Chromoendoscopy using indigo carmine dye spraying with magnifying observation is the most reliable method for differential diagnosis between non-neoplastic and neoplastic colorectal lesions: a prospective study.
OBJECTIVE
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.


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.


CONCLUSIONS
Chromoendoscopy with magnification is the most reliable method for determining whether a colorectal lesion is non-neoplastic or neoplastic.
Fu
K-I
KI
Division of Gastrointestinal Oncology and Digestive Endoscopy, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Sano
Y
Y
Kato
S
S
Fujii
T
T
Nagashima
F
F
Yoshino
T
T
Okuno
T
T
Yoshida
S
S
Fujimori
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology; D020685:Colonoscopes; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology*; D004396:Coloring Agents; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007203:Indigo Carmine; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012007:Rectum / Q000473:pathology; D015203:Reproducibility of Results
D004396:Coloring Agents; D007203:Indigo Carmine