Improving the Detection of Fungi in CRS Histopathology

Objective: To investigate the improvement in histologic detection of fungi with Gomori methenamine silver (GMS) stain by trypsin predigestion in the mucus of chronic rhinosinusitis patients (CRS).Method: Prospective, single group, descriptive analysis conducted in multiple institutions. Thirty-four sinus specimens from 12 CRS surgical patients were stained with hematoxylin and eosin, GMS stain, GMS stain with trypsin digestion, and immunofluorescence for chitinase and anti-Alternaria. Patients received skin testing, IgE serology, and radioallergosorbent tests for 23 fungal IgE antibodies.Results: The conventional GMS stain detected fungi only in 9/34 (27%) of the specimens. Predigesting the specimen with trypsin dramatically improved the visualization of fungi; 31 out of 34 specimens (91%) stained positive for fungi. The Chitinase immunofluorescence visualized fungi in 32/34 (94%), and anti-Alternaria was visualized in 33/34 specimens (97%). Only 8/12 (75%) patients had detectable allergies.Conclusion: Th...