| [ Summary ] |
The natural history of colorectal adenomas, especially diminutive ones, has not been fully clarified yet. In this study, we investigated the growth of 275 small colorectal adenomas by means of the prospective colonoscopic follow-up. Each tumor, which was diagnosed as an adenoma, colonoscopically without biopsy, was randomly selected with patients' informed consent, and was marked with India ink near the tumor. The size of the adenomas was measured relative to that of the biopsy forceps. During the mean follow-up period of 33.7 months, the mean size of the adenomas increased significantly from 3.8 +/- 1.7 mm to 4.0 +/- 1.9 mm (p<0.01), and 12(4.4%) of the studied adenomas had changed their macroscopic form. Two adenomas had disappeared spontaneously. However, the change of size and macroscopic form of the adenomas did not relate to the follow-up period. Moreover, 19.7% of the adenomas observed by using a magnifying colonoscope had changed their pit pattern. The change in pit pattern correlated with the growth rate and the change in macroscopic form of adenomas. It may be necessary to draw up a logical and suitable treatment for diminutive colorectal adenomas based on their natural history. |