The Button Mushroom (Agaricus bisporus): An Alternative Control Source for the Grocott Methenamine Silver Technique

Authors: From University of Texas M.D. Anderson Cancer Center Center, Houston, TX- Fatimah Ansar; Carla Arredondo; Tran Huynh; Victoria Jones; Jennifer Le; Duong Nguyen; Andres Ronquillo-Erazo; Minnu Varghese; Kaleena Ramirez; Toysha Mayer; Mark A. Bailey

Identifying the presence of fungi through special histotechniques is a critical diagnostic histopathology test for patients who may have acquired a fungal infection localized in the lungs. The purpose of this study was to determine if the mushroom species Agaricus bisporus, generally known as the Button Mushroom and, commonly used for cooking, may be used a special stain control slide. Is the Button Mushroom a reliable fungal control to use when performing a Grocott Methenamine Silver technique test? The investigators hypothesize the Agaricus bisporus mushroom is a good substitute control for result verification of the GMS staining technique and readily available compared to tissue controls. The button mushrooms were purchased from a local grocer in Houston, TX, subsequently grossed into eight 1.0x1.0x0.4cm representative sections and submitted for routine tissue processing, embedding, sectioning and stained using the H&E and Grocott Methenamine methods. Inclusive, for the test a commercially available human lung tissue control (+) for fungi was compared to the Button Mushroom results and to ensure the GMS technique produced the appropriate result. The processed button mushrooms GMS stain did not yield a definitive result to conclude the outcome of the staining method. The stained GMS slides demonstrated an indistinguishable contrast between the morphology of the mushroom and the presence of fungi; however, the H&E demonstrated the morphology well, however, further studies are necessary to confirm the presence of fungi. The use of alternative controls are dependent on the specific clinical; research goals or experimental conditions to provide appropriate and relevant results. The limitations of the research was, not together with, the GMS to perform a PAS stain on the button mushrooms. Subsequently, we will perform the PAS technique on the button mushrooms and test a different alternative source to establish a viable control for the substitution of human tissue (+) for fungi.