The regions of abnormal growth are confined by the basement membrane adjacent to the epithelial tissue and are thought to represent pre-cancerous lesions.
[1] It begins with normal tissue and long-term inflammation causes the cells to undergo atrophy, metaplasia, dysplasia, and finally, becomes an adenoma or carcinoma.
A number of conditions may also increase your risk of colorectal cancer such as irritable bowel disease, familial adenomatous polyposis, lynch syndrome, and cystic fibrosis.
When examining the samples, the histologist looks for evidence of dysplasia which is defined as “unequivocal neoplastic epithelium confined to the basement membrane”.
The Paris Classification system, established in 2002, is used to classify superficial neoplastic lesions of the gastrointestinal tract based on their endoscopic appearance.
[19] s: sessile b: flat c: slightly depressed The Vienna classification of gastrointestinal neoplasia was published in 2000 in an attempt to resolve differences in diagnoses between Eastern and Western trained pathologists.
This system utilizes visual and endoscopic features for classification and was developed to better assess which lesions were at higher risk of invasion.