Optical Diagnosis Of Small Polyps Research Articles

NBI International Colorectal Endoscopic–derived high-confidence optical diagnosis of small polyps compared with histology: understanding errors to improve diagnostic accuracy

Developments in image-enhancing endoscopy and polyp classification systems have led to a number of gastroenterology societies endorsing an optical diagnosis (OD) approach for small polyps at colonoscopy. In this study we performed a root-cause analysis of ODs to determine the most likely causes of OD error. As part of a prospective feasibility study, DISCARD3 (Detect InSpect ChAracterise Resect and Discard 3), evaluating implementation and quality assurance of a "resect and discard" strategy for consecutive small polyps<10mm, a root-cause analysis of 184 cases of high-confidence OD error was performed. In all cases, histopathology underwent a second blinded review and, where discrepancy persisted, further review with deeper levels. After a root-cause analysis, 133 of 184 true OD errors were identified and classified into 4 types: A (OD, adenoma; histology, serrated), 45/133 (33.8%); B (OD, serrated; histology, adenoma), 55/133 (41.4%); C (OD, adenoma; histology, normal), 19/133 (14.3%); and D (OD, serrated; histology, normal), 14/133 (10.5%). The remaining 51 of 184 errors were because of a pathology error requiring deeper levels (43/184), pathology observer or laboratory error (7/184), or other error (1/184). OD errors can be related to endoscopist-related factors such as poor photodocumentation, failures of current classification systems, and incomplete histology. We identified a subset of serrated polyps frequently misdiagnosed as adenomas ("pseudoadenomas") using the NBI International Colorectal Endoscopic (NICE) classification. An enhanced algorithm for OD is proposed based on the NICE classification including morphologic and adjunct polyp features.

Optical Diagnosis of Small Polyps

In vivo prediction of the histology of diminutive (≤5 mm) colorectal polyps detected at colonoscopy can be achieved using currently available

Optical diagnosis of small colorectal polyps at routine colonoscopy (Detect InSpect ChAracterise Resect and Discard; DISCARD trial): a prospective cohort study

Accurate optical diagnosis of small (<10 mm) colorectal polyps in vivo, without formal histopathology, could make colonoscopy more efficient and cost effective. The aim of this study was to assess whether optical diagnosis of small polyps is feasible and safe in routine clinical practice. Consecutive patients with a positive faecal occult blood test or previous adenomas undergoing surveillance at St Mark's Hospital (London, UK), from June 19, 2008, to June 16, 2009, were included in this prospective study. Four colonoscopists with different levels of experience predicted polyp histology using optical diagnosis with high-definition white light, followed by narrow-band imaging without magnification and chromoendoscopy, as required. The primary outcome was accuracy of polyp characterisation using optical diagnosis compared with histopathology, the current gold standard. Accuracy of optical diagnosis to predict the next surveillance interval was also assessed and compared with surveillance intervals predicted by current guidelines using histopathology. This study is registered with ClinicalTrials.gov, NCT00888771. 363 polyps smaller than 10 mm were detected in 130 patients, of which 278 polyps had both optical and histopathological diagnosis. By histology, 198 of these polyps were adenomas and 80 were non-neoplastic lesions (of which 62 were hyperplastic). Optical diagnosis accurately diagnosed 186 of 198 adenomas (sensitivity 0.94; 95% CI 0.90-0.97) and 55 of 62 hyperplastic polyps (specificity 0.89; 0.78-0.95), with an overall accuracy of 241 of 260 (0.93, 0.89-0.96) for polyp characterisation. Using optical diagnosis alone, 82 of 130 patients could be given a surveillance interval immediately after colonoscopy, and the same interval was found after formal histopathology in 80 patients (98%) using British guidelines and in 78 patients (95%) using US multisociety guidelines. For polyps less than 10 mm in size, in-vivo optical diagnosis seems to be an acceptable strategy to assess polyp histopathology and future surveillance intervals. Dispensing with formal histopathology for most small polyps found at colonoscopy could improve the efficiency of the procedure and lead to substantial savings in time and cost. Leigh Family Trust, London, UK.