Special Stains Use in Fungal Infections

H istologic evaluation of tissues is a quick and easy way to identify fungal organisms, and a strong adjunct to microbiologic culture for diagnosis of fungal infections. Histologic evaluation of granulomatous inflammation and granulomas must include special stains to exclude or include presence of fungi and acid fast bacteria. Gomori Methenamine Silver (GMS) and Periodic acid-Schiff (PAS) are the two most common stains used to look for fungi in tissues and in cytology specimens in the daily practice of pathology. The presence of fungus in the tissue sections provides an indisputable evidence of invasive infection. Because of their size and morphologic diversity, many fungi can be seen in tissue sections by conventional light microscopic examination of Hematoxylin and Eosin (H&E) stained sections. In cytology specimens, fungi can be identified by their size and specific morphology.