IS case 452: Angioinvasive pulmonary aspergillosis
Imaging Sciences URMC 2010
Publication Date: 2010-08-30
History
Patient is a 54 year-old male with chronic lymphocytic leukemia (CLL) initially diagnosed two years prior now presenting with recurrent febrile neutropenia.
Findings
Contrast enhanced CT demonstrated multiple spiculated nodules bilaterally (Fig. 1A), a wedge-shaped pleural based opacity in the left lower lobe (Fig. 1B), and a large right lower lobe opacity (Figs. 2A&B) with air bronchograms and central low density consistent with necrosis. The largest lesion in the right lower lobe also demonstrated the peripheral ground glass "halo sign" which is representative of hemorrhage (Fig. 3).
Diagnosis
Angioinvasive pulmonary aspergillosis
Discussion
Aspergillosis is an opportunistic fungal infection most commonly caused by Aspergillus fumigatus. This organism is widely encountered in the soil and when disturbed the spores are released into the air where they are inhaled. Franquet, et al. [1] divide pulmonary aspergillosis into five subcategories:
1.
Saprophytic aspergillosis (aspergilloma) typically presents as an “air crescent sign” due to a mobile soft tissue mass within a pre-existing lung cavity. 2.
Allergic bronchopulmonary aspergillosis is caused by a hypersensitivity reaction to fungal organisms found in mucous plugs within the airways and manifests radiologically as tubular “finger-in-glove” opacities with bronchiectasis proximally. This type is more common in patients with asthma or cystic fibrosis. 3.
Semi-invasive aspergillosis (chronic necrotizing) is associated with chronically debilitated patients and may manifest radiographically as slowly progressive areas of consolidation with or without cavitation or pleural thickening. 4.
Airway invasive aspergillosis is confirmed histologically by organism invasion into the airway basement membrane. CT may show no abnormalities or just tracheobronchial thickening [1]. Alternatively, patchy peribronchial consolidation and centrilobular nodules forming tree-in-bud type opacities have also been described [2]. 5.
Angioinvasive aspergillosis is characterized by invasion of the pulmonary arteries leading to occlusion and distal infarction. At CT this appears as pleural based, wedge shaped opacities and necrotic nodules with a halo of ground glass attenuation representing hemorrhage.
References
- Franquet T, Müller NL, Giménez A, et al. Spectrum of pulmonary aspergillosis: histologic, clinical, and radiologic findings. Radiographics. 2001 Jul-Aug;21(4):825-37. PMID: 11452056
- Logan PM, Primack SL, Miller RR, Müller NL. Invasive aspergillosis of the airways: radiographic, CT, and pathologic findings. Radiology. 1994 Nov;193(2):383-8. PMID: 7972747
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