Non-polypoid Colorectal Neoplasms: Characteristics and Endoscopic Management

The progress in endoscopy has led to an easier identification, a better characterization, and a correct therapeutic approach to preneoplastic lesions. Non-polypoid colorectal lesions account for 5–36% of all colorectal cancers in Western nations and, compared to polypoid lesions, are more frequently located in the right colon, and are found in older patients. They also carry a higher risk of deeper invasions (only for depressed subtype), and require dedicated endoscopic techniques to be removed endoscopically. These lesions can be removed by endoscopic resection/dissection if limited to the mucosa (or superficial layer of submucosa), while deeper invasion makes endoscopic therapy inappropriate. The use of advanced endoscopy, such as magnifying chromoendoscopy and narrowband imaging helps to identify invasive lesions with a specificity higher than 98%, avoiding useless endoscopy resections, and providing instead immediate surgery indication. When endoscopy resection is considered possible, the dimensional criteria of the lesion and the operator’s expertise should define which type of techniques to use: Endoscopic Mucosal Resection (EMR) or Endoscopic Submucosal Dissection (ESD).