| [ Summary ] |
Rectal tumors, displaying a multi-nodular appearance, which are partially or mostly composed of villous components, can be eradicated by local excision, including endoscopic mucosal resection (EMR) and transanal endoscopic microsurgery (TEM), because they tend to develop and spread mucosally, without submucosal invasion. Such rectal tumors measuring less than 3cm, are a good indication of EMR. Those measuring over 3cm should be resected with TEM or local excision, because of high rate of recurrence when removed with EMR. Recently, however, even those measuring over 3cm have been removed endoscopically with advancements in EMR techniques. Consequently, indications for local resection or TEM have been limited to a very small number of large rectal tumors. We observed thirty seven cases of classical local resection for rectal tumors from 1980 to 1995, and observed nine cases (24%) of histologically positive mucosal cut ends in specimens resected by local resection. In our practice, since 1997, the marginal borders of multi-nodular type rectal tumors have been marked by clips, using magnifying colonoscopy, before surgery, because the marginal borders are mostly unclear to the naked eye. Such procedures have reduced the incidence of positive mucosal cut ends, which may prevent local recurrence after local excision or TEM. |