Role of Mucin Histochemistry in Gastric Mucosal Lesions

Introduction: Intestinal metaplasia (IM) refers to the progressive replacement of the gastric mucosa by epithelium having the characteristics of the intestinal mucosa. IM has been observed in various gastric lesions. Aims and Objectives: To determine the mucin histochemistry of various gastric mucosal lesions and the possible relationship of various epithelial mucins with gastric tumors. Materials and Methods: This study was conducted on 105 endoscopic gastric biopsy specimens and 15 gastrectomy specimens. The sections were stained with routine haematoxylin and eosin stain and histochemical stains for mucin such as Alcian blue (AB) pH 2.5/periodic acid-Schiff (PAS) and AB pH 1.0/PAS to detect neutral mucins and acidic mucins. Sections were further stained with aldehyde fuchsin/AB pH 2.5, for subtyping of IM. Results: We observed that the normal glands stained predominantly for neutral mucin, whereas in chronic inflammation, there was a predominance of mixture of acidic and neutral mucins. The cases of IM stained predominantly for sialomucin, while sulfomucin positivity was seen mostly in carcinoma. Conclusion: We conclude that mucin histochemistry helps in identifying the specific subtype of mucin secretion in various gastric mucosal lesions and subsequent typing of IM.