Periodic Acid Schiff (PAS) Staining: A Useful Technique for Demonstration of Carbohydrates

Abstract

The term mucosubstances is used to denote all tissue components other than glycogen, rich in carbohydrates,which are present in connective tissue or as secretion of certain epithelial structures. Connective tissuemucosubstances are called “mucopolysaccharides”, while those secreted by epithelia are referred as“mucins”.Objectives: To show the usefulness of PAS staining in identification of carbohydrates in normal andmalignant lesions of mammary gland and endocervical gland .Methodology: This is a retrospective, observational, analytical, case control study aimed to evaluatemucin histochemical pattern in normaland diseased lesions of mammary and endocervical glands. Twentyfive histologically proven blocks of normal and Intraductal carcinoma of mammary gland, normal andadenocarcinoma of endocervical glands were taken. Tissue sections were stained by PAS technique.Results: Results were tabulated according to colour intensity into different grades ranging from + to ++++.PAS staining of normal endocervical glands showed presence of PAS +ve substances like carbohydrate& mucins. PAS stain for adenocarcinoma cervix gave mild reaction with focal magenta shade, suggestiveof presence of few neutral mucosubstances. PAS staining of normal mammary gland and of Intraductalcarcinoma showed similar results. Ducts and lobules stained with magenta showed the presence of PASpositive substances like carbohydrate and neutral mucins.Conclusion: Mucin histochemical patterns serve as valuable, cost-effective tool for diagnosis inhistopathology and for the researchers in histology, where a slight change in the mucin pattern may helpin the early diagnosis of disease process. PAS technique is perhaps the most versatile and widely used oftechniques for the demonstration of glycoproteins, carbohydrates and mucins.