Premalignancy of the mucosal polyp in the large intestine

Histologic gradation by simple, concrete criteria based on the extent of epithelial pseudostratification was applied to biopsy specimens of 230 mucosal polyps and 130 invasive carcinomas of the large intestine. This gradation was in excellent agreement with the atypias studied, such as increases in mitotic figures, nuclear chromatin and pleomorphism, and decreased mucin secretion. Foci and/or tendency towards glandular fusion and/or glands back-to-back were found in 26 of 28 polyps showing grade V pseudostratification, against two of 202 polyps showing grades 0 to IV. Adenomatous residues of grade III and/or grade IV were found in 42 of 130 cases of invasive carcinoma. Most polyps consisted of glands that had two or more grades of pseudostratification often appearing in series and an overview of the entire study suggested a gradual transition from normal tissue to invasive carcinoma through the processes of hyperplasia, adenoma, and carcinomain situ. Glandular branching was also studied, and an intimate relation between complexity of branching and epithelial atypism in the mucosal polyps.