Diagnosis Of Pancreatic Masses Research Articles

Preclinical models derived from endoscopic ultrasound-guided tissue acquisition for individualized treatment of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with poor outcomes. Although the management strategies have evolved in recent years, the PDAC 5-year survival rate remains at only 9%; it may become the second leading cause of cancer death in the USA by 2030. Only 15-20% of PDAC patients are eligible to undergo surgery; diagnostic biopsies and individualized treatment present a more significant challenge for the remaining group. Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has been widely used in the diagnosis of pancreatic masses. With the advancement of this sampling technique, adequate specimens can be obtained from all patients with PDAC in both early and late clinical stages. Recent data suggest that the specimens obtained from EUS-TA might be used to establish viable preclinical models, which conserve the genetic mutation and preserve the heterogeneity of the original tumors. Additionally, any drug sensitivity evident in the EUS-TA-derived preclinical models might predict the clinical response, thus guiding the prospective therapeutic selection. As we move toward the era of precision medicine, this review provides an update on the role of EUS-TA as a method for obtaining genetic material used in preclinical models that can assess and stratify individuals according to their individual cancer biology.

Performance of EUS-FNB in solid pancreatic masses: a lesson from 463 consecutive procedures and a practical nomogram.

The study's main goal was the diagnostic adequacy of pancreatic endoscopic ultrasonographic (EUS) fine-needle biopsy (FNB) and associated predictive factors. The secondary objective was to define the diagnostic accuracy of EUS-FNB in the diagnosis of pancreatic masses and pancreatic malignancies. None of the studies reported the diagnostic adequacy and accuracy of EUS. We retrospectively identified patients with solid pancreatic lesions that underwent EUS-FNB between 2013, and 2018. We calculated diagnostic adequacy and related factors. Using definitive histology on the surgically resected specimen as the gold standard, we calculated diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNB. We identified a total of 463 procedures. Diagnostic specimens were adequate in 436 procedures (94.1%), while 27 biopsies provided insufficient samples (5.9%). The multivariate analysis showed that lesion size and needle caliper were the only factors influencing diagnostic adequacy. The use of a biopsy needle (OR 0.69, 95% CI 0.30-0.1.63, P 0.400) did not improve sample adequacy. We calculated sensitivity (100%), specificity (93.2%), diagnostic accuracy (93.2%), positive predictive value (97.1%), and negative predictive value (100%) using resected specimen as the gold standard. We found no significant complications. EUS-FNB is a reliable technique for the histological characterization of solid pancreatic masses.

Effect of histological examination on the diagnosis of pancreatic mass using endoscopic ultrasound fine-needle aspiration.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a well-established method for the diagnosis of solid pancreatic lesions. However, the diagnostic yield of EUS-FNA for pancreatic lesions varies at around 70-90%. Samples from EUS-FNA consist of cells and tissues that can be analyzed separately, and the results can be combined for a final diagnosis. To investigate the effect of cytological and histological analysis of EUS-FNA samples on the final diagnosis, and identify factors that may affect the accuracy of the cytological, histological, and overall analysis. A single-center prospective observational study was conducted at a tertiary university hospital from July 2018 to June 2019. Patients who underwent EUS-FNA for pancreatic solid lesions with a 22-gauge EUS-FNA needle were included in our study. Liquid-based cytological analysis of the specimen and histological analysis of the whitish core were performed, and factors that affected the diagnostic accuracy of each analysis were evaluated. In 63 EUS-FNA samples, the overall diagnostic accuracy was 87.3%, which was significantly higher than the cytological accuracy of 73.8% (p = 0.031) and the histological accuracy of 69.8% (p = 0.001). Factors that affected the results differed in each group: 1) cytological analysis: size, location, and approach method; 2) histological analysis: specimen weight; and 3) overall analysis: size, location, and approach method. Histologic evaluation of core material obtained from EUS-FNA improved diagnostic accuracy, and factors that affected each result were analyzed. Further studies with prospective randomized trials are recommended to support our data.

Technical and Cytomorphologic Analysis of Repeat Endoscopic Ultrasound-Guided Fine Needle Aspiration Procedures for Diagnosis of Pancreatic Masses: A Five Year Institutional Experience

Technical and Cytomorphologic Analysis of Repeat Endoscopic Ultrasound-Guided Fine Needle Aspiration Procedures for Diagnosis of Pancreatic Masses: A Five Year Institutional Experience

Endoscopic ultrasound elastography in the diagnosis of pancreatic masses: A meta-analysis

Background and aimsEndoscopic ultrasound (EUS) elastography is a novel non-invasive technique that can be used for distinguishing benign from malignant pancreatic masses. However, the studies have reported widely varied sensitivities and specificities. A meta-analysis was performed to assess the performance of EUS elastography for the differentiation of benign and malignant pancreatic masses. MethodsAll the eligible studies were searched by PubMed, Medline, Embase, and the Cochrane Library. Sensitivity, specificity, positive likelihood ratio (LR), negative LR, and area under the curve (AUC) were calculated to examine the accuracy. ResultsA total of nineteen studies which included 1687 patients were analyzed. The pooled sensitivity and specificity for the diagnosis of malignant pancreatic masses were 0.98 (95% confidence interval [CI] 0.96–0.99) and 0.63 (95% CI 0.58–0.69) for qualitative EUS elastography, 0.95 (95% CI 0.93–0.97) and 0.61 (95% CI 0.56–0.66) for quantitative EUS elastography, respectively. The positive and negative LR were 2.60 (95% CI 1.84–3.66) and 0.05 (95% CI 0.02–0.10) for qualitative EUS elastography, 2.64 (95% CI 1.82–3.82) and 0.10 (95% CI 0.06–0.16) for quantitative EUS elastography, respectively. The summary diagnostic odds ratio (DOR) and the AUC were 60.59 (95% CI 28.12–130.56) and 0.91 (Q* = 0.842) for qualitative EUS elastography, 30.09 (95% CI 15.40–58.76) and 0.93 (Q* = 0.860) for quantitative EUS elastography. ConclusionsOur meta-analysis shows that both qualitative and quantitative EUS elastography have high accuracy in the detection of malignant pancreatic masses, which could be used as a valuable complementary method to EUS-FNA for the differentiation of pancreatic masses in the future.

A meta-analysis of contrast-enhanced harmonic endoscopic ultrasonography on differential diagnosis of pancreatic mass

Objective To estimate the value of contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) on differential diagnosis of pancreatic mass. Methods Multiple Chinese and English databases were retrieved to selected relevant literature. The quality of literature was assessed, and the data were meta-analyzed using Metadisc 1.4 and STATA 14.0 software. Results A total of 16 researches with 1 352 patients were included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio was 93% (95%CI: 92%-95%), 84% (95%CI: 80%-87%), 5.82 (95%CI: 4.06-8.33), 0.08 (95%CI: 0.06-0.10), and 77.33 (95%CI: 52.37-114.17), respectively. The area under the summary receiver operating characteristic curve was 0.96 (95%CI: 0.94-0.97). The results of subgroup analysis demonstrated that the number of cases, region, QUADAS scores, the diameter and type of mass, and the experience of diagnostician were not the source of heterogeneity. After 2 articles with larger bias were eliminated, the heterogeneity dropped to an acceptable range, and the pooled sensitivity, specificity, positive predictive value and negative predictive value had no significant change. All these suggested that the results of meta-analysis were reliable. Conclusion CEH-EUS has a high accuracy in differential diagnosis of pancreatic mass, and can be used as an effective diagnostic method. Key words: Endoscopic ultrasonography; Contrast-enhanced harmonic; Pancreatic neoplasms; Diagnosis; Meta-analysis

MR elastography of pancreatic masses: preliminary results

Objective To investigate the feasibility of spin-echo echo-planar imaging(SE-EPI) of magnetic resonance elastography (MRE) for the diagnosis of pancreatic mass and to evaluate the difference of stiffness value in different pancreatic mass. Methods In a retrospective study, MRE was performed in 20 healthy volunteer (control group) and 62 patients with surgery-proved pancreatic masses, including pancreatic cystadenoma in 5 cases and solid masses of pancreas in 57 cases (39 with malignant mass and 18 with benign mass) using 3.0 T MRE. The differences of stiffness between two groups were evaluated using non-parametric Mann-Whitney U test. ROC was used to assess the diagnostic ability of elastogram for the detection of pancreatic masses, and to evaluate MRE-determined stiffness for the differentiation of masses from healthy pancreas, and malignancy from benign solid masses. Results The total detection rate of elastogram was 91.9% (57/62),with false positive rate of 5.0% (1/20) and false negative rate of 8.1% (5/62). The median stiffness value in the control group vs patient group were 1.18 kPa (interquantile range:1.15 to 1.30) kPa and 2.43 kPa (interquantile range:1.94 to 3.64 kPa) respectively, with statistically significant differences (Z=-5.967,P<0.01). The sensitivity and specificity of stiffness (≥1.36 kPa) to differentiate pancreatic mass from healthy pancreas was 93.6% and 100.0%, respectively, and to differentiate benign and malignant solid masses (≥2.17 kPa) was 82.1% and 83.3%, respectively. Conclusion MRE is a promising method in detecting and distinguishing different pancreatic masses. Key words: Pancreas; Magnetic resonance imaging; Stiffness

Su1369 A New Model Construted by Logistic Regression of Eus-Elastography for the Differential Diagnosis of Pancreatic Masses: A Two-Step Prospective Study in 115 Patients

Su1369 A New Model Construted by Logistic Regression of Eus-Elastography for the Differential Diagnosis of Pancreatic Masses: A Two-Step Prospective Study in 115 Patients

Can endoscopic ultrasound-guided needle-based confocal laser endomicroscopy replace fine-needle aspiration for pancreatic and mediastinal diseases?

New applications of confocal laser endomicroscopy (CLE) have been developed, such as needle-based CLE (nCLE) for pancreatic masses, pancreatic cystic tumors, and lymph nodes. nCLE is feasible during endoscopic ultrasound (EUS) examination, and preliminary results are very encouraging and suggest this technology may be used in future as a useful adjunct in cases of inconclusive EUS-guided fine-needle aspiration. The aim of this paper is to give an update in this new technology and to define its place in the diagnosis of pancreatic masses and mediastinal diseases.

Endoscopic ultrasound-guided fine needle aspiration cytology in pancreatic mass lesions: Our experience

Background and Objectives:Endoscopic ultrasound (EUS) is considered as the most reliable, accurate test in the detection of pancreatic masses, in whom a need for early, accurate detection, and confirmation of neoplasm is important, at the same time avoidance of surgery.Materials and Methods:This was a prospective study of EUS and fine needle aspiration (FNA)/fine needle aspiration biopsy in patients with pancreatic mass between January 2014 and 2017 at Gandhi Hospital, a tertiary government hospital in the state of Telangana. At the time of EUS size, echo characteristics of lesions, vascularity, lymph nodes (LNs) were noted. In 22 patients, 22-gauge, and in 3 patients, 25-gauge were used.Results:Male to female ratio was18:7, with mean age of 54 years. All had pain abdomen - 100%, mass per abdomen - 5, jaundice, vomiting - 3, and hypoglycemic attacks - 2 (8%). 14 (56%) had lesion in head, 3 - head and body, 2 - isthmus, and 5 - body and tail. Metastasis to LN and liver in 2 (8%). FNA results: Adenocarcinoma - 5 (25%), papillary adenoma - 1 (4%), serous cystadenoma - 1 (4%), mucinous cyst adenoma - 1 (4%), insulinoma - 1 (4%) each, gastrointestinal stromal tumor - 2 (8%), atypical cells - 4 (16%), neuroendocrine tumor - 2 (8%), negative for malignancy - 6 (24%). Minor hemorrhage and abdominal pain were noted in three. All positive and atypical cells patients treated accordingly. All negative cases were followed.Conclusion:EUS is a safe, reliable method in the diagnosis of pancreatic mass in providing accurate cytological diagnosis and exact location of small lesions.

Endoscopic ultrasonography with fine-needle aspiration for histological diagnosis of solid pancreatic masses: a meta-analysis of diagnostic accuracy studies.

BackgroundPrevious studies have demonstrated that endoscopic ultrasound-fine needle aspiration (EUS-FNA) is a reliable tool for diagnosing pancreatic lesions; however, the reported sensitivity and specificity vary greatly across studies. The aim of this study was to pool the existing literature and assess the overall performance of EUS-FNA in the diagnosis of solid pancreatic lesions.MethodsA systematic search of MEDLINE, Cochrane Database for Systematic Reviews, and EMBASE was performed to identify original and review articles published between January 1995 and January 2014 that reported the accuracy of EUS-FNA in the diagnosis of pancreatic masses. Quality of the included studies was assessed using the quality assessment of diagnosis accuracy studies score tool. Meta-DiSc software was used to calculate the pooled sensitivity and specificity, positive and negative likelihood ratios, and to construct the summary receiver operating characteristics curve.ResultsTwenty studies involving a total of 2,761 patients were included in the study. The pooled sensitivity and specificity of EUS-FNA in the diagnosis of solid pancreatic lesions were 90.8 % [95 % confidence interval (CI), 89.4–92 %] and 96.5 % (95 % CI, 94.8–97.7 %), respectively. The positive and negative likelihood ratios were 14.8 (95 % CI, 8.0–27.3) and 0.12 (95 % CI, 0.09–0.16), respectively. The overall diagnostic accuracy was 91.0 %.ConclusionsOur findings suggest that EUS-FNA has high sensitivity and specificity in the diagnosis of solid pancreatic lesions.

PTU-007 Comparison of Diagnostic Performance Between Two Core Biopsy Needles for Endoscopic Ultrasound-Guided Tissue Acquisition of Solid Pancreatic Lesions

<h3>Introduction</h3> A new core biopsy needle (SharkCore) with a novel design has recently been introduced for endoscopic ultrasound guided biopsy. There is as yet no data on how its diagnostic performance compares to the existing core biopsy needle (Procore) in the diagnosis of pancreatic masses. The aim of this study was to compare the diagnostic performance and yield of the two core biopsy needles i.e. the ProCore and the Sharkcore needles in the biopsy of solid pancreatic lesions. This is the first study in literature to compare 2 core biopsy needles. <h3>Methods</h3> A retrospective comparison of a prospectively maintained database. Consecutive patients who had EUS guided fine needle biopsy with Procore (100) and Sharkcore (101) were included in the study. Demographic details, site of lesion, number of passes and histological diagnosis. Final diagnosis was based on positive histology or at least 6 months follow up in cases with a benign pathology. Primary outcome was to compare the diagnostic accuracy of the two needles using only samples graded as definitely malignant as diagnostic for malignancy. The secondary outcome was to compare the diagnostic yield for both needles. <h3>Results</h3> The sensitivity, specificity, negative predictive value and accuracy between the groups were - Procore =71%, 100%, 28% and 74% vs. Sharkcore =91%, 100%, 53% and 94%. There was a significant difference in sensitivity (p = 0.0003) and accuracy (p = 0.006). The proportion of samples classified as adequate for histological analysis was 87% for Procore and 99% for Sharkcore - this was significantly different (p = 0.0009). There were no complications in either group. <h3>Conclusion</h3> In this study the SharkCore biopsy needle demonstrated significantly better diagnostic accuracy and tissue yield. Prospective randomised studies are required. <h3>Disclosure of Interest</h3> None Declared

Pancreatic Involvement of Burkitt Lymphoma in a Child and Review of the Literature

Pancreatic involvement of non-Hodgkin lymphoma is extremely rare in childhood and can be overlooked in differential diagnosis of pancreatic masses. In this report we describe a 10-year-old boy who presented with pancreatitis and obstructive jaundice, which was the result of pancreatic involvement of Burkitt lymphoma.

Adjuvant surgery following chemotherapy with gemcitabine plus S-1 for initially unresectable pancreatic cancer diagnosed during perioperative re-evaluation

Introduction: Endoscopic Ultrasound (EUS) with fine-needle aspiration (FNA) is an important tool for the study and diagnosis of pancreatic masses. We know that a rapid on-site evaluation (ROSE) of pancreatic masses samples increase the diagnostic accuracy to over 90%. In the abscense of ROSE, we don't know if these results could be achieved by an EUS-FNA experienced endoscopist. Aims: To evaluate the diagnostic accuracy of USE-FNA in the study of pancreatic masses in the presence and abscense of ROSE and the role of the endoscopist experience. Patients & methods: We performed 379 USE-FNA procedures from January 2007 to may 2014 in patients with pancreatic solid masses. Finally we included 375 procedures. 67.3% were male and the mean age was 62.8 (12.7) years. Results: We found 298 (79.5%) malign lesions (adenocarcinoma 253, neuroendocrin 26, others 19) and 77 (20.5%) benign lesions. 162 (43.2%) procedures were performed with ROSE. The global diagnostic accuracy was 89.3%. Diagnostic accuracy was 93.8% with ROSE and 85.95% without ROSE, p1⁄40.0014. However, the diagnostic accuracy was significantly higher with ROSE at the beginning: 92.6% vs 88%, p1⁄40.014, comparing with the last years when there were no differences with and without ROSE, 97.5% vs 88%, p1⁄40.074. Conclusion: We show that the diagnostic accuracy for USE-FNA in the study of solid pancreatic masses increases with the experience of both pathologist and endoscopist. However, USE-FNA with ROSE is still necessary to get a diagnostic accuracy over 90%.

Tu1635 A Randomized Multicenter Trial Comparing Capillary Suction and Standard Suction for Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) of Solid Pancreatic Lesions

Tu1635 A Randomized Multicenter Trial Comparing Capillary Suction and Standard Suction for Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) of Solid Pancreatic Lesions Payal Saxena*, Mohamad H. El Zein, Tyler Stevens, Ahmed Abdelgelil, Sepideh Besharati, Ahmed A. Messallam, Vivek Kumbhari, Alba Azola, Saowanee Ngamruengphong, Jennifer Brainard, Eun Ji Shin, Anne Marie Lennon, Vikesh K. Singh, Mouen Khashab Johns Hopkins, Baltimore, MD; Digestive Disease Institute, Cleveland Clinic, Cleveland, OH; Pathology and Laboratory Medicine, Cleveland Clinic, Cleveland, OH Background: Standard EUS-FNA procedures involve use of no-suction or suction (ST) aspiration techniques. A new aspiration method, the capillary suction technique (CT), involves pulling the needle stylet back slowly to create minimum negative pressure. A prior retrospective study showed higher sensitivity for diagnosis of pancreatic masses using the CT technique. There have been no randomized trials comparing the efficacy of the CT with standard ST Aim: 1) Primary aim was to compare the sensitivity of EUS-FNA using ST or CT for solid pancreatic lesions using a standard 22g needle. 2) Secondary endpoints were first pass diagnostic rate and acquisition of core tissue. Methods: All consecutive patients presenting for EUS-FNA of a solid pancreatic mass at two tertiary academic centers from 9/2013 to 11/2014 were randomized to CT or ST using a 22g needle (Expect, Boston Scientific). CT was performed with an assistant withdrawing 50% of the stylet length. ST was performed with a 10mL suction syringe. Both techniques were standardized to 15 to-and-fro movements for each pass until an adequate specimen was achieved as determined by rapid onsite cytology examination (ROSE). Fanning was performed at the discretion of the endoscopist. Patients were crossed-over to the alternate technique after 4 non-diagnostic passes. All visible core specimens were measured. Positive cytology or surgical histopathology was considered gold standard for malignancy. Negative cytology was confirmed with clinical data and/or imaging at 6 month followup. Results: Of 147 patients screened, 119 (mean age 65yr, 58% male) met inclusion criteria and were randomized to CT (nZ59) or ST (nZ60) (Figure 1). Baseline patient characteristics, including mean mass size, (2.9cm vs 3.2cm, pZ0.22) were similar in both groups. Malignant and benign diagnoses, use of fanning technique, technical success rates (96.6% vs 100%, pZ0.24) and cross-over rates (18.6% vs 18.3%, pZ0.97) were comparable. There were no adverse events. In an intention-totreat analysis, there was no difference in first pass diagnosis rate (40.7% vs 38.3%, pZns) or core specimen acquisition rates (59.3% vs 46.6%, pZns). Mean number of passes to diagnosis (1.9 vs 1.6, pZ 0.22) were equivalent. There was no significant difference in the sensitivity (90 % vs 89%, pZ 1.0), specificity (100% vs 100%, pZ 1.0), or diagnostic accuracy (88.1% vs 85%, pZ0.79) (table 1). Fanning was a not a predictor of diagnostic yield in either group (OR 2.29, pZ0.350 and OR 0.78, pZ0.75). Conclusion: Both capillary suction and standard suction techniques offer high and comparable diagnostic sensitivity of 90% with an average of less than 2 passes required for diagnosis of solid pancreatic lesions. The endosonographer may choose either technique; however, the suction technique may be preferable as coordination with an assistant is not required during FNA.

The Challenging Diagnosis of Pancreatic Masses: Not All Tumors Are Cancers

In the elderly patients, where biopsy-induced complications could outweigh the benefit, the identification of pancreatic masses is generally referred to as a synonymous of pancreatic cancer and patients are dismissed with no further options than palliative and supportive care. Notwithstanding, not all pancreatic tumors are cancers and therefore alternative diagnoses need to be investigated, especially when patients are unfit for invasive diagnostic procedures. Here, we report a case of an aged patient that was admitted to an internal medicine division for a previously diagnosed pancreatic cancer. The reassessment of the diagnosis has allowed identifying the pancreatic mass as a manifestation of focal pancreatitis in the context of an IgG4-related disease. Accordingly, patient was treated with steroids with rapid clinical improvement. This clinical case suggests that autoimmune diseases should always be considered in the differential diagnosis of pancreatic masses of the elderly.

Mo1167 Needle-Based Confocal Laser Endomicroscopy (nCLE) for the Diagnosis of Pancreatic Masses: Preliminary Criteria (Contact Study)

Introduction: With increased use and sensitivity of cross sectional imaging more incidental pancreatic cystic lesions are found. Studies have demonstrated a prevalence of 2.5% of cystic pancreatic lesions in asymptomatic patients on MRI & CT scanning. Cystic lesions have a wide variety of radiological appearances and prognostic outcomes. We aimed to review cases found to have incidental pancreatic cysts on CT scanning and ascertain the concordance between CT and EUS and the management of such lesions in a non-pancreatic centre. Method: We retrospectively reviewed patients undergoing EUS for pancreatic cystic lesions found on incidentally on CT scan between 2010 and 2012. Twenty-five patients were included. Solid lesions with a cystic component were excluded. Results: There were 15 female; 10 male. Indications for CT scan included abdominal pain 32%; weight loss 16%; jaundice and suspected stone disease with abnormal USS 16%. In all cases there was no preceding clinical suspicion of pancreatic cysts/disease. Median number of cysts was 1 (14); mean size 3cm (1-11cm). In 70% of cases the cyst was >3cm; and <3cm in 30%. They were located in the HOP 36%; BOP 32%; TOP 16%; NOP 4%; multiple sites 12%. The cyst was aspirated +/biopsy in 12 (48%) cases, of which in 2 (16%) this changed the CT diagnosis. Final diagnosis was pseudocyst 10 (40%); IPMN 6 (24%); simple cyst 2 (8%); serous cystadenoma 2 (8%); mucinous cystadenoma (MCA) 1 (4%); cystic adenoca 1 (4%); wegeners cyst 1 (4%); renal cyst 1 (4%). In 32% (8 cases), the EUS findings were inconsistent with CT findings, due to IPMN and MCA in the vast majority. Greatest concordance between EUS and CT findings was in the diagnosis of pseudocysts. Conclusion: Increasing number of asymptomatic pancreatic cysts found incidentally will undoubtedly cause increased referrals to tertiary pancreatic centres. EUS is a better imaging modality with additional benefit of attaining samples. Performing EUS +/cyst FNA provided an alternative diagnosis to CT in a significant percentage (32%) of patients and helped streamline referrals for tertiary opinion. EUS should be considered in all patients presenting with incidental pancreatic cysts on cross-sectional imaging. This may be performed at the index hospital (if non-pancreatic centre) and should not be restricted to tertiary HPB centres if operator experience and confidence allows.

Contrast-Enhanced Harmonic Endoscopic Ultrasonography in Pancreatic Diseases

Endoscopic ultrasonography (EUS) is the most sensitive imaging method for diagnosis of pancreatic tumors. However, it still has limits in the differentiation between pancreatic cancers and inflammatory tumor-like masses. A novel technology, contrast-enhanced harmonic EUS (CH-EUS), has been developed recently. It can visualize both parenchymal perfusion and microvasculature in pancreas without Doppler-related artifacts. Therefore, it is superior to EUS and CT in detecting small pancreatic masses and differential diagnosis of pancreatic masses. CH-EUS could be used for adequate sampling of pancreatic tumors and may predict the pathological features of the pancreatic solid lesions but still cannot replace EUS-FNA now.

Image enhancement by endoscopic ultrasonography-elastography

Elastography has been shown to increase the accuracy of endoscopic ultrasonography for the differential diagnosis of pancreatic masses. Recent data have led to questions about the validity of its use in a routine clinical setting, outside controlled studies. Further improvements of the technique are needed to increase the reproducibility of its results and make it a useful clinical tool.

Contrast-enhanced EUS in differential diagnosis of benign and malignant pancreatic masses: a meta-analysis

Objective To assess the accuracy of contrast-enhanced EUS in differential diagnosis of benign and malignant pancreatic masses. Methods We systematically searched the Medline, PubMed, Web of Science, Embase, Cochrane Central Trials, CNKI and VIP databases for relevant studies published. Study selection, quality assessment and data extraction were performed by two reviewers independently. Meta-Disc （version 1.4） software was used to perform this meta-analysis for sensitivity, specificity, positive likelihood ratio （LR）, and negative LR. Pooling results were derived by using the fixed-effect model when significant heterogeneity was not present. The random-effect model was applied otherwise. A summary receiver-operating characteristic （SROC） curve was constructed. Furthermore, to explore the potential sources of heterogeneity, we used meta-regression to estimate the effect of the following characteristics of the studies on the diagnostic accuracy of contrast-enhanced EUS. In addition, the outliers were identified with the method described by Deville and a subgroup analysis was performed by excluding the outliers. We used Stata statistical software （version 10. 0） to assess the publication bias with the Begg-Mazumdar indictor and HarbordEgger indictor. Results Twelve studies involving 1139 patients were included. The pooled sensitivity ofcontrast-enhanced EUS for the differential diagnosis of pancreatic masses was 94% （95% CI, O. 91 ～0. 95）, the specificity was 89% （95% CI, O. 85 ～0. 92）, the positive LR was 8.09 （95% CI, 4. 47 ～ 14. 64）, and the negative LR was 0, 08 （95% CI, O. 06 ～ 0. 10）. The area under the curve （AUC） under SROC was 0. 9732 （ SE = 0.02）. The subgroup analysis by excluding two outliers provided a sensitivity of 93 % （95% C1, O. 91～0. 95） and a specificity of 93% （95% C1, O. 89～0. 95）. Additionally, the subgroup analysis showed that the heterogeneities were eliminated in pooled estimates when the outliers were excluded and the AUC under SROC was 0. 9745 （SE = 0. 02）. Moreover, no significant publication bias was found with the Begg-Mazumdar indictor （ P = 0.244） or the Harbord-Egger indictor （ P = 0.442 ）. Conclusion Contrastenhanced EUS is a valuable method in the differential diagnosis of pancreatic masses. Key words: Endoscopic ultrasonography ; Image enhancement ; Pancreatic neoplasms ; Meta-analysis