[Prevalence of adenomatous and hyperplastic polyps of the colon in the population of the General Hospital of Mexico. An autopsy study].

A prospective survey of 450 autopsies was conducted to determine the prevalence of colorectal dysplastic polyps in the population of the General Hospital of Mexico City. The colon and rectum were removed and examined for the presence of polypoid lesions; their size, location, and appearance were described. All of the lesions were examined and classified according to their microscopic diagnosis. Results revealed a single polypoid lesion in nine cases; four were classified as regenerative or inflammatory and five as dysplastic. Four of the latter were in females and one in a male; their mean age was 64 years. Macroscopically four were pedunculated and one sessil; all measured less than 0.6 cm; two were located in the transverse colon and three in the left colon. No hyperplastic polyps were found. After standardization for age, comparison with similar studies performed in other countries showed an extremely low prevalence rate for dysplastic colorectal polyps (2.7%) in our patient population, similar to one reported in Iran and higher than that found in the African Bantus, but it is one of the lowest when compared with European and US series.