Abstract
Although laterally spreading tumor (LST) lager than 20 mm in diameter tends to be piecemeal endoscopic mucosal resection (EMR), Cutting the adenomatous part never makes significant effects on pathological examination and curability of the lesion. LST-G showing adenoma or focal cancer in adenoma is the indication for piecemeal EMR with the condition that cancer part is resected en bloc perfectly. In such a procedure magnifying observation of pit pattern is essential prier to piecemeal EMR. On the other hand, the indication of colorectal ESD is as follows:1) Lesions difficult to be removed en bloc with a snare EMR in the size, such as LST-NG (particularly pseudo-depressed type), lesions showing type VI pit pattern, and large lesion with protruded type suspected to be carcinoma. 2) Lesions with fibrosis due to biopsy or peristalsis. 3) Sporadic localized lesions in chronic inflammation such as ulcerative colitis. 4) Local residual carcinoma after EMR. Technically in ESD, however, lesion with severe fibrosis is very difficult. To select best endoscopic therapy, we should consider not only clinicopathological features of the lesion but also skill level of colonoscopist, location of the lesion, capability of scope handling and predictive time for procedures including the possibility of surgical resection.
