Case #2

• Angioinvasive aspergillosis

• Pulmonary aspergillosis has many different imaging appearances. Think about it as four different entities which are distinguished by the immune status of the patient:
• Hyperimmune – allergic bronchopulmonary aspergillosis (ABPA)
  • Especially patients with asthma
  • Upper lobe predominant bronchiectasis and bronchial plugging (finger-in-glove appearance)
• Normal immune – aspergilloma
  • Patients with preexisting lung cavities
  • Look for soft tissue density filling a cavity. A rim of gas around a fungal ball can look like a crescent, but is more correctly referred to as the Monod sign to separate this from the more ominous crescent sign of angioinvasive aspergillosis
• Mildly immunocompromised – semi-invasive (aka chronic necrotizing) aspergillosis
  • Patients at risk include those with chronic diseases like diabetes, COPD, or malnutrition as well as those with chronic corticosteroid use
  • Imaging features are very similar to those of reactivation tuberculosis with areas of consolidation and nodularity, sometimes with cavitation
• Full-blown immunocompromised – invasive aspergillosis
  • Neutropenic patients and patients with AIDS
  • Airways invasive subtype: bronchial thickening and tree-in-bud nodularity, which can appear identical to atypical bacterial infections
  • Angioinvasive subtype: nodular opacities with groundglass halos or peripheral wedge shaped areas of consolidation. Air crescent sign can be seen during the healing phase as tissue necroses and retracts

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