Determining when endoscopic ultrasound (EUS) changes management for patients with pancreatic cystic neoplasms.

Abstract

641 Background: Pancreatic cystic neoplasms (PCNs) are being incidentally detected at an increased rate due to the widespread use of CT and MRI. CT and MRI cannot always differentiate between malignant and benign PCNs. EUS is an emerging tool that provides higher quality descriptions of pancreatic cysts and can be used to differentiate between benign and malignant features. Considering that EUS is a resource dependent tool, we hope to identify the PCN cases in which EUS changes management. Methods: We conducted a retrospective case-control chart review evaluating patients, who were diagnosed with pancreatic cysts and underwent EUS for analysis between January 1, 2010 and December 31, 2017. We determined whether EUS correctly identified high-risk features (HRFs) relative to CT/MRI and whether EUS upstaged or downstaged the CT/MRI diagnosis to change overall patient management. Results: EUS was found to have a high specificity (> 95%) for all high-risk features identified in the AGA and FG guidelines and a low sensitivity ( < 70%) for all high risk features except cyst size > 3cm (82.35%) and mural nodule < 5mm (100%). EUS was found to change management in 29.4% of cases (18.2% upstaged, 11.2% downstaged). EUS screening led to a total of three adenocarcinoma diagnoses, in which two were reported to be invasive. Conclusions: The high specificity of EUS supports its use in the differentiation of high risk PCNs identified on cross-sectional imaging. Its low sensitivity indicates that the reliance on operator experience may be a substantial limitation resulting in inconclusive diagnoses. In conclusion, considering that EUS is successful in changing patient management of PCNs, it should be readily referred when any HRF is identified on cross-sectional imaging.