Tsai JH, Yang CY, Yuan RH, et al. - By using targeted next-generation sequencing of 11 genes generally mutated in gastrointestinal neoplasms, researchers assessed the genetic characteristics of a series of 47 appendiceal epithelial neoplasms of different morphologies and associated the genetic characteristics with morphology. BRAF mutations were harbored by seven of nine serrated polyps, which are rare in other types of appendiceal tumors. GNAS and KRAS mutations were found in most cases of low-grade appendiceal mucinous neoplasms (LAMNs). LAMNs with a coexisting serrated polyp were all had KRAS mutations. Four LAMNs with mutations in the Wnt/β-catenin pathway had a focal proliferation of mucin-poor low-grade tumor cells, suggestive of colorectal adenomas; this was either through inactivating mutations in APC or RNF43 or activating mutations in CTNNB1. High-grade appendiceal mucinous neoplasms also displayed mutations in the Wnt/β-catenin pathway, inferring that activation of the Wnt/β-catenin pathway was the motivating force for LAMN to progress to a higher-grade lesion. In appendiceal neoplasms, there seems to be a close relationship between morphology and genetic events, indicating a phylogenetic association between various entities.