The changed histologic paradigm of colorectal polyps.

BACKGROUND

Previous literature has recorded the preponderance of hyperplastic over neoplastic polyps. This study evaluated the histopathologic characteristics of colonic polyps, excised during colonoscopic polypectomy, and further determined their relationship to age, location, and gender.

METHODS

Of 5132 colonoscopies reviewed between 1976 and 1999, 757 were performed on 582 patients who had polyp removal. Patients with previous colon resection or incomplete cecal intubation were excluded.

RESULTS

The mean age was 67 +/- 11 years for men and 66 +/- 11 years for women. Of the 1050 lesions histologically analyzed, 871 (83.0%) were neoplastic, 129 (12.3%) were hyperplastic, and 50 (4.8%) were miscellaneous lesions (29 inflammatory polyps, 14 lipomas, 2 leiomyomas, 1 juvenile polyp, and 4 no pathology identified). Hyperplastic polyps were always less than 1 cm (with one exception) and were located predominantly in the left colon, the majority residing in the sigmoid colon. Peak prevalence of hyperplastic polyps occurred in the 50-70 years old age group. Of the neoplastic polyps, 566 (65.0%) were tubular, 225 (25.8%) villotubular, 63 (7.2%) villous adenomas, 4 (0.5%) mixed adenomatous hyperplastic polyps, and 12 (1.4%) invasive carcinomas. The peak prevalence of neoplastic polyps occurred in the same age group as did hyperplastic polyps. Even though adenomatous polyps outnumbered hyperplastic polyps throughout the colon and within each age group, a greater percentage of hyperplastic polyps were found distally and in younger patients compared to location and age groups for neoplastic polyps.

CONCLUSION

Adenomatous polyps outnumber hyperplastic polyps 7:1, even in the distal colon. Even small polyps seen during colonoscopy should be removed and subjected to histologic analysis because of the advisability of follow-up examinations of patients with neoplastic polyps. The increase in the incidence of neoplastic polyps beginning at the age of 50 years supports the need for colonoscopy in these individuals.