Radiological patterns of pulmonary fungal infection in pediatric hematology and oncology patients

Abstract

Objective: To describe the radiological findings in pediatric patients with hematological or oncological diseases who also have an invasive fungal infection (IFI). Materials and Methods: This was a retrospective study of all patients with IFI admitted to a pediatric hematology and oncology hospital in Brazil between 2008 and 2014. Clinical and demographic data were collected. Chest computed tomography (CT) scans of the patients were reviewed by two independent radiologists. Results: We evaluated the chest CT scans of 40 pediatric patients diagnosed with an IFI. Twenty-seven patients (67.5%) had nodules with the halo sign, seven (17.5%) had cavities, two (5.0%) had nodules without the halo sign, and seven (17.5%) had consolidation. The patients with the halo sign and cavities were older (123 vs. 77 months of age; p = 0.03) and had less severe disease (34% vs. 73%; p = 0.04). Ten patients had a proven IFI: with Aspergillus sp. (n = 4); with Candida sp. (n = 5); or with Fusarium sp. (n = 1). Conclusion: A diagnosis of IFI should be considered in children and adolescents with risk factors and abnormal CT scans, even if the imaging findings are nonspecific.

The Challenge of Diagnosing Invasive Pulmonary Aspergillosis in Children: A Review of Existing and Emerging Tools

“…CT Imaging in Paediatric IPA: Typical Findings Several studies have documented the CT imaging findings of children with IPA ( 123 [3,9,10,[23][24][25], predominantly in children with malignancy or undergoing HSCT. Most studies included a small number of patients, with one exception which described the CT and or plain radiograph findings in 110 children with IPA [3].…”

“…A recent systematic review reported high specificity of the halo sign (> 90%) for diagnosis of invasive fungal disease (IFD) in immunocompromised adults and children [ 31 ] although data on specificity for IPA are conflicting [ 14 , 27 ]. Notably, although earlier paediatric studies report a lower frequency of the halo sign (0–11%) [ 3 , 10 , 23 ], prevalence is higher in more recent studies (56–100%), possibly reflecting improvements in CT resolution and earlier timing of diagnostic scans [ 9 , 25 ]. In two previous paediatric studies, presence of the halo sign was highly specific for pulmonary IFD, although very few patients with IPA were included [ 24 , 29 ].…”

“…Paediatric studies documenting imaging changes in IPA predominantly include patients and images from the 1990s or early 2000s, including the largest series by Burgos et al [ 3 , 10 , 23 , 24 ] More recent studies have included relatively small numbers (< 40) [ 9 , 25 ]. Updated studies documenting CT findings in children with IPA in the setting of improvements in CT techniques, changes in immunosuppressive regimens and supportive care including use of anti-mould prophylaxis are required [ 14 , 22 ].…”

“…Similarly, agreement in radiologist assessment of the halo sign is imperfect [ 22 ]. In contrast, Bain et al reported substantial agreement between two radiologists in identifying nodules (Kappa = 0.649), halo sign (Kappa = 0.609) and cavities (Kappa = 0.860) from CT images of 40 children diagnosed IFD (29 possible), although few cases of IPA (5) were included [ 9 ]. As typical imaging changes are not consistently present in IPA in children, and common findings (e.g.…”

“…Early diagnosis is key to facilitate timely initiation of optimal antifungal therapy, yet this can be challenging as clinical features are non-specific, with most patients presenting with isolated fever, occasionally accompanied by chest pain, cough or dyspnoea [9][10][11]. The diagnosis of IPA is based on a combination of diagnostic imaging, microbiological testing of respiratory samples and serum biomarkers.…”