Presentation
Immunocompromised patient with necrotizing pancreatitis.
Patient Data
CT abdomen with contrast
Incidental finding: in supradiaphragmatic scans, in the middle lobe there is a little nodule with a rim of ground-glass opacity that surrounding the nodule (halo sign); bilaterally there is pleural effusion with passive atelectasis of the lower lobes. In the abdomen there is large pancreatic fluid collection, peritoneal effusion, gallbladder lithiasis and inflammatory infiltration of peripancreatic fat.
CT chest and abdomen with contrast
After thirteen days CT shows in the middle lobe a thin walls cavity containing a little “fungus-ball” mass with the lucency that surrounding it: the "crescent sign". Right pleural effusion is present with passive atelectasis of the lower lobe. In abdomen there is large fluid collection containing gas bubbles in pancreatic bed due to abscess complicating acute pancreatitis with inflammatory infiltration of peripancreatic fat and gallstones.
Broncho-Alveolar Lavage (BAL) and cultural examination
Microbial population absent.
Negative search for aerobic bacteria and yeasts.
Research aspergillus, filamentous fungi: positive for Aspergillus fumigatus.
Galactomannan: increased.
Case Discussion
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