Efficacy of Magnifying Narrow Band Imaging with Acetic Acid Spray in Diagnosing Superficial Non-Ampullary Duodenal Epithelial Tumors

Background/Aims: The aim of the present study was to evaluate the efficacy of magnifying narrow band imaging with acetic acid spray (MA-NBI) in differentiating category 4/5 lesions from category 3 lesions of superficial non-ampullary duodenal epithelial tumors (SNADETs) as per Vienna Classification and to compare the diagnostic performances of both MA-NBI and magnifying narrow band imaging (M-NBI). Methods: We retrospectively identified 60 resected SNADETs (31 category 3 lesions and 29 category 4/5 lesions) in 60 patients who underwent M-NBI and MA-NBI preoperatively. We evaluated vascular and surface patterns using M-NBI and MA-NBI for characterizing category 3 and 4/5 lesions. The surface pattern was classified as tubular, villous, or mix structure using MA-NBI. In addition, lesions with disorganized and unclear structures with irregular margins that can be clearly recognized by MA-NBI were defined as irregular surface structures. Results: For MA-NBI, category 4/5 lesions had a significantly higher mix structure rate and higher irregular surface structure rate than category 3 lesions (62 vs. 16%, p < 0.001, and 86 vs. 19%, p < 0.001, respectively). The diagnostic accuracy of MA-NBI using mix and irregular surface structures for identifying category 4/5 lesions was as follows: sensitivity, 62/86%; specificity, 84/77%; positive predictive value, 78/78%; negative predictive value, 70/86%; and accuracy, 73/82%. The diagnostic accuracy of MA-NBI using irregular surface structure was significantly higher than that of M-NBI (p < 0.05). Conclusion: MA-NBI may be useful in differentiating between category 3 and category 4/5 lesions of SNADETs.