Histologic Analysis of Endoscopic Ultrasound-Guided Through the Needle Microforceps Biopsies Accurately Identifies Mucinous Pancreas Cysts

Endoscopic Ultrasound-Guided Through-the-Needle Biopsy: A Narrative Review of the Technique and Its Emerging Role in Pancreatic Cyst Diagnosis

Pancreatic cystic lesions (PCLs) pose a diagnostic challenge due to their increasing incidence and the limitations of cross-sectional imaging and endoscopic-ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-guided through the needle biopsy (EUS-TTNB) has emerged as a promising tool for improving the accuracy of cyst type determination and neoplastic risk stratification. EUS-TTNB demonstrates superior diagnostic performance over EUS-FNA, providing critical preoperative information that can significantly influence patient management and reduce unnecessary surgeries. However, the procedure has risks, with an overall adverse event rate of approximately 9%. Preventive measures and further prospective studies are essential to optimize its safety and efficacy. This review highlights the potential of EUS-TTNB to enhance the diagnostic and management approaches for patients with PCLs. It examines the current state of EUS-TTNB, including available devices, indications, procedural techniques, specimen handling, diagnostic yield, clinical impact, and associated adverse events.

Risk of Pancreatitis After Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Pancreatic Cystic Lesions: A Systematic Review and Meta-Analysis

INTRODUCTION

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is frequently used to risk-stratify pancreatic cystic lesions (PCLs). Rising PCL incidence and developments in tissue acquisition and specimen analysis necessitate updated appraisal of EUS-FNA safety, particularly the risk of postprocedure pancreatitis, the most common EUS-FNA-related adverse event. Our systematic review aims to accurately quantify the risk of EUS-FNA-related pancreatitis to best inform decisions regarding EUS-FNA's optimal role in PCL workup.

METHODS

We performed systematic searches in 4 databases from inception to April 2024 for original English-language studies investigating EUS-FNA-related pancreatitis. We extracted data on demographics and EUS-FNA-related pancreatitis risk, severity, and risk factors. These were meta-analyzed through the DerSimonian Laird Method using a random-effects model. Meta-regression of pancreatitis risk was performed to delineate associations with clinical and procedural characteristics.

RESULTS

Sixty-four studies comprised 8,086 patients and reported 110 EUS-FNA-related pancreatitis events. Pooled risk of EUS-FNA-related pancreatitis was 1.4% (95% confidence intervals, -0.8% to 3.5%; I2 = 0.00), which was predominantly of mild severity (67%) and uniformly nonfatal. Pancreatitis risk lacked significant association with sample size, age, sex, cyst size, needle caliber, or passes, although we noted trends toward higher risk in studies published after 2015, those using higher gauge needles (19 G vs 22 G/25 G), and those performing EUS-guided through-the-needle biopsy.

DISCUSSION

We note with high certainty that pancreatitis after EUS-FNA of PCLs is infrequent and mild in severity with no mortality in the included cohort. EUS-guided through-the-needle biopsy may serve as a significant risk factor for EUS-FNA-related pancreatitis risk; however, further studies are needed to delineate other predisposing characteristics.

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.

Value of Endoscopic Ultrasound-Guided Through-the-Needle Biopsy in Pancreatic Cystic Lesions. A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Endoscopic ultrasound-guided through-the-needle biopsy (EUS-TTNB) has been used over the past few years to increase diagnostic accuracy for pancreatic cystic lesions (PCLs). However, many concerns remain regarding its widespread use. This systematic review and meta-analysis aimed to pool the data from high-quality studies to evaluate the utility of EUS-TTNB in diagnosing PCLs.

METHODS

Electronic databases (PubMed, Embase, and Cochrane Library) from January 2010 through October 2022 were searched for publications addressing the diagnostic performance of EUS-TTNB in the diagnosis of pancreatic cystic lesions. Pooled proportions were calculated using fixed (inverse variance) and random-effects (DerSimonian-Laird) models.

RESULTS

The initial search identified 635 studies, of which 35 relevant articles were reviewed. We extracted data from 11 studies that met the inclusion criterion, comprising a total of 575 patients. Mean patient age was 62.25 years ± 6.12 with females constituting 61.39% of the study population. Pooled sensitivity of EUS-TTNB in differentiating a PCL as neoplastic or non-neoplastic was 76.60% (95% CI = 72.60-80. 30). For the same indication, EUS TTNB had a pooled specificity of 98.90% (95% CI = 93.80-100.00). The positive likelihood ratio was 10.28 (95% CI = 4.77-22.15), and the negative likelihood ratio was 0.26 (95% CI = 0.22-0.31). The pooled diagnostic odds ratio for EUS-TTNB in diagnosing PCLs as malignant/pre-malignant vs. non-malignant was 41.34 (95% CI = 17.42-98.08). Pooled adverse event rates were 3.04% (95% CI = 1.83-4.54) for pancreatitis, 4.02% (95% CI = 2.61-5.72) for intra-cystic bleeding, 0.94% (95% CI = 0.33-1.86) for fever, and 1.73% (95% CI = 0.85-2.91) for other minor events.

CONCLUSIONS

EUS-TTNB has good sensitivity with excellent specificity in accurately classifying PCLs as neoplastic or non-neoplastic. Adding EUS-TTNB to EUS-FNA increases the accuracy of EUS-guided approach in diagnosing PCLs. However, it could significantly increase the risk of post-procedural pancreatitis.

Endoscopic Imaging of Pancreatic Cysts

Pancreatic cystic lesions (PCLs) have been diagnosed with increasing frequency likely due to the widespread use of cross-sectional imaging. A precise diagnosis of the PCL is important because it helps identify patients in need of surgical resection and those who can undergo surveillance imaging. A combination of clinical and imaging findings as well as cyst fluid markers can help classify PCLs and guide management. This review focuses on endoscopic imaging of PCLs including endoscopic and endosonographic features and fine needle aspiration. We then review the role of adjunct techniques, such as microforceps, contrast-enhanced endoscopic ultrasound, pancreatoscopy, and confocal laser endomicroscopy.

Pancreatic Cystic Neoplasms: Translating Guidelines into Clinical Practice

A combination of several factors, including the increasing use of cross-sectional imaging and an aging population, has led to pancreatic cystic lesions (PCLs) becoming the most detected incidental pancreatic lesions. Accurate diagnosis and risk stratification of PCLs is challenging. In the last decade, several evidence-based guidelines have been published addressing the diagnosis and management of PCLs. However, these guidelines cover different subsets of patients with PCLs and offer varying recommendations regarding diagnostic assessment, surveillance, and surgical resection. Further, recent studies comparing the accuracy of various guidelines have reported significant variations in the rate of missed cancer versus unnecessary surgical resections. In clinical practice, it is challenging to decide which guideline to follow specifically. This article reviews the varying recommendations of the major guidelines and results of comparative studies, provides an overview of newer modalities not included in the guidelines, and offers perspectives on translating the guidelines into clinical practice.

Comparative Performance of Endoscopic Ultrasound-Based Techniques in Patients With Pancreatic Cystic Lesions: A Network Meta-Analysis

INTRODUCTION

Evidence on the comparative diagnostic performance of endoscopic ultrasound (EUS)-based techniques for pancreatic cystic lesions (PCLs) is limited. This network meta-analysis comprehensively compared EUS-based techniques for PCL diagnosis.

METHODS

A comprehensive literature search was performed for all comparative studies assessing the accuracy of 2 or more modalities for PCL diagnosis. The primary outcome was the diagnostic efficacy for mucinous PCLs. Secondary outcomes were the diagnostic efficacy for malignant PCLs, diagnostic success rate, and adverse event rate. A network meta-analysis was conducted using the ANOVA model to assess the diagnostic accuracy of each index.

RESULTS

Forty studies comprising 3,641 patients were identified. The network ranking of the superiority index for EUS-guided needle-based confocal laser endomicroscopy (EUS-nCLE) and EUS-guided through-the-needle biopsy (EUS-TTNB) were significantly higher than other techniques for differentiating mucinous PCLs; besides, EUS-TTNB was also the optimal technique in identifying malignant PCLs. The evidence was inadequate for EUS-nCLE diagnosing malignant PCLs and contrast-enhanced harmonic EUS diagnosing both mucinous and malignant PCLs. Glucose showed a high sensitivity but low specificity, and molecular analysis (KRAS, GNAS, and KRAS + GNAS mutations) showed a high specificity but low sensitivity for diagnosing mucinous PCLs. Satisfactory results were not obtained during the evaluation of the efficiency of pancreatic cyst fluid (PCF) biomarkers in detecting malignant PCLs.

DISCUSSION

For centers with relevant expertise and facilities, EUS-TTNB and EUS-nCLE were better choices for the diagnosis of PCLs. Further studies are urgently required for further improving PCF biomarkers and validating the diagnostic performance of the index techniques.

Targeted next-generation sequencing of EUS-guided through-the-needle-biopsy sampling from pancreatic cystic lesions

BACKGROUND AND AIMS

Recent advances have introduced molecular subtyping of pancreatic cystic lesions (PCLs) as a possible amendment to the diagnostic algorithm. The study evaluated the feasibility and diagnostic accuracy of molecular analysis and subtyping of PCLs using the recently introduced EUS-guided through-the-needle-biopsy (TTNB) sampling.

METHODS

We prospectively included 101 patients in the study who presented with PCLs >15 mm in the largest cross-section. EUS-guided TTNB samples were obtained by a micro-biopsy forceps introduced through a 19-gauge needle. The TTNB samples were analyzed by next-generation sequencing (NGS) for point mutations in tumor suppressors and oncogenes using a 51-gene customized hotspot panel. Sensitivity and specificity were calculated with the histologic diagnosis as reference.

RESULTS

After initial microscopic evaluation of the samples, 91 patients had residual TTNB samples available for NGS. Of these, 49 harbored mutations, most frequently in KRAS and GNAS, reflecting an excess frequency of intraductal papillary mucinous neoplasms (IPMNs) in the study population. A sensitivity and specificity of 83.7% (95% confidence interval [CI], 70.3-92.7) and 81.8% (95% CI, 48.2-97.7), respectively, were demonstrated for the diagnosis of a mucinous cyst and 87.2% (95% CI, 74.2-95.2) and 84.6% (95% CI, 54.5-98.1) for the diagnosis of an IPMN.

CONCLUSIONS

Thus, molecular analysis of TTNB samples by NGS has high sensitivity and specificity for diagnosing mucinous cysts and IPMNs. Although the procedure comes with a risk of adverse events of 9.9%, TTNB samples are a robust alternative to cyst fluid for a combined histologic and molecular diagnosis of PCLs. (Clinical trial registration number: NCT03578445.).

Predictors of adverse events after endoscopic ultrasound-guided through-the-needle biopsy of pancreatic cysts: a recursive partitioning analysis

BACKGROUND AND STUDY AIMS : Endoscopic ultrasound-guided through-the-needle biopsy (TTNB) of pancreatic cystic lesions (PCLs) is associated with a non-negligible risk for adverse events (AEs). We aimed to identify the hierarchic interaction among independent predictors for TTNB-related AEs and to generate a prognostic model using recursive partitioning analysis (RPA). PATIENTS AND METHODS : Multicenter retrospective analysis of 506 patients with PCLs who underwent TTNB. RPA of predictors for AEs was performed and the model was validated by means of bootstrap resampling. RESULTS : Mean cysts size was 36.7 mm. Most common diagnoses were intraductal papillary mucinous neoplasm (IPMN, 45 %), serous cystadenoma (18.8 %), and mucinous cystadenoma (12.8 %). Fifty-eight (11.5 %) AEs were observed. At multivariate analysis, age (odds ratio [OR] 1.32, 1.09-2.14; p = 0.05), number of TTNB passes (OR from 2.17, 1.32-4.34 to OR 3.16, 2.03-6.34 with the increase of the number of passes), complete aspiration of the cyst (OR 0.56, 0.31-0.95; p = 0.02), and diagnosis of IPMN (OR 4.16, 2.27-7.69; p < 0.001) were found to be independent predictors of AEs, as confirmed by logistic regression and random forest analyses. RPA identified three risk classes: high-risk (IPMN sampled with multiple microforceps passes, 28 % AEs rate), low-risk (1.4 % AE rate, including patients < 64 years with other-than-IPMN diagnosis sampled with ≤ 2 microforceps passes and with complete aspiration of the cyst) and middle-risk class (6.1 % AEs rate, including the remaining patients). CONCLUSION : TTNB should be selectively used in the evaluation of patients with IPMN. The present model could be applied during patient selection as to optimize the benefit/risk of TTNB.

New and emerging technology in the diagnosis and treatment of pancreatic cysts

Pancreatic cysts have always presented as a diagnostic dilemma due to the difficulties in identifying patients with current imaging modalities that could most benefit from surgical intervention. Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystadenomas (MCNs) carry the highest malignant potential of all pancreatic cysts and pancreatic adenocarcinoma carries a high mortality as the fourth leading cause of cancer-related deaths. However, surgery to remove benign cysts also carries a high morbidity and occasional mortality. Opportunities to identify and reduce pre-cancer lesions must be aggressively pursued. Multidetector helical CT (MDHCT) or an up-to-date MRI is the first diagnostic tool to evaluate a suspected pancreatic lesion. Currently, review by a multidisciplinary group who specialize in pancreatic cysts and pancreatic cancer is advised to review factors such as a patient's comorbidities, the type of surgery needed to remove the cyst and the estimated morbidity and mortality associated with the procedure. Some recent data are emerging to assist with identifying those at highest risk such as cyst fluid analysis, laser endomicroscopy, and artificial intelligence (AI). This article reviews the current status, benefits, challenges and future prospects on diagnosis and treatment of pancreatic cysts. Further prospective randomized control trials are needed to determine the optimal management and treatment for patients with pancreatic cysts.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy and needle-based confocal laser-endomicroscopy increase detection of potentially malignant pancreatic cystic lesions: A single-center study

BACKGROUND

Currently, there is insufficient data about the accuracy in the diagnosing of pancreatic cystic lesions (PCLs), especially with novel endoscopic techniques such as with direct intracystic micro-forceps biopsy (mFB) and needle-based confocal laser-endomicroscopy (nCLE).

AIM

To compare the accuracy of endoscopic ultrasound (EUS) and associated techniques for the detection of potentially malignant PCLs: EUS-guided fine needle aspiration (EUS-FNA), contrast-enhanced EUS (CE-EUS), EUS-guided fiberoptic probe cystoscopy (cystoscopy), mFB, and nCLE.

METHODS

This was a single-center, retrospective study. We identified patients who had undergone EUS, with or without additional diagnostic techniques, and had been diagnosed with PCLs. We determined agreement among malignancy after 24-mo follow-up findings with detection of potentially malignant PCLs via the EUS-guided techniques and/or EUS-guided biopsy when available (EUS malignancy detection).

RESULTS

A total of 129 patients were included, with EUS performed alone in 47/129. In 82/129 patients, EUS procedures were performed with additional EUS-FNA (21/82), CE-EUS (20/82), cystoscopy (27/82), mFB (36/82), nCLE (44/82). Agreement between EUS malignancy detection and the 24-mo follow-up findings was higher when associated with additional diagnostic techniques than EUS alone [62/82 (75.6%) vs 8/47 (17%); OR 4.35, 95%CI: 2.70-7.37; P < 0.001]. The highest malignancy detection accuracy was reached when nCLE and direct intracystic mFB were both performed, with a sensitivity, specificity, positive predictive value, negative predictive value and observed agreement of 100%, 89.4%, 77.8%, 100% and 92.3%, respectively (P < 0.001 compared with EUS-alone).

CONCLUSION

The combined use of EUS-guided mFB and nCLE improves detection of potentially malignant PCLs compared with EUS-alone, EUS-FNA, CE-EUS or cystoscopy.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy and needle-based confocal laser-endomicroscopy increase detection of potentially malignant pancreatic cystic lesions: A single-center study

BACKGROUND

Currently, there is insufficient data about the accuracy in the diagnosing of pancreatic cystic lesions (PCLs), especially with novel endoscopic techniques such as with direct intracystic micro-forceps biopsy (mFB) and needle-based confocal laser-endomicroscopy (nCLE).

AIM

To compare the accuracy of endoscopic ultrasound (EUS) and associated techniques for the detection of potentially malignant PCLs: EUS-guided fine needle aspiration (EUS-FNA), contrast-enhanced EUS (CE-EUS), EUS-guided fiberoptic probe cystoscopy (cystoscopy), mFB, and nCLE.

METHODS

This was a single-center, retrospective study. We identified patients who had undergone EUS, with or without additional diagnostic techniques, and had been diagnosed with PCLs. We determined agreement among malignancy after 24-mo follow-up findings with detection of potentially malignant PCLs via the EUS-guided techniques and/or EUS-guided biopsy when available (EUS malignancy detection).

RESULTS

A total of 129 patients were included, with EUS performed alone in 47/129. In 82/129 patients, EUS procedures were performed with additional EUS-FNA (21/82), CE-EUS (20/82), cystoscopy (27/82), mFB (36/82), nCLE (44/82). Agreement between EUS malignancy detection and the 24-mo follow-up findings was higher when associated with additional diagnostic techniques than EUS alone [62/82 (75.6%) vs 8/47 (17%); OR 4.35, 95%CI: 2.70-7.37; P < 0.001]. The highest malignancy detection accuracy was reached when nCLE and direct intracystic mFB were both performed, with a sensitivity, specificity, positive predictive value, negative predictive value and observed agreement of 100%, 89.4%, 77.8%, 100% and 92.3%, respectively (P < 0.001 compared with EUS-alone).

CONCLUSION

The combined use of EUS-guided mFB and nCLE improves detection of potentially malignant PCLs compared with EUS-alone, EUS-FNA, CE-EUS or cystoscopy.

Through-the-needle biopsy of pancreatic cystic lesions: current evidence and implications for clinical practice

INTRODUCTION

There is increasing evidence to support the efficacy of endoscopic ultrasound (EUS)-guided through-the-needle biopsy (TTNB) technique as a means of sampling pancreatic cystic lesions (PCLs). Results provide evidence demonstrating the benefits of this procedure over standard EUS fine-needle aspiration (FNA), thus supporting a push for its widespread implementation in clinical practice. Though this technique has demonstrated advantages, achieving these advantages in clinical practice is contingent upon careful considerations to ensure safety and efficacy.

AREAS COVERED

The purpose of this review is to assess the level of evidence supporting the use of through-the-needle biopsy, revise its main technical and procedural characteristics, and to develop suggested guidelines outlining the safe assimilation of this device in clinical practice.

EXPERT OPINION

EUS-TTNB enables more definitive and accurate diagnosis of PCLs by providing higher-quality histological samples. However, EUS-TTNB is not appropriate for all PCLs. Selection of suitable patients as well as morphology and risk factors of the cystic lesion is a crucial component of achieving the described benefits of this procedure while minimizing risks of adverse effects. Subjects with weak or absent indications for this procedure are susceptible to a range of complications and may even result in fatality.

Management of pancreatic cysts and guidelines: what the gastroenterologist needs to know

The prevalence of pancreatic cysts has increased significantly over the last decade, partly secondary to increased quality and frequency of cross-sectional imaging. While the majority never progress to cancer, a small number will and need to be followed. The management of pancreatic cysts can be both confusing and intimidating due to the multiple guidelines with varying recommendations. Despite the differences in the specifics of the guidelines, they all agree on several high-risk features that should get the attention of any clinician when assessing a pancreatic cyst: presence of a mural nodule or solid component, dilation of the main pancreatic duct (or presence of main duct intraductal papillary mucinous neoplasm), pancreatic cyst size ⩾3–4 cm, or positive cytology on pancreatic cyst fluid aspiration. Other important criteria to consider include rapid cyst growth (⩾5 mm/year), elevated serum carbohydrate antigen 19-9 levels, new-onset diabetes mellitus, or acute pancreatitis thought to be related to the cystic lesion.

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.

Molecular heterogeneity of pancreatic intraductal papillary mucinous neoplasms and implications for novel endoscopic tissue sampling strategies

AIMS

Intraductal papillary mucinous neoplasms (IPMNs) may be precursor lesions of pancreatic cancer. The path towards malignancy is associated with mutations in tumour suppressor-and oncogenes that may serve as biomarkers during diagnostic investigation. A novel micro forceps has made it possible to obtain biopsies from the cyst wall for analysis by next generation sequencing (NGS), providing an opportunity for early detection and intervention. However, the impact of spatial tumour heterogeneity on the representability of the biopsies has not been determined. The primary aim is to characterise the impact of molecular heterogeneity of the luminal cyst wall on tissue sampling strategies with small biopsies.

METHODS

We performed NGS and immunohistochemical phenotyping on 18 resected IPMNs with varying degrees of dysplasia and for a subset, concomitant carcinoma, using a commercially available NGS-panel of 51 oncogenes. We simulated endoscopic biopsies by performing punch biopsies (PBs) of the cyst wall from resected specimens.

RESULTS

In total, 127 NGS analyses were performed. Concomitant KRAS and GNAS was a common feature of the IPMNs. Mutations in KRAS and GNAS were associated with low-grade dysplasia whereas alterations in TP53, SMAD4, CDKN2A and PIK3CA were associated with high-grade dysplasia and/or carcinoma. The mutational analysis of the PBs from the cyst wall was compared with the whole lesion. No difference was detected between PBs and whole lesions when the cumulated mutational profile in increasing order of randomly performed PBs was compared.

CONCLUSIONS

Small IPMN biopsies from the cyst wall are adequate to yield a molecular diagnosis.

Histopathological evaluation of resected intraductal papillary mucinous neoplasms reveals distinct patterns of invasion in associated carcinomas

Invasive intraductal papillary mucinous neoplasms (inv-IPMNs) have a better prognosis than regular pancreatic ductal adenocarcinoma (PDAC), but no association with status of surgical margins and microscopic infiltration patterns has previously been described. The aim of this study is to review patterns of invasion and the predictive value of clinical guidelines in terms of rates of resection of high-grade dysplasia (HGD) and cancer among intraductal papillary mucinous neoplasms (IPMNs). Consecutively, resected IPMNs between 2011 and 2017 were analyzed. Data were obtained from a prospectively maintained database. A total of 132 patients were identified. Out of these, 38 patients with inv-IPMNs, initially identified as solid lesions suspicious of cancer, were compared with a control group of 101 patients with ordinary PDAC. Lower rates of vascular invasion, perineural invasion, lymph node metastasis, advanced T stage, and R1 status were characteristic of the inv-IPMNs in addition to better overall survival (OS) for a low tumor stage. Furthermore, as novel findings, the PDACs presented with resection margin involvement of 3 or more positive margins (31.3% vs. 9.5%, p = 0.044), associated with poor OS. Of the patients presenting as pT3, the inv-IPMN less often invaded more than one extrapancreatic anatomical structure (40.1% vs. 63.9%, p = 0.03). Regarding the predictive value of clinical guidelines, the frequency of resected HGD in IPMNs with high-risk stigmata (n = 54) and IPMNs with worrisome features was 30.7%, and the frequency of invasive carcinoma was 5.7%. In conclusion, we report a low resection rate of high-risk IPMNs and present novel findings describing inv-IPMNs as a less infiltrative phenotype compared with regular PDAC.

A Review of the Diagnosis and Management of Premalignant Pancreatic Cystic Lesions

Pancreatic cystic lesions are an increasingly common clinical finding. They represent a heterogeneous group of lesions that include two of the three known precursors of pancreatic cancer, intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN). Given that approximately 8% of pancreatic cancers arise from these lesions, careful surveillance and timely surgery offers an opportunity for early curative resection in a disease with a dismal prognosis. This review summarizes the current evidence and guidelines for the diagnosis and management of IPMN/MCN. Current pre-operative diagnostic tests in pancreatic cysts are imperfect and a proportion of patients continue to undergo unnecessary surgical resection annually. Balancing cancer prevention while preventing surgical overtreatment, continues to be challenging when managing pancreatic cysts. Cyst fluid molecular markers, such as KRAS, GNAS, VHL, PIK3CA, SMAD4 and TP53, as well as emerging endoscopic technologies such as needle-based confocal laser endomicroscopy and through the needle microbiopsy forceps demonstrate improved diagnostic accuracy. Differences in management and areas of uncertainty between the guidelines are also discussed, including indications for surgery, surveillance protocols and if and when surveillance can be discontinued.

Diagnostic accuracy of EUS-guided through-the-needle-biopsies and simultaneously obtained fine needle aspiration for cytology from pancreatic cysts: A systematic review and meta-analysis

OBJECTIVES

To address the diagnostic accuracy of endoscopic ultrasound guided through-the-needle-biopsies (TTNBs) and simultaneously obtained cytology samples from pancreatic cysts compared to the final histopathological diagnosis of the surgical specimen, and to give an overview of ancillary tests performed on TTNBs.

METHODS

A literature search was conducted in MEDLINE, Embase and Scopus. Studies were included in the meta-analysis, if they had data for TTNB, cytology and a surgical specimen of pancreatic cysts as reference standard. The assessment of the risk of bias and quality of the included studies was conducted using the modified QUADAS-2 tool.

RESULTS

Ten studies with 99 patients were included in the meta-analysis. Data regarding study design and clinicopathological features were extracted systematically. For TTNB, pooled sensitivity was 0.86 (95 % CI 0.62-0.96), specificity 0.95 (95 % CI 0.79-0.99) and area under the curve (AUC) 0.86 for the diagnosis of a mucinous cyst and pooled sensitivity was 0.78 (95 % CI 0.61-0.89), specificity 0.99 (95 % CI 0.90-0.99) and AUC 0.92 for the diagnosis of a high-risk cyst. For a specific diagnosis, pooled sensitivity was 0.69 (95 % CI 0.50-0.83), specificity 0.47 (95 % CI 0.28-0.68) and AUC 0.49. For cytology performed simultaneously, pooled sensitivity was 0.46 (95 % CI 0.35-0.57), specificity 0.90 (95 % CI 0.46-0.99) and AUC 0.64 for the diagnosis of mucinous cysts, and pooled sensitivity was 0.38 (95 % CI 0.23-0.55), specificity 0.99 (95 % CI 0.90-0.99) and AUC 0.84 for the diagnosis of a high-risk cyst. For a specific diagnosis, pooled sensitivity was 0.29 (95 % CI 0.21-0.39), specificity 0.45 (95 % CI 0.25-0.66) and AUC 0.30. Furthermore, immunohistochemical stains can be useful to establish the specific cyst subtype.

CONCLUSIONS

TTNBs have a higher sensitivity and specificity than cytology for the diagnosis of mucinous cyst and high- risk cysts of the pancreas.

Quality assessment for systematic reviews and meta-analyses of cohort studies

BACKGROUND AND AIMS

There is a growing need for valid, efficient, and easy scoring scales to rate the quality of cohort studies. We aimed to develop and validate a quality assessment score to be used for cohort studies.

METHODS

We followed a rigorous process to establish content, face, and construct validity. Most questions were scored at 0 or 1. Inter-rater reliability and test-retest reliability were assessed using the Spearman correlation coefficient (r_s) and Cohen's κ statistic. Internal consistency was measured using the Kuder-Richardson formula 20 (KR20).

RESULTS

The final tool consists of 9 questions with a maximum score of 10. The inter-rater reliability was high with the Spearman correlation coefficient (r_s = .66). Agreement for inclusion was 90%. Test-retest reliability was high. For rater 1, r_s = .91, κ = .38 for scores, and κ = 1 for inclusion. For rater 2, r = .94, 80% agreement for scores, and 100% agreement for inclusion. Internal consistency was reasonable based on 2 studies: KR20 = .21 and KR20 = .65. The novel scale rated highest in efficiency, understandably, ease of use, and ease of interpretation when compared with 3 other scales.

CONCLUSIONS

This novel scale has favorable performance characteristics, is efficient to conduct, and is easy to interpret and will be very helpful for physicians and researchers conducting systematic reviews and meta-analyses.

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.

Clinical impact of endoscopic ultrasound-guided through-the-needle microbiopsy in patients with pancreatic cysts

BACKGROUND

The limited data on the utility of endoscopic ultrasound (EUS)-guided through-the-needle biopsies (TTNBs) in patients with pancreatic cystic lesions (PCLs) originate mainly from retrospective studies. Our aim was to determine the clinical impact of TTNBs, their added diagnostic value, and the adverse event rate in a prospective setting.

METHODS

This was a prospective, single-center, open-label controlled study. Between February 2018 and August 2019, consecutive patients presenting with a PCL of 15 mm or more and referred for EUS were included. Primary outcome was a change in clinical management of PCLs following TTNB compared with cross-sectional imaging and cytology. Adverse events were defined according to the ASGE lexicon.

RESULTS

101 patients were included. TTNBs led to a change in clinical management in 11.9 % of cases (n = 12). Of these, 10 had serous cysts and surveillance was discontinued, while one of the remaining two cases underwent surgery following diagnosis of a mucinous cystic neoplasm. The diagnostic yield of TTNBs for a specific cyst diagnosis was higher compared with FNA cytology (69.3 % vs. 20.8 %, respectively; P < 0.001). The adverse event rate was 9.9 % (n = 10; 95 % confidence interval 5.4 % - 17.3 %), with the most common event being acute pancreatitis (n = 9). Four of the observed adverse events were severe, including one fatal outcome.

CONCLUSIONS

TTNBs resulted in a change of clinical management in about one in every 10 patients; however, the associated adverse event risk was substantial. Further studies are warranted to elucidate in which subgroups of patients the clinical benefit outweighs the risks.

EUS-through-the-needle microbiopsy forceps in pancreatic cystic lesions: A systematic review

Pancreatic cystic lesions (PCLs) are being increasingly encountered in clinical practice, and sometimes, they can represent a diagnostic challenge. Recently, a through-the-needle micro forceps biopsy (MFB) device was introduced in the endosonography practice to facilitate EUS-guided sampling of PCLs. The aim was to perform a systematic review of studies evaluating the technical aspects, safety, and efficacy of the EUS-guided MFB for PCLs. A literature search was performed in three major databases, PubMed, Embase, and Web of Science in September 2019 using the search terms: "through-the-needle," "biopsy forceps," "microforceps," "endoscopic ultrasound," and "endosonography." Case reports and case series with <10 patients were excluded from the analysis. Altogether nine studies reporting on 463 patients were included in our systematic review. The mean age of the patients was 68.3 years, with a slight female predominance (60.9%). Most of the cysts were located in the body/tail of the pancreas (61.2%), with an overall mean size of 33 mm. The technical success of EUS-guided MFB was reported in 98.5%. The tissue acquisition yield reported was 88.2%, and the diagnostic accuracy was 68.6%. Adverse events were reported in 9.7%. EUS-guided MFB is technically feasible, safe, and has a high diagnostic accuracy for PCLs.

EUS-guided biopsy versus confocal laser endomicroscopy in patients with pancreatic cystic lesions: A systematic review and meta-analysis

Background and Objectives:

Pancreatic cystic lesions (PCLs) are frequent incidental findings on cross-sectional imaging and represent a diagnostic challenge as different kinds of PCLs harbor a dissimilar risk of malignancy. Two diagnostic tools have recently been developed and introduced: through-the-needle biopsy (TTNB) and needle-based confocal laser endomicroscopy (nCLE). The aim of this meta-analysis was to compare the diagnostic yield and performance, as well as the safety profile of the two methods.

Methods:

This meta-analysis was performed in accordance with the PRISMA statement. Medline, Embase, Web of Science, and Cochrane Library databases were searched for studies with five or more patients undergoing either endoscopic ultrasound (EUS)-TTNB or EUS-nCLE for a PCL. Reviews, case reports, editorials, conference abstracts, and studies on exclusively solid pancreatic lesions were excluded. Outcomes of interest were diagnostic yield and performance, safety, and technical success.

Results:

Twenty studies with 1023 patients were included in the meta-analysis. Pooled diagnostic yield of EUS-nCLE was higher compared to EUS-TTNB (85% vs. 74%, P < 0.0001), while diagnostic performance was high and comparable for both methods (pooled sensitivity: 80% vs. 86% and pooled specificity: 80% vs. 83% for TTNB and nCLE, respectively, P > 0.05). Pooled estimate of total adverse event (AE) rate was 5% in the TTNB group and 3% in the nCLE group, P = 0.302. Technical success rates were high and comparable (94% and 99% for EUS-TTNB and nCLE, respectively; P = 0.07).

Conclusion:

EUS-TTNB and EUS-nCLE have a similar safety profile with a relatively low number of AEs. Technical success, sensitivity, and specificity are comparable; however, EUS-nCLE seems to have a slightly higher diagnostic yield.

Diagnostic performance of current guidelines and postoperative outcome following surgical treatment of cystic pancreatic lesions - a 10-year single center experience

OBJECTIVE

Pancreatic cystic lesions (PCLs) are diagnostically challenging and there are currently several different guidelines. The aim of this study was to compare diagnostic performance of the most widely utilized International Association of Pancreatology (IAP) guidelines and the recent evidence-based European guidelines and to report on postoperative outcomes following surgical treatment of PCLs.

METHODS

This is a retrospective single-center study of patients undergoing surgery due to a PCL between 2010 and 2019. Primary outcome was a comparison of diagnostic performance between IAP and European guidelines, measured in area under the receiver operating characteristic curve (AUC). Other outcomes included diagnostic performance of different risk features, 30-day postoperative mortality and major morbidity, final diagnosis, and overall survival.

RESULTS

We identified 137 patients, three of whom did not undergo curative surgery due to metastatic disease. Overall, there was no difference in the performance of the two guidelines with AUC values ranging from 0.572-0.610 and 0.607-0.621 for IAP and European guidelines respectively. Postoperative 30-day mortality and major morbidity were 0% (95% CI 0.0-2.7%) and 37.3% (95% CI 29.1-46.1%), respectively. More than half of the resected lesions (52.6%) were low-grade dysplastic or non-neoplastic.

CONCLUSIONS

Overall, the IAP and the European guidelines performed equally, although European guidelines had a slightly higher mean specificity. Pancreatic surgery is associated with high major morbidity, and there is a need for new diagnostic tools and strategies in order to decrease the amount of overtreatment in patients with PCL.

Diagnostic performance of endoscopic ultrasound through-the-needle microforceps biopsy of pancreatic cystic lesions: Systematic review with meta-analysis

OBJECTIVES

Endoscopic ultrasound through-the-needle biopsy (EUS-TTNB) is a useful tool for differential diagnosis among pancreatic cystic lesions (PCLs). Cystic fluid cytology (CFC) is recommended by guidelines, but its diagnostic accuracy is about 50%. The aim of this meta-analysis is to assess the clinical impact of EUS-TTNB in terms of technical success (TS), histological accuracy (HA) and diagnostic yield (DY).

METHODS

Original studies in English language on EUS-TTNB were searched in MEDLINE and EMBASE until October 2019. Diagnostic accuracy of EUS-TTNB for identification of mucinous PCLs was calculated using individual diagnostic data of patients who underwent CFC and surgery.

RESULTS

Nine studies, including 454 patients who underwent EUS-TTNB, met the inclusion criteria for the meta-analysis. TS and HA of EUS-TTNB were, respectively, 98.5% (95% Confidence Interval [CI] 97.3%-99.6%) and 86.7% (95%CI 80.1-93.4). DY was 69.5% (95%CI 59.2-79.7) for EUS-TTNB and 28.7% (95%CI 15.7-41.6) for CFC. Heterogeneity persisted significantly high in most of subgroup analyses. In the multivariate meta-regression, cyst size was independently associated with higher DY. Sensitivity and specificity for mucinous PCLs were 88.6 and 94.7% for EUS-TTNB, and 40 and 100% for CFC. Adverse events rate was 8.6% (95%CI 4.0-13.1).

CONCLUSIONS

This meta-analysis shows that EUS-TTNB is a feasible technique that allows a high rate of adequate specimens to be obtained for histology; in about two-thirds of patients a specific histotype diagnosis could be assessed. The number of adverse events is slightly higher respect to standard EUS-FNA, but complications are very rarely severe.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy improves diagnostic yield for pancreatic cystic lesions: a systematic review and meta-analysis

Background and study aims  Given variable diagnostic yield of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) for pancreatic cystic lesions (PCLs), a through-the-needle (TTN) microforceps biopsy device passed through a 19-gauge FNA needle has been devised to improve tissue sampling. This was a systematic review and meta-analysis to evaluate the feasibility, diagnostic yield, and safety of EUS-guided TTN microforceps biopsy for diagnosis of PCLs. Methods  Individualized searches were developed in accordance with PRISMA and MOOSE guidelines. This was a cumulative meta-analysis performed by calculating pooled proportions with rates estimated using random effects models. Measured outcomes included pooled technical success, diagnostic yield, accuracy, and procedure-associated adverse events (AEs) as well as comparison to conventional FNA. Results  Eleven studies (n = 518 patients; mean age 64.13 ± 5.83 years; 58.19 % female) were included. Mean PCL size was 33.39 ± 3.72 mm with the pancreatic head/uncinate (35.50 %) being the most common location. A mean of 2.47 ± 0.92 forceps passes were performed with a mean of 2.79 ± 0.81 microbiopsies obtained per lesion. Pooled technical success was 97.12 % (95 % CI, 93.73-98.71; I ²  = 34.49) with a diagnostic yield of 79.60 % (95 % CI, 72.62-85.16; I ²  = 56.00), and accuracy of 82.76 % [(95 % CI, 77.80-86.80; I ²  = 0.00). The pooled serious adverse event rate was 1.08 % (95 % CI, 0.43-2.69; I ²  = 0.00). Compared to conventional FNA, TTN microforceps biopsy resulted in significant improvement in diagnostic yield [OR 4.79 (95 % CI: 1.52-15.06; P  = 0.007)] and diagnostic accuracy [OR 8.69 (95 % CI, 1.12-67.12; P  = 0.038)], respectively. Conclusions  EUS-guided TTN microforceps biopsy appears to be safe and effective for diagnosis of PCLs with improvement in diagnostic yield and accuracy when compared to FNA alone.

Endoscopic ultrasound-guided, through-the-needle forceps biopsy for diagnosis of pancreatic cystic lesions: a systematic review

Background and study aims  Pancreatic cystic lesions (PCL), are a heterogeneous group of cystic lesions. Some patients with PCLs have a significantly higher overall risk of pancreatic cancer and the only test that can differentiate benign and malignnat PCL is fine-needle aspiration plus cytological analysis, but its sensitivity is very low. Through-the-needle direct intracystic biopsy is a technique that allows acquisition of targeted tissue from PCLs and it may improve the diagnostic yield for them. The aim of this study was to review articles about endoscopic ultrasound (EUS)-guided through-the-needle intracystic biopsy for targeted tissue acquisition and diagnosis of PCLs. Methods  A systematic review of computerized bibliographic databases was carried out for studies of EUS-guided through-the-needle forceps biopsy (EUS-TTNB) of PCLs. The percentages and their 95 % confidence intervals (CIs) were calculated for all the considered endpoints (technical success, adequate specimens, adverse events (AEs), and overall diagnosis). Results  Overall, eight studies with a total of 423 patients were identified. Pooled technical success was 95.6 % of the cases (399/423), (95 % CI, 93.2 %-97.3 %). Technical failure rate was 5.1 % (24 cases). Frequency of adequate specimens was 82.2 %, (95 % CI, 78.5 %-85.8 %). Adverse events were reported in seven of the eight studies. Forty-two total adverse events were reported (10.1 %) (95 % CI, 7.3 %-13.6 %). The overall ability to provide a specific diagnosis with EUS-TTNB for diagnosis of pancreatic cystic lesions was 74.6 % (313 cases), (95 % CI: 70.2 %-78.7 %). The most frequent diagnoses found with EUS-TTNB were mucinous cystic neoplasms (MCN) in 96 cases (30.6 %), IPMN in 80 cases (25.5 %), and serous cystoadenoma neoplasm (SCN) in 48 cases (15.3 %). Conclusions  Through-the-needle forceps biopsy appears to be effective and safe, with few AE for diagnosis of pancreatic cystic lesions. This technique had acceptable rates of technical and clinical success and an excellent safety profile. TTNB is associated with a high tissue acquisition yield and provided additional diagnostic yield for mucinous pancreatic lesions. TTNB may be a useful adjunctive tool for EUS-guided assessment of PCLs.

Current Status of Needles in the Optimization of Endoscopic Ultrasound-Guided Procedures

Endoscopic ultrasound (EUS) is among the most important tools for the evaluation of gastrointestinal tumors and affected areas around the gastrointestinal tract. It enables the acquisition of material from abnormal lesions via the gastrointestinal wall for tissue confirmation via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-FNA has played a vital role in oncological care and has become the standard method for tissue sampling. The choice of needle type is an important factor determining tissue acquisition and has been evaluated by many researchers. New needles are introduced into the market almost every year, and opinions vary regarding proper needle selection. While there are diverse opinions but no definitive recommendations about the use of one particular device, fine-needle biopsy needles may provide detailed information on a tissue’s architecture based on greater sample yields. This permits additional analyses, including genetic sequencing and phenotyping, thereby enabling the provision of more personalized treatment plans. Furthermore, other EUS-guided procedures have been developed, including interventional EUS and through-the-needle devices. Given the continued attempts to improve the diagnostic ability and therapeutic techniques, we review in detail the available types of puncture needles to provide guidance on the selection of the appropriate needle types.

Diagnostic yield of EUS-guided through-the-needle biopsy in pancreatic cysts: a meta-analysis

BACKGROUND AND AIMS

There is currently limited evidence supporting the use of EUS-guided through-the-needle biopsy for sampling pancreatic cystic lesions. The aim of this meta-analysis was to provide a pooled estimate of the diagnostic performance of through-the-needle biopsy for sampling of pancreatic cysts.

METHODS

A bibliographic search on the main databases was performed in September 2019. Pooled effects were calculated using a random-effects model by means of the DerSimonian and Laird test. The primary outcome was sample adequacy. Additional endpoints were diagnostic accuracy, optimal histologic core procurement, mean number of needle passes, pooled specificity, and sensitivity. Adverse event rates were also analyzed.

RESULTS

Eleven studies enrolling 490 patients were included. Eight articles compared through-the-needle biopsy with cytology/cystic fluid analysis. Most patients were female, and the body/tail was the most frequent location of cystic lesions. Sample adequacy with through-the-needle biopsy was 85.3% (78.2%-92.5%), and subanalysis performed according to cyst morphology, size, and location confirmed the result. Through-the-needle biopsy clearly outperformed FNA both in terms of sample adequacy (odds ratio, 4.83; 95% confidence interval, 1.63-14.31; P =.004) and diagnostic accuracy (odds ratio, 3.44; 95% confidence interval, 1.32-8.96; P =.01). The pooled diagnostic accuracy rate, sensitivity, and specificity of through-the-needle biopsy were 78.8%, 82.2%, and 96.8%, respectively. A mean of 3.121 (2.98-3.25) passes through the cyst was needed to obtain adequate histologic samples. The incidence rates of mild bleeding and pancreatitis were 4% and 2%, respectively.

CONCLUSION

Our meta-analysis speaks in favor of the use of through-the-needle biopsy as a safe and effective tool in EUS-guided tissue acquisition of pancreatic cysts.

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.

Diagnostic yield of EUS-guided through-the-needle microforceps biopsy versus EUS-FNA of pancreatic cystic lesions: a systematic review and meta-analysis

Background and study aims  Accurate diagnosis and risk stratification of pancreatic cysts (PCs) is challenging. The aim of this study was to perform a systematic review and meta-analysis to assess the feasibility, safety, and diagnostic yield of endoscopic ultrasound-guided through-the-needle biopsy (TTNB) versus fine-needle aspiration (FNA) in PCs. Methods  Comprehensive search of databases (PubMed, EMBASE, Cochrane, Web of Science) for relevant studies on TTNB of PCs (from inception to June 2019). The primary outcome was to compare the pooled diagnostic yield and concordance rate with surgical pathology of TTNB histology and FNA cytology of PCs. The secondary outcome was to estimate the safety profile of TTNB. Results: Eight studies (426 patients) were included. The diagnostic yield was significantly higher with TTNB over FNA for a specific cyst type (OR: 9.4; 95 % CI: [5.7-15.4]; I ²  = 48) or a mucinous cyst (MC) (OR: 3.9; 95 % CI: [2.0-7.4], I ²  = 72 %). The concordance rate with surgical pathology was significantly higher with TTNB over FNA for a specific cyst type (OR: 13.5; 95 % CI: [3.5-52.3]; I ²  = 48), for a MC (OR: 8.9; 95 % [CI: 1.9-40.8]; I ²  = 29), and for MC histologic severity (OR: 10.4; 95 % CI: [2.9-36.9]; I ²  = 0). The pooled sensitivity and specificity of TTNB for MCs were 90.1 % (95 % CI: [78.4-97.6]; I ²  = 36.5 %) and 94 % (95 % CI: [81.5-99.7]; I ²  = 0), respectively. The pooled adverse event rate was 7.0 % (95 % CI: [2.3-14.1]; I ²  = 82.9). Conclusions  TTNB is safe, has a high sensitivity and specificity for MCs and may be superior to FNA cytology in risk-stratifying MCs and providing a specific cyst diagnosis.

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.

Utility of endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration for the diagnosis and management of pancreatic cystic lesions: Differences between the guidelines

Recent advances and frequent use of cross-sectional imaging studies have increased opportunities for incidental diagnoses of pancreatic cystic lesions (PCL). In the management of PCL, distinguishing between mucinous versus non-mucinous and malignant versus benign cysts is important to diagnose pancreatic cancer in its early stage. For this reason, there have been several guidelines to manage PCL. Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (FNA) play important roles in the guidelines, although there are some differences in their roles. In this review, we aimed to evaluate the current status of EUS and EUS-FNA in the management of PCL and the status of these procedures in the guidelines.

EUS-guided through-the-needle microbiopsy of pancreatic cysts: Technical aspects (with video)

Pancreatic cystic lesions are frequently encountered and diagnostically challenging as some of the cysts may have malignant potential (mucinous) while others are completely benign (serous). EUS-guided through-the-needle biopsy (EUS-TTNB) of the cyst wall has recently been introduced as an alternative to cyst fluid cytology. Several studies have shown that microbiopsies outperform cytology in terms of distinction between mucinous and nonmucinous lesions, but also in determining the specific cyst diagnosis. However, little is known about the technical aspects of tissue sampling with TTNB. Herein, we summarize our experience with the procedure in a tertiary referral center and discuss indications, technical aspects, and safety of the procedure. Most adverse events (AEs) associated with the procedure are mild, but there is emerging evidence that the rate of postprocedural pancreatitis is higher compared to standard fine-needle aspiration. The added diagnostic yield should therefore be placed in perspective with an increased risk of AEs. Prospective studies are warranted to fully identify which patient groups could benefit from EUS-TTNB.

Association between macroscopically visible tissue samples and diagnostic accuracy of EUS-guided through-the-needle microforceps biopsy sampling of pancreatic cystic lesions

BACKGROUND AND AIMS

EUS-guided through-the-needle biopsy (TTNB) sampling has been reported to improve diagnostic yield compared with cytology for the evaluation of pancreatic cystic lesions (PCLs). The number of macroscopically visible tissue samples needed to reach an adequate diagnosis is still unknown.

METHODS

This is a retrospective, single-center study on consecutive patients with PCLs with risk features (cyst >3 cm, thickened wall, cyst growth during follow-up, and mural nodules) who underwent TTNB sampling. The capability of differentiating mucinous versus nonmucinous cysts, ability to obtain a cyst-lining epithelium, definition of the grade of dysplasia, and specific diagnosis of cyst histotype were evaluated for 1, 2, or 3 TTNB macroscopically visible specimens.

RESULTS

Sixty-one patients were evaluated. A 100% histologic adequacy was reached by 2 samples (P = .05 versus 1). Compared with cytology, 1 TTNB specimen improved the possibility of defining cyst histotype (P < .0001), whereas 2 specimens increased all 4 diagnostic categories (P < .003). Two specimens also increased diagnostic yield compared with 1 sample (P < .085). The collection of a third sample did not improve the value of any diagnostic categories. A specific diagnosis was reached in 74% of patients with 2 histologic samples. The diagnostic reliability of TTNB sampling compared with surgical histology was 90%, with a 22.9% rate of adverse events.

CONCLUSIONS

Two TTNB macroscopically visible specimens reached 100% histologic adequacy and a specific diagnosis in 74% of patients. The collection of a third specimen did not add any additional information and should be avoided to possibly decrease the risk of adverse events.

Endoscopic ultrasound-through-the-needle biopsy in pancreatic cystic lesions: A large single center experience

BACKGROUND

Establishing a diagnosis of pancreatic cystic lesions (PCLs) preoperatively still remains challenging. Recently, endoscopic ultrasound (EUS)-through-the-needle biopsy (EUS-TTNB) using microforceps in PCLs has been made available.

AIM

To assess the efficacy and safety of EUS-TTNB in the diagnosis of PCLs.

METHODS

We retrospectively collected data of patients with PCLs who underwent both EUS-fine-needle aspiration (FNA) for cytology and EUS-TTNB at our institution since 2016. EUS-FNA for cytology was followed by EUS-TTNB in the same session. Evaluation of the cyst location, primary diagnosis, adverse events, and comparison between the cytologic fluid analyses and histopathology was performed. Technical success of EUS-TTNB was defined as visible tissue present after biopsy. Clinical success was defined as the presence of a specimen adequate to make a histologic or cytologic diagnosis.

RESULTS

A total of 56 patients (mean age 66.9 ± 11.7, 53.6% females) with PCLs were enrolled over the study period. The mean cyst size was 28.8 mm (12-85 mm). The EUS-TTNB procedure was technically successful in all patients (100%). The clinical success rate using EUS-TTNB was much higher than standard EUS-FNA, respectively 80.4% (45/56) vs 25% (14/56). Adverse events occurred in 2 patients (3.6%) who developed mild pancreatitis that resolved with medical therapy. Using TTNB specimens, 23 of 32 cases (71.9%) with intraductal papillary mucinous neoplasm were further differentiated into gastric type (19 patients) and pancreaticobiliary type (4 patients) based on immunochemical staining.

CONCLUSION

EUS-TTNB for PCLs was technically feasible and had a favorable safety profile. Furthermore, the diagnostic yield for PCLs was much higher with EUS-TTNB than standard EUS-FNA cytology and fluid carcinoembryonic antigen. EUS-TTNB should be considered as an adjunct to EUS-FNA and cytologic analysis in the diagnosis and management of PCLs.

Interobserver agreement among expert pathologists on through-the-needle microforceps biopsy samples for evaluation of pancreatic cystic lesions

BACKGROUND AND AIMS

The recent development of microforceps for EUS through-the-needle biopsy (TTNB) sampling of the wall of pancreatic cystic lesions (PCLs) allows the collection of histologic specimens never handled and evaluated before by pathologists. We aimed to estimate the interobserver agreement among pathologists in evaluating such samples.

METHODS

TTNB specimen slides from 40 PCLs with worrisome features were retrieved and independently evaluated for specimen adequacy, presence of lining epithelium, grade of epithelial dysplasia, presence of ovarian type stroma, and specific diagnosis by 6 expert pathologists from 6 different tertiary care centers. The Gwet's AC1 was used to assess interobserver agreement.

RESULTS

An almost perfect agreement was observed for specimen adequacy (AC1, .82; 95% confidence interval [CI], .79-.98), presence of lesional epithelium (AC1, .90; 95% CI, .86-.92), epithelial dysplasia (AC1, .97; 95% CI, .95-.99), and ovarian-like stroma (AC1, .90; 95% CI, .86-.93). When considering all diagnoses separately, a moderate to substantial agreement was observed (AC1, .62; 95% CI, .57-.67), similarly to mucinous cysts versus serous adenoma versus other diagnoses (AC1, .65; 95% CI, .59-.70) and for mucinous cysts versus all other diagnoses (AC1,.74; 95% CI, .68-.84). The agreement for diagnosis of mucinous cystic neoplasm versus intraductal mucinous papillary neoplasm was almost perfect (AC1, .88; 95% CI, .81-.95).

CONCLUSIONS

Interobserver agreement between expert pathologists in the evaluation of TTNB samples from PCLs with worrisome features was close to perfection for all evaluated parameters, except definitive diagnosis. When mucinous cystic lesions were compared versus all other diagnoses, the agreement became substantial, thus indicating that TTNB specimens can provide important information for PCL management decisions.