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

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.

The World Health Organization classification of pancreaticobiliary cytopathology stratifies risk of malignancy and outcome for endoscopic ultrasound-guided fine-needle aspiration of the pancreas

BACKGROUND

The World Health Organization (WHO) has recently published a classification for reporting pancreaticobiliary cytopathology with differences compared to the Papanicolaou Society of Cytopathology (PSC) classification.

METHODS

Retrospective data were collected from pancreatic endoscopic ultrasound-guided fine-needle aspirations from 2014 to 2017 at a pancreatic cancer center. Absolute risk of malignancy (AROM), relative risk (to benign), performance characteristics, and overall survival were calculated for the entire cohort with comparison of cysts and solid lesions.

RESULTS

In total, 2562 cases were included: 16% cyst (n = 411) and 84% solid (n = 2151). The histologic confirmation rate was 43% (n = 1101) and the median follow-up (for benign) was 56 months. For WHO I-VII, overall AROM (%) was 23, 22, 62, 13, 65, 97, and 100; cyst AROM was 7, 0, 19, 13, 38, 78, and 100; and solid AROM was 50, 29, 70, 15, 100, 99, and 100. For PSC I-VI, overall AROM (%) was 23, 29, 64, 0 (IVa), 60 (IVb), 97, and 100; cyst AROM was 7, 0, 19, 0, 21, 78, and 100; and solid AROM was 50, 35, 73, 0, 92, 99, and 100. The difference in relative risk for a cyst (vs. solid) overall was 0.38 for WHO and 0.26 for PSC. WHO and PSC categories showed stratification for the probability of overall survival.

CONCLUSIONS

Cystic versus solid lesion type can dramatically affect AROM, particularly for nondiagnostic (I), benign (II), atypical (III), and WHO V categories. WHO IV conveys a similarly low AROM for cystic and solid types. Both classifications stratify the probability of overall survival, including the newly introduced categories WHO IV and WHO V.

Exploring a novel composite method using non-contrast EUS enhanced microvascular imaging and cyst fluid analysis to differentiate pancreatic cystic lesions

BACKGROUND AND AIMS

Differentiating pancreatic cystic lesions (PCLs) remains a diagnostic challenge. The use of high-definition imaging modalities which detect tumor microvasculature have been described in solid lesions. We aim to evaluate the usefulness of cystic microvasculature when used in combination with cyst fluid biochemistry to differentiate PCLs.

METHODS

We retrospectively analyzed 110 consecutive patients with PCLs from 2 Italian Hospitals who underwent EUS with H-Flow and EUS fine needle aspiration to obtain cystic fluid. The accuracy of fluid biomarkers was evaluated against morphological features on radiology and EUS. Gold standard for diagnosis was surgical resection. A clinical and radiological follow up was applied in those patients who were not resected because not surgical indication and no signs of malignancy were shown.

RESULTS

Of 110 patients, 65 were diagnosed with a mucinous cyst, 41 with a non-mucinous cyst, and 4 with an undetermined cyst. Fluid analysis alone yielded 76.7% sensitivity, 56.7% specificity, 77.8 positive predictive value (PPV), 55.3 negative predictive value (NPV) and 56% accuracy in diagnosing pancreatic cysts alone. Our composite method yielded 97.3% sensitivity, 77.1% specificity, 90.1% PPV, 93.1% NPV, 73.2% accuracy.

CONCLUSIONS

This new composite could be applied to the holistic approach of combining cyst morphology, vascularity, and fluid analysis alongside endoscopist expertise.

Next-generation sequencing of pancreatic cyst wall specimens obtained using micro-forceps for improving diagnostic accuracy

Background and study aims Pancreatic cysts are common incidental findings, with an estimated prevalence of 13% to 15% in imaging done for other reasons. Diagnosis often relies on collection of cyst fluid, but tissue sampling using micro-forceps may allow for a more reliable diagnosis and higher yield of DNA for next-generation sequencing (NGS). The primary aim was to assess the performance of NGS in identifying mucinous cyst. The secondary aims were to assess DNA yield between the cyst fluid and cyst wall tissue, complication rate and performance of conventional investigations. Patients and methods Twenty-four patients referred for endoscopic ultrasound were recruited. Biopsies were taken using micro-forceps and the AmpliSeq Cancer Hotspot panel was used for NGS, a polymerase chain reaction assay targeting several hotspots within 50 genes, including GNAS , KRAS and VHL . Results The concentration of DNA extracted from 24 cyst wall samples was significantly higher than in the nine of 24 available matched cyst fluid samples. The sensitivity, specificity, and diagnostic accuracy of NGS for diagnosing mucinous cyst were 93%, 50% and 84%; for standard of care, they were -66.6%, 50% and 63.1%; and for standard of care with NGS, they were 100%, 50%, and 89.4% respectively. Cyst wall biopsy was able to diagnose 19 of 24 cysts (4 high risk, 7 intraductal papillary mucinous neoplasms, 4 cysts of mucinous origin, and 4 benign). Conclusions NGS data correlate well with histology and may aid in diagnosis and risk stratification of pancreatic cysts. Cyst wall biopsy performs well in diagnosing cysts but was inadequate in five of 24 patients.

The Hong Kong consensus recommendations on the diagnosis and management of pancreatic cystic lesions

Background

The finding of pancreatic cystic lesions (PCL) on incidental imaging is becoming increasingly common. International studies report a prevalence of 2.2-44.7% depending on the population, imaging modality and indication for imaging, and the prevalence increases with age. Patients with PCL are at risk of developing pancreatic cancer, a disease with a poor prognosis. This publication summarizes recommendations for the diagnosis and management of PCL and post-operative pancreatic exocrine insufficiency (PEI) from a group of local specialists.

Methods

Clinical evidence was consolidated from narrative reviews and consensus statements formulated during two online meetings in March 2022. The expert panel included gastroenterologists, hepatobiliary surgeons, oncologists, radiologists, and endocrinologists.

Results

Patients with PCL require careful investigation and follow-up due to the risk of malignant transformation of these lesions. They should undergo clinical investigation and pancreas-specific imaging to classify lesions and understand the risk profile of the patient. Where indicated, patients should undergo pancreatectomy to excise PCL. Following pancreatectomy, patients are at risk of PEI, leading to gastrointestinal dysfunction and malnutrition. Therefore, such patients should be monitored for symptoms of PEI, and promptly treated with pancreatic enzyme replacement therapy (PERT). Patients with poor response to PERT may require increases in dose, addition of a proton pump inhibitor, and/or further investigation, including tests for pancreatic function. Patients are also at risk of new-onset diabetes mellitus after pancreatectomy; they should be screened and treated with insulin if indicated.

Conclusions

These statements are an accurate summary of our approach to the diagnosis and management of patients with PCL and will be of assistance to clinicians treating these patients in a similar clinical landscape.

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.

Glycemic Abnormalities in Pancreatic Cystic Lesions—A Single-Center Retrospective Analysis

Background and Objectives: Glucose metabolism alterations are very common in solid pancreatic lesions, particularly in pancreatic cancer. Similarly, diabetes and especially new-onset diabetes (NOD) have been associated with the malignant transformation of pancreatic cysts. We aimed to assess the prevalence and relevant associations of glycemic abnormalities in pancreatic cystic lesions (PCLs) in a retrospective analysis. Materials and Methods: We retrospectively recruited all patients who underwent endoscopic ultrasound for a PCL over a period of 36 months (January 2018 to December 2021). Final diagnosis was set by means of tissue acquisition, surgery, follow-up, or board decision. Demographic and clinical data, laboratory workup, and imaging features were extracted from the patients’ charts according to a predefined protocol. We considered fasting blood glucose (FBG) and HbA1c values and stratified the patients as nondiabetic (FBG ≤ 99 mg/dL, HbA1c ≤ 5.6%, no history of glycemic abnormalities), prediabetic (FBG 100–125 mg/dL, HbA1c 5.7–6.4%), or diabetic (long-lasting diabetes or NOD). Results: Altogether, 81 patients were included, with a median age of 66 years, and 54.3% of them were male. The overall prevalence of fasting hyperglycemia was 54.3%, comprising 34.6% prediabetes and 22.2% diabetes, of which 16.7% had NOD. The mean FBG and HbA1c levels were higher in malignant and premalignant PCLs (intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), cystadenocarcinoma, and cystic neuroendocrine tumor) compared to the benign lesions (pseudocysts, walled-off necrosis, and serous cystadenoma): 117.0 mg/dL vs. 108.3 mg/dL and 6.1% vs. 5.5%, respectively. Conclusions: Hyperglycemia and diabetes are common in PCLs, with a high prevalence in premalignant and malignant cysts. Screening and follow-up for glycemic abnormalities should be routinely conducted for PCLs, as they can contribute to a tailored risk assessment of cysts.

Role of Endoscopic Ultrasound in the Evaluation of Pancreatic Cystic Neoplasms: A Concise Review

Pancreatic cystic lesions are being discovered as incidental lesions during cross-sectional imaging studies of the abdomen with increasing frequency. Endoscopic ultrasound is an important diagnostic modality for managing pancreatic cystic lesions. There are various types of pancreatic cystic lesions, from benign to malignant. Endoscopic ultrasound has a multifactorial role in delineating the morphology of pancreatic cystic lesions, ranging from fluid and tissue acquisition for analysis-fine needle aspiration and through-the-needle biopsy, respectively-to advanced imaging techniques, such as contrast-harmonic mode endoscopic ultrasound and EUS-guided needle-based confocal laser endomicroscopy. In this review, we will summarize and provide an update on the specific role of EUS in the management of pancreatic cystic lesions.

Pancreatic Cystic Neoplasms

Early detection of high-risk pancreatic cystic lesions enables potentially curative surgical resection, and early detection of lesions without worrisome features may lead to appropriate surveillance. Regrettably, differentiating premalignant and malignant cysts from nonmalignant ones remains challenging. However, emerging additional diagnostic tools, including the needle biopsy with microforceps and needle-based confocal laser endomicroscopy, are of exciting potential along with cyst fluid analysis".

Advances in the Diagnosis of Pancreatic Cystic Lesions

Pancreatic cystic lesions (PCLs) are a heterogenous group of lesions ranging from benign to malignant. There has been an increase in PCLs prevalence in recent years, mostly due to advances in imaging techniques, increased awareness of their existence and population aging. Reliable discrimination between neoplastic and non-neoplastic cystic lesions is paramount to ensuring adequate treatment and follow-up. Although conventional diagnostic techniques such as ultrasound (US), magnetic resonance imaging (MRI) and computer tomography (CT) can easily identify these lesions, assessing the risk of malignancy is limited. Endoscopic ultrasound (EUS) is superior to cross-sectional imaging in identifying potentially malignant lesions due to its high resolution and better imaging characteristics, and the advantage of allowing for cyst fluid sampling via fine-needle aspiration (FNA). More complex testing, such as cytological and histopathological analysis and biochemical and molecular testing of the aspirated fluid, can ensure an accurate diagnosis.

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.

Updates in diagnosis and management of pancreatic cysts

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