Putative preneoplastic changes identified by enzyme histochemical and immunohistochemical techniques

Microscopic evaluation of whole-mount colons stained with methylene blue and/or hexosaminidase has identified putative preneoplastic lesions in the colons of rodents treated with carcinogen and in the grossly normal colons of humans. Enzyme histochemistry with glycol methacrylate sections has permitted the identification of putative premalignant lesions in rodent livers, human and rodent colons, and human prostates. Immunohistochemistry with paraffin-embedded tissues has been used to identify and characterize putative premalignant lesions in human colons and prostates.