The presence of dysplasia predicts the development of colorectal carcinoma in ulcerative colitis and Crohn disease
Dysplasia is best evaluated in areas without significant acute inflammation
If acute inflammation is present, dysplasia should be diagnosed only if the dysplastic findings are clearly disproportionate to the degree of inflammation
Dysplastic features should be present on the luminal bowel surface
Reactive atypia rarely extends to the luminal surface
Dysplasia may be focal, requiring adequate sampling
Recommended sampling is 4 biopsies every 10 cm of colorectum
A diagnosis of dysplasia should be confirmed by an experienced gastrointestinal pathologist
Low grade dysplasia demonstrates cytologic features identical to those of colorectal adenomas
Densely packed, enlarged, elongated nuclei
Mucin depletion is common
High grade dysplasia demonstrates markedly atypical features
Marked cytologic atypia
Complete loss of polarity
Cribriform gland formations
Indefinite for dysplasia should be used if the lesion is suggestive of but not diagnostic of dysplasia
Frequently used if acute inflammation is present
Sporadic adenomas can be confused with dysplasia
Polypoid growths that resemble sporadic tubular adenomas both endoscopically and microscopically and can be completely removed endoscopically can be considered sporadic adenomas rather than dysplasia
Sessile lesions in areas involved by inflammatory bowel disease should be considered dysplasia
Both sessile and polypoid lesions in areas not involved by the inflammatory bowel disease should be considered adenomas
