Presentation
The middle aged female on chemotherapy for a known hematological malignancy is generally unwell with a fever.
Patient Data
Round soft tissue density surrounded by semicircular lucency, noted in the right upper zone suggestive of air crescent sign of invasive aspergillosis.
Scanogram to represent a CXR ( original CXR could not be traced)
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Annotation illustrating the origin of the term - the air crescent sign.
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Right upper lobe cavity with a 'ball' of fungus within. Consolidation surrounding the cavity.
Case Discussion
In invasive fungal infections the nodule is composed of necrosed tissue, later this necrotic nodule is reabsorbed peripherally and retracted and air gets trapped inside the nodule and give rise to air crescent.