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

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 tissue mucosubstances 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 and malignant lesions of mammary gland and endocervical gland . Methodology: This is a retrospective, observational, analytical, case control study aimed to evaluate mucin histochemical pattern in normaland diseased lesions of mammary and endocervical glands. Twenty five histologically proven blocks of normal and Intraductal carcinoma of mammary gland, normal and adenocarcinoma 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, suggestive of presence of few neutral mucosubstances. PAS staining of normal mammary gland and of Intraductal carcinoma showed similar results. Ducts and lobules stained with magenta showed the presence of PAS positive substances like carbohydrate and neutral mucins. Conclusion: Mucin histochemical patterns serve as valuable, cost-effective tool for diagnosis in histopathology and for the researchers in histology, where a slight change in the mucin pattern may help in the early diagnosis of disease process. PAS technique is perhaps the most versatile and widely used of techniques for the demonstration of glycoproteins, carbohydrates and mucins. [ABSTRACT FROM AUTHOR]