Staining Effectiveness of Keratin Using Hematoxylin & Eosin and Special Stains: A Comparative Study

Abstract Introduction: Keratin is a stiff fibrous structural protein, which is present in epithelial cells and creates intermediate filaments that give tissues strength, rigidity and protection. Because of its high cysteine content, keratin can form strong disulfide connections that make it extremely resilient and long-lasting. Defects in the keratinization process cause a variety of inherited and premalignant diseases hence keratin can be used as crucial diagnostic marker in both histopathology and immunohistochemistry. Special stains for histopathological analysis could be a quicker and more affordable approach and can help in faster diagnosis. Aims and objectives: Aim of the study was to compare the staining effectiveness of specific stains (Rapid PAP, AB-PAS, Aldehyde fuschin stain) to H&E stain for keratin. Materials and methods: 80 histopathologically confirmed cases of well-differentiated squamous cell carcinoma (OSCC) were included. 4 micrometer thick sections were cut and stained using special stains - Rapid Papanicolaou (Rapid PAP), Alcian Blue-Periodic Acid Schiff (AB-PAS), Aldehyde Fuschin stain. These were studied under microscope for staining effectiveness. The outcomes were statistically examined. Results: Each of these stains distinguishes keratin with AB-PAS showing better staining quality compared to other two suggesting that it might be used as a substitute stain for keratin. Conclusion: Among special stains the staining capacity of alcian blue- periodic acid Schiff stain was in par with H&E stain and can be used as an alternative for fast and economical staining along with H&E as compared to immunohistochemistry techniques for rapid diagnosis of OSCC.