In vivo characterization of pancreatic cystic lesions by needle-based confocal laser endomicroscopy (nCLE): proposition of a comprehensive nCLE classification confirmed by an external retrospective evaluation. Surg Endosc. 2016;30:2603-2612. [PMID: 26428198 DOI: 10.1007/s00464-015-4510-5]

Mucinous cystic neoplasm mimicking pancreatic pseudocyst and progressing to adenocarcinoma: A case report

BACKGROUND

As a heterogeneous group of lesions, pancreatic cystic lesions (PCLs) vary enormously in malignant potential, mandating different treatment strategies. Despite significant advances in diagnostic imaging and laboratory tests, the accurate diagnosis of PCLs remains challenging, leading to overtreatment or delayed/missed surgical timing in patients with PCLs.

CASE SUMMARY

We present a case of a 64-year-old female patient in whom an asymptomatic, incidental cystic mass was found in the pancreatic tail on a routine abdominal ultrasound. After a comprehensive work-up with laboratory examinations, contrast-enhanced computed tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography, a pancreatic pseudocyst was suspected. Subsequent endoscopic ultrasound with fine-needle aspiration and needle-based confocal laser endomicroscopy supported a benign diagnosis. Follow-up computed tomography and magnetic resonance imaging examinations five months later showed significant cyst shrinkage without any abnormalities. However, three years after being lost to follow-up, the patient was readmitted and diagnosed with pancreatic adenocarcinoma with multiple metastases, suggesting that the initial lesion was a mucinous cystic neoplasm misdiagnosed as a pancreatic pseudocyst.

CONCLUSION

Comprehensive integration of all available information (e.g., cyst features, abnormal imaging findings, cyst biochemistry, clinical history, and patient demographics) rather than over-reliance on imaging or endoscopic findings is pivotal to diagnosing PCLs, and patients with concerning features should undergo strict surveillance.

Endoscopic ultrasound-guided tissue sampling: European Society of Gastrointestinal Endoscopy (ESGE) Technical and Technology Review

This Technical and Technology Review from the European Society of Gastrointestinal Endoscopy (ESGE) represents an update of the previous document on the technical aspects of endoscopic ultrasound (EUS)-guided sampling in gastroenterology, including the available types of needle, technical aspects of tissue sampling, new devices, and specimen handling and processing. Among the most important new recommendations are:ESGE recommends end-cutting fine-needle biopsy (FNB) needles over reverse-bevel FNB or fine-needle aspiration (FNA) needles for tissue sampling of solid pancreatic lesions; FNA may still have a role when rapid on-site evaluation (ROSE) is available.ESGE recommends EUS-FNB or mucosal incision-assisted biopsy (MIAB) equally for tissue sampling of subepithelial lesions ≥20 mm in size. MIAB could represent the first choice for smaller lesions (<20 mm) if proper expertise is available.ESGE does not recommend the use of antibiotic prophylaxis before EUS-guided tissue sampling of solid masses and EUS-FNA of pancreatic cystic lesions.

Endoscopic ultrasound-guided needle-based confocal laser endomicroscopy for pancreatic cystic lesions: current status and future prospects

Pancreatic cystic lesions (PCLs) have increased in prevalence due to the increased usage and advancements in cross-sectional abdominal imaging. Current diagnostic techniques cannot distinguish between PCLs requiring surgery, close surveillance, or expectant management. This has increased the morbidity and healthcare costs from inappropriately aggressive and conservative management strategies. Endoscopic ultrasound (EUS) needle-based confocal laser endomicroscopy (nCLE) allows for microscopic examination and delineation of the surface epithelium of PCLs. Landmark studies have identified characteristics distinguishing various types of PCLs, confirmed the high diagnostic yield of EUS-nCLE (especially for PCLs with an equivocal diagnosis), and shown that EUS-nCLE helps to change management and reduce healthcare costs. Refining procedure technique and reducing procedure length have improved the safety of EUS-nCLE. The utilization of artificial intelligence and its combination with other EUS-based advanced diagnostic techniques would further improve the results of EUS-based PCL diagnosis. A structured training program and device improvements to allow more complete mapping of the pancreas cyst epithelium will be crucial for the widespread adoption of this promising technology.

Endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions: a comprehensive review

Advancements in diagnostic radiology have amplified the incorporation of these techniques into routine clinical practice. Concurrently, the frequency of incidentally identifying pancreatic cystic lesions (PCLs) has surged. PCLs encompass diverse categories contingent upon their origin. Among them, branch duct-intraductal papillary mucinous neoplasms (BD-IPMN) and mucinous cystic neoplasms (MCN) are categorized as mucinous cystic lesions that have malignant potential. Even solid neoplasms occasionally show cystic degeneration. Therefore, precise differential PCL diagnosis is crucial to optimize clinical management strategies and detect malignant transformations. Endoscopic ultrasound (EUS) affords comprehensive visualization of the pancreas with high-resolution ultrasound, complemented by fine-needle aspiration (FNA) under real-time EUS guidance, which is a minimally invasive procedure for obtaining pathological samples. This synergy has established EUS and EUS-FNA as vital procedures in the management of PCLs, enabling differentiation of PCLs. Cyst fluid analysis has played a pivotal role in deciding the optimal management strategy. The efficacy of cytological analysis is limited by scant cytologic material. The "string sign" test evaluates fluid viscosity, and its simplicity warrants initial consideration. Amylase and tumor markers, such as CEA, have been studied, but they yield varied sensitivity and specificity. Glucose and genetic mutations (KRAS, GNAS) exhibit promise, while comprehensive genomic profiling underscores genetic insights. Through-the-needle biopsy and needle-based confocal laser endomicroscopy also show high diagnostic yield. EUS-FNA, however, entails risks like infection and needle tract seeding, emphasizing the need for proper utilization. Pancreatic cyst fluid analysis augments diagnostic accuracy and informs clinical decisions, making it a valuable adjunct to imaging.

The application of artificial intelligence in EUS

Artificial intelligence (AI) is an epoch-making technology, among which the 2 most advanced parts are machine learning and deep learning algorithms that have been further developed by machine learning, and it has been partially applied to assist EUS diagnosis. AI-assisted EUS diagnosis has been reported to have great value in the diagnosis of pancreatic tumors and chronic pancreatitis, gastrointestinal stromal tumors, esophageal early cancer, biliary tract, and liver lesions. The application of AI in EUS diagnosis still has some urgent problems to be solved. First, the development of sensitive AI diagnostic tools requires a large amount of high-quality training data. Second, there is overfitting and bias in the current AI algorithms, leading to poor diagnostic reliability. Third, the value of AI still needs to be determined in prospective studies. Fourth, the ethical risks of AI need to be considered and avoided.

Structured training program on confocal laser endomicroscopy for pancreatic cystic lesions: a multicenter prospective study among early-career endosonographers (with video)

BACKGROUND AND AIMS

Data on how to teach endosonographers needle-based confocal laser endomicroscopy (nCLE)-guided histologic diagnosis of pancreatic cystic lesions (PCLs) are limited. Hence, we developed and tested a structured educational program to train early-career endosonographers in nCLE-guided diagnosis of PCLs.

METHODS

Twenty-one early-career nCLE-naïve endosonographers watched a teaching module outlining nCLE criteria for diagnosing PCLs. Participants then reviewed 80 high-yield nCLE videos, recorded diagnoses, and received expert feedback (phase 1). Observers were then randomized to a refresher feedback session or self-learning at 4 weeks. Eight weeks after training, participants independently assessed the same 80 nCLE videos without feedback and provided histologic predictions (phase 2). Diagnostic performance of nCLE to differentiate mucinous versus nonmucinous PCLs and to diagnose specific subtypes were analyzed using histopathology as the criterion standard. Learning curves were determined using cumulative sum analysis.

RESULTS

Accuracy and diagnostic confidence for differentiating mucinous versus nonmucinous PCLs improved as endosonographers progressed through nCLE videos in phase 1 (P < .001). Similar trends were observed with the diagnosis of PCL subtypes. Most participants achieved competency interpreting nCLE, requiring a median of 38 assessments (range, 9-67). During phase 2, participants independently differentiated PCLs with high accuracy (89%), high confidence (83%), and substantial interobserver agreement (κ = .63). Accuracy for nCLE-guided PCL subtype diagnoses ranged from 82% to 96%. The learned nCLE skills did not deteriorate at 8 weeks and were not impacted by a refresher session.

CONCLUSIONS

We developed a practical, effective, and durable educational intervention to train early-career endosonographers in nCLE-guided diagnosis of PCLs.

Surveillance of Pancreatic Cystic Neoplasms

Pancreatic cystic neoplasms (PCNs) are increasingly detected because of the widespread use of cross-sectional imaging and overall aging population. While the majority of these cysts are benign, some can progress to advanced neoplasia (defined as high-grade dysplasia and invasive cancer). As the only widely accepted treatment for PCNs with advanced neoplasia is surgical resection, accurate preoperative diagnosis, and stratification of malignant potential for deciding about surgery, surveillance or doing nothing remains a clinical challenge. Surveillance strategies for pancreatic cysts (PCNs) combine clinical evaluation and imaging to assess changes in cyst morphology and symptoms that may indicate advanced neoplasia. PCN surveillance heavily relies on various consensus clinical guidelines that focus on high-risk morphology, surgical indications, and surveillance intervals and modalities. This review will focus on current concepts in the surveillance of newly diagnosed PCNs, especially on low-risk presumed intraductal papillary mucinous neoplasms (those without worrisome features and high-risk stigmata), and appraise current clinical surveillance guidelines.

Artificial Intelligence in the Diagnosis and Treatment of Pancreatic Cystic Lesions and Adenocarcinoma

Pancreatic cancer is projected to become the second leading cause of cancer-related mortality in the United States by 2030. This is in part due to the paucity of reliable screening and diagnostic options for early detection. Amongst known pre-malignant pancreatic lesions, pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasms (IPMNs) are the most prevalent. The current standard of care for the diagnosis and classification of pancreatic cystic lesions (PCLs) involves cross-sectional imaging studies and endoscopic ultrasound (EUS) and, when indicated, EUS-guided fine needle aspiration and cyst fluid analysis. However, this is suboptimal for the identification and risk stratification of PCLs, with accuracy of only 65-75% for detecting mucinous PCLs. Artificial intelligence (AI) is a promising tool that has been applied to improve accuracy in screening for solid tumors, including breast, lung, cervical, and colon cancer. More recently, it has shown promise in diagnosing pancreatic cancer by identifying high-risk populations, risk-stratifying premalignant lesions, and predicting the progression of IPMNs to adenocarcinoma. This review summarizes the available literature on artificial intelligence in the screening and prognostication of precancerous lesions in the pancreas, and streamlining the diagnosis of pancreatic cancer.

Deep-Learning-Enabled Computer-Aided Diagnosis in the Classification of Pancreatic Cystic Lesions on Confocal Laser Endomicroscopy

Accurate classification of pancreatic cystic lesions (PCLs) is important to facilitate proper treatment and to improve patient outcomes. We utilized the convolutional neural network (CNN) of VGG19 to develop a computer-aided diagnosis (CAD) system in the classification of subtypes of PCLs in endoscopic ultrasound-guided needle-based confocal laser endomicroscopy (nCLE). From a retrospectively collected 22,424 nCLE video frames (50 videos) as the training/validation set and 11,047 nCLE video frames (18 videos) as the test set, we developed and compared the diagnostic performance of three CNNs with distinct methods of designating the region of interest. The diagnostic accuracy for subtypes of PCLs by CNNs with manual, maximal rectangular, and U-Net algorithm-designated ROIs was 100%, 38.9%, and 66.7% on a per-video basis and 88.99%, 73.94%, and 76.12% on a per-frame basis, respectively. Our per-frame analysis suggested differential levels of diagnostic accuracy among the five subtypes of PCLs, where non-mucinous PCLs (serous cystic neoplasm: 93.11%, cystic neuroendocrine tumor: 84.31%, and pseudocyst: 98%) had higher diagnostic accuracy than mucinous PCLs (intraductal papillary mucinous neoplasm: 84.43% and mucinous cystic neoplasm: 86.1%). Our CNN demonstrated superior specificity compared to the state-of-the-art for the classification of mucinous PCLs (IPMN and MCN), with high specificity (94.3% and 92.8%, respectively) but low sensitivity (46% and 45.2%, respectively). This suggests the complimentary role of CNN-enabled CAD systems, especially for clinically suspected mucinous PCLs.

Pancreatic Cystic Neoplasms: Diagnosis and Management

Pancreatic cancer is one of the most lethal cancers, largely related to the difficulties with early detection, as it typically presents in later stages. Pancreatic cystic neoplasms (PCN) are commonly diagnosed as incidental findings on routine imaging. PCN is becoming more frequently detected with the increasing ease and frequency of obtaining cross-sectional images. Certain subtypes of pancreatic cysts have the potential to progress to malignancy, and therefore, clinicians are tasked with creating a patient-centered management plan. The decision of whether to undergo surgical resection or interval surveillance can be challenging given the criteria, including PCN size, pancreatic duct dilation, presence of a mural nodule, and clinical symptoms that play a potential role in risk stratification. Furthermore, the guidelines available from the major gastrointestinal societies all differ in their management recommendations. In this review, we detail an overview of the different types of PCNs and compare major guidelines for both diagnosis and management. We include emerging evidence for next-generation sequencing as well as confocal needle endomicroscopy to aid in the diagnosis and determination of malignancy potential and diagnosis.

Accuracy and agreement of a large panel of endosonographers for endomicroscopy-guided virtual biopsy of pancreatic cystic lesions

BACKGROUND

Although emerging data evidences that EUS-guided needle-based confocal laser endomicroscopy (nCLE) accurately diagnoses pancreatic cystic lesions (PCLs), there are a lack of interobserver agreement (IOA) studies utilizing reference histopathological diagnosis and for specific PCL subtypes. Hence, we sought to assess the IOA, intra-observer reliability (IOR), and diagnostic performance of EUS-nCLE using a large cohort of patients with histopathological diagnosis amongst a broad panel of international observers.

METHODS

EUS-nCLE videos (n = 76) of subjects with PCLs [intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystadenoma (SCA), pseudocyst, and cystic-neuroendocrine tumors/solid pseudopapillary neoplasm (cystic-NET/SPN)], simulating clinical prevalence rates were obtained from 3 prospective studies. An international panel of 13 endosonographers with nCLE experience, blinded to all PCL data, evaluated the video library twice with a two-week washout for PCL differentiation (mucinous vs. non-mucinous) and subtype diagnosis.

RESULTS

The IOA (κ = 0.82, 95% CI 0.77-0.87) and IOR (κ = 0.82, 95% CI 0.78-0.85) were "almost perfect" to differentiate mucinous vs. non-mucinous PCLs. For PCL subtype, IOA was highest for SCA (almost perfect; κ = 0.85), followed by IPMN (substantial, κ = 0.72), and cystic-NET/SPN (substantial, κ = 0.73). The IOA was moderate for MCN (κ = 0.47), and pseudocyst (κ = 0.57). Compared to histopathology, observers differentiated mucinous vs. non-mucinous PCLs with high accuracy (94.8%, 95% CI 93.3-96.1). For detecting specific PCLs subtypes, EUS-nCLE was highly accurate in diagnosing non-mucinous cysts (SCA: 98%; cystic-NET/SPN: 96%; pseudocyst: 96%) and slightly less accurate for mucinous lesions (IPMN: 86%; MCN: 84%).

CONCLUSION

Diagnosis of PCLs by EUS-nCLE guided virtual biopsy is very accurate and reliable for the most prevalent pancreatic cysts in clinical practice.

Endoscopic techniques for diagnosis and treatment of gastro-entero-pancreatic neuroendocrine neoplasms: Where we are

BACKGROUND

The correct localization of the primary tumor site and a complete histological diagnosis represent the milestones for the proper management of gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs).

AIM

To analyze current evidence on the role of endoscopy in the diagnosis/treatment of GEP-NENs.

METHODS

An extensive bibliographical search was performed in PubMed to identify guidelines and primary literature (retrospective and prospective studies, systematic reviews, case series) published in the last 15 years, using both medical subject heading (MeSH) terms and free-language keywords: gastro-entero-pancreatic neuroendocrine neoplasms; endoscopy; ultrasound endoscopy; capsule endoscopy; double-balloon enteroscopy; diagnosis; therapy; staging.

RESULTS

In the diagnostic setting, endoscopic ultrasonography (EUS) represents the diagnostic gold standard for pancreatic NENs and the technique of choice for the locoregional staging of gastric, duodenal and rectal NENs. The diagnosis of small bowel NENs (sbNENs) has been improved with the advent of video capsule endoscopy and double-balloon enteroscopy, which allow for direct visualization of the entire small bowel; however, data regarding the efficacy/safety of these techniques in the detection of sbNENs are scanty and often inconclusive. From a therapeutic point of view, endoscopic removal is the treatment of choice for the majority of gastric NENs (type 1/2), for well-differentiated localized nonmetastatic duodenal NENs < 1 cm, confined to the submucosa layer and for < 10 mm, stage T1-T2, rectal NENs. EUS-guided pancreatic locoregional ablative treatments have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients.

CONCLUSION

Standard axial endoscopy and EUS still play a pivotal role in several GEP-NENs. Advanced techniques for increasing the rate of R0 resection should be reserved for high-volume referral centers.

Endoscopic ultrasound as a reliable tool for assessment of pancreatic adenocarcinoma treatment: Example of in situ gene therapy

Background and study aims  In pancreatic cancer, the antitumor effect can only be assessed by means of a computed tomography (CT) scan using RECIST (Response Evaluation Criteria in Solid Tumours) criteria. The aim of this study was to assess the intra-observer and interobserver agreement of endoscopic ultrasound (EUS) imaging in assessing tumor volume in primary pancreatic cancer. Patients and methods  During a Phase 1 gene therapy trial, 21 patients had EUS before the first and second EUS-guided in situ gene therapy injections. All anonymized EUS files were then randomly distributed to three gastroenterologists/endosonographers and three radiologists (blind status). The largest tumor diameter was measured and the intraclass correlation coefficient (ICC) was determined. Results  Intra-observer and interobserver agreements were good to excellent, regardless of operator experience (junior versus senior member of staff) (ICC: 0.65 to 0.84). A comparison of pretreatment and post-treatment measurements by the investigators highlighted a significant antitumor effect (-11 %; P  = 0.0098), similar to that obtained during the generic protocol (-10 %; P  = 0.0045). Conclusions  Interobserver agreement regarding primary pancreatic adenocarcinoma measurements appears good to excellent, thus paving the way for the future inclusion of EUS assessments, particularly in trials assessing local therapies for pancreatic tumors.

Needle-based confocal laser endomicroscopy for diagnosis of pancreatic cystic lesions: a meta-analysis

BACKGROUND AND AIM

The role of needle-based confocal laser endomicroscopy (nCLE) in the diagnosis of pancreatic cystic lesions (PCLs) remains controversial. This study aimed to systematically evaluate the diagnostic accuracy and adverse effects of nCLE in the detection of pathological subtypes in patients with PCLs.

MATERIAL AND METHODS

We conducted a comprehensive literature search using MEDLINE, EMBASE, and Cochrane for identifying studies that reported the use of nCLE for PCLs diagnosis (dated prior to 10 October 2020). Studies with a sample size >10 were included. We used the QUADAS-2 criteria for quality evaluation. We first extracted the diagnostic rates and the information on adverse events (AEs) from the studies; then used STATA15.0 to calculate the variables, draw forest plots and summary receiver operating characteristic (SROC) curves; and finally, we completed subgroup analyses to explore the heterogeneity.

RESULTS

Overall, 299 article titles were identified after an initial search, and ten studies with 547 individuals with PCLs were included in the analysis. The pooled sensitivity, specificity, positive likelihood ratio, and pooled negative likelihood ratio of nCLE in detecting gastric disorders were 90%, 96%, 20.4, and 0.11, respectively. The pooled sensitivity and specificity showed a substantial heterogeneity. An ROC curve was constructed with an area under the curve (AUC) of 0.94. The overall AEs rate of pancreatitis was 2.7%.

CONCLUSIONS

We showed that nCLE had a relatively high sensitivity and specificity for diagnosing PCLs with a relatively low rate of AEs occurring. We suggest that nCLE has good diagnostic accuracy for PCLs.

Targeted detection of cancer at the cellular level during biopsy by near-infrared confocal laser endomicroscopy

Suspicious nodules detected by radiography are often investigated by biopsy, but the diagnostic yield of biopsies of small nodules is poor. Here we report a method-NIR-nCLE-to detect cancer at the cellular level in real-time during biopsy. This technology integrates a cancer-targeted near-infrared (NIR) tracer with a needle-based confocal laser endomicroscopy (nCLE) system modified to detect NIR signal. We develop and test NIR-nCLE in preclinical models of pulmonary nodule biopsy including human specimens. We find that the technology has the resolution to identify a single cancer cell among normal fibroblast cells when co-cultured at a ratio of 1:1000, and can detect cancer cells in human tumors less than 2 cm in diameter. The NIR-nCLE technology rapidly delivers images that permit accurate discrimination between tumor and normal tissue by non-experts. This proof-of-concept study analyzes pulmonary nodules as a test case, but the results may be generalizable to other malignancies.

State-of-the-Art Update of Pancreatic Cysts

Andrew Canakis.

Recent advances in the diagnostic evaluation of pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are becoming more prevalent due to more frequent abdominal imaging and the increasing age of the general population. It has become crucial to identify these PCLs and subsequently risk stratify them to guide management. Given the high morbidity associated with pancreatic surgery, only those PCLs at high risk for malignancy should undergo such treatment. However, current diagnostic testing is suboptimal at accurately diagnosing and risk stratifying PCLs. Therefore, research has focused on developing new techniques for differentiating mucinous from non-mucinous PCLs and identifying high risk lesions for malignancy. Cross sectional imaging radiomics can potentially improve the predictive accuracy of primary risk stratification of PCLs at the time of detection to guide invasive testing. While cyst fluid glucose has reemerged as a potential biomarker, cyst fluid molecular markers have improved accuracy for identifying specific types of PCLs. Endoscopic ultrasound guided approaches such as confocal laser endomicroscopy and through the needle microforceps biopsy have shown a good correlation with histopathological findings and are evolving techniques for identifying and risk stratifying PCLs. While most of these recent diagnostics are only practiced at selective tertiary care centers, they hold a promise that management of PCLs will only get better in the future.

Risk Stratification of Pancreatic Cysts With Confocal Laser Endomicroscopy

In the modern era of high-quality cross-sectional imaging, pancreatic cysts (PCs) are a common finding. The prevalence of incidental PCs detected on cross-sectional abdominal imaging (such as CT scan) is 3%-14% which increases with age, up to 8% in those 70 years or older. Although PCs can be precursors of future pancreatic adenocarcinoma, imaging modalities such as CT scan, MRI, or endoscopic ultrasound with fine-needle aspiration (EUS-FNA) are suboptimal at risk stratifying the malignant potential of individual cysts. An inaccurate diagnosis could potentially overlook premalignant lesions, which can lead to missed lesions, lead to unnecessary surveillance, or cause significant long-term surgical morbidity from unwarranted removal of benign lesions. Although current guidelines recommend an EUS or MRI for surveillance, they lack the sensitivity to risk stratify and guide management decisions. Needle-based confocal laser endomicroscopy (nCLE) with EUS-FNA can be a superior diagnostic modality for PCs with sensitivity and accuracy exceeding 90%. Despite this, a significant challenge to the widespread use of nCLE is the lack of adequate exposure and training among gastroenterologists for the real-time interpretation of images. Better understanding, training, and familiarization with this novel technique and the imaging characteristics can overcome the limitations of nCLE use, improving clinical care of patients with PCs. Here, we aim to review the types of CLE in luminal and nonluminal gastrointestinal disorders with particular attention to the evaluation of PCs. Furthermore, we discuss the adverse events and safety of CLE.

Confocal laser endomicroscopy in gastro-intestinal endoscopy: technical aspects and clinical applications

Confocal laser endomicroscopy (CLE) is an advanced endoscopic imaging technology that provides a magnified, cellular level view of gastrointestinal epithelia. In conjunction with topical or intravenous fluorescent dyes, CLE allows for an "optical biopsy" for real-time diagnosis. Two different CLE system have been used in clinical endoscopy, probe-based CLE (pCLE) and endoscope-based CLE (eCLE). Using pCLE, the device can be delivered: (I) into the luminal gastrointestinal tract through the working channel of standard endoscopes; (II) into extraluminal cystic and solid parenchymal lesions through an endoscopic ultrasound (EUS) needle; or (III) into the biliary system through an endoscopic retrograde cholangiopancreatography (ERCP) accessory channel. With eCLE, the probe is directly integrated into the tip of a conventional endoscope, however, these endoscopes are no longer commercially available. CLE has moderate to high diagnostic accuracy for neoplastic and inflammatory conditions through the gastrointestinal tract including: oesophageal, gastric and colonic neoplasia, pancreatic cysts and solid lesions, malignant pancreatobiliary strictures and inflammatory bowel disease. Some studies have demonstrated the diagnostic benefit of CLE imaging when combined with either conventional white light endoscopy or advanced imaging technologies. Therefore, optical biopsies using CLE can resolve diagnostic dilemmas in some cases where conventional imaging fails to achieve conclusive results. CLE could also reduce the requirement for extensive tissue sampling during surveillance procedures. In the future, CLE in combination with molecular probes, could allow for the molecular characterization of diseases and assess response to targeted therapy. However, the narrow field of view, high capital costs and specialized operator training requirements remain the main limitations. Future multi-center, randomized trials with a focus on conventional diagnostic applications, cost-effectiveness and standardized training will be required for definitive evidence. The objective of this review is to evaluate the technical aspects and current applications of CLE in patients with gastrointestinal and pancreatobiliary diseases and discuss future directions for this technique.

Needle-based confocal endomicroscopy in the discrimination of mucinous from non-mucinous pancreatic cystic lesions

BACKGROUND

Pancreatic cystic lesions (PCLs) are considered a precursor of pancreatic cancer. Needle-based confocal endomicroscopy (nCLE) is an imaging technique that enables visualization of the mucosal layer to a micron resolution. Its application has demonstrated promising results in the distinction of PCLs. This study evaluated the utility of nCLE in patients with indeterminate PCLs undergoing endoscopic ultrasound fine-needle aspiration (EUS-FNA) to distinguish mucinous from non-mucinous lesions.

AIM

To evaluate the accuracy of nCLE in indeterminate PCLs undergoing EUS-FNA to distinguish mucinous from non-mucinous lesions.

METHODS

Patients who required EUS-FNA between 2015 and 2017 were enrolled prospectively. During EUS-FNA, confocal imaging, analyses of the tumor markers carcinoembryonic antigen and amylase, and cytologic examination were conducted. All patients were followed for at least 12 mo and underwent laboratory testing and computed tomography scanning or magnetic resonance imaging. nCLE videos were independently reviewed by 6 observers to reach a final diagnosis (mucinous vs non-mucinous) based on criteria derived from previous studies; if there was disagreement > 20%, a final diagnosis was discussed after consensus re-evaluation. The sensitivity, specificity, and accuracy of nCLE were calculated. Adverse events were recorded.

RESULTS

Fifty-nine patients were included in this study. Final diagnoses were derived from surgery in 10 patients, cytology in 13, and imaging and multidisciplinary team review in 36. Three patients were excluded from final diagnosis due to problems with nCLE acquisition. Fifty-six patients were included in the final analysis. The sensitivity, specificity, and accuracy of nCLE were 80% [95% confidence interval (CI): 65-90], 100% (95%CI: 72-100), and 84% (95%CI: 72-93), respectively. Post-procedure acute pancreatitis occurred in 5%.

CONCLUSION

EUS-nCLE performs better than standard EUS-FNA for the diagnosis of indeterminate PCL.

The Role of Confocal Endomicroscopy in the Diagnosis and Management of Pancreatic Cysts

Pancreatic cystic lesions are an increasingly common clinical finding. Current diagnostic techniques cannot reliably differentiate patients with high-risk lesions requiring surgical resection from those that can be safely surveyed or discharged. As a result, some patients may undergo unnecessary surgery with associated morbidity while others enter long-term surveillance with associated healthcare costs. Needle-based confocal laser endomicroscopy enables real time microscopic examination of the epithelial lining of a cyst wall at the time of a standard endoscopic ultrasound examination. The procedure is associated with low rates of adverse events, especially when the probe is loaded into the fine-needle aspiration needle before the procedure and examination times are limited. Needle-based confocal laser endomicroscopy has consistently been shown to have better diagnostic accuracy than cytology, which is often paucicellular and non-diagnostic in pancreatic cystic lesions. Studies have shown that diagnostic accuracy in needle-based confocal laser endomicroscopy is 84–95% in mucinous lesions and 39–99% in serous lesions. However, this technology is expensive and its place in diagnostic algorithms remains uncertain. Despite this, health economic analyses in certain health systems have been favourable, largely because of its potential to be able to discharge patients with benign lesions, such as serous cystic neoplasms, from long-term surveillance. Widespread adoption of this technology is unlikely but it has the potential to have an important role in indeterminate pancreatic cystic lesions.

Application of EUS-based techniques in the evaluation of pancreatic cystic neoplasms

Pancreatic cystic neoplasms (PCNs) are being detected increasingly frequently due to the widespread use of high-resolution abdominal imaging modalities. Some subtypes of PCNs have the potential for malignant transformation. Therefore, accurate diagnosis of PCNs is crucial to determine whether surgical resection or surveillance is the best management strategy. However, the current cross-section imaging modalities are not accurate enough to enable definite diagnoses. In the last decade, EUS-based techniques have emerged, aiming to overcome the limitations of standard cross-section imaging modalities. These novel EUS-based techniques were primarily designed to acquire distinct images to make radiological diagnoses, collect cyst fluid to undergo biochemical or molecular analyses, and obtain tissue to conclude the pathological diagnoses. In this article, we present a comprehensive and critical review of these emerging EUS techniques for the diagnosis of PCNs, with emphasis being placed on the advantages, feasibilities, diagnostic performances, and limitations of these novel techniques.

Cystic pancreatic lesions, the endless dilemma

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic lesions. The proper diagnosis, differentiation, and staging of these cystic lesions are considered a crucial issue in planning further management. There are great challenges for their diagnostic models. In our time, new emerging methods for this diagnosis have been discovered. Endoscopic ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needle-based confocal laser endomicroscopy, through the needle microforceps biopsy, and single-operator cholangioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic lesions. Hereby we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.

A new needle-based confocal laser endomicroscopy pattern of malignant pancreatic mucinous cystic lesions (with video)

Background and Objectives:

The diagnosis of malignant pancreatic cystic lesions (PCLs) remains challenging. Needle-based confocal laser endomicroscopy (nCLE) is an emerging promising imaging technique capable of real-time in vivo microscopic imaging of the cyst wall. We aimed to develop and validate a new nCLE diagnostic criteria for malignant mucinous cystic lesions (MLs).

Methods:

Patients referred for EUS-FNA of indeterminate PCLs with at least one worrisome features according to Fukouka consensus were consecutively prospectively enrolled from July 2016 to July 2018. The final diagnosis was based on surgical histology, cytopathology, or committee consensus. Five investigators nonblindly reviewed nCLE features and identified potential diagnostic feature for malignant MLs, which was also reviewed in histology imaging accordingly. Furthermore, the nCLE diagnostic feature was evaluated with an independent nCLE dataset by two investigators in a double-blind manner.

Results:

A nCLE pattern of dark aggregates of neoplastic cells was identified as diagnostic for MLs, which was consistent with histological findings of irregular branching and budding in malignant MLs. An independent validation revealed that the accuracy, sensitivity, and specificity of this feature for the diagnosis of malignant MLs were 94%, 75%, and 100%, respectively.

Conclusion:

The new nCLE criterion is promising for diagnosis of malignant MLs which warrants further confirmation in large cohort.

Confocal endomicroscopy for evaluation of pancreatic cystic lesions: a systematic review and international Delphi consensus report

Background and study aims  The aim of thi systematic review and consensus report is to standardize the practice of endoscopic ultrasound (EUS-guided needle-based confocal laser endomicroscopy (nCLE) for pancreatic cystic lesion (PCL) evaluation. Methods  We performed an international, systematic, evidence-based review of the applications, outcomes, procedural processes, indications, training, and credentialing of EUS-nCLE in management of PCLs. Based on available clinical evidence, preliminary nCLE consensus statements (nCLE-CS) were developed by an international panel of 15 experts in pancreatic diseases. These statements were then voted and edited by using a modified Delphi approach. An a priori threshold of 80 % agreement was used to establish consensus for each statement. Results  Sixteen nCLE-CS were discussed. Thirteen (81 %) nCLE-CS reached consensus addressing indications (non-communication PCL meeting criteria for EUS-FNA or with prior non-diagnostic EUS-FNA), diagnostic outcomes (improved accuracy for mucinous PCLs and serous cystadenomas with substantial interobserver agreement of image patterns), low incidence of adverse events (fluorescein-associated and pancreatitis), procedural processes (nCLE duration, manipulation of needle with probe), and training (physician knowledge and competence). Conclusion  Based on a high level of agreement pertaining to expert consensus statements, this report standardizes the practice of EUS-nCLE. EUS-nCLE should be systematically considered when EUS-FNA is indicated for PCL evaluation.

Confocal endomicroscopy for the diagnosis of pancreatic lesions

Confocal endomicroscopy (EMC) is a thriving technology that allows real-time and non-invasive imaging in vivo. EMC demonstrated its effectiveness to differentiate neoplastic from normal tissue and to search dysplasia. In addition to the significant developments of this technique in Barrett oesophagus, celiac disease, characterization of colonic polyps, or monitoring of chronic inflammatory bowel disease, EMC is currently developing in bilio-pancreatic pathology. Indeed, it is currently used to characterize biliary stenosis as well as pancreatic lesions (especially cystic). The aim of our study was to evaluate through a review of the literature the value of this technique in the characterization of pancreatic lesions.

Endosonographic diagnosis of advanced neoplasia in intraductal papillary mucinous neoplasms

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.

Management of Incidental Pancreatic Cystic Lesions: Integrating Novel Diagnostic and Prognostic Factors With Current Clinical Guidelines

Owing to increased detection rates, the diagnosis and management of incidental pancreatic cysts has become a common predicament. Up to 13% of patients undergoing cross-sectional imaging studies for other indications are found to have pancreatic cystic lesions. Although most cystic lesions are benign, the malignant potential of several types of pancreatic cysts makes accurate classification vital to directing therapy. To this end, advances in the last decade led to better characterization of pancreatic cyst morphology and hence enhanced the ability to predict underlying histopathology, and biological behavior. Although accurate classification remains a challenge, the utilization of complementary diagnostic tools is the optimal approach to dictate management. The following review includes a description of pancreatic cysts, a critical review of current and emerging diagnostic techniques and a review of recent guidelines in the management of incidental pancreatic cysts.

Impact of EUS-guided microforceps biopsy sampling and needle-based confocal laser endomicroscopy on the diagnostic yield and clinical management of pancreatic cystic lesions

BACKGROUND AND AIMS

EUS-guided microforceps biopsy sampling (MFB) and needle-based confocal laser endomicroscopy (nCLE) are emerging diagnostic tools for pancreatic cystic lesions (PCLs). There is a paucity of data regarding their performance and impact. The aim of this study was to compare diagnostic outcomes and changes in clinical management resulting from MFB and nCLE use in PCLs.

METHODS

This was a single-center retrospective study of patients with PCLs who underwent combined EUS-guided FNA, MFB, and nCLE. Primary outcomes included diagnostic yield (specific PCL type) and change in clinical management for each modality compared with the current "composite standard" (CS) obtained by combining clinical, morphologic, cyst fluid cytology, and chemical analysis.

RESULTS

Forty-four cysts were studied in 44 patients. Technical success was 100% for EUS-FNA, 88.6% for MFB, and 97.7% for nCLE. Of 44 procedures, there was 1 adverse event (2.3%, an infected pseudocyst). Diagnostic yield for each individual modality was 34.1% for CS, 75.0% for MFB (P < .05 vs CS), and 84.1% for nCLE (P < .05 vs CS). Diagnostic yield for combined tests was 79.5% for CS/MFB, 88.6% for CS/nCLE, and 93.2% for CS/MFB/nCLE (P = not significant). Compared with the CS, the use of MFB, nCLE, and their combination led to overall change in clinical management in 38.6%, 43.2%, and 52.3% of cases, respectively. MFB and nCLE led to an overall increase in discontinuation of surveillance (MFB, 34.1% [P < .05]; nCLE, 31.8% [P < .05]), led by a reduction in the indication for follow-up radiologic or endoscopic studies (MFB, 34.1% [P < .05]; nCLE, 38.6% [P < .05]). Based on MFB and nCLE, 2 of 28 (7.1%) and 3 of 28 (10.7%) patients who would have undergone further surveillance were referred for surgery.

CONCLUSIONS

In the evaluation of PCLs, the use of combined EUS-guided FNA, MFB, and nCLE is safe. MFB and nCLE led to significant improvements in specific PCL diagnosis, which in turn has major impacts in clinical management.

The Role of Needle-Based Confocal Laser Endomicroscopy in the Evaluation of Pancreatic Cystic Lesions: A Systematic Review

The prevalence of pancreatic cystic lesions (PCLs) has increased recently due to the increased use of cross-sectional abdominal imaging and the ageing global population. Current diagnostic techniques are inadequate to distinguish between PCLs that require surgery, close surveillance, or expectant management. This has resulted in increased morbidity from both inappropriately aggressive and conservative management strategies. Needle-based confocal laser endomicroscopy (nCLE) has allowed microscopic examination and visual delineation of the surface epithelium of PCLs. Landmark studies in this decade have correlated nCLE and histological findings and identified characteristics differentiating various types of PCLs. Subsequent studies have confirmed the high diagnostic yield of nCLE and its diagnostic utility in PCLs with an equivocal diagnosis. Moreover, nCLE has been shown to improve the diagnostic yield of PCLs. This will help avoid unnecessary pancreatic surgery, which carries significant morbidity and mortality risks. The early detection of high-grade dysplasia in PCLs will provide early surgical treatment and improve outcomes for pancreatic cancer. Despite the high upfront cost of nCLE, the improved diagnostic accuracy and resultant appropriate management have resulted in improved cost effectiveness. Refining the procedure technique and limiting the procedure length have significantly improved the safety of nCLE. A structured training program and device improvements to allow more complete mapping of the pancreatic cyst epithelium will be crucial for the widespread adoption of this promising technology.

Review of the diagnosis and management of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms are common lesions with the potential of harbouring/developing a pancreatic cancer. An accurate evaluation of intraductal papillary mucinous neoplasms with high-resolution imaging techniques and endoscopic ultrasound is mandatory in order to identify patients worthy either of surgical treatment or surveillance. In this review, the diagnosis and management of patients with intraductal papillary mucinous neoplasms are discussed with a specific focus on current guidelines. Areas of uncertainty are also discussed, as there are controversies related to the optimal indications for surgery, surveillance protocols and surveillance discontinuation.

EUS-guided confocal laser endomicroscopy: prediction of dysplasia in intraductal papillary mucinous neoplasms (with video)

BACKGROUND AND AIMS

Previous studies have validated EUS-guided needle-based confocal laser endomicroscopy (nCLE) diagnosis of intraductal papillary mucinous neoplasms (IPMNs). We sought to derive EUS-guided nCLE criteria for differentiating IPMNs with high-grade dysplasia/adenocarcinoma (HGD-Ca) from those with low/intermediate-grade dysplasia (LGD).

METHODS

We performed a post hoc analysis of consecutive IPMNs with a definitive diagnosis from a prospective study evaluating EUS-guided nCLE in the diagnosis of pancreatic cysts. Three internal endosonographers reviewed all nCLE videos for the patients and identified potential discriminatory EUS-guided nCLE variables to differentiate HGD-Ca from LGD IPMNs (phase 1). Next, an interobserver agreement (IOA) analysis of variables from phase 1 was performed among 6 blinded external nCLE experts (phase 2). Last, 7 blinded nCLE-naïve observers underwent training and quantified variables with the highest IOA from phase 2 using dedicated software (phase 3).

RESULTS

Among 26 IPMNs (HGD-Ca in 16), the reference standard was surgical histopathology in 24 and cytology confirmation of metastatic liver lesions in 2 patients. EUS-guided nCLE characteristics of increased papillary epithelial "width" and "darkness" were the most sensitive variables (90%; 95% confidence interval [CI], 84%-94% and 91%; 95% CI, 85%-95%, respectively) and accurate (85%; 95% CI, 78%-90% and 84%; 95% CI, 77%-89%, respectively) with substantial (κ = 0.61; 95% CI, 0.51-0.71) and moderate (κ = 0.55; 95% CI, 0.45-0.65) IOAs for detecting HGD-Ca, respectively (phase 2). Logistic regression models were fit for the outcome of HGD-Ca as predictor variables (phase 3). For papillary width (cut-off ≥50 μm), the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for detection of HGD-Ca were 87.5% (95% CI, 62%-99%), 100% (95% CI, 69%-100%), and 0.95, respectively. For papillary darkness (cut-off ≤90 pixel intensity), the sensitivity, specificity, and AUC for detection of HGD-Ca were 87.5% (95% CI, 62%-99%), 100% (95% CI, 69%-100%), and 0.90, respectively.

CONCLUSIONS

In this derivation study, quantification of papillary epithelial width and darkness identified HGD-Ca in IPMNs with high accuracy. These quantifiable variables can be used in multicenter studies for risk stratification of IPMNs. (Clinical trial registration number: NCT02516488.).

Endoscopic Ultrasound-Guided Confocal Laser Endomicroscopy Increases Accuracy of Differentiation of Pancreatic Cystic Lesions

BACKGROUND & AIMS

Imaging patterns from endoscopic ultrasound (EUS)-guided needle-based confocal laser endomicroscopy (nCLE) have been associated with specific pancreatic cystic lesions (PCLs). We compared the accuracy of EUS with nCLE in differentiating mucinous from nonmucinous PCLs with that of measurement of carcinoembryonic antigen (CEA) and cytology analysis.

METHODS

We performed a prospective study of 144 consecutive patients with a suspected PCL (≥20 mm) who underwent EUS with fine-needle aspiration of pancreatic cysts from June 2015 through December 2018 at a single center; 65 patients underwent surgical resection. Surgical samples were analyzed by histology (reference standard). During EUS, the needle with the miniprobe was placed in the cyst, which was analyzed by nCLE. Fluid was aspirated and analyzed for level of CEA and by cytology. We compared the accuracy of nCLE in differentiating mucinous from nonmucinous lesions with that of measurement of CEA and cytology analysis.

RESULTS

The mean size of dominant cysts was 36.4 ± 15.7 mm and the mean duration of nCLE imaging was 7.3 ± 2.8 min. Among the 65 subjects with surgically resected cysts analyzed histologically, 86.1% had at least 1 worrisome feature based on the 2012 Fukuoka criteria. Measurement of CEA and cytology analysis identified mucinous PCLs with 74% sensitivity, 61% specificity, and 71% accuracy. EUS with nCLE identified mucinous PCLs with 98% sensitivity, 94% specificity, and 97% accuracy. nCLE was more accurate in classifying mucinous vs nonmucinous cysts than the standard method (P < .001). The overall incidence of postprocedure acute pancreatitis was 3.5% (5 of 144); all episodes were mild, based on the revised Atlanta criteria.

CONCLUSIONS

In a prospective study, we found that analysis of cysts by nCLE identified mucinous cysts with greater accuracy than measurement of CEA and cytology analysis. EUS with nCLE can be used to differentiate mucinous from nonmucinous PCLs. ClincialTrials.gov no: NCT02516488.

New Devices for Endoscopic Treatments in Gastroenterology: A Narrative Review

Endoscopy is in a period of continuous innovations in terms of image quality, endoscopes, post-processing software and lastly, application of Artificial Intelligence. Therapeutic boundaries have expanded, widening the grey zone between endoscopy and surgery, and increasing endoscopic approaches in clinical scenarios where, until a few years ago, surgery was the only option. New scopes and accessories have made it easier to access critical areas such as the biliary tree and the small bowel intestine. In the field of hepato-pancreato-biliary endoscopy (HPB), it is now possible to directly access the biliary ducts or cystic lesions though dedicated stents and scopes, rather than having to rely only on fluoroscopy and ultrasound, increasing the diagnostic and therapeutic options by applying a three-dimensional approach. This narrative review will give an overview of some of the most relevant emerging fields in luminal and HPB endoscopy, highlighting advantages and main limitations of the techniques, and providing considerations for future development.

Diagnosis and management of pancreatic cystic neoplasms: current evidence and guidelines

Pancreatic cystic neoplasms (PCN) are a heterogeneous group of pancreatic cysts that include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystic neoplasms and other rare cystic lesions, all with different biological behaviours and variable risk of progression to malignancy. As more pancreatic cysts are incidentally discovered on routine cross-sectional imaging, optimal surveillance for patients with PCN is becoming an increasingly common clinical problem, highlighting the need to balance cancer prevention with the risk of (surgical) overtreatment. This Review summarizes the latest developments in the diagnosis and management of PCN, including the quality of available evidence. Also discussed are the most important differences between the PCN guidelines from the American Gastroenterological Association, the International Association of Pancreatology and the European Study Group on Cystic Tumours of the Pancreas, including diagnostic and follow-up strategies and indications for surgery. Finally, new developments in the management of patients with PCN are addressed.

Position statement on EUS-guided ablation of pancreatic cystic neoplasms from an international expert panel

Background and aim  Recently, several guidelines with divergent recommendations on management of pancreatic cystic neoplasm have been published but the role of endoscopic ultrasound (EUS)-guided pancreatic cyst ablation has not been thoroughly addressed. The aim of the current paper is to explore the issues surrounding EUS-guided pancreatic cyst ablation by generating a list of clinical questions and providing answers based on best scientific evidence available. Methods  An expert panel in EUS-guided pancreatic cyst ablation was recruited from members of the Asian EUS group and an international expert panel. A list of clinical questions was created and each question allocated to one member to generate a statement in response. The statements were then discussed in three Internet conference meetings between October 2016 and October 2017. The statements were changed until consensus was obtained. Afterwards, the complete set of statements was sent to all the panelist to vote on strength of the statements, classification of the statement sand grading of the evidence. Results  Twenty-three statements on EUS-guided drainage of pancreatic cyst ablation were formulated. The statements addressed indications for the procedures, technical aspects, pre-procedure and post-procedure management, management of complications, and competency and training in the procedures. Conclusion  The current set of statements on EUS-guided pancreatic cyst ablation are the first to be published by any endoscopic society. Clinicians interested in developing the technique should reference these statements and future studies should address the key issues raised in the document.

Endoscopic diagnosis of pancreatic cysts

PURPOSE OF REVIEW

Pancreatic cystic lesions (PCLs) are increasingly identified on abdominal imaging. Given the malignant potential of certain cyst subtypes and the poor survival rates of pancreatic cancer, accurate diagnosis and appropriate management of these cysts are critical.

RECENT FINDINGS

Advances in endoscopic ultrasound (EUS)-guided diagnostics have increased the accuracy of differentiating PCLs. These include cyst fluid molecular analysis, EUS-guided needle-based confocal laser endomicroscopy, and EUS-guided through the needle microforceps biopsy. This review encapsulates recent advances in the endoscopic management of PCLs with a specific focus on EUS-guided diagnosis.

SUMMARY

It is important to accurately diagnose pancreatic cystic lesions with malignant potential where the definitive management is surgical resection. Misdiagnosis can result in inadvertent surgery of an otherwise benign lesion or malignant progression of a precancerous cyst. Moreover, pancreatic surgery is associated with significant morbidity and mortality. Recent advances in EUS-guided tissue acquisition, imaging, and molecular biomarkers have resulted in improved diagnostic accuracy of pancreatic cystic lesions. Future studies need to define efficient and accurate diagnostic algorithms for improved management of pancreatic cysts.

Impact of needle-based confocal laser endomicroscopy on the therapeutic management of single pancreatic cystic lesions

Background and aim

The diagnosis and therapeutic management of large single pancreatic cystic lesions (PCLs) represent major issues for clinicians and essentially rely on endoscopic ultrasound fine-needle aspiration (EUS-FNA) findings. Needle-based confocal laser endomicroscopy (nCLE) has high diagnostic performance for PCLs. This study aimed to evaluate the impact of nCLE on the therapeutic management of patients with single PCLs.

Methods

Retrospective and comparative study. Five independent pancreatic disease experts from tertiary hospitals independently reviewed data from a prospective database of 206 patients with single PCL, larger than 2 cm and who underwent EUS-FNA and nCLE. Two evaluations were performed. The first one included the sequential review of clinical information, EUS report and FNA results. The second one included the same data + nCLE report. Participants had to propose a therapeutic management for each case.

Results

The addition of nCLE to EUS-FNA led to significant changes in therapeutic management for 28% of the patients (p < 0.001). nCLE significantly increased the interobserver agreement of 0.28 (p < 0.0001), from 0.36 (CI 95% 0.33–0.49) to 0.64 (CI 95% 0.61–0.67). nCLE improved the rates of full agreement among the five experts of 24% (p < 0.0001), from 30 to 54%. With nCLE, the surveillance rate of benign SCAs fell by 35%, from 40 (28/70) to 5% (4/76).

Conclusion

The addition of nCLE to EUS-FNA significantly improves reliability of PCL diagnosis and could impact the therapeutic management of patients with single PCLs. ClinicalTrials.gov number, NCT01563133.

Electronic supplementary material

The online version of this article (10.1007/s00464-019-07062-9) contains supplementary material, which is available to authorized users.

Advanced diagnostics for pancreatic cysts: Confocal endomicroscopy and molecular analysis

Technological advances and the widespread use of medical imaging have led to an increase in the identification of pancreatic cysts in patients who undergo cross-sectional imaging. Current methods for the diagnosis and risk-stratification of pancreatic cysts are suboptimal, resulting in both unnecessary surgical resection and overlooked cases of neoplasia. Accurate diagnosis is crucial for guiding how a pancreatic cyst is managed, whether with surveillance for low-risk lesions or surgical resection for high-risk lesions. This review aims to summarize the current literature on confocal endomicroscopy and cyst fluid molecular analysis for the evaluation of pancreatic cysts. These recent technologies are promising adjuncts to existing approaches with the potential to improve diagnostic accuracy and ultimately patient outcomes.

Needle-based confocal laser endomicroscopy for real-time diagnosing and staging of lung cancer

Diagnosing lung cancer in the absence of endobronchial abnormalities is challenging. Needle-based confocal laser endomicroscopy (nCLE) enables real-time microscopic imaging of cells. We assessed the feasibility and safety of using nCLE for real-time identification of lung cancer.

In patients with suspected or proven lung cancer scheduled for endoscopic ultrasound (EUS), lung tumours and mediastinal lymph nodes were imaged with nCLE before fine-needle aspiration (FNA) was performed. nCLE lung cancer characteristics were identified by comparison with pathology. Multiple blinded raters validated CLE videos of lung tumours and mediastinal nodes twice.

EUS-nCLE-FNA was performed in 22 patients with suspected or proven lung cancer in whom 27 lesions (six tumours, 21 mediastinal nodes) were evaluated without complications. Three nCLE lung cancer criteria (dark enlarged pleomorphic cells, dark clumps and directional streaming) were identified. The accuracy of nCLE imaging for detecting malignancy was 90% in tumours and 89% in metastatic lymph nodes. Both inter-observer agreement (mean κ=0.68, 95% CI 0.66–0.70) and intra-observer agreement (mean±sd κ=0.70±0.15) were substantial.

Real-time lung cancer detection by endosonography-guided nCLE was feasible and safe. Lung cancer characteristics were accurately recognised.

The Impact of Repeating Endosonography with Confocal Endomicroscopy for the Diagnosis of Cystic Neuroendocrine Tumor

Cystic pancreatic neuroendocrine tumors represent around 13% of all neuroendocrine tumors (Hurtado-Pardo 2017). There has been an increase in the incidence of cases due to improvement in imaging modalities. This is a case of a 68-year-old male with the incidental finding of a pancreatic cyst on CT. Initial Endoscopic Ultrasound with Fine Needle Aspiration (EUS-FNA) showed sonographic and cytology features suggestive of a pancreatic pseudocyst. However the cyst persisted with no change in size after aspiration leading to a follow-up EUS- FNA, which was combined with needle based confocal laser endomicroscopy (nCLE). The nCLE features were consistent with a cystic pancreatic neuroendocrine tumor, which was later confirmed on histology after surgical resection.

In Vivo and Ex Vivo Microscopy: Moving Toward the Integration of Optical Imaging Technologies Into Pathology Practice

The traditional surgical pathology assessment requires tissue to be removed from the patient, then processed, sectioned, stained, and interpreted by a pathologist using a light microscope. Today, an array of alternate optical imaging technologies allow tissue to be viewed at high resolution, in real time, without the need for processing, fixation, freezing, or staining. Optical imaging can be done in living patients without tissue removal, termed in vivo microscopy, or also in freshly excised tissue, termed ex vivo microscopy. Both in vivo and ex vivo microscopy have tremendous potential for clinical impact in a wide variety of applications. However, in order for these technologies to enter mainstream clinical care, an expert will be required to assess and interpret the imaging data. The optical images generated from these imaging techniques are often similar to the light microscopic images that pathologists already have expertise in interpreting. Other clinical specialists do not have this same expertise in microscopy, therefore, pathologists are a logical choice to step into the developing role of microscopic imaging expert. Here, we review the emerging technologies of in vivo and ex vivo microscopy in terms of the technical aspects and potential clinical applications. We also discuss why pathologists are essential to the successful clinical adoption of such technologies and the educational resources available to help them step into this emerging role.