Endoscopic Ultrasound for Risk Stratification of Pancreatic Cystic Neoplasms

Abstract

Introduction: Endoscopic Ultrasound (EUS) plays a large role in the workup and evaluation of both incidental and symptomatic pancreatic cysts. EUS can aid in risk stratification of pancreatic cystic neoplasms (PCNs). A subset of PCN, intraductal papillary mucinous neoplasms (IPMNs) have the potential for malignant transformation and risk is stratified from high to low. EUS can aid in differentiation between benign and malignant IPMNs and is used in current guidelines used to direct patients to observation or resection. Methods: A total of 80 patients were identified who underwent both endoscopic ultrasound and surgical resection of a cystic pancreatic lesion between the dates of January 2008 to January 2014. A total of 36 were found to have IPMNs. A retrospective chart analysis was conducted on patients with diagnosis of IPMN to identify features seen at the time of EUS and to collect data such as age, gender and CEA value. Descriptive statistics, including counts and percentages and means and standard deviations, were calculated and reported for patient specific demographics and cyst characteristics including cyst pathology, mural nodules, wall and duct characteristics, CEA level and cyst size. Low risk IPMNs were identified on surgical pathology by the presence of low grade dysplasia or no dysplasia. High risk IPMNs were identified on surgical pathology as high grade dysplasia or invasive adenocarcinoma. The two groups were compared. For data measured on an interval scale, student's t-test was used. If the data were ordinal or not normally distributed, the Wilcoxon rank-sum test was employed. For nominal data, the chi-square test or Fisher's exact test was performed. SAS Enterprise Guide®, version 5.1, was used for all analyses. A two-tailed p-value of less than 0.05 was considered statistically significant. Results: A comparison of high and low risk IPMNs showed a statistically significant difference in main ductal dilatation and in cytology obtained during EUS. gender, presence of mural nodule, tortuosity of the pancreatic duct, wall thickness, age, CEA level and cyst size were not found to be significantly different between the two groups. Conclusion: For IPMNs, measurement of main ductal dilatation and results of cytology observed and obtained during EUS were statistically significant differences between low and high risk IPMNsTable 1: Results