Invasive pulmonary aspergillosis in acute leukemia: characteristic findings on CT, the CT halo sign, and the role of CT in early diagnosis.

Abstract

Invasive pulmonary aspergillosis (IPA) in immunocompromised patients is often difficult to diagnose. Many pathogens present initially with similar, nonspecific pulmonary findings. Air crescent formation has been reported to be highly suggestive of IPA in the appropriate clinical setting, but this is a late sign in an otherwise rapidly fatal infection. The authors reviewed the available chest computed tomography (CT) scans of nine patients with acute leukemia and documented IPA, including four patients with serial scans obtained during the course of infection. Typical CT findings of IPA were multiple inflammatory nodules, often with one large dominant mass, or a single peripheral masslike infiltrate. Cavitation or air crescent formation occurred late in the course of infection, usually at the time of bone marrow recovery from chemotherapy. CT scans obtained early in the course of infection in two patients demonstrated a distinctive feature of one or more pulmonary masslike infiltrates surrounded by a halo of low attenuation. These lesions subsequently progressed to cavitation or air crescent formation typical of IPA. While this CT halo sign may not be pathognomonic for Aspergillus, seen in the appropriate host, it may suggest early on the possibility of IPA.

Tomografia computadorizada na avaliação da aspergilose pulmonar angioinvasiva em pacientes com leucemia aguda

“…This finding is different from those of Kuhlman et al (11) , whose percentages were respectively 55% and 22%. Cavitation was found in only one of our cases of mass (25%), while Kuhlman et al (4) observed percentages of up to 71%.…”

“…Consolidations were predominantly peripheral in 83.3% in this casuistic, while in the great majority of studies in the literature these percentages have reached approximately 100%. In our study, consolidations were multiple in 66.6% of cases which is in agreement with authors like Kuhlman et al (11) and Won et al (19) .…”

“…A ground-glass halo was found in 83.4% of cases presenting nodules, which is in agreement with the studies of Kuhlman et al (11) and Franco et al (16) , where the halo sign in nodules was found respectively in 88.8% and 80% of cases. On the other hand, Mori et al (18) and Won et al (19) have found this sign respectively in only 19% and 40% of cases.…”

“…On the other hand, Mori et al (18) and Won et al (19) have found this sign respectively in only 19% and 40% of cases. No cavitation was found in any case, differently from the findings of Kuhlman et al (11) , where cavitation was observed in five of seven cases (71.4%). In the histopathological study areas of necrosis were found with radially-disposed hyphae in the central region of the lesions, involved by inflammatory cells and blood-filled alveoli.…”

Glossar thoraxradiologischer Begriffe entsprechend der Terminologie der Fleischner Society

“…14). Initial wurde es bei der invasiven pulmonalen Aspergillose als Manifestation perifokaler Hämorrhagien beschrieben [21], es ist jedoch unspezifisch und kommt auch bei Hämorrhagien anderer Ursache [22] wobei die Basis der Pleura anliegt und die Spitze in Richtung des Hilus gerichtet ist [23,24]. Die radiologisch sichtbaren Verände-rungen entsprechen überwiegend pulmonalen Hämorrhagien infolge des Infarkts, eventuell auch einer Nekrose.…”