Abstract
Endoscopic resection has become the most valuable method for diagnosis and treatment of colorectal lesions, especially for adenomas and early cancers. We investigated the incidence of lymph node metastasis of colorectal submucosal invasive cancer (sm cancer). In 146 surgical cases of sm cancer, 15 (10.3%) had lymph node metastasis. No lymph node metastasis was detected in the patient with pedunculated cancers which were smaller than 15 mm or in those with sessile cancers whose depth of invasion was smla. These lesions, mucosal cancers and adenomas, seem to be curatively treated by endoscopic resection. Clinically there are many differences between pedunculated and sessile lesions. We should choose appropriate treatment according to the shape of the colorectal tumor. Most of the pedunculated tumors should be resected endoscopically. Then sm cancers should be resected endoscopically. Then sm cancers should be treated by a curative operation except for those smaller than 15 mm with no lymphatic or vascular invasion. Sessile tumors should be treated according to accurate preoperative diagnosis of depth of invasion, because it is easier to distinguish the depth of invasion of sessile tumors than pedunculated tumors. Sessile sm cancers except for those whose depth of invasion is smla with no lymphatic or vascular invasion, should be treated by a curative operation. Massively invasive sessile sm cancer preoperatively diagnosed should also be treated by a curative operation. Sessile smla cancers with little invasion should be resected endoscopically and diagnosed histologically, then the treatment to be given next should be determined.
