Mucin histochemistry in colonic polyps and cancer.

Mucins are the predominant glycoproteins found in gastrointestinal epithelia, and their structures differ according to the location in the GI tract and the state of cellular differentiation. Different forms of mucin are secreted in colonic polyps and cancers compared to those found in the normal colon. This paper reviews the methods available to probe mucin structure and the state of knowledge regarding the structures of neoplasia-associated mucins. Many of the assumptions made in the interpretation of classical histochemical stains on tissue sections have recently been questioned, and new insight into mucin structure has been gained from the development of newer methodologies such as lectin histochemistry and immunocytochemistry that use well-defined monoclonal antibodies.