The serrated pathway to
colorectal cancers (
CRCs) is a significant pathway encompassing five distinct types of lesions, namely hyperplastic
polyps (HPs), sessile serrated lesions (SSLs), sessile serrated lesions with dysplasia (SSL-Ds), traditional serrated
adenomas (TSAs), and serrated
adenoma unclassified. In contrast to the conventional
adenoma-
carcinoma pathway, the serrated pathway primarily involves two mechanisms: BRAF/KRAS mutations and CpG island methylator phenotype (CIMP). HPs are the most prevalent non-malignant lesions, while SSLs play a crucial role as precursors to
CRCs, On the other hand, traditional serrated
adenomas (TSAs) are the least frequently encountered subtype, also serving as precursors to
CRCs. It is crucial to differentiate these lesions based on their unique morphological characteristics observed in histology and colonoscopy, as the identification and management of these serrated lesions significantly impact
colorectal cancer screening programs. The management of these lesions necessitates the crucial steps of removing premalignant lesions and implementing regular surveillance. This article provides a comprehensive summary of the epidemiology, histologic features, molecular features, and detection methods for various serrated
polyps, along with recommendations for their management and surveillance.