Diagnostic Efficacy of Calcofluor White Staining Versus PAS and GMS Staining for Human Sporotrichosis in FFPE Specimens.

This study aimed to evaluate the diagnostic efficacy of calcofluor white (CFW) staining for sporotrichosis using archival formalin-fixed paraffin-embedded (FFPE) specimens, compared with conventional histochemical stains. A total of 75 FFPE specimens collected between 2010 and 2023 from patients with culture- or sequencing-confirmed sporotrichosis cases were enrolled, with 70 specimens from non-fungal infection cases using as controls. Serial tissue sections were stained with CFW, periodic acid-Schiff (PAS), and Gomori methenamine silver (GMS) staining, respectively. The detection rates, diagnostic accuracy metrics, and storage duration effects were assessed. CFW staining yielded a fungal detection rate of 78.6