[Correlation between hyperplastic and adenomatous polyps of the colon]

Although hyperplastic polyps are considered to be non-neoplastic, they nevertheless have a number of characteristics in common with adenomatous polyps.

Since hyperplastic polyps and adenomas frequently occur together, the question arises as to whether hyperplastic polyps, found for example during sigmoidoscopy, might not be an indicator of possibly neoplastic polyps in the more proximal part of the bowel. In a retrospective analysis of first-time total colonoscopies in 685 patients, we investigated the relationship between hyperplastic and adenomatous polyps.

Twenty-one patients proved to have only hyperplastic polyps in the rectosigmoid, while 12 of these patients (11.8%) also had adenomatous polyps in the more proximal parts of the colon. In contrast, 30.8% of the patients (n = 109) with rectosigmoidal adenomas also had adenomas in the more proximal colon. Irrespective of histology, as the size of rectosigmoidal polyps increased, so did the percentage of patients with adenomas in the proximal colon--from 22.4% in the case of small polyps not exceeding 5 mm in diameter to more than 31.2% in the case of polyps larger than 5 mm in diameter. When both hyperplastic and adenomatous polyps appeared together, hyperplastic polyps were found in larger numbers in the same or anatomically adjacent segment of the colon.

The results of this study suggest that the presence of hyperplastic polyps in the rectosigmoid is not associated with an increase in the incidence of proximal adenomas, while rectosigmoidal adenomas must be considered indicators of adenomas in the more proximal parts of the bowel.