| [ Summary ] |
Although rectal cancer has been decreasing in relation to colorectal cancer, a high number of rectal cancers are still detected. It is unclear how to define pre-cancerous lesion in the lower rectum. The aim of this study is to try to clarify the definition of pre-cancerous lesions in the lower rectum. However, the elucidation of these conditions has not yet been performed. There are many types of hyperplastic nodules or polyps, granular tumors, laterally spreading tumors, and carcinoid tumors which occur in the lower rectum. On the other hand, depressed type cancer and non-granular laterally spreading tumors are less common. These tumors tend to exhibit rapid malignant growth when located in the sigmoid colon and rectum as compared to other locations. Methods to observe the rectum with the U-turn technique are described. It is considered important to observe the middle rectum with this U-turn technique, to prevent overlooking lesions in the lower rectum. |