P0828 - Characterization of Intraductal Papillary Mucinous Neoplasm Subtypes Using EUS-Guided Confocal Laser Endomicroscopy

Award: Presidential Poster Award

Bryn Koehler, MD¹, Da Yeon Ryoo, MD¹, Matt Leupold, MD², Wei Chen, MD, PhD¹, Troy Cao, BS¹, Somashekar Krishna, MD^3
1Ohio State University Wexner Medical Center, Columbus, OH; ²The Ohio State University Wexner Medical Center, Columbus, OH; ³The Ohio State Wexner Medical Center, Columbus, OH

Introduction: Branch duct (BD)-intraductal papillary mucinous neoplasms (IPMNs) are the most common type of neoplastic pancreatic cystic lesion. Recent studies have evaluated EUS-guided needle-based confocal laser endomicroscopy (nCLE) differentiation of dysplasia in IPMNs. We sought to characterize pathological subtypes of these lesions as seen on endomicroscopy.

Methods: Subjects with IPMNs and reference histopathology were enrolled from prospective databases at a single center (2015-2023). 63 IPMNs were characterized by histological subtype and degree of neoplasia. One nCLE expert blindly reviewed nCLE video records and graded the IPMNs on the following: presence of papillae, papillae size, epithelial darkness, epithelial thickness, and density of papillae and epithelium (Figure 1).

Results: In 63 subjects with BD-IPMNs with reference histopathology, the mean (±SD) age was 68.0±9.0 years, and 46% were female. The mean (±SD) BD-IPMN diameter was 35.3±12.4 mm. High-grade dysplasia or adenocarcinoma (HGD-Ca) was detected in 21 (33.3%) BD-IPMNs.

44 (70%) were classified as gastric foveolar, 12 as pancreatobiliary, 4 as intestinal, and 3 as oncocytic (Table 1). Of the gastric foveolar IPMNs, 35 (92.1%) had medium or large papillae. 29 of the 44 IPMNs (65.9%) had moderate or high epithelial darkness (nuclear stratification) and epithelial thickness (cellular stratification), and 75.0% (n=33) had moderate or high papillary density. Of these, 9 IPMNs (20%) had histopathologic evidence of HGD-Ca.

Of the pancreatobiliary IPMNs, all had medium and large papillae; 50% had moderate or high epithelial darkness and thickness, and 83% had a moderate or high density of papillae. In this subtype, 5 IPMNs (42%) had HGD-Ca.

All intestinal and oncocytic (or intraductal oncocytic papillary neoplasms) IPMNs (n=7, 11%) had large papillae, moderate or high epithelial thickness and darkness, moderate or high papillary density, and HGD-Ca.

Discussion: In this analysis, intestinal-type and intraductal oncocytic papillary neoplasms (IOPNs) comprised a small proportion of BD-IPMNs, but were universally associated with HGD-Ca. In contrast, the gastric foveolar and pancreatobiliary subtypes exhibited a wider spectrum of dysplasia, characterized by variations in papillary epithelial thickness and darkness, indicative of cellular and nuclear stratification. These unique features represent the first in vivo description of endomicroscopy findings in IPMNs and have the potential to enhance risk stratification and management strategies.




Disclosures:


Bryn Koehler, MD¹, Da Yeon Ryoo, MD¹, Matt Leupold, MD², Wei Chen, MD, PhD¹, Troy Cao, BS¹, Somashekar Krishna, MD³. P0828 - Characterization of Intraductal Papillary Mucinous Neoplasm Subtypes Using EUS-Guided Confocal Laser Endomicroscopy, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.