Data suggests that more than 30% of all adenomatous colorectal lesions are of flat morphology. However, reporting of anatomical preponderance has been inconsistent in Western cohorts.
The malignant potential in this group is significant.
Diagnosis, management and eventual screening in the United Kingdom will be influenced by anatomical distribution.
In this study, researchers from Sheffield, England, evaluated the anatomical distribution of JRSC type II colorectal lesions. They also assessed any association between lesion site and dysplastic/neoplastic transformation.
The research team performed total colonoscopies on 600 consecutive patients.
|78% of lesions were located in the right colon.|
The team used 0.5% indigo carmine to facilitate detection.
They recorded anatomical site for each lesion identified.
In addition, morphology was documented using the JRSC system.
The researchers obtained histological analysis on all specimens by cold biopsy, endoscopic mucosal resection or en-block resection.
The team found that, for lesions with severe dysplasia or beyond, 78% were located in the right colon, 15% in the left, and 7% in the rectum.
The team determined that 93% of lesions with severe dysplasia or beyond had a depressed component morphologically.
Dr Hurlstone’s team concluded, “Flat lesions with areas of depression are associated with severe dysplasia and show a right-hemi-colonic preponderance”.
“Total colonoscopy is required for adequate detection of these lesions (95% would not be detected using flexible sigmoidoscopy alone).”