Diagnostic investigation using pancreatic juice

Although endoscopic retrograde pancreatography to collect pancreatic juice sample for intraductal papillary mucinous neoplasms (IPMNs) of the pancreas is not routinely recommended because of its possible severe complication of pancreatitis, assessments of cytology and molecular markers in pancreatic juice are often useful to diagnose malignant IPMNs. In addition, pancreatic juice cytology is the only way to detect early stage pancreatic ductal adenocarcinoma concomitant with IPMNs which cannot be detected by imaging modalities such as computed tomography, magnetic resonance imaging, or endoscopic ultrasonography. The sensitivity of pancreatic juice cytology for malignant IPMNs is not high, ranging from 10 % to 50 %; however, several molecular markers in pancreatic juice such as carcinoembryonic antigen level, MUC1 level, and the activity of telomerase improve the sensitivity. Pancreatic juice cytology also provides the information regarding subtypes of IPMNs, namely, gastric, intestinal, pancreatobiliary, and oncocytic by the assessments of morphological features and immunohistochemistry. On the other hand, it remains unclear which patients with IPMN are indication for pancreatic juice assessment and which patients really get benefits of such investigation.