Histopathological techniques for the diagnosis of combat-related invasive fungal wound infections

Abstract

BackgroundEffective management of trauma-related invasive fungal wound infections (IFIs) depends on early diagnosis and timely initiation of treatment. We evaluated the utility of routine staining, histochemical stains and frozen section for fungal element identification.MethodsA total of 383 histopathological specimens collected from 66 combat-injured United States military personnel with IFIs were independently reviewed by two pathologists. Both periodic acid-Schiff (PAS) and Gomori methenamine silver (GMS) stains were used on 74 specimens. The performance of the two special stains was compared against the finding of fungal elements via any histopathological method (ie, special stains or hematoxylin and eosin). In addition, the findings from frozen sections were compared against permanent sections.ResultsThe GMS and PAS results were 84 % concordant (95 % confidence interval: 70 to 97 %). The false negative rate of fungal detection was 15 % for GMS and 44 % for PAS, suggesting that GMS was more sensitive; however, neither stain was statistically significantly superior for identifying fungal elements (p = 0.38). Moreover, 147 specimens had frozen sections performed, of which there was 87 % correlation with permanent sections (60 % sensitivity and 98 % specificity). In 27 permanent sections, corresponding cultures were available for comparison and 85 % concordance in general species identification was reported.ConclusionsThe use of both stains does not have an added benefit for identifying fungal elements. Furthermore, while the high specificity of frozen section may aid in timely IFI diagnoses, it should not be used as a stand-alone method to guide therapy due to its low sensitivity.

Invasive Fungal Infections Secondary to Traumatic Injury

“…New techniques may provide a more rapid diagnosis, but widespread implementation is often hindered by cost and decreased sensitivity or specificity. For example, frozen sections have a positive predictive value of 92% and negative predictive value of 87% when compared to permanent sections (Warkentien et al, 2012;Heaton et al, 2016). Protocols for early screening may provide an alternate avenue to minimize delays between injury, diagnosis, and treatment.…”

Clinicopathological spectrum of fungal infections in a Tertiary Care Centre

“…Guarner and Brandt and Sundaram et al have shown the difficulties in differentiating colonization and contamination of fungi. 2,10 In our study out of 47 cases of fungal infections, accounting for 0.2% of total histopathological specimens, Phaeohypomycosis constitute a significant proportion of all fungal infections. Phaeohyphomycosis is a collective term for a heterogeneous group of fungal infections caused by dematiaceous fungi and the commonly isolated ones are Exophiala jeanselmei, E. spinifera, and Wangiella dermatitidis.…”

Histopathology of hair follicle epithelium in patients of recurrent and recalcitrant dermatophytosis: A diagnostic cross-sectional study

“…Consistent with our findings, Heaton et al . [21] evaluated the utility of routine staining, histochemical stains, and frozen section for fungal element identification. They found that results of GMS and PAS were 84% concordant in findings.…”