Allergic Bronchopulmonary Aspergillosis

Allergic Bronchopulmonary Aspergillosis

Gerald F. Abbott, MD

Axial HRCT shows cylindrical bronchiectasis of the segmental and subsegmental bronchi of the right upper lobe and mucoid impaction manifesting as a nodular opacity image.

Axial HRCT shows cylindrical and mild varicose bronchiectasis of the segmental and subsegmental bronchi of the right upper lobe with airway wall thickening image.


Abbreviations and Synonyms

  • Allergic bronchopulmonary aspergillosis (ABPA)


  • Chronic airway inflammation and injury from colonization and sensitization by Aspergillus fumigatus and related species

  • Hypersensitivity reaction that occurs almost exclusively in patients with asthma and cystic fibrosis


General Features

  • Best diagnostic clue: Central bronchiectasis and mucoid impaction in asthmatic patient

  • Patient position/location

    • Central bronchiectasis (may spare peripheral airways)

    • Predominantly upper lobes

CT Findings

  • Bronchiectasis (95%)

    • Bronchiectasis ranges from cylindrical (early) to saccular (advanced)

    • May be air-filled or filled with soft tissue (mucoid impaction)

    • Y- or V-shaped tubular opacities emanating from hilum

  • Mucoid impaction (70%)

    • Homogeneous tubular &/or branching “finger-in-glove” opacities

    • Mucoid impaction may have higher attenuation than soft tissue (30%)

    • Centrilobular nodules, tree-in-bud opacities in distal lung (90%)

    • May contain air-fluid levels

    • Distal lung (curiously) usually remains aerated rather than collapsed

  • Eosinophilic pneumonia

    • Migratory fleeting pulmonary opacities may be seen early, before development of bronchiectasis

  • Associated findings

    • Areas of consolidation, ground-glass opacity due to pneumonia or atelectasis distal to airway obstruction

    • Pleural effusions absent

    • Lymphadenopathy, mild in 5%

  • Location

    • Zonal distribution of bronchiectasis

      • Upper lobes (50%)

      • Lower lobes (20%)

      • Random (30%)

    • Axial distribution of bronchiectasis

      • Central (60%)

      • Random (30%)

      • Peripheral (10%)

    • Mainly involves segmental and subsegmental bronchi

    • Bronchiectasis in 3 or more lobes in asthmatics highly suggestive of ABPA

  • Observer accuracy

    • Confident diagnosis of ABPA in 90% of patients with eosinophilic lung disease

Radiographic Findings

  • Radiography: May be normal

Imaging Recommendations

  • Best imaging tool: CT much more sensitive for bronchiectasis


Cystic Fibrosis

  • ABPA seen in 10% of patients with cystic fibrosis

  • Usually younger

  • Positive sweat chloride skin test

  • Distribution of bronchiectasis identical


  • Mucoid impaction may be seen in absence of ABPA

  • Mild cylindrical bronchiectasis may also be seen in asthma alone

  • ABPA needs to be excluded

Endobronchial Neoplasm

  • Mucoid impaction usually seen only with slow-growing tumors

    • Carcinoid or benign tumors such as hamartomas

  • Usually unilateral in single lobar or segmental distribution

Congenital Bronchial Atresia

  • Likely sequela of vascular insult to lung during early fetal development

  • Thin membranous point of atresia; normal airway distal to atresia

  • Segmental bronchus does not communicate with central airway

  • Mucocele develops distal to point of obstruction; round, ovoid, or tubular opacity that may be branching

  • Often misdiagnosed as arteriovenous malformation

  • Apical posterior segment of left upper lobe most common but may occur in any part of lung

  • Difficult to distinguish from ABPA

    • Look for

      • Wedge-shaped area of hyperinflation of lung with decreased vascular markings surrounding mucocele

      • No history of allergies or cystic fibrosis

Primary Ciliary Dyskinesia

  • Characterized by immotile or dyskinetic cilia; leads to poor mucociliary clearing and development of bronchiectasis

  • Other manifestations include hearing loss and male infertility

  • Dextrocardia in patients with Kartagener syndrome

Airway Obstruction from Foreign Body

  • Look for radiopaque foreign body or broncholith

  • Unilateral distribution in single segment or lobe

Bronchocentric Granulomatosis

  • Rare hypersensitivity lung disease may be caused by Aspergillus species

  • Can be seen with ABPA or separate from it as response to infection with Mycobacterium, other fungi, or Echinococcus

  • Distal airway lumen replacement by necrotizing granulomas

  • Imaging similar to ABPA, may predominantly affect more distal airway

  • Can have focal mass or lobar consolidation with atelectasis

Williams-Campbell Syndrome

  • Rare congenital deficiency of cartilage in subsegmental bronchi

  • Bronchiectasis limited to 4th, 5th, and 6th generation bronchi


General Features

Sep 20, 2016 | Posted by in RESPIRATORY IMAGING | Comments Off on Allergic Bronchopulmonary Aspergillosis

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