Endoscopic Appearance of Dysplasia in Ulcerative Colitis and the Role of Staining

Abstract

Objectives Cancer Risk and SurveillancePatients with longstanding extensive ulcerative colitis are at increased risk of developing colorectal cancer. Colonoscopic surveillance is recommended by most authorities in an attempt to reduce the associated mortality. Surveillance relies on the detection of premalignant dysplastic tissue, and where dysplasia is detected, proctocolectomy has historically been and currently remains the management of choice, although there is increasing evidence that adenoma-like dysplastic lesions may safely be resected endoscopically. Detection of Dysplasia in Ulcerative ColitisIn patients without ulcerative colitis, the premalignant dysplastic lesion, the adenoma, usually occurs as a clearly delineated macroscopically visible abnormality. However, in ulcerative colitis there is no clear-cut adenoma±carcinoma sequence. Dysplasia can occur in polypoid lesions, but often appears as a more subtle mucosal irregularity, or may be macroscopically invisible. Because of this, most endoscopists worldwide take multiple random biopsies of flat mucosa. It has been estimated that 33 biopsies are required to provide a 90 % chance of finding the highest degree of dysplasia present [1]. It has been recommended that four random biopsies per site over nine sites throughout the colon be undertaken, with increased sampling from the rectosigmoid and with additional biopsies from raised or suspicious lesions [2]. However, it is time-consuming to take 30 ± 50 nontargeted random biopsies throughout the colon, and dysplastic lesions might still be overlooked.Recent improvements in endoscopic equipment and technique, particularly the use of dyesprays (chromoendoscopy), have improved dysplasia detection in ulcerative colitis [3 ± 5],

Narrow-band imaging as an alternative to chromoendoscopy for the detection of dysplasia in long-standing inflammatory bowel disease: a prospective, randomized, crossover study

“…In recent years, several studies have shown that chromoendoscopy (CE) is more accurate in detecting dysplasia in patients with long-standing inflammatory bowel disease (IBD) [1][2][3][4][5][6][7][8][9] than is conventional endoscopy. In fact, a recent consensus guideline endorsed the use of CE as the standard detection method in this subset of patients.…”

Endoscopy in the Diagnosis and Management of Complications of Inflammatory Bowel Disease

“…In contrast to sporadic CRC, in which the premalignant dysplastic lesion is often a macroscopically visible adenoma, dysplasia in IBD may occur as a subtle mucosal irregularity. 93 These lesions may be plaque-like, irregularly raised areas, verrucous lesions, or a combination of any of the above morphology. 94 It is known that small, flat, or depressed dysplastic lesions may be endoscopically invisible in 50% to 80%.…”

Chromoendoscopy in Inflammatory Bowel Disease

“…Three classes of dyes used for chromoendoscopy are mainly differentiated. 7,8 (C) Virtual chromoendoscopy using i-scan highlights the overall appearance of the lesion (arrow). (D) A spraying catheter is advanced and intravital staining with methylene blue is applied using a spraying catheter (arrow).…”