Background and study aims: Magnifying colonoscopy with indigo carmine dye and the analysis of the capillary and the pit patterns by computed virtual chromoendoscopy (Fujinon Intelligent Color Enhancement, FICE) with magnification are effective for the differential diagnosis of neoplastic and non-neoplastic lesions. This study aimed to compare the accuracy of virtual and real chromoendoscopy in differentiating neoplastic and non-neoplastic colorectal lesions.
Patients and methods: A prospective randomized trial of magnification colonoscopy with targeted FICE (Group I - 72 patients/111 lesions) versus magnification colonoscopy with targeted indigo carmine dye (Group II - 72 patients/137 lesions) was performed in consecutive patients with lesions 1 cm or less. Histopathology of the specimens was regarded as the gold standard.
Results: In group I, 86 (77.5%) lesions showed an intense vascular pattern (positive capillary meshwork), of which 80 (93%) were histologically confirmed as adenomas. From 25 lesions with negative capillary meshwork, 23 (92%) were non-neoplastic. Sensitivity, specificity, accuracy, positive and negative predictive values of the capillary meshwork for the differential diagnosis of these lesions was 97.8, 79.3, 92.8, 93 and 92%, respectively. The same parameters for pit pattern analysis by FICE were 92.7, 82.3, 90.1, 93.8 and 80%, respectively. Indigo carmine magnified chromoscopy showed sensitivity, specificity, accuracy, positive and negative predictive values of 97, 88.9, 94.9, 96.1 and 91.4%, respectively in the discrimination between neoplastic and non-neoplastic lesions.
Conclusion: Magnified virtual chromoendoscopy is as accurate as indigo carmine magnified chromoendoscopy in distinguishing between neoplastic from non-neoplastic small colorectal lesions.