opacities more suggestive of infectious or inflammatory abnormalities rather than malignancy


Helpful Clues for Common Diagnoses



  • Asthma



    • Airway inflammation resulting in reversible airflow obstruction


    • Imaging for complications: Pneumomediastinum, pneumonia, pneumothorax


    • Patchy distribution


    • Bronchial wall thickening and bronchial dilation


    • Air-trapping or mosaic attenuation


    • Mucus plugging, subsegmental to lobar atelectasis


    • Occasional bronchiectasis


  • Recurrent Aspiration



    • Consolidation in gravity-dependent portions of lungs


    • Predisposed patients (i.e., those with alcoholism, epilepsy, hiatal hernia, esophageal dysmotility or obstruction, neuromuscular disorders)


    • Supine: Superior segments of lower lobes and posterior segments of upper lobes


    • Upright: Basilar segments of lower lobes


    • Centrilobular or tree in bud opacities common


    • May progress to necrotizing pneumonia or pulmonary abscess without treatment


    • Bland aspiration clears quickly (within hours)


  • Atelectasis



    • Recurrent mucus plugging can result in fleeting or migratory atelectasis



      • Subsegmental to lobar in distribution


      • Low-density material visible in airways


    • Recurrent atelectasis or pneumonitis due to incomplete obstruction of airway by aspirated foreign body or endobronchial lesion


  • Pulmonary Infarct



    • Lower lung predominant, peripheral/subpleural, wedge-shaped consolidation


    • Acute pulmonary arterial thromboembolism


    • CT: Reverse halo configuration common (central ground-glass opacity and peripheral rim of consolidation)



      • Also central lucencies and absence of air bronchograms


    • Often in setting of superimposed cardiac dysfunction (cardiomyopathy, congestive heart failure)



      • Both pulmonary and bronchial arterial supply to lung reduced


    • May be migratory: Recurrent emboli lead to new pulmonary infarcts as old infarcts resolve


Helpful Clues for Less Common Diagnoses



  • Septic Emboli



    • Multiple, peripheral, and basilar consolidation or nodules with early cavitation


    • Feeding artery sign: Pulmonary artery branches extend to nodules, implying hematogenous spread


    • Loculated pleural effusion common


    • Risk factors: Indwelling intravenous catheter or right heart endocarditis


    • Migratory appearance from recurrent septic embolic events


  • Organizing Pneumonia



    • Bilateral basal-predominant peripheral and peribronchovascular consolidation


    • Scattered areas of ground-glass opacities and nodules


    • Atoll sign (a.k.a. reverse halo sign): Central ground-glass opacity surrounded by rim of consolidation



    • Perilobular opacities: Ill-defined opacities outlining interlobular septa of secondary pulmonary lobule


    • Opacities may wax and wane


    • Waxing and waning pulmonary opacities in breast cancer following radiation therapy



      • Not isolated to irradiated portion of lungs


  • Cystic Fibrosis



    • Diffuse, upper lung preponderant bronchiectasis and bronchial wall thickening


    • Mucus plugging in airways: Centrilobular or tree in bud opacities


    • Air-trapping or mosaic lung attenuation


    • Hyperinflation


    • Recurrent areas of consolidation: Pneumonia or atelectasis distal to secretions in airways


    • Fatty atrophy of pancreas in combination with above findings highly suggestive


  • Allergic Bronchopulmonary Aspergillosis



    • Occurs in patients with cystic fibrosis and asthma


    • Central bronchiectasis in multiple lobes; often severe (cystic or varicoid)


    • Mucus-filled bronchi; may have gas-fluid levels


    • Centrilobular nodules


    • Fleeting pulmonary opacities and atelectasis


  • Eosinophilic Pneumonia



    • Simple eosinophilic pneumonia



      • Usually asymptomatic


      • Patchy mid and upper lung consolidation


      • Migratory; changes rapidly; spontaneous regression


    • Chronic eosinophilic pneumonia



      • Photographic negative of pulmonary edema: Upper and peripheral preponderant consolidation


      • May shift in distribution


      • Most peripheral portions resolve 1st in response to steroids


      • Tendency to recur in same locations


Helpful Clues for Rare Diagnoses

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Aug 8, 2016 | Posted by in CARDIOLOGY | Comments Off on Migratory Distribution

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