fig2

Figure 2. A case of a colorectal lateral spreading tumor. The lesion shown in Figure 2 is a lateral spreading tumor (LST) detected during colonoscopy, followed by endoscopic submucosal dissection. The pathological diagnosis after treatment was tubular adenoma with high-grade dysplasia. LSTs are known to have high malignant potential, but they are easily overlooked and can cause post-colonoscopy cancer. The detection of LSTs is essential, and the detection rate of these flat lesions may be a quality measurement of colonoscopy.