Failure of colonoscopic surveillance in ulcerative colitis.

Ulcerative colitis and cancer

“…DALM is described as a plaque, mass, stricture, sessile nodule, or pedunculated polyp (resembling an adenoma) or it may assume a nodular, warty or papillary appearance [11,[31][32][33]. Dysplasia may be focal but most commonly multifocal and can be LGD, intermediate dysplasia (IDD), or HGD [12,24,[34][35][36].…”

“…Dysplasia is quite common in long-standing UC and the great majority of patients after 40 years of disease exhibit LGD and HGD [35][36][37][38]. The prevalence of different grades of dysplasia varies due to inter-observer variability, criteria used by pathologists to diagnose dysplasia, and variability in number of biopsies.…”

“…Dysplasia is a marker of malignancy and the precise predictive value of different types of dysplasia remains uncertain [24,36,44,45,46]. Multifocal dysplasia is considered an ominous finding [39,44].…”

“…Multifocal dysplasia is considered an ominous finding [39,44]. Patients with dysplasia may go on to develop invasive carcinoma [36,41,47]. Dysplasia occurs remote from a cancer in 60-73% of cases and 13-40% of patients with cancer do not harbor dysplasia in any region of the colon [48,49,50].…”

“…A minimum of 33 samples and a total 40-50 or more biopsies is required to achieve a 90-95% confidence of detecting neoplasia [24,62,63]. Surveillance is considered a success when colectomy yields high-risk pre-invasive lesions or curable stage I or II cancer [36]. The diagnosis of advanced cancer by surveillance colonoscopy is of questionable benefit [36].…”