A negative polyp lifting sign is defined as a complete failure to lift the lesion of a colonic polyp.
Negative polyp lifting sign means that the lesion area of the colon polyp is not lifted at all and the mucosal layers cannot be separated. When submucosal injection is performed, only the surrounding mucosa is elevated, while the lesion itself is not elevated, forming a depression, which is called a negative lifting sign, which is an indication that the cancerous tissue has invaded the intrinsic muscularis mucosae or that there is a large amount of infiltration of the submucosal layer.
Three common causes of negative lifting sign in polyps include scarring at the base of the ulcer, infiltration of the tumor into the submucosa, and abnormal growth of the muscularis propria muscle bundles into the mucosa.
Endoscopic treatment is usually not possible when colon polyps have a negative elevation sign because the mucosal layers cannot be separated, requiring prompt open surgical treatment to minimize the patient’s pain.