| [ Summary ] |
We studied the endoscopic and histopathological features of colorectal villous tumors. During the period from April 1985 to August 2000, we observed 17,077 colorectal lesions, which were treated endoscopically and surgically. We analyzed 1,329 lesions, including those with villous structures, which were diagnosed pathologically. The lesions, which had villous structures were mostly of the protruding type. However, half of the lesions which did not have a villous structure, were protruding type. The lesions, which had villous structures, showed an eqaul or a low rate of early cancer and submucosal invading cancer, compared with lesions which did not have villous structures. Therefore we consider that it must not necessary to discriminate endoscopically lesions which include villous structure or not. 89.7% of lesions, having villous structures, displayed a type IV pit pattern, and 51.0% of lesions displayed a shaggy appearance. However, only 15.5% of early cancers, having villous structures displayed an amorphous pit pattern. Only 8.6% of these lesions displayed a nonstructural pit pattern. 63.8% of these lesions displayed a type IV pit pattern. Only 36.4% of submucosal invading cancer, having a villous structure, displayed a nonstructural pit pattern. 45.5% of these lesions displayed a type IV pit pattern. Accordingly, we think that it is difficult to endoscopically diagnose early cancer and submucosal invading cancer, having villous structures. |