Endoscopic Hallmarks of Sessile Serrated Lesions: A Systematic Review of an Evolving Concept

Background and Objectives: Sessile serrated lesions (SSLs) are increasingly recognized as relevant precursors in alternative pathways of colorectal carcinogenesis, yet their endoscopic recognition remains challenging. Materials and Methods: We conducted a systematic review of studies reporting endoscopic and patient-related features associated with SSLs. PubMed/MEDLINE was searched for studies published between 2003 and November 2025. Eleven studies including 13,453 participants were identified. Results: Frequently reported endoscopic hallmarks included proximal colon location, larger lesion size, flat or slightly elevated morphology, indistinct borders, mucous cap, cloud-like surface, and pit-pattern features consistent with Kudo/Fujii types III-IV. Considerable heterogeneity in definitions and analytical reporting was observed. Conclusions: Although several features may raise suspicion for SSLs, standardized evidence remains limited, supporting a cautious and comprehensive approach to polyp assessment.