| [ Summary ] |
We investigated lymph node metastasis and local recurrence of colorectal tumors after endoscopic mucosal resection (EMR). First, we investigated the relationship between histological factors such as the level of invasion, lymphatic invasion, venous invasion, budding, histologic grade and lymph node metastasis in surgical cases. There was a definite influence of some unfavorable histological factors, such as level of invasion, lymphatic invasion, budding and histologic grade on lymph node metastasis. Indeed, lymph node metastasis was found in 1 out of 8 cases which had unfavorable histological factors after EMR. Therefore, the treatment for lesions, limited to the sm type, slight invasion and unfavorable histological factors needs to be colectomy, with lymph node excision. In contrast, lesions limited to the sm type with slight invasions, without unfavorable histological factors, may be treated radically with EMR alone. For local recurrence, there was no evidence of intramucosal local recurrence with negative margins. However, intramucosal local recurrence occured in 5 of 49 lesions, with positive margins. Therefore, tumors removed by using EMR that appear margin negative through use of endoscopy, but are found to be margin positive through histology and stereomicroscopy, may recur locally. In these cases, careful follow-up, using endoscopy, is required. |