Invasive pulmonary aspergillosis has two main radiologic signs: halo sign occurs in neutropenic patients with a hemorrhagic nodule resulting from angioinvasion. The halo sign is a rim of ground-glass opacity that surrounding the nodule. These early lesions than change into a cavitary lesion with an air crescent sign. Galactomannan is a heteropolysaccharide of the aspergilluscell wall. Is a biomarker that is released into the circulation and alveolar spaces during invasive aspergillosis.

Case courtesy Dr.ssa Sara Zanzani