Serrated polyps of the large intestine: current understanding of diagnosis, pathogenesis, and clinical management

Abstract

Approximately 30 % of colorectal carcinomas develop via the serrated neoplasia pathway characterized by widespread DNA methylation and frequent BRAF mutation. Serrated polyps represent a heterogeneous group of polyps which are the precursor lesions to serrated pathway colorectal carcinomas. The histological classification of serrated polyps has evolved over the last two decades to distinguish three separate entities: hyperplastic polyp, sessile serrated adenoma (SSA), and traditional serrated adenoma (TSA). The malignant potential of SSAs and TSAs has been clearly demonstrated. SSAs are more challenging to detect by colonoscopy and are likely to account for some interval carcinomas of the proximal colon. Serrated polyposis syndrome is now widely recognized as conferring a high risk of colorectal carcinoma although its cause remains elusive. The current understanding of the actual malignant potential of each serrated polyp subtype is still limited due to the lack of large-scale prospective studies. Patient management guidelines have been recently updated although high-level evidence to support them is still required.

Impact of reassessment of colonic hyperplastic polyps by expert GI pathologists

“…Up to now, these polyps were mainly differentiated into hyperplastic polyps and adenomas. In recent years, sessile and TSAs have been identified as separate lesions which may be precursor lesion in the so-called serrated and alternate pathways of colorectal carcinogenesis [3,20]. Therefore, correct diagnosis and differential diagnosis of serrated lesions (hyperplastic polyps, sessile and TSAs) is very important for further management including follow-up.…”

“…The biological behaviour of those two types is considered to be different: SSA are widely recognized as precursor lesions of serrated pathway colorectal carcinoma [2,3], while HP are still considered to have no malignant potential. The prevalence of SSA remains unclear, varying between 2.8 % (standard care) and 9 % (single-expert endoscopy and pathology reports) in patients undergoing screening and/or diagnostic colonoscopy [4][5][6][7].…”

Serrated polyps as precursor lesions of colorectal cancer: current status and future directions. Mini-review.

“…Sessile serrated adenoma/polyp (SSA/P) SSA/P are less common than HP and their incidence is 15 to 25 % of all serrated polyps and 1,7 to 9 % of all colon polyps [32]. They develop mainly in the proximal colon (75 %) and their size is greater than HP (50 %> 5 mm, 15-20 %> 10 mm).…”

“…They develop mainly in the proximal colon (75 %) and their size is greater than HP (50 %> 5 mm, 15-20 %> 10 mm). SSA/P are diffi cult to detect by colonoscopy due to their fl at shape, as compared with TSA which project into the lumen and have a bright red surface [32].…”

Endoscopic semiotics. Diagnostics and the choice of the methods for the treatment of squamous epithelial tumours of the colon

“…-гиперпластические, имеющие очень низкий злокачественный потенциал [1,2]; -зубчатые, встречаемость дисплазии тяжелой степени или фокусов внутрислизистого рака в кото-рых колеблется, по данным разных исследователей, от 4 до 37% [3][4][5][6][7]; -аденоматозные, в которых тяжелая дисплазия или комплексы аденокарциномы встречаются в 8-12% случаев [8].…”