ABSTRACT
In countries with a high or intermediate r1sk for colorectai cancer, the incidence of colonic adenomas increases with age. In the United States and other Western countries at autopsy adenomas are found in 30-509·b of indivicluals older than 60 years of age. in Hawaii, the incidence of colorectal cancer among people of Japanese descent is extremely hig~J and parallels the high prevalence rate of adenomas. Other US and European populations have
Neopla~;tic' Tubular adenoma Tubular villous adenoma Villous adenoma
Non-neopiastic Hyperpl astic po lyp Serrated adenoma 0
(mixed hyperplastic and adenomatous po lyp) Juve n ilE~ po!yp (po!yposis)b Peutz-Jeghers polypst Inflammatory polyp
Submucosai iesion Lipoma Carcinoid Colit is cystic profunda
Malignant potentllal
+ + + l l
- ,!+ ++ - /+
COLORECTAL CANCER IN CLINICAL PRACTICE
(a)
Figure 7.1. (a) A large adenomatous polyp removed at colonoscopy. (b) Histologic section demonstrated a tubular adenorna with an area of localized high-grade dysplasia. Note the dark-staining crowded nuclei in the superficial portion of the section. (c) A villous adenoma. Note the frond-like appearance of tile n1ucosa on the right side of the section, and the area of high-grade dysplasia with dark staining and crowded and disorganized nuclei on the left side of tile section. (d) Polyp fron1 a patient with familial juvenile polyposis. The polyp demonstrates dilated glands lined by normal-appearing epithelium with inflan1n1atory cells densely packed in the stron1a, typical of a juvenile polyp. However, some of the glands are lined by dark oval nuclei typical of adenomatous changes.
