NATURAL-HISTORY OF MINUTE SESSILE COLONIC ADENOMAS BASED ON RADIOGRAPHIC FINDINGS - IS ENDOSCOPIC REMOVAL OF EVERY COLONIC ADENOMA NECESSARY

PURPOSE: With the development of colonoscopy and double-contrast bariu m enema, detection of minute sessile colonic adenomas has increased. W e evaluated progression of these lesions radiologically and attempted to clarify the natural history. METHODS: A total of 125 minute sessile adenomas (less than or equal to 5 mm in size) with histologic confirm ation were examined by double-contrast barium enema at an interval of more than one year. The average follow-up period was 24 (range, 12-36; standard deviation, 9.4) months. To allow for differences in magnific ation, adenomas increasing in size by 2 mm or more were defined as gro wing, and the other lesions were defined as unchanged. RESULTS: Eighty -six adenomas showed no interval change in size. Four adenomas decreas ed 1 mm in size, and 27 adenomas increased 1 mm in size. The remaining eight adenomas (6 percent) increased by 2 or 3 mm in size. None of th e adenomas showed any morphologic changes. There was also no differenc e in degree of histologic atypia between growing and unchanged adenoma s. None of the adenomas developed into carcinomas during the follow-up period. CONCLUSIONS: These data show that most minute sessile adenoma s remain unchanged in size and morphology over the long term. Accordin gly, these adenomas probably should be followed up radiologically or e ndoscopically to avoid excessive polypectomy.