Repeated endoscopic ultrasound-guided fine-needle biopsy of solid pancreatic lesions after previous nondiagnostic or inconclusive sampling.

OBJECTIVES: Repeated endoscopic ultrasound (EUS)-guided tissue acquisition represents the standard practice for solid pancreatic lesions after previous nondiagnostic or inconclusive results. Since data are lacking, we aimed to evaluate the diagnostic performance of repeated EUS fine-needle biopsy (rEUS-FNB) in this setting. The primary outcome was diagnostic accuracy; sample adequacy, sensitivity, specificity, and safety were secondary outcomes. METHODS: Consecutive patients undergoing rEUS-FNB for solid pancreatic lesions at 23 Italian centers from 2019 to 2021 were retrieved. Pathology on the surgical specimen, malignant histology together with ≥6-month follow-up, and benign pathology together with ≥12-month follow-up were adopted as gold standards. RESULTS: Among 462 patients, 56.5% were male, with a median age of 68 (59-75) years, malignancy prevalence 77.0%. Tumor size was 26 (20-35) mm. Second-generation FNB needles were used in 89.6% cases. Diagnostic accuracy, sensitivity, and specificity of rEUS-FNB were 89.2%, 91.4%, and 81.7%, respectively (19 false-negative and 12 false-positive results). On multivariate analysis, rEUS-FNB performed at high-volume centers (odds ratio [OR] 2.12; 95% confidence interval [CI] 1.10-3.17; P = 0.03) and tumor size (OR 1.03; 95% CI 1.00-1.06; P = 0.05) were independently related to diagnostic accuracy. Sample adequacy was 94.2%. Use of second-generation FNB needles (OR 5.42; 95% CI 2.30-12.77; P < 0.001) and tumor size >23 mm (OR 3.04; 95% CI 1.31-7.06; P = 0.009) were independently related to sample adequacy. CONCLUSION: Repeated EUS-FNB allowed optimal diagnostic performance after nondiagnostic or inconclusive results. Patients' referral to high-volume centers improved diagnostic accuracy. The use of second-generation FNB needles significantly improved sample adequacy over standard EUS-FNB needles.

Reliability of grading preoperative pancreatic neuroendocrine tumors on EUS specimens: a systematic review with meta-analysis of aggregate and individual data.

BACKGROUND AND AIMS: Therapy and prognosis of pancreatic neuroendocrine tumors (PanNETs) are strictly related to the Ki-67 index, which defines tumor grading. The criterion standard for the assessment of grading of PanNETs is EUS-guided FNA (EUS-FBAFNA) or EUS-guided fine-needle biopsy sampling (EUS-FNB). Because data on diagnostic accuracy of EUS-FNA and EUS-FNB are heterogeneous, we aimed to analyze the variability in concordance between EUS grading and surgical grading. METHODS: The MEDLINE, SCOPUS, and EMBASE databases were searched until November 2021 to identify studies reporting the concordance rate between EUS grading and surgical grading. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled events were calculated using a random-effects model and expressed in terms of pooled prevalence rates. A multivariate meta-regression was performed to find possible sources of heterogeneity. Where available, individual data were analyzed. RESULTS: Twenty-six studies with 864 patients undergone EUS-FNA or EUS-FNB and surgical resection for PanNETs were included. The pooled estimate rate for the overall concordance of EUS grading and surgical grading was 80.3% (95% confidence interval, 75.6-85.1). Undergrading (EUS grading < surgical grading) was significantly more frequent with respect to overgrading (14.7% vs 3.5%, P < .001). Individual data analysis showed that among nonconcordant patients, the median Ki-67 difference was 3% (interquartile range, 2-6.15). The type of World Health Organization classification adopted and the median lesion diameter were significantly associated with heterogeneity at meta-regression. CONCLUSIONS: EUS is an accurate technique in defining grading in patients with PanNETs, but a margin of error still exists, which should be the focus of future studies to minimize the risk of over- and/or undertreatment.

Comparison between endoscopic ultrasound-guided fine-needle biopsy and bite-on-bite jumbo biopsy for sampling of subepithelial lesions.

BACKGROUND AND AIMS: A direct comparison between endoscopic ultrasound (EUS) fine-needle biopsy (FNB) and current endoscopic biopsy techniques in patients with subepithelial lesions (SELs) is still lacking. Aim of this multicenter study was to compare the diagnostic performance and safety profile between EUS-FNB and bite-on-bite jumbo biopsy. METHODS: Out of 416 patients undergoing endoscopic sampling of SELs between 2017 and 2021, after propensity score matching two groups were compared: 120 undergoing EUS-FNB and 120 sampled with bite-on-bite jumbo biopsy. Primary outcome was sample adequacy. Secondary outcomes were diagnostic accuracy, sensitivity, specificity, and adverse events. RESULTS: Median age was 61 years and most patients were male in both groups. Final diagnosis was GIST in 65 patients (54.1%) in the EUS-FNB group and 62 patients in the bite-on-bite biopsy group (51.6%; p = 0.37). Sample adequacy was significantly higher in the EUS-FNB group as compared to the bite-on-bite biopsy group (94.1% versus 77.5%, p<0.001). EUS-FNB outperformed bite-on-bite biopsy also in terms of diagnostic accuracy (89.3% versus 67.1%, p<0.001) and sensitivity (89% vs 64.5%; p<0.001), whereas specificity was 100% in both groups (p = 0.89). These findings were confirmed in subgroup analysis according to SEL location, final diagnosis, and wall layers of the sampled SEL. Adverse event rate was 6.6% in the EUS-FNB group and 30% in the bite-on-bite biopsy group (p<0.001). CONCLUSION: EUS-FNB outperforms bite-on-bite biopsy both in terms of diagnostic yield and safety profile.

Diagnostic yield of endoscopic ultrasound-guided tissue acquisition in autoimmune pancreatitis: a systematic review and meta-analysis.

Background and study aims There is limited evidence on the diagnostic performance of endoscopic ultrasound (EUS)-guided tissue acquisition in autoimmune pancreatitis (AIP). The aim of this meta-analysis was to provide a pooled estimate of the diagnostic performance of EUS-guided fine-needle aspiration (FNA) and fine-needle biopsy (FNB) in patients with AIP. Patients and methods Computerized bibliographic search was performed through January 2020. Pooled effects were calculated using a random-effects model by means of DerSimonian and Laird test. Primary endpoint was diagnostic accuracy compared to clinical diagnostic criteria. Additional outcomes were definitive histopathology, pooled rates of adequate material for histological diagnosis, sample adequacy, mean number of needle passes. Diagnostic sensitivity and safety data were also analyzed. Results Fifteen studies with 631 patients were included, of which four were prospective series and one randomized trial. Overall diagnostic accuracy of EUS tissue acquisition was 54.7 % (95 % confidence interval, 40.9 %-68.4 %), with a clear superiority of FNB over FNA (63 %, 52.7 % to 73.4 % versus 45.7 %, 26.5 %-65 %; p < 0.001). FNB provided level 1 of histological diagnosis in 44.2 % of cases (30.8 %-57.5 %) as compared to 21.9 % (10 %-33.7 %) with FNA ( P  < 0.001). The rate of definitive histopathology of EUS tissue sampling was 20.7 % (12.9 %-28.5 %) and it was significantly higher with FNB (24.3 %, 11.8 %-36.8 %) as compared to FNA (14.7 %, 5.4 %-23.9 %; P  < 0.001). Less than 1 % of subjects experienced post-procedural acute pancreatitis. Conclusion The results of this meta-analysis demonstrate that the diagnostic performance of EUS-guided tissue acquisition is modest in patients with AIP, with an improved performance of FNB compared to FNA.

Impact of biliary stents on the diagnostic accuracy of EUS-guided fine-needle biopsy of solid pancreatic head lesions: A multicenter study.

BACKGROUND AND OBJECTIVES: There is no clear evidence of a negative impact of biliary stents on the diagnostic yield of EUS-guided fine-needle biopsy (EUS-FNB) for diagnosing pancreatic head lesions. We aimed to evaluate the association between the presence of biliary stents and the diagnostic accuracy of EUS-FNB. MATERIALS AND METHODS: A multicenter retrospective study including all jaundiced patients secondary to pancreatic head masses was performed. Patients were divided into two groups according to the presence of a biliary stent placed before EUS-FNB. Pathological results were classified according to the Papanicolaou classification and compared against the final diagnosis. Diagnostic measures in the two groups were compared. Multivariate logistic regression analyses including potential factors affecting EUS-FNB accuracy were performed. RESULTS: Overall, 842 patients were included, 495 (58.8%) without and 347 (41.2%) with biliary stent. A plastic or a metal stent was placed in 217 (62.5%) and 130 (37.5%) cases, respectively. Diagnostic sensitivity and accuracy were significantly higher in patients without biliary stent than in those with stent (91.9% and 92.1% vs. 85.9% and 86.4%, P = 0.010 At multivariate analyses, lesion size (odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.02-1.09, P = 0.01) and presence of biliary stent (OR: 0.51, 95% CI: 0.32-0.89, P = 0.01) were independently associated with diagnostic accuracy. In the subgroup of patients with biliary stent, the type of stent (plastic vs. metal) did not impact EUS-FNB yield, whereas the use of larger bore needles enhanced diagnostic accuracy (OR: 2.29, 95% CI: 1.28-4.12, P = 0.005). CONCLUSIONS: In this large retrospective study, an indwelling biliary stent negatively impacted the diagnostic accuracy of EUS-FNB. Preferably, EUS-FNB should precede endoscopic retrograde cholangiopancreatography, especially in the case of small tumors.

Chronic use of statins and risk of post-endoscopic retrograde cholangiopancreatography pancreatitis: a systematic review and meta-analysis.

BACKGROUND: There is limited evidence on the role of chronic statin therapy in the prevention of acute pancreatitis after ERCP. The aim of this meta-analysis was to evaluate the efficacy of statins in the prophylaxis of post-ERCP pancreatitis. RESEARCH DESIGN AND METHODS: Bibliographic search was performed through May 2020. The primary outcome was post-ERCP pancreatitis rate. An additional endpoint was the rate of severe pancreatitis. RESULTS: Nine studies, of which 1 prospective and 8 retrospective series, with 9374 patients were included. Baseline clinical and technical features were well balanced between the two study groups. Overall, pooled rate of post-ERCP pancreatitis was 4.8% (3.2%-6.4%) in the statin group and 7.1% (5.9%-8.3%) in the control group, with no difference in terms of pancreatitis rate (odds ratio 0.66, 95% confidence interval 0.43-1.02). This finding was confirmed in the multivariate analysis adjusted for several clinical and technical characteristics (adjusted odds ratio 0.68, 0.40-1.15). No difference was observed between the two study groups in terms of severe pancreatitis rate (odds ratio 1.07, 0.61-1.89). CONCLUSIONS: Our meta-analysis seems to suggest the non-superiority of chronic statin therapy in preventing post-ERCP pancreatitis.

Use of antibiotic prophylaxis is not needed for endoscopic ultrasound-guided fine-needle aspiration of pancreatic cysts: a meta-analysis.

BACKGROUND: There is limited evidence on the use of antibiotic prophylaxis prior to endoscopic ultrasound-guided fine-needle aspiration of pancreatic cysts. The aim of this meta-analysis was to evaluate the efficacy of antibiotic prophylaxis in this setting. RESEARCH DESIGN AND METHODS: Bibliographic search was performed through January 2020. The primary outcome was infection rate. Additional endpoints were severe infection rate and overall rates of adverse events. RESULTS: Six studies, of which one was a randomized controlled trial and five were retrospective, with 1706 patients were included. Most patients were female, and body/tail was the most frequent location of cystic lesions. Overall, eight infectious events were observed in the antibiotic group (0.77%), whereas 12 events were registered in the control group (1.7%), with no difference in terms of infection rate (odds ratio 0.65, 95% confidence interval 0.24-1.78; p = 0.40). Again, no difference was observed between the two study groups in terms of either severe infection (odds ratio 0.88, 0.13-5.82; p = 0.89) and overall adverse event rate (odds ratio 1.09, 0.73-1.65; p = 0.67). CONCLUSIONS: Prophylactic antibiotics do not seem to substantially reduce the risk of infections after endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions, and routine use of prophylactic antibiotics should be questioned.

EUS-guided tissue acquisition in chronic pancreatitis: Differential diagnosis between pancreatic cancer and pseudotumoral masses using EUS-FNA or core biopsy.

Background and Objective: EUS-FNA sensitivity for malignancy in parenchymal masses of patients with concurrent chronic pancreatitis (CP) has been reported to be unsatisfactory. The aim of the present study was to directly compare the diagnostic accuracy of EUS-FNA and EUS-fine-needle biopsy (FNB) in differentiating between inflammatory masses and malignancies in the setting of CP. Methods: We performed a retrospective analysis of prospective, multicentric databases of all patients with pancreatic masses and clinico-radiological-endosonographic features of CP who underwent EUS-FNA or FNB. Results: Among 1124 patients with CP, 210 patients (60% males, mean age: 62.7 years) with CP and pancreatic masses met the inclusion criteria and were enrolled. In the FNA group (110 patients), a correct diagnosis was obtained in all but 18 cases (diagnostic accuracy 83.6%, sensitivity 69.5%, specificity 100%, positive predictive value [PPV] 100%, and negative predictive value [NPV] 73.9%); by contrast, among 100 patients undergoing FNB, a correct diagnosis was obtained in all but seven cases (diagnostic accuracy 93%, sensitivity 86.8%, specificity 100%, PPV 100%, and NPV 87%) (P = 0.03, 0.03, 1, 1, and 0.07, respectively). At binary logistic regression, focal pancreatitis (odds of event occurrence [OR]: 4.9; P < 0.001), higher Ca19-9 (OR: 2.3;P= 0.02), and FNB (OR: 2.5; P < 0.01) were the only independent factors associated with a correct diagnosis. Conclusion: EUS-FNB is effective in the differential diagnosis between pseudotumoral masses and solid neoplasms in CP, showing higher diagnostic accuracy and sensitivity than EUS-FNA. EUS-FNB should be considered the preferred diagnostic technique for diagnosing cancer in the setting of CP.

Epidemiology, clinical features and diagnostic work-up of cystic neoplasms of the pancreas: Interim analysis of the prospective PANCY survey.

INTRODUCTION: A prospective survey to evaluate the diagnostic workup of cystic pancreatic neoplasms (CPNs) according to the Italian guidelines. METHODS: An online data sheet was built. RESULTS: Fifteen of the 1385 patients (1.1%) had non cystic neoplastic lesions. Forty percent (518/1295) had at least one 1st degree relative affected by a solid tumor of the digestive and extra-digestive organs. Symptoms/signs associated with the cystic lesion were present in 24.5% of the patients. The cysts were localized in the head of the pancreas in 38.5% of patients. Of the 2370 examinations (1.7 examinations per patient) which were carried out for the diagnosis, magnetic resonance imaging was performed as a single test in 48.4% of patients and in combination with endoscopic ultrasound in 27% of the cases. Of the 1370 patients having CPNs, 89.9% had an intraductal papillary mucinous neoplasm (IPMN) (70.1% a branch duct IPMN, 6.2% a mixed type IPMN and 4.6% a main duct IPMN), 12.7% had a serous cystadenoma, 2.8% a mucinous cystadenoma, 1.5% a non-functioning cystic neuroendocrine neoplasm, 0.7% a solid-pseudopapillary cystic neoplasm, 0.3% a cystic adenocarcinoma, and 1.2% an undetermined cystic neoplasm. Seventy-eight (5.7%) patients were operated upon after the initial work-up. CONCLUSIONS: This prospective study offers a reliable real-life picture of the diagnostic work-up CPN.

Stylet slow-pull vs. standard suction technique for endoscopic ultrasound-guided fine needle biopsy in pancreatic solid lesions using 20 Gauge Procore™ needle: A multicenter randomized trial.

BACKGROUND: Standard suction and slow-pull techniques have been utilized during endoscopic ultrasound-guided fine needle aspiration of pancreatic solid lesions, but the correct sampling technique remains unclear. New needles designed to obtain samples suitable for histological evaluation have become available. We performed a study comparing the two sampling methods during endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) in patients with pancreatic solid lesions. METHODS: We performed EUS-FNB with a 20 Gauge FNB needle using slow-pull or standard suction techniques in a prospective, randomized, multicenter study. The primary aim was bloodiness of the collected specimens. Secondary aims were technical success and performance of the two techniques. RESULTS: 110 patients were included (55 per group). No difference in blood contamination was observed (slow-pull 80% vs. suction 74%, p = 0.917). Technical success was 95% (96% vs. 94%, p = 0315). Sensitivity (96% vs. 93%), specificity (100% vs. 100%), positive likelihood ratio (NA), negative likelihood ratio (0.04 vs. 0.07), diagnostic accuracy (96 vs. 93%) did not differ between the two groups. CONCLUSION: EUS-FNB with slow-pull and standard suction techniques are comparable in terms of blood contamination providing similar high diagnostic sensitivity and accuracy in pancreatic solid lesions. The use of the new generation FNB needle allows to reach such high level of diagnostic adequacy regardless of the technique utilized.

High diagnostic adequacy and accuracy of the new 20G procore needle for EUS-guided tissue acquisition: Results of a large multicentre retrospective study.

BACKGROUND AND OBJECTIVE: EUS-guided fine-needle biopsy has become the standard for tissue sampling. A new 20G ProCore™ (PC) needle has been developed to overcome the limitations of tissue acquisition of the smaller needles (22G, 25G) and the rigidity of the larger one (19G). The aim of this study is to assess the performance of the 20G PC needle. MATERIALS AND METHODS: Patients who underwent EUS-guided tissue acquisition with the 20G PC needle of pancreatic and extra-pancreatic mass lesions were retrospectively identified at three Italian centers (Bologna, Fermo, and Palermo). Diagnostic adequacy, accuracy, and tissue core acquisition were the outcome measures. All the cases were performed without rapid on-site evaluation. RESULTS: A total of 384 patients with pancreatic (62.2%) and extra-pancreatic lesions were included in the study. For pancreatic lesions, adequacy, accuracy, sensitivity, and specificity were 92.4%, 91.5%, 90.8%, and 100%, respectively, with a number needed to misdiagnose (NNM) of 11.8. The tissue core was obtained in 72% of cases. Transduodenal approach was performed in 150 pancreatic lesions; adequacy, accuracy, and tissue core acquisition were 88.7%, 90%, and 66%, respectively (NNM 10). For extrapancreatic lesions, adequacy, accuracy, sensitivity, specificity, and tissue core sampling were 95.3%, 95.3%, 92.6%, 100%, and 84.5% (NNM 21.3). CONCLUSIONS: The 20G PC needle showed high diagnostic adequacy and accuracy, regardless the access route.

EUS-guided tissue sampling with a 20-gauge core biopsy needle for the characterization of gastrointestinal subepithelial lesions: A multicenter study.

BACKGROUND AND OBJECTIVE: A new 20-gauge (G) biopsy needle with a core-trap technology has been developed with a large core size and enhanced flexibility. The aim of this multicenter study was to determine the feasibility, efficacy, and safety of EUS-guided fine-needle biopsy (EUS-FNB) with the new 20G needle in diagnosing subepithelial lesions (SELs). MATERIALS AND METHODS: Retrospectively collected data from consecutive patients with SELs undergoing EUS-FNB with the 20G needle at five centers were analyzed. RESULTS: A total of 50 SELs were included. The mean lesion size was 43.1 ± 17.5 mm. The lesion locations were esophagus (n = 1), stomach (n = 37), distal duodenum (n = 5), rectum (n = 6), and colon (n = 1). The procedure was technically feasible in all patients. Definitive diagnosis with full histological assessment including immunohistochemistry was obtained in 88% (44/50) of the patients. Considering malignant versus benign lesions, the sensitivity, specificity, positive predictive value, and negative predictive value were 85% (95% confidence interval [CI] 70.2-94.3), 100% (95% CI 58.7%-100%), 100% (95% CI 85.1%-100%), and 62.5 (95% CI 27.7-84.8), respectively. No major complications requiring additional care have been observed. CONCLUSIONS: In this multicenter study, we found that EUS-FNB with the new 20G core needle is an effective and safe method for the diagnosis of SELs with a high rate of producing adequate histological material and high diagnostic accuracy even from difficult-to-approach anatomical locations.

EUS-guided sampling with 25G biopsy needle as a rescue strategy for diagnosis of small subepithelial lesions of the upper gastrointestinal tract.

BACKGROUND AND STUDY AIMS: This study was designed to evaluate the impact of additional tissue obtained with endoscopic ultrasound (EUS)-guided 25-gauge core biopsy needle (25G-PC) following an unsuccessful fine-needle biopsy (FNB) performed with larger-bore needles for the characterization of gastrointestinal subepithelial lesions (GI-SELs). PATIENTS AND METHODS: We prospectively collected and retrospectively analyzed information in our database from January 2013 to June 2017 for all patients with GI-SELs who received a EUS-guided FNB (EUS-FNB) with 25G-PC during the same procedure after failure of biopsy performed with larger-bore needle. Diagnostic yield, diagnostic accuracy and procedural complications were evaluated. RESULTS: Sixteen patients were included in this study, 10 men and 6 women, median age 67.8 (range 43 to 76 years). Five patients were found to have a SEL localized in the distal duodenum, five in the gastric antrum, two in the gastric fundus and four in the gastric body. The mean size of the lesions was 20.5 mm (range 18 - 24 mm). EUS-FNB with 25G-PC enabled final diagnosis in nine patients (56.2 %). Regarding the subgroup of duodenal lesions, the procedure was successful in four of five (80 %). Final diagnoses with EUS-guided sampling were GIST (n = 6), leiomyoma (n = 2) and metastatic ovarian carcinoma (n = 1). No procedure-related complications were recorded. CONCLUSION: In patients with small GI-SELs, additional tissue obtained with 25G-PC could represents a "rescue" strategy after an unsuccessful procedure with larger-bore needles, especially when lesions are localized in the distal duodenum.

Pancreatic enzyme replacement therapy after gastric resection: An update.

Exocrine pancreatic insufficiency (EPI) is one of the possible mechanisms of fat maldigestion following gastric surgery, together with reduced food intake, loss of gastric reservoir, small bowel bacterial overgrowth and rapid small bowel transit. Oral pancreatic enzyme replacement therapy (PERT) is the mainstay of treatment for EPI. The efficacy and safety of pancreatic enzyme substitution in patients following gastric resection remains unclear. This review article summarizes relevant studies addressing PERT after gastric resection.

Gastric metastasis from ovarian adenocarcinoma presenting as a subepithelial tumor and diagnosed by endoscopic ultrasound-guided tissue acquisition.

We describe an uncommon case of a patient with a metastatic adenocarcinoma of ovarian origin presented as a gastric subepithelial tumor (SET) and that was diagnosed by endoscopic ultrasound fine-needle biopsy (EUS-FNB). Malignant gastric lesions are rarely metastatic and the primary tumor is mainly breast, lung, esophageal cancer or cutaneous melanoma. Gastric metastasis from ovarian cancer is unusual, presenting synchronously with the primary tumor but also several years later than the initial diagnosis. From an endoscopic point of view, gastric metastasis does not present specific features. They may mimic both a primary gastric tumor or, less frequently, an SET. This case demonstrates the importance of EUS-FNB in distinguishing SETs and how this may alter treatment and prognosis.

Biliary plastic stent does not influence the accuracy of endoscopic ultrasound-guided sampling of pancreatic head masses performed with core biopsy needles.

OBJECTIVE: While the presence of biliary stent significantly decreases the accuracy of endoscopic ultrasound (EUS) for pancreatic head cancer staging, its impact on the EUS-guided sampling accuracy is still debated. Furthermore, data on EUS-fine needle biopsy (EUS-FNB) using core biopsy needles in patients with pancreatic mass and biliary stent are lacking. The aim of this study was to evaluate the influence of biliary stent on the adequacy and accuracy of EUS-FNB in patients with pancreatic head mass. METHODS: All patients who underwent EUS-guided sampling with core needles of solid pancreatic head masses causing obstructive jaundice were retrospectively identified in a single tertiary referral center. Adequacy, defined as the rate of cases in which a tissue specimen for proper examination was achieved, with and without biliary stent, was the primary outcome measure. The diagnostic accuracy and complication rate were the secondary outcome measures. RESULTS: A total of 130 patients with pancreatic head mass causing biliary obstruction were included in the study: 74 cases of them were sampled without stent and 56 cases with plastic stent in situ. The adequacy was 96.4% in the stent group and 90.5% in the group without stent (p=0.190). No significant differences were observed for sensitivity (88.9% vs. 85.9%), specificity (100% for both groups), and accuracy (89.3% vs. 86.5%) between those with and without stent, respectively. The accuracy was not influenced by the timing of stenting (<48h or ≥48h before EUS). No EUS-FNB related complications were recorded. CONCLUSION: The presence of biliary stent does not influence the tissue sampling adequacy, the diagnostic accuracy and the complication rate of EUS-FNB of pancreatic head masses performed with core biopsy needles.