Related Experiment Video
Updated: Jun 11, 2026

Establishment and Evaluation of a Risk Prediction Model for Pathological Escalation of Gastric Low-Grade Intraepithelial Neoplasia
Published on: February 16, 2024
Colonic adenomas found via colonoscopy: yield and risk factors for high-grade dysplasia
Sjofn Kristjansdottir1, Jon G Jonasson, Nick Cariglia
1Speglun ehf, Reykjavík, Iceland. skris@mmedia.is
Background And Aims:
The adenoma-carcinoma sequence is the model for colorectal carcinoma (CRC) developing through high-grade dysplasia (HGD) to CRC. The aim was to assess prevalence and location of adenomas found during colonoscopy and risk factors for HGD.
Material And Methods:
A population-based study using all colonoscopies and polyp specimens registered between 2000 and 2004 in Iceland. Multiple logistic regression analysis was used to assess independent risk factors for HGD.
Results:
A total of 3,315 adenomas were removed from 2,385 patients. Only 14.0% were >1 cm in size. HGD was found in 135 (4.1%) of the adenomas and tubulovillous/villous histology in 15.0%. The prevalence of adenomas in the 50- to 69-year age group was 15.5%, and 21.5% in the >or=70-year group. 60.9% of them were located distal to the splenic flexure. Independent risk factors for HGD were in the order of importance: size; multiplicity; tubulovillous/villous histology; location in rectum, and age. The prevalence of HGD in the group with an adenoma size of 0.6-1.0 cm was 4.1% and in the 40- to 69-year age group it was 3.7%.
Conclusion:
The study suggests a potential 15% yield per colonoscopy of adenomas in 50- to 69-year-olds. There is an appreciable risk of HGD in diminutive polyps and in middle age.
Related Concept Videos
Cellular Adaptation IV: Dysplasia and Metaplasia
Diverticular Disease of the Colon
Assessment of the Rectum and Anus
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
Barrett Esophagus-I: Introduction
This constant acid exposure transforms the esophagus's pink mucosal lining (stratified squamous epithelium) into a type of lining more similar...
Endoscopic Procedures II: Colonoscopy
Inflammatory Bowel Disease I: Ulcerative Colitis
Inflammatory bowel disease, or IBD, encompasses a group of disorders characterized by chronic inflammation or ulceration of the gastrointestinal tract.
Risk Factors
The exact cause of IBD remains unclear, although it is believed to be due to a mix of genetic, environmental, microbial, and immune factors. Genetic factors are significant in determining susceptibility to IBD, with family history being a critical risk factor. Individuals with a first-degree relative who has IBD are at...

