Endosonographic diagnosis of advanced neoplasia in intraductal papillary mucinous neoplasms

Abstract

Pancreatic cancer has a high mortality rate with minimal proven interventions. Intraductal Papillary Mucinous Neoplasms (IPMNs) are known precursor lesions for pancreatic cancer. Identification of pancreatic cysts has improved from advances in abdominal imaging. Despite multiple revisions of the international consensus recommendations and various guidelines by other major societies, successful risk stratification of the malignant potential of mucinous pancreatic cysts remains challenging. Specifically, detection and accurate classification of advanced neoplasia (high-grade dysplasia and/or adenocarcinoma) in IPMNs is suboptimal with current diagnostic strategies. Development of interventional techniques utilizing endoscopic ultrasound include - through-the-needle microforceps biopsy, next-generation or whole genome molecular analysis of cyst fluid, and needle-based confocal laser endomicroscopy. These techniques suffer from a series of limitations in technical success, diagnostic yield, and clinical feasibility, but a combination approach may offer a solution that optimizes their cyst evaluation and risk stratification. Assessment and comparison of these techniques is restricted by lack of adequate surgical specimens for testing of diagnostic accuracy, resulting in a possible sample bias. Additional large-scale multicenter studies are needed to accumulate evidence for the utility and feasibility of their translation into clinical practice. Great strides have been made in pancreatic cyst evaluation, but further research is required to improve diagnostic accuracy and clinical management of IPMNs.

Comparison of Society Guidelines for the Management and Surveillance of Pancreatic Cysts

“…As there is no reliable way to differentiate IPMNs with low- and high-grade dysplasia, some patients may undergo unnecessary surgery . For example, advanced neoplasia in resected BD-IPMNs was reported in 70% of patients who underwent resection of a BD-IPMN secondary to the presence of worrisome features that lacked advanced neoplasia on final pathology .…”

“…In another study examining dysplasia grade in resected IMPNs, 45% of lesions were low grade, 32% were high grade, and 23% had invasive cancer . EUS-FNA with cyst fluid analysis can distinguish between IPMN and nonmucinous PCLs; however, its potential to identify advanced neoplasia within IPMNs is limited . Cyst fluid next-generation sequencing analysis guided detection of variants in KRAS and/or GNAS genes can diagnose IPMNs with a high specificity .…”

Modern aspects of the management of pancreatic intraductal papillary mucinous neoplasms: a narrative review

“…Novel diagnostic tools, including cyst fluid analysis, laser endomicroscopy and AI, can assist in the recognition of patients at the highest risk for malignancy [ 44 ]. EUS is the most accurate method for detecting mural nodules in the pancreatic parenchyma and cystic component [ 2 , 45 , 46 ]. For the former, contrast harmonic enhanced EUS is superior to conventional EUS and can assess the blood flow of mural nodules, discerning them from mucin plugs [ 44 ].…”

“…EUS is the most accurate method for detecting mural nodules in the pancreatic parenchyma and cystic component [2,45,46]. For the former, contrast harmonic enhanced EUS is superior to conventional EUS and can assess the blood flow of mural nodules, discerning them from mucin plugs [44].…”

State-of-the-Art Update of Pancreatic Cysts

“…Instead, pull the instrument back, and then, gently place the catheter tip on the new area as perpendicular as possible to the epithelial surface [ 85 ]. Despite using this technique, a limitation of nCLE is that the entire cyst wall cannot be visualized (at best, approximately 30% to 50% can be scanned) [ 96 ]. However, the same limitation occurs with performing EUS-TTNB.…”