COMPARISON OF PERIODIC ACID-SCHIFF STAIN WITH SILVER STAIN FOR FUNGAL IDENTIFICATION IN NASOFACIAL LESIONS
Invasive fungal infections (IFIs) can cause severe illness with high mortality, and with the lowest survival rates seen in cancer patients. Early and accurate diagnosis of these infections is important not only for timely institution of antifungal therapy, but it can also significantly reduce mortality. Our study aims to determine diagnostic accuracy of periodic acid-schiff stain (PAS) in diagnosis of fungal infection among nasofacial biopsies by taking gomorimethenamine silver stain (GMS) as gold standard. The cross-sectional study was conducted at Department of Pathology KEMU, Mayo Hospital, Lahore during February 20, 2019 to August 20, 2019. The biopsy specimen showing evidence of abundant brightly eosinophilic hypocellular mucin on hematoxylin and eosin (H&E) stain was stained with PAS stain and Silver stain. Fungal identification for PAS stain was assessed and confirmed by Silver stain. Data was analyzed by SPSS version 20.0. Data was stratified for age and gender. Post-stratification, Chi-Square test was used taking p-value ≤0.05 as significant. In this study, 99 patients with nasofacial biopsies showing abundant brightly eosinophilic hypocellular mucin on hematoxylin and eosin (H&E) stain were enrolled. Among these patients, 64(64.6%) were males, while 35(35.4%) were females. Age range in this study was from 10 to 90 years with mean age of 44.3±17.2 years. In this study, Sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy of fungal identification on PAS stain was 82.3%, 85.7%, 97.2%, 44.4% and 82.8% respectively. But PAS staining is superior to GMS staining in displaying fungal septa and eliminating interference from pigment-containing cells and other cells. Also it takes less time and is easier to operate.
