| Theme | Update on laterally spreading tumor (LST) | |
|---|---|---|
| Title | Endoscopic diagnosis and management of laterally spreading tumors greater than 20 mm in the colorectum | |
| Publish Date | 2006/09 | |
| Author | Toshio Uraoka | Endoscopic Division, National Cancer Center Hospital / Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine |
| Author | Yutaka Saito | Endoscopic Division, National Cancer Center Hospital |
| Author | Takahisa Matsuda | Endoscopic Division, National Cancer Center Hospital |
| Author | Tsuyoshi Kikuchi | Endoscopic Division, National Cancer Center Hospital |
| Author | Yumi Mashimo | Endoscopic Division, National Cancer Center Hospital |
| Author | Hisatomo Ikehara | Endoscopic Division, National Cancer Center Hospital |
| Author | Daizo Saito | Endoscopic Division, National Cancer Center Hospital |
| Author | Takahiro Fujii | Takahiro Fujii Clinic |
| [ Summary ] | Recently, laterally spreading tumors (LSTs) in the colorectum has been accepted not only in Japan but, also in Western countries. The frequency of LSTs with invasive carcinoma is lower than that for polypoid lesions of similar size. LSTs are usually removed, therefore, by endoscopic mucosal resection (EMR), but greater than 20 mm such tumors may require piecemeal resection. It is clinically important to accurately diagnose submucosal (SM) invasion before treatment, especially with LSTs greater than 20 mm. The clinicopathological analysis clarified that LST granular type (LST-G type) and LST non-granular type (LST-NG type) lesions differ both in terms of their frequency of SM invasion and their meeting respective endoscopic criteria for predicting such SM invasion. When considering the most suitable therapeutic strategy for LST-G type, we recommend endoscopic piecemeal resection of the area, with large nodules resected first and collected. In contrast, the LST-NG type should be removed en bloc because of a higher potential for malignancy and greater difficulty in diagnosing sm depth and extent of invasion compared to the LST-G type. En bloc resections, using endoscopic submucosal dissection (ESD) procedures provided more accurate histological assessments. Use of the bipolar current electronic knife (B-knife) to perform ESD appeared to be sale and more effective. Therefore, we choose ESD using B-knife for LST-NG greater than 20 mm. |
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