Adenomatous polyp; Intraepithelial neoplasia
Adenomas, the precursor lesions of colorectal carcinomas, are dysplastic and noninvasive proliferations of colonic epithelium. Dysplastic epithelium is characterized by enlarged, hyperchromatic nuclei and nuclear stratification. Adenomas are well recognized histologically, with an abrupt transformation between dysplastic and nondysplastic epithelium. Adenomas are further classified as tubular, tubulovillous, and villous according to their architectural pattern.
Autopsy series reveal an incidence of approximately 30–35% in adults. Lifetime prevalence of an adenoma is 30–50% (Western countries) and increases with age. African-Americans have a lower prevalence than Caucasians.
The frequency increases by age (20–30% by 50, 40–50% by 60). In the first two or three decades of life, adenomas are extremely uncommon unless the patient has some form of polyposis. By the fifth decade of life,...
References and Further Reading
- Fenoglio-Preiser, C. M. (2008). Epithelial neoplasms of colon. In Gastrointestinal Pathology an atlas and text (pp. 899–1035). Philadelphia: Wolters Kluwer.Google Scholar