Proposal of a new hypothesis on the development of colorectal epithelial neoplasia: nonspecific inflammation--colorectal Paneth cell metaplasia--colorectal epithelial neoplasia.

Colorectal epithelial neoplasia (CR-EN), both adenoma and adenocarcinoma, may develop from the essential tubules of the colorectum. In order to conclude the carcinogenesis of the colorectal cancer more clearly, the biological features including the genetic abnormality of the nonneoplastic mucosal epithelium of colon and rectum, which coexist in connection with CR-EN, should be investigated. In this review, the importance of Paneth cell metaplasia of colorectum as one of the original mucosal regions of the development of CR-EN, and the new hypothesis on the development of CR-EN (nonspecific inflammation - colorectal Paneth cell metaplasia - colorectal epithelial neoplasia) are examined.