Methods: 3 centres in France (7 investigators) took part in this prospective study. Any pancreatic mass studied by EUSFNA could be imaged by nCLE, but if a patient had multiple masses, only one of them could be imaged. The definition of the preliminary interpretation criteria was done by consensus, with 5 investigators, including one pathologist. 35 patients with a pancreatic mass were included prospectively during the study (June 2012 to March 2013) and the corresponding nCLE recordings were reviewed. For each case, the investigators had the following data: patient’s clinical history, information on the EUS procedure preceding nCLE imaging, cytology, histology findings, nCLE sequences,

and, JQ1 price in certain cases, histological images. When reviewing the video sequences, they were asked to identify characteristic descriptive criteria, and correlate them with a final diagnosis if possible. The localization of the pancreatic masses was: head (17 cases), body (12 cases), tail (6 cases). PLX4032 cell line There were 17 men, and

16 women (2 na), mean age 66 years, (extreme: 32–87 years old). The puncture of the mass was done in all cases with a 19 G puncture needle. Mean size is 30 mm (+/− 9 mm). Results: No complication occured during the nCLE procedure or the puncture. A definitive histological diagnosis was obtained in 31/35 patients. It was the following: adenocarcinoma (21 cases), fibrous stroma adenocarcinoma (1 case), neuroendocrine tumor (4 cases), pseudopapillary tumor (1), chronic pancreatitis (3). During this review, all exocrine adenocarcinomas showed 2 signs, dark cells aggregates with pseudo-glandular aspects, and straight hyperdense elements more or less thick corresponding to tumoral fibrosis. This last element was preposterous in the fibrous stroma tumor. However, both signs were

absent in the tumor with acini cells and neuroendocrine tumor. This one showed a very dense network of small vesselson a dark background. Moreover, normal pancreas shows an aspect of coffee beans corresponding to acinis. Conclusion: This preliminary classification of nCLE images obtained in pancreatic masses could help in the differentiation of adenocarcinomas and neuroendocrine tumors, and between malignant tumors from normal pancreatic tissue. nCLE could therefore facilitate the diagnosis of these lesions, by bringing in vivo microscopic information, in real-time. Key Word(s): 1. endomicroscopy; 2. masses; see more 3. needle; 4. differentiation; Presenting Author: CHEOL KIM Additional Authors: JONG HO MOON, HYUN JONG CHOI, YUN NAH LEE, DONG CHOON KIM, HEE KYUNG KIM, TAE HOON LEE, SANG-WOO CHA, YOUNG DEOK CHO, SANG-HEUM PARK, SUN-JOO KIM Corresponding Author: JONG HO MOON Affiliations: Digestive Disease Center and Research Institute, Department of Internal Medicine, Soon Chun Hyang University School of Medicine; Department of Pathology, Soon Chun Hyang University School of Medicine Objective: EUS-FNA is becoming the standard tool for tissue acquisition for pancreatic mass lesion.