Endosonography in the diagnosis and management of pancreatic cysts

Rapid advances in radiologic technology and increased cross-sectional imaging have led to a sharp rise in incidental discoveries of pancreatic cystic lesions. These cystic lesions include non-neoplastic cysts with no risk of malignancy, neoplastic non-mucinous serous cystadenomas with little or no risk of malignancy, as well as neoplastic mucinous cysts and solid pseudopapillary neoplasms both with varying riskof malignancy. Accurate diagnosis is imperative as management is guided by symptoms and risk of malignancy. Endoscopic ultrasound(EUS) allows high resolution evaluation of cyst morphology and precise guidance for fine needle aspiration(FNA) of cyst fluid for cytological, chemical and molecular analysis. Initially, clinical evaluation and radiologic imaging, preferably with magnetic resonance imaging of the pancreas and magnetic resonance cholangiopancreatography, are performed. In asymptomatic patients where diagnosis is unclear and malignant risk is indeterminate, EUSFNA should be used to confirm the presence or absence of high-risk features, differentiate mucinous from non-mucinous lesions, and diagnose malignancy. After analyzing the cyst fluid for viscosity, cyst fluid carcinoembryonic antigen, amylase, and cyst wall cytology should be obtained. DNA analysis may add useful information in diagnosing mucinous cysts when the previous studies are indeterminate. New molecular biomarkers are being investigated to improve diagnostic capabilities and management decisions in these challenging cystic lesions. Current guidelines recommend surgical pancreatic resection as the standard of care for symptomatic cysts and those with high-risk features associated with malignancy. EUSguided cyst ablation is a promising minimally invasive, relatively low-risk alternative to both surgery and surveillance.

Endoscopic ultrasound-guided techniques for diagnosing pancreatic mass lesions: Can we do better?

The diagnostic approach to a possible pancreatic mass lesion relies first upon various non-invasive imaging modalities, including computed tomography, ultrasound, and magnetic resonance imaging techniques. Once a suspect lesion has been identified, tissue acquisition for characterization of the lesion is often paramount in developing an individualized therapeutic approach. Given the high prevalence and mortality associated with pancreatic cancer, an ideal approach to diagnosing pancreatic mass lesions would be safe, highly sensitive, and reproducible across various practice settings. Tools, in addition to radiologic imaging, currently employed in the initial evaluation of a patient with a pancreatic mass lesion include serum tumor markers, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasound-guided fine needle aspiration(EUS-FNA). EUS-FNA has grown to become the gold standard in tissue diagnosis of pancreatic lesions.

Clinical approach to incidental pancreatic cysts

The approach to incidentally noted pancreatic cysts is constantly evolving. While surgical resection is indicated for malignant or higher risk cysts, correctly identifying these highest risk pancreatic cystic lesions remains difficult. Using parameters including cyst size, presence of solid components, and pancreatic duct involvement, the 2012 International Association of Pancreatology(IAP) and the 2015 American Gastroenterological Association(AGA) guidelines have sought to identify the higher risk patients who would benefit from further evaluation using endoscopic ultrasound(EUS). Not only can EUS help further assess the presence of solid component and nodules, but also fine needle aspiration of cyst fluid aids in diagnosis by obtaining cellular, molecular, and genetic data. The impact of new endoscopic innovations with novel methods of direct visualization including confocal endomicroscopy require further validation. This review also highlights the differences between the 2012 IAP and 2015 AGA guidelines, which include the thresholds for sending patients for EUS and surgery and methods, interval, and duration of surveillance for unresected cysts.

Updates in diagnosis and management of pancreatic cysts

Incidental pancreatic cysts are commonly encountered with some cysts having malignant potential.The most common pancreatic cystic neoplasms include serous cystadenoma,mucinous cystic neoplasm and intraductal papillary mucinous neoplasm.Risk stratifying pancreatic cysts is important in deciding whether patients may benefit from endoscopic ultrasound(EUS)or surgical resection.Surgery should be reserved for patients with malignant cysts or cysts at high risk for developing malignancy as suggested by various risk features including solid mass,nodule and dilated main pancreatic duct.EUS may supplement magnetic resonance imaging findings for cysts that remain indeterminate or have concerning features on imaging.Various cyst fluid markers including carcinoembryonic antigen,glucose,amylase,cytology,and DNA markers help distinguish mucinous from nonmucinous cysts.This review will guide the practicing gastroenterologist in how to evaluate incidental pancreatic cysts and when to consider referral for EUS or surgery.For presumed low risk cysts,surveillance strategies will be discussed.Managing pancreatic cysts requires an individualized approach that is directed by the various guidelines.

Current updates and future directions in diagnosis and management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms are a heterogenous group of rare neoplasms that are increasingly being discovered,often incidentally,throughout the gastrointestinal tract with varying degrees of activity and malignant potential.Confusing nomenclature has added to the complexity of managing these lesions.The term carcinoid tumor and embryonic classification have been replaced with gastroenteropancreatic neuroendocrine neoplasm,which includes gastrointestinal neuroendocrine and pancreatic neuroendocrine neoplasms.A comprehensive multidisciplinary approach is important for clinicians to diagnose,stage and manage these lesions.While histological diagnosis is the gold standard,recent advancements in endoscopy,conventional imaging,functional imaging,and serum biomarkers complement histology for tailoring specific treatment options.In light of developing technology,our review sets out to characterize diagnostic and therapeutic advancements for managing gastroenteropancreatic neuroendocrine tumors,including innovations in radiolabeled peptide imaging,circulating biomarkers,and endoscopic treatment approaches adapted to different locations throughout the gastrointestinal system.

Machine learning in endoscopic ultrasonography and the pancreas:The new frontier?

Pancreatic diseases have a substantial burden on society which is predicted to increase further over the next decades.Endoscopic ultrasonography(EUS)remains the best available diagnostic method to assess the pancreas,however,there remains room for improvement.Artificial intelligence(AI)approaches have been adopted to assess pancreatic diseases for over a decade,but this methodology has recently reached a new era with the innovative machine learning algorithms which can process,recognize,and label endosonographic images.Our review provides a targeted summary of AI in EUS for pancreatic diseases.Included studies cover a wide spectrum of pancreatic diseases from pancreatic cystic lesions to pancreatic masses and diagnosis of pancreatic cancer,chronic pancreatitis,and autoimmune pancreatitis.For these,AI models seemed highly successful,although the results should be evaluated carefully as the tasks,datasets and models were greatly heterogenous.In addition to use in diagnostics,AI was also tested as a procedural real-time assistant for EUS-guided biopsy as well as recognition of standard pancreatic stations and labeling anatomical landmarks during routine examination.Studies thus far have suggested that the adoption of AI in pancreatic EUS is highly promising and further opportunities should be explored in the field.