Serrated colorectal cancer: Molecular classification, prognosis, and response to chemotherapy

Figure 3 Features of sessile serrated adenoma and traditional serrated adenomas. Pathological analysis shows that sessile serrated adenoma (SSAs) are more common than traditional serrated adenomas (TSAs). While TSA is preferentially located on the left colon, SSA is preferentially located on the right side. In addition, both SSAs and TSAs are found in high-grade CIMP tumors, although several studies show a relationship between low-grade CIMP tumors and TSAs. BRAF mutations are often observed in SSA, whereas KRAS mutations are often observed in TSAs. Contrary to what is found in serrated adenocarcinomas, MSI is almost never present in serrated polyps.