Background: Adenomatous colonic polyps are accepted as premalignant lesions. There is controversy regarding the significance of the hyperplastic polyp. The aim of this study was to determine the incidence of further polyps in patients with only hyperplastic polyps on a first colonoscopy in comparison with patients without polyps and with adenomatous polyps.
Methods: Ninety patients had only hyperplastic polyps (group I). These patients were paired according to age and sex with subjects having no polyps (group II) and with patients having adenomas (group III).
Results: Fifty-six patients in group I had at least one follow-up examination. New polyps were found in 46.4% in group I versus 15.5% in group II (p < 0.001) and 50% in group III (NS). In group I, 30.7% of new polyps were hyperplastic and 69.3% were adenomas. In fact, 32.2% of group I patients developed further adenomas (mean 1.5 +/- 0.8 adenomas). These adenomas occurred 1 to 4 years after the first polypectomy (mean 2.4 +/- 0.8 years). Most of these adenomas were small and tubular, but 16.6% were villous or had severe dysplasia.
Conclusion: Patients with hyperplastic polyps were 2.4 times more likely to have further adenomas than were those without polyps.