Background and Aims : Differential diagnosis between non-neoplastic and neoplastic lesions is very important
at colonoscopy, since removal or biopsy of non-neoplastic polyps wastes time and resources.
We therefore conducted a prospective study to examine whether indigo carmine dye spraying
with and without magnification is more reliable than the conventional method for differential
diagnosis.
Patients and Methods : 122 patients with 206 lesions of 10 mm or smaller were recruited into this study.
All lesions detected on colonoscopy were first diagnosed using the conventional view,
then at chromoendoscopy using 0.2 % indigo carmine, and finally at chromoendoscopy
with magnification. The diagnosis at each step were recorded consecutively. All lesions
were finally categorized as neoplastic or non-neoplastic according to pit pattern;
non-neoplastic lesions were biopsied for histological evaluation, and all the neoplastic
ones were removed endoscopically. The accuracy rate of each type of endoscopic diagnosis
was evaluated, using histological findings as reference.
Results : Histologically, 46 lesions (22 %) were non-neoplastic and 160 (78 %) were neoplastic.
The overall diagnostic accuracies by conventional view, chromoendoscopy, and chromoendoscopy
with magnification were 84.0 % (173/206), 89.3 % (184/206) and 95.6 % (197/206), respectively.
Conclusion : Chromoendoscopy with magnification is the most reliable method for determining whether
a colorectal lesion is non-neoplastic or neoplastic.
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Y. Sano, M. D.
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center
Hospital East
6-5-1 Kashiwanoha · Kashiwa 277-8577 · Chiba · Japan
Fax: + 81-4-71314724 ·
Email: ysano@east.ncc.go.jp