Small polyps found at sigmoidoscopy: are they significant?

In this study we prospectively examined the significance of small polyps found at screening flexible sigmoidoscopy and studied in particular, the possibility that hyperplastic polyps in the rectosigmoid can serve as potential markers for neoplastic polyps proximal to this area. During the last three years we performed sigmoidoscopy on 1500 patients. One hundred and five patients (7%) had one or more polyps in the rectosigmoid. Exclusion criteria were polyps of > 1 cm in size, a history of bleeding, inflammatory bowel disease or past polypectomy. After excluding 30 patients, 75/1500 (5%) patients with small polyps remained in the study. All these patients were submitted to total colonoscopy with removal of all polyps found. Histopathology showed that 45/75 (60%) patients had hyperplastic polyps and 30/75 (40%) had at least one adenomatous polyp. Among the 45 patients with hyperplastic polyps at flexible sigmoidoscopy, 16 (35.5%) had a more proximal adenomatous polyp. Nine of the 30 patients (30%) who had at least one adenomatous polyp in the rectosigmoid were found to have them more proximally. We conclude that a) size alone is not an accurate predictor of the histology of the polyp, b) because small polyps, either hyperplastic or adenomatous, in the rectosigmoid indicate a risk for adenomatous polyps more proximally, all patients with small polyps found during flexible sigmoidoscopy should be submitted to total colonoscopy.