The most common malignancy in the gastrointestinal tract is colorectal
carcinomas (CRC), which is the second most common cancer in women and the third
most in men worldwide. Adenomas are the most frequently observed precursor lesions
for CRC. Two basic pathways have been defined for CRCs: the classical adenomacarcinoma
sequence and serrated pathway developing from sessile serrated lesions or
adenomas. In the previously reported literature, there is no potential for malignancy,
but now the serrated neoplasia pathway is observed in approximately 30% of all CRCs.
In large colonoscopic series studies, the prevalence of serrated polyp is approximately
20%. Colorectal serrated lesions are characterized by sawtooth or stellate
morphological features of the epithelium. For sessile serrated lesion (SSL) definition,
according to the World Health Organization (WHO) Classification of Tumors of the
Digestive System 2019, the presence of at least 1unequivocal distorted crypt is
considered sufficient for diagnosis. There is major variability in the morphology of
colorectal serrated lesions or polyps, and as a consequence, a number of pathological
subtypes have been described and 3 significant types have been defined; hyperplastic
polyp (HP), sessile serrated lesion (SSL), and traditional serrated adenoma (TSA). HP
is the most common lesion among all serrated polyps, and the potential for colorectal
cancer development is very low. Improving the detection of SSLs reduces both the
incidence and mortality of CRCs and reduces the risk of developing cancer of interval
cancers. In this article, we will discuss serrated polyps, nomenclature, the particularly
associated risk of cancer, terminology and classifications, molecular features and
colonoscopic follow-up with the current designation.
Keywords: Cancer, Colonoscopy, Colorectal, Distorted, Dysplasia, Epidemiology,
Gastrointestinal Tract, Histopathology, Hyperplastic, Immunohistochemistry,
Localization, Macroscopic Appearance, Molecular, Polyps, Prognosis,
Sessile, Serrated, Traditional, Unequivocal, WHO.
