Diagnostic Utility of Single Nucleotide Polymorphism Microarray in Evaluating Pancreaticobiliary Brushing Specimens in Conjunction with Conventional Cytology.

Bile duct brushings are noninvasive samplings of cells from the biliary tract for cytologic evaluation and are useful to diagnose pancreaticobiliary malignancies. Although specificity of cytology is satisfactory, sensitivity is inherently low because of challenging or absent morphologic features. Using molecular markers by incorporating fluorescence in situ hybridization has significantly improved sensitivity and diagnosis. To further advance the use of molecular markers, OncoScan microarray was used, which has genome-wide coverage and significantly higher resolution compared with fluorescence in situ hybridization. This study tested 128 pancreaticobiliary brushing specimens with OncoScan and compared them with cytology while using the biopsy of these patients as a reference. OncoScan was able to detect more malignant cases compared with cytology. In addition, the study identified potential molecular markers that have not been previously studied or reported. This study demonstrates that OncoScan is a useful additional diagnostic tool with cytology for pancreaticobiliary brushing specimens by improving the sensitivity to detect malignancies.