Serrated adenoma prevalence in inflammatory bowel disease surveillance colonoscopy, and characteristics revealed by chromoendoscopy and virtual chromoendoscopy.

BACKGROUND

Sessile or nonpolypoid neoplastic lesions, including sessile serrated adenomas (SSAs), are difficult to detect in patients with inflammatory bowel disease (IBD).

OBJECTIVES

To assess the prevalence and endoscopic features of SSA in IBD patients undergoing surveillance colonoscopy using novel endoscopic techniques.

METHODS

Histology results of biopsies from a cohort of 87 patients (47 men; median age 51.4 years; median duration of disease 16.9 years; ulcerative colitis [n=40], Crohn disease [n=43], ischemic colitis [n=4]) with longstanding colonic IBD undergoing surveillance colonoscopy were reviewed. Lesions of dysplasia (adenoma-like mass, or dysplasia-associated lesion or mass), SSAs, adenoma-like polyps, hyperplastic polyps and inflammatory polyps were identified. Surveillance colonoscopy using high-definition alone, or with iScan (Pentax, USA) dye-sprayed or virtual chromoendoscopy was performed. Lesion characteristics were described before histological diagnosis.

RESULTS

Fourteen SSAs were detected in 87 (11%) IBD patients. The endoscopic characteristics of SSA lesions were: nonpolypoid appearance (86%), predominant localization in the proximal colon (79%), >6 mm in size (79%), cloudy cover (64%), Kudo pit pattern modified type IIO (86%) and irregular spiral vascular pattern (79%). Among the 44 SSAs and hyperplastic polyps found in the present study, the above characteristics of SSA at colonoscopy had a sensitivity of 92.86% (95% CI 66.06% to 98.8%) and specificity of 93.33% (95% CI 77.89% to 98.99%) in predicting a histological diagnosis of SSA (positive predictive value 86.67%, negative predictive value 96.55%).

CONCLUSION

SSAs are a common finding at surveillance colonoscopy in IBD and have several characteristic features. Further studies are needed to evaluate the natural history of these lesions in IBD patients.