HPB PLENARY: OR-HPB-01: Endoscopic ultrasonography-guided needle-based confocal laser endomicroscopy has improved accuracy compared to the current standard of care for differentiating mucinous from nonmucinous pancreatic cystic lesions

BACKGROUND AND OBJECTIVES: Endoscopic ultrasonography (EUS)-guided needle-based confocal laser endomicroscopy (nCLE) patterns for diagnosing mucinous pancreatic cystic lesions (PCLs) have been recently validated. The aim of this study was to compare the accuracy of EUS-nCLE to the standard of care for differentiating mucinous from nonmucinous PCLs. METHODS: In a prospective study evaluating EUS-nCLE, fluid from 59 PCLs was analyzed by carcinoembryonic antigen (CEA), cytology, and next generation sequencing (NGS). The final diagnosis of PCLs was based on surgical histopathology (n = 36 [61%]) or clinical diagnosis based on imaging features, specific NGS results, follow-up >1 year, and/or resolution of PCL (n = 23 [39%]). Diagnostic indices and area under receiver operator curve (ROC) of different modalities were computed for all subjects. RESULTS: Among the 59 subjects (31 females; mean age 59.4 years), 36 cysts were mucinous and 23 nonmucinous. The ROC analyses associated with the detection of patterns of “epithelial bands/papillae” for mucinous PCLs demonstrated the greatest area under the curve (96%). The sensitivity, specificity, and accuracy of nCLE were significantly greater than the accuracy of CEA, cytology, and combination of CEA/cytology (P < 0.001). When the study population was restricted to those with surgical histopathology (n = 36; mucinous 26 [72%]), diagnostic accuracy of nCLE for mucinous PCLs continued to be higher than the combination of CEA/cytology (94% vs. 67%, P = 0.006). CONCLUSIONS: Among the current diagnostic modalities, EUS-nCLE detection of “epithelial bands or papillae” is more accurate than the current “standard of care” for the differentiation of mucinous from nonmucinous PCLs. These preliminary results warrant further validation in larger, multicenter studies.