Yield of EUS-guided FNA of pancreatic masses in the presence or the absence of chronic pancreatitis

Differentiation of pancreatic cancer and chronic pancreatitis using computer-aided diagnosis of endoscopic ultrasound (EUS) images: a diagnostic test

Background

Differentiating pancreatic cancer (PC) from normal tissue by computer-aided diagnosis of EUS images were quite useful. The current study was designed to investigate the feasibility of using computer-aided diagnostic (CAD) techniques to extract EUS image parameters for the differential diagnosis of PC and chronic pancreatitis (CP).

Methodology/Principal Findings

This study recruited 262 patients with PC and 126 patients with CP. Typical EUS images were selected from the sample sets. Texture features were extracted from the region of interest using computer-based techniques. Then the distance between class algorithm and sequential forward selection (SFS) algorithm were used for a better combination of features; and, later, a support vector machine (SVM) predictive model was built, trained, and validated. Overall, 105 features of 9 categories were extracted from the EUS images for pattern classification. Of these features, the 16 were selected as a better combination of features. Then, SVM predictive model was built and trained. The total cases were randomly divided into a training set and a testing set. The training set was used to train the SVM, and the testing set was used to evaluate the performance of the SVM. After 200 trials of randomised experiments, the average accuracy, sensitivity, specificity, the positive and negative predictive values of pancreatic cancer were 94.2±0.1749%,96.25±0.4460%, 93.38±0.2076%, 92.21±0.4249% and 96.68±0.1471%, respectively.

Conclusions/Significance

Digital image processing and computer-aided EUS image differentiation technologies are highly accurate and non-invasive. This technology provides a kind of new and valuable diagnostic tool for the clinical determination of PC.

Ratio of pancreatic duct caliber to width of pancreatic gland by endosonography is predictive of pancreatic cancer

OBJECTIVES

This study aimed to determine whether (1) a pancreatic duct (PD) diameter to pancreatic gland width (G) ratio (PDG) by endoscopic ultrasonography (EUS) predicts pancreatic cancer (PC) and (2) whether this ratio better indicates PC compared to PD dilation alone.

METHODS

Patients presenting for EUS were classified into the following 4 categories: (1) normal, (2) noncalcific chronic pancreatitis (NCCP), (3) calcific CP (CCP), and (4) PC.

RESULTS

There were 198 patients enrolled. Final diagnoses were PC (n = 34), CCP (n = 16), and normal/NCCP (n = 148). The median PD diameter (8, 5, and 2 mm, respectively; P = <0.001), G (16, 20, and 17 mm, respectively; P = 0.002), and PDG ratio were significantly different among groups (0.54, 0.25, and 0.12, respectively; P < 0.001). Patients with PC were more likely to have a PDG ratio of greater than or equal to 0.34 compared to CCP, and normal/NCCP groups (94%, 19%, 1.3%, respectively; P < 0.001). The positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of PDG greater than or equal to 0.34 for detecting cancer were 87%, 99%, 94%, 97%, and 97%, respectively. The accuracy and positive predictive value of PD dilation alone for diagnosing PC were 83% and 50%, respectively.

CONCLUSIONS

A PDG ratio is a good predictor of PC and is better than PD dilation. This sign should be routinely used by endosonographers to improve EUS diagnostic capability of PC.

The role of endoscopic ultrasound in biliary obstruction

The role of endoscopic ultrasound (EUS) in the diagnosis of biliary obstruction is well established, and emerging evidence suggests it may also play a therapeutic role. Differentiating between benign and malignant causes of biliary obstruction can be challenging, but EUS is a crucial tool in the armamentarium of the physician. Evolving technologies such as elastography and contrast enhancement may further supplement the diagnostic abilities of EUS. Therapeutic applications of EUS are evolving rapidly, and EUS-guided cholangiography may aid biliary decompression when endoscopic retrograde cholangiopancreatography (ERCP) has failed or is not possible.

EUS elastography for diagnosis of solid pancreatic masses: a meta-analysis

BACKGROUND

The differential diagnosis of solid pancreatic masses has been a significant challenge up until now. EUS elastography is now used as a new technique to distinguish benign from malignant pancreatic masses. However, the sensitivity, specificity, and accuracy are still questionable.

OBJECTIVE

To evaluate the accuracy of EUS elastography for diagnosis of solid pancreatic masses.

DESIGN

Thirteen articles for EUS elastography diagnosing solid pancreatic masses were selected. The Mantel-Haenszel and DerSimonian Laird methods were used to analyze pooled results.

PATIENTS

This study involved 1044 patients.

INTERVENTION

EUS elastography.

MAIN OUTCOME MEASUREMENTS

The pooled sensitivity, specificity, likelihood ratios, diagnostic odds ratio, and summary receiver operating characteristic (sROC) curve.

RESULTS

The pooled sensitivity, specificity, and diagnostic odds ratio of EUS elastography distinguishing benign from malignant solid pancreatic masses were 0.95 (95% confidence interval [CI], 0.94-0.97), 0.67 (95% CI, 0.61-0.73), and 42.28 (95% CI, 26.90-66.46), respectively. The sROC area under the curve was 0.9046. The subgroup analysis based on excluding the outliers showed that the heterogeneity was eliminated, and the pooled sensitivity and specificity were 0.95 (95% CI, 0.93-0.97) and 0.7 (95% CI, 0.63-0.76), respectively. The sROC area under the curve was 0.8872.

LIMITATIONS

Varied diagnostic standards for EUS elastography were used in the enrolled studies.

CONCLUSION

EUS elastography is a reliable technique for the characterization of solid pancreatic masses and may be a useful complementary tool for EUS-guided FNA. However, a more accurate computer-aided diagnosis method for EUS elastography is in demand to reduce various biases and improve the accuracy of EUS elastography for diagnosis of solid pancreatic masses.

A proposal of a diagnostic algorithm with validation of International Consensus Diagnostic Criteria for autoimmune pancreatitis in a Japanese cohort

BACKGROUND

Among many diagnostic criteria for autoimmune pancreatitis (AIP), the International Consensus Diagnostic Criteria (ICDC) first enabled us to diagnose and compare type 1 and type 2 AIP, which permitted tailoring individual diagnostic algorithms depending on local expertise. We compared them and validated ICDC with special reference to levels 1 and 2, and proposed a diagnostic algorithm for AIP in Japan.

METHODS

The diagnostic sensitivity of 5 major criteria (ICDC, Korean, Japanese-2011, Asian, and HISORt criteria) was compared, using 61 patients with AIP. Fifty six patients with pancreatic cancer served as a control. Pancreas imaging on computed tomography (CT) and endoscopic retrograde pancreatography (ERP) were independently evaluated by 3 pancreatologists (5, 10, and 20 years of career experience) and each diagnostic criterion of ICDC was validated with special reference to levels 1 and 2.

RESULTS

The sensitivities of 5 major criteria were 95.1% (ICDC), 90.2% (Korean), 86.9% (Japanese), 83.6% (Asian), and 83.6% (HISORt) with 100% of specificity in each. In the evaluation of pancreas imaging, diagnostic sensitivities of combination with CT and ERP in segmental/focal type AIP were significantly higher than single imaging (26% in CT (P < 0.01) or 35% in ERP (P < 0.05) vs 63% in CT + ERP), but not significantly different in the diffuse type.

CONCLUSIONS

Of the 5 criteria, ICDC is the most sensitive and useful for diagnosing AIP. We have proposed a diagnostic algorithm with CT for the diffuse type of AIP, and combination with CT + ERP followed by EUS-FNA for the segmental/focal type.

[Chronic pancreatitis or pancreatic malignancy: clinical and radiological differential diagnosis of pancreas head space-occupying mass]

Chronic pancreatitis can be complicated both by an inflammatory benign mass and by the development of pancreatic cancer. The distinction of these complications is not only difficult but also crucial as patients suffering from either of the two have significantly different prognoses. This article describes typical clinical and radiological findings, which may help the physician in differentiating these two maladies. Furthermore, we conducted a retrospective study where we evaluated the clinical patterns in patients with chronic pancreatitis who underwent resection for a pancreatic mass. Although certain findings may be indicative for benign tumors, none of the diagnostic tools available offers a sufficient degree of certainty. In cases of tumors secondary to autoimmune pancreatitis the diagnostic error is exceptionally high. Because of the poor prognosis related to untreated pancreatic cancer, the general recommendation is to perform resection of the tumor when technically possible and when carcinoma cannot be ruled out completely.

Diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration for pancreatic cancer: a meta-analysis

BACKGROUND AND OBJECTIVE

EUS-FNA of pancreatic lesion has been put into clinical use widely in many centers. The present meta-analysis was conducted to study the diagnostic role of EUS-FNA in pancreatic cancer.

METHODS

A comprehensive review of study on the precision of EUS-FNA in the diagnosis of pancreatic cancer. A random effects model was used to pool the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR). A summary receiver-operating characteristic (SROC) was constructed to summarize the overall test performance.

RESULTS

Thirty-one articles were eligible for the meta-analysis. The pooled sensitivity, specificity, PLR, NLR and DOR of EUS-FNA in the diagnosis of pancreatic cancer were 0.89 (95% CI: 0.88-0.90), 0.96 (95% CI: 0.95-0.97), 16.88 (95% CI: 10.63-26.79), 0.13 (95%CI: 0.10-0.16) and 150.80 (95%CI: 95.94-237.03) respectively. In subgroup meta-analysis of the prospective studies, the pooled sensitivity, specificity, PLR, NLR and DOR were 0.91 (95% CI: 0.90-0.93), 0.94 (95% CI: 0.91-0.96), 11.19 (95% CI: 6.36-19.69), 0.10 (95% CI: 0.07-0.15) and 125.22 (62.37-251.41). The area under the curve (AUC) was 0.97, indicating a good performance of overall accuracy.

CONCLUSION

EUS-FNA has the high sensitivity and specificity in differentiating pancreatic cancer. Moreover, it is also a safe diagnostic modality with little complications.

Endoscopic ultrasound fine-needle aspiration characteristics of primary adenocarcinoma versus other malignant neoplasms of the pancreas

BACKGROUND

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is often used to assist in the evaluation of pancreatic lesions and may help to diagnose benign versus malignant neoplasms. However, there is a paucity of literature regarding comparative EUS characteristics of various malignant pancreatic neoplasms (primary and metastatic).

OBJECTIVE

To compare and characterize primary pancreatic adenocarcinoma versus other malignant neoplasms, hereafter referred to as nonprimary pancreatic adenocarcinoma (NPPA), diagnosed by EUS-guided FNA.

METHODS

The present study was a retrospective analysis of a prospectively maintained database. The setting was a tertiary care, academic medical centre. Patients referred for suspected pancreatic neoplasms were evaluated. Based on EUS-FNA characteristics, primary pancreatic adenocarcinoma was differentiated from other malignant neoplasms. The subset of other neoplasms was defined as malignant lesions that were 'NPPAs' (ie, predominantly solid or solid⁄cystic based on EUS appearance and primary malignant lesions or metastatic lesions to the pancreas). Pancreatic masses that were benign cystic lesions (pseudocyst, simple cyst, serous cystadenoma) and focal inflammatory lesions (acute, chronic and autoimmune pancreatitis) were excluded.

RESULTS

A total of 230 patients were evaluated using EUS-FNA for suspected pancreatic mass lesions. Thirty-eight patients were excluded because they were diagnosed with inflammatory lesions or had purely benign cysts. One hundred ninety-two patients had confirmed malignant pancreatic neoplasms (ie, pancreatic adenocarcinoma [n=144], NPPA [n=48]). When comparing adenocarcinoma with NPPA lesions, there was no significant difference in mean age (P=0.0675), sex (P=0.3595) or average lesion size (P=0.3801). On average, four FNA passes were necessary to establish a cytological diagnosis in both lesion subtypes (P=0.396). Adenocarcinomas were more likely to be located in the pancreatic head (P=0.0198), whereas masses in the tail were more likely to be NPPAs (P=0.0006). Adenocarcinomas were also more likely to exhibit vascular invasion (OR 4.37; P=0.0011), malignant lymphadenopathy (P=0.0006), pancreatic duct dilation (OR 2.4; P=0.022) and common bile duct dilation (OR 2.87; P=0.039).

CONCLUSIONS

Adenocarcinoma was more likely to be present in the head of the pancreas, have lymph node and vascular involvement, as well as evidence of pancreatic duct and common bile duct obstruction. Of all malignant pancreatic lesions analyzed by EUS-FNA, 25% were NPPA, suggesting that FNA is crucial in establishing a diagnosis and may be helpful in preoperative planning.

Endoscopic management of chronic pancreatitis

Chronic pancreatitis (CP) is a common gastrointestinal illness, which affects the quality of life with substantial morbidity and mortality. The management includes medical, endoscopic and surgical approaches with the need for interaction between various specialties, calling for a concerted multidisciplinary approach. However, at the time of this publication, guidelines to establish care of these patients are lacking. This review provides the reader with a comprehensive overview of the studies summarizing the various treatment options available, including medical, surgical and endoscopic options. In addition, technological advances such as endoscopic retrograde cholangiopancreatogrophy, endoscopic shock wave lithotripsy and endoscopic ultrasound can now be offered with reasonable success for pancreatic decompression, stricture dilatation with stent placement, stone fragmentation, pseudocyst drainage, and other endoscopic interventions such as celiac plexus block for pain relief. We emphasize the endoscopic options in this review, and attempt to extract the most up to date information from the current literature. The treatment of CP and its complications are discussed extensively. Complications such as biliary strictures. pancreatic pseudocysts, and chronic pain are common issues that arise as long-term complications of CP. These often require endoscopic or surgical management and possibly a combination of approaches, however choosing amongst the various therapeutic and palliative modalities while weighing the risks and benefits, makes the management of CP challenging. Treatment goals should be not just to control symptoms but also to prevent disease progression. Our aim in this paper is to advocate and emphasize an evidence based approach for the management of CP and associated long term complications.

Designing and developing S100P inhibitor 5-methyl cromolyn for pancreatic cancer therapy

We have previously shown that the antiallergic drug cromolyn blocks S100P interaction with its receptor receptor for advanced glycation end product (RAGE) and improves gemcitabine effectiveness in pancreatic ductal adenocarcinoma (PDAC). However, the concentration required to achieve its effectiveness was high (100 μmol/L). In this study, we designed and synthesized analogs of cromolyn and analyzed their effectiveness compared with the parent molecule. An ELISA was used to confirm the binding of S100P with RAGE and to test the effectiveness of the different analogs. Analog 5-methyl cromolyn (C5OH) blocked S100P binding as well as the increases in NF-κB activity, cell growth, and apoptosis normally caused by S100P. In vivo C5OH systemic delivery reduced NF-κB activity to a greater extent than cromolyn and at 10 times lesser dose (50 mg vs. 5 mg). Treatment of mice-bearing syngeneic PDAC tumors showed that C5OH treatment reduced both tumor growth and metastasis. C5OH treatment of nude mice bearing orthotopic highly aggressive pancreatic Mpanc96 cells increased the overall animal survival. Therefore, the cromolyn analog, C5OH, was found to be more efficient and potent than cromolyn as a therapeutic for PDAC.

How good is endoscopic ultrasound-guided fine-needle aspiration in diagnosing the correct etiology for a solid pancreatic mass?: A meta-analysis and systematic review

OBJECTIVES

The objective of this study was to evaluate the accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in diagnosing the correct etiology for a solid pancreatic mass.

METHOD

Data extracted from EUS-FNA studies with a criterion standard (either confirmed by surgery or appropriate follow-up) were selected. Articles were searched in MEDLINE, CINAHL, and Cochrane Central Register of Controlled Trials & Database of Systematic Reviews. Pooling was conducted by both fixed- and random-effects models.

RESULTS

Initial search identified 3610 reference articles, of these 360 relevant articles were selected and reviewed. Data were extracted from 41 studies (N = 4766) which met the inclusion criteria. Pooled sensitivity of EUS-FNA in diagnosing the correct etiology for solid pancreatic mass was 86.8% (95% confidence interval [CI], 85.5-87.9). Endoscopic ultrasound-guided FNA had a pooled specificity of 95.8% (95% CI, 94.6-96.7). Positive likelihood ratio of EUS was 15.2 (95% CI, 8.5-27.3), and the negative likelihood ratio was 0.17 (95% CI, 0.13-0.21).

CONCLUSIONS

Endoscopic ultrasound-guided FNA is an excellent diagnostic tool to detect the correct etiology for solid pancreatic masses. When available, EUS-FNA should be strongly considered as the first diagnostic tool for sampling these lesions to optimize patient management.

The Spanish Pancreatic Club recommendations for the diagnosis and treatment of chronic pancreatitis: part 1 (diagnosis)

Chronic pancreatitis (CP) is a relatively uncommon, complex and heterogeneous disease. The absence of a gold standard applicable to the initial phases of CP makes its early diagnosis difficult. Some of its complications, particularly chronic pain, can be difficult to manage. There is much variability in the diagnosis and treatment of CP and its complications amongst centers and professionals. The Spanish Pancreatic Club has developed a consensus on the management of CP. Two coordinators chose a multidisciplinary panel of 24 experts on this disease. A list of questions was drafted, and two experts reviewed each question. Then, a draft was produced and shared with the entire panel of experts and discussed in a face-to-face meeting. This first part of the consensus addresses the diagnosis of CP and its complications.

Diagnostic accuracy of quantitative EUS elastography for discriminating malignant from benign solid pancreatic masses: a prospective, single-center study

BACKGROUND

Recent data suggest that quantitative EUS elastography, a novel technique that allows real-time quantification of tissue stiffness, can accurately differentiate malignant from benign solid pancreatic masses.

OBJECTIVE

To externally validate the diagnostic utility of this technique in an independent cohort.

DESIGN AND SETTING

Prospective, single-center study. PATIENTS, INTERVENTIONS, AND METHODS: A total of 104 patients with evidence of a solid pancreatic mass on cross-sectional imaging and/or endosonography underwent 111 quantitative EUS elastography procedures. Multiple elastographic measurements of the mass lesion and soft-tissue reference areas were undertaken, and the corresponding strain ratios (SRs) were calculated. The final diagnosis was based on pancreatic cytology or histology.

MAIN OUTCOME MEASUREMENTS

The area under the receiver-operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of quantitative EUS elastography for discriminating malignant from benign pancreatic masses.

RESULTS

The final diagnoses were primary pancreatic carcinoma (71.2%), neuroendocrine tumor (10.6%), metastatic cancer (1.9%), and pancreatitis (16.3%). Malignant masses had a higher SR (P = .01) and lower mass elasticity (P = .003) than inflammatory ones. The areas under the receiver-operating characteristic curve for the detection of pancreatic malignancy of both SR and mass elasticity (0.69 and 0.72, respectively) were less favorable than reported recently. At the cut points providing the highest accuracy in this cohort (4.65 for SR and 0.27% for mass elasticity), quantitative EUS elastography had a sensitivity of 100.0% and 95.7%, specificity of 16.7% and 22.2%, positive predictive value of 86.1% and 86.4%, negative predictive value of 100.0% and 50.0%, and overall accuracy of 86.5% and 83.8%, respectively.

LIMITATIONS

Relatively small number of patients with benign disease.

CONCLUSION

In the largest single-center study to date, the diagnostic utility of quantitative EUS elastography for discriminating pancreatic masses was modest, suggesting that it may only supplement rather than supplant the role of pancreatic tissue sampling in the future.

Prospective evaluation of the optimal number of 25-gauge needle passes for endoscopic ultrasound-guided fine-needle aspiration biopsy of solid pancreatic lesions in the absence of an onsite cytopathologist

INTRODUCTION

A prior study with 22-gauge needles recommended more than seven needle passes for endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) of solid pancreatic lesions (SPL) without onsite cytopathology for optimal acquisition of cytopathological diagnosis. The feasibility of this recommendation should be re-evaluated considering the later development and popularity of 25-gauge EUS-FNA needles. We aimed to determine the optimal number of needle passes for cytopathological specimen acquisition with 25-gauge needles for EUS-FNA of SPL.

METHODS

A preliminary prospective study of 22 patients with an onsite cytopathology technician showed a sensitivity of 93.3% and a specificity of 100% with four needle passes that was not statistically different from five needle passes. Based on our preliminary study, we fixed the number of needle passes to four (Group A). As a control group, we carried out sampling in consecutive patients using 25-gauge needles with an onsite cytopathologist (Group B). Sampling rate, diagnostic value and complications were evaluated.

RESULTS

We enrolled 20 patients in each group. Sampling rate was higher in Group B (20/20, 100%) than in Group A (19/20, 95%), but there was no statistical difference between them (P-value = 0.31). In Group A, sensitivity, specificity and accuracy were 100% among 19. In Group B, sensitivity was 94.1%, specificity 100%, accuracy 95%. There were also no statistical differences between the groups. No complications were seen.

CONCLUSION

Our study suggests that four needle passes using a 25-gauge needle may be sufficient for EUS-FNA of SPL where onsite cytology is not available.

Pancreatico-biliary endoscopic ultrasound: A systematic review of the levels of evidence, performance and outcomes

Our aim was to record pancreaticobiliary endoscopic ultrasound (EUS) literature of the past 3 decades and evaluate its role based on a critical appraisal of published studies according to levels of evidence (LE). Original research articles (randomized controlled trials, prospective and retrospective studies), meta-analyses, reviews and surveys pertinent to gastrointestinal EUS were included. All articles published until September 2011 were retrieved from PubMed and classified according to specific disease entities, anatomical subdivisions and therapeutic applications of EUS. The North of England evidence-based guidelines were used to determine LE. A total of 1089 pertinent articles were reviewed. Published research focused primarily on solid pancreatic neoplasms, followed by disorders of the extrahepatic biliary tree, pancreatic cystic lesions, therapeutic-interventional EUS, chronic and acute pancreatitis. A uniform observation in all six categories of articles was the predominance of LE III studies followed by LE IV, IIb, IIa, Ib and Ia, in descending order. EUS remains the most accurate method for detecting small (< 3 cm) pancreatic tumors, ampullary neoplasms and small (< 4 mm) bile duct stones, and the best test to define vascular invasion in pancreatic and peri-ampullary neoplasms. Detailed EUS imaging, along with biochemical and molecular cyst fluid analysis, improve the differentiation of pancreatic cysts and help predict their malignant potential. Early diagnosis of chronic pancreatitis appears feasible and reliable. Novel imaging techniques (contrast-enhanced EUS, elastography) seem promising for the evaluation of pancreatic cancer and autoimmune pancreatitis. Therapeutic applications currently involve pancreaticobiliary drainage and targeted fine needle injection-guided antitumor therapy. Despite the ongoing development of extra-corporeal imaging modalities, such as computed tomography, magnetic resonance imaging, and positron emission tomography, EUS still holds a leading role in the investigation of the pancreaticobiliary area. The major challenge of EUS evolution is its expanding therapeutic potential towards an effective and minimally invasive management of complex pancreaticobiliary disorders.

Randomized trial comparing the 22-gauge aspiration and 22-gauge biopsy needles for EUS-guided sampling of solid pancreatic mass lesions

BACKGROUND

To overcome limitations of cytology, biopsy needles have been developed to procure histologic samples during EUS.

OBJECTIVE

To compare 22-gauge (G) FNA and 22G biopsy needles (FNB) for EUS-guided sampling of solid pancreatic masses.

DESIGN

Randomized trial.

SETTING

Tertiary-care medical center.

PATIENTS

This study involved 56 patients with solid pancreatic masses.

INTERVENTION

Sampling of pancreatic masses by using 22G FNA or 22G FNB devices.

MAIN OUTCOME MEASUREMENTS

Compare the median number of passes required to establish the diagnosis, diagnostic sufficiency, technical performance, complication rates, procurement of the histologic core, and quality of the histologic specimen.

RESULTS

A total of 28 patients were randomized to the FNA group and 28 to the FNB group. There was no significant difference in median number of passes required to establish the diagnosis (1 [interquartile range 1-2.5] vs 1 [interquartile range 1-1]; P = .21), rates of diagnostic sufficiency (100% vs 89.3%; P = .24), technical failure (0 vs 3.6%; P = 1.0), or complications (3.6% for both) between FNA and FNB needles, respectively. Patients in whom diagnosis was established in passes 1, 2, and 3 were 64.3% versus 67.9%, 10.7% versus 17.9%, and 25% versus 3.6%, respectively, for FNA and FNB cohorts. There was no significant difference in procurement of the histologic core (100% vs 83.3%; P = .26) or the presence of diagnostic histologic specimens (66.7% vs 80%; P = .66) between FNA and FNB cohorts, respectively.

LIMITATIONS

Only pancreatic masses were evaluated.

CONCLUSION

Diagnostic sufficiency, technical performance, and safety profiles of FNA and FNB needles are comparable. There was no significant difference in yield or quality of the histologic core between the 2 needle types.

Diagnostic value of EUS elastography in differentiation of benign and malignant solid pancreatic masses: a meta-analysis

BACKGROUND/AIMS

EUS elastography is a novel technique that can be used for distinguishing benign from malignant lymph nodes and focal pancreatic masses. However, the studies pertaining to EUS elastography for differential diagnosis of solid pancreatic masses have reported widely varied sensitivities and specificities. A meta-analysis of all relevant articles was performed to estimate the overall diagnostic accuracy of EUS elastography for differentiating benign and malignant solid pancreatic masses.

METHODS

The literatures were identified by searching in PubMed and Embase databases. Two reviewers independently extracted the information from the literatures for constructing 2 × 2 table. A random-effect model or a fixed-effect model was used to estimate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. A summary receiver operating characteristic curve (SROC) also was constructed. Meta-regression and subgroup analysis were used to explore the sources of heterogeneity.

RESULTS

13 studies including a total of 1042 patients with solid pancreatic masses were selected for meta-analysis. The pooled sensitivity and specificity of EUS elastography for differentiating benign and malignant solid pancreatic masses were 95% (95% confidence interval [CI], 93%-96%), 69% (95% CI, 63%-75%), respectively. The area under SROC (AUC) was 0.8695. Two significant variables were associated with heterogeneity: color pattern and blinding.

CONCLUSION

As a less invasive modality, EUS elastography is a promising method for differentiating benign and malignant solid pancreatic masses with a high sensitivity, and it can prove to be a valuable supplement to EUS-FNA.

Hereditary pancreatic cancer: molecular bases and their application in diagnosis and clinical management: a guideline of the TTD group

Pancreatic carcinoma (PC) represents the fourth leading cause of cancer death in Spain with a death rate of 2,400 males and 2,000 females per year. Poor outcome related to its silent nature and the lack of reliable secondary prevention measures translate into advanced-stage diagnosis, 75 % of deaths within the first year of diagnosis and 5-year survival rate of <5 %. Family history was first recognized as a risk factor for PC. Further population-based and case-control studies subsequently found that 7.8 % of patients with PC have a family history of the same tumor and individuals with a first-degree relative with PC have a 3.2-fold increased risk of developing PC. Overall, it is estimated that up to 10 % of PC have a familial component. However, known genetic syndromes account for <20 % of the observed familial aggregation of PC. We review the most important aspects in epidemiology, molecular biology and clinical management of familial PC.

Vascularisation pattern of chronic pancreatitis compared with pancreatic carcinoma: results from contrast-enhanced endoscopic ultrasound

Discriminating between focal chronic pancreatitis and pancreatic cancer is always a challenge in clinical medicine. Contrast-enhanced endoscopic ultrasound using Doppler techniques can uniquely reveal different vascularisation patterns in pancreatic tissue alterated by chronic inflammatory processes and even allows a discrimination from pancreatic cancer. This paper will describe the basics of contrast-enhanced high mechanical index endoscopic ultrasound (CEHMI EUS) and contrast enhanced low mechanical index endoscopic ultrasound (CELMI EUS) and explain the pathophysiological differences of the vascularisation of chronic pancreatitis and pancreatic carcinoma. Furthermore it will discuss how to use these techniques in daily clinical practice.

Novel quantitative perfusion analysis with contrast-enhanced harmonic EUS for differentiation of autoimmune pancreatitis from pancreatic carcinoma

OBJECTIVE

Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic carcinoma (PC) despite recent advances in imaging tests. The aim of the study was to evaluate whether the quantitative perfusion analysis using software "Time intensity curve" with contrast-enhanced harmonic EUS (CH-EUS) facilitate the differentiation of AIP from PC.

METHODS

Consecutive patients with focal AIP and pancreatic carcinoma who underwent CH-EUS from January 2009 to September 2010 were analyzed. CH-EUS was performed with intravenous administration of an ultrasonographic contrast (Sonazoid) and electronic radial echoendoscope. The graph of time intensity curve (TIC) for pancreatic mass was generated to depict the changes in signal intensity over time within the region of interest (ROI). ROI was placed to cover an area with a pancreatic mass lesion. Based on the analysis of TIC, base intensity before injection (BI), peak intensity (PI), time to peak, and maximum intensity gain (MIG: PI-BI) were calculated.

RESULTS

Eight patients with focal AIP and twenty-two patients with PC were evaluated by TIC. PI and MIG of mass lesion of AIP were significantly higher than that of PC (21.4 dB vs. 9.6 dB, 17.5 vs. 6.6). Receiver operating characteristics analysis yielded an optimal MIG cutoff value of 12.5 with high sensitivity and specificity.

CONCLUSION

Pancreatic mass lesions of AIP and PC exhibited markedly different patterns with the TIC. This novel diagnostic modality using TIC generated by CH-EUS might offer an opportunity to improve accuracy in the differential diagnosis between pancreatic mass lesion of AIP and PC.

Impact of biliary stents on EUS-guided FNA of pancreatic mass lesions

BACKGROUND

Few studies have evaluated the impact of biliary stents on EUS-guided FNA.

AIM

To compare diagnostic yield of EUS-FNA in patients with or without biliary stents.

DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

Patients with obstructive jaundice secondary to solid pancreatic mass lesions who underwent EUS-FNA over 5 years.

MAIN OUTCOME MEASURES

The primary objective was to compare the diagnostic accuracy of EUS-FNA in patients with or without biliary stents and between patients with plastic stents or self-expandable metal stents (SEMSs). Secondary objectives were to assess the technical difficulty of EUS-FNA by comparing the number of passes required to establish diagnosis and to identify predictors of a false-negative diagnosis.

RESULTS

Of 214 patients who underwent EUS-FNA, 150 (70%) had biliary stents and 64 (30%) had no stents in place. Of 150 patients with biliary stents, 105 (70%) were plastic and 45 (30%) were SEMSs. At EUS-FNA, the diagnosis was pancreatic cancer in 155 (72%), chronic pancreatitis in 17 (8%), other cancer in 31 (14%), and indeterminate in 11 (5%). There was no difference in rates of diagnostic accuracy between patients with or without stents (93.7% vs 95.3%; P = .73) and between plastic or SEMSs (95.2% vs 95.5%, P = .99), respectively. Median number of passes to diagnosis was not significantly different between patients with or without stents (2 [interquartile ratio range (IQR) = 1-3] vs 2 [IQR = 1-4]; P = .066) and between plastic or SEMS (2.5 [IQR = 1-4] vs 2 [IQR = 1-4], P = .69), respectively. On univariate analysis, EUS-FNA results were false-negative in patients with large pancreatic masses (>3 cm vs <3 cm, 9.35% vs 0.93%, P = .005) that required more FNA passes (<2 vs >2 passes, 0% vs 11.8%, P < .0001).

LIMITATIONS

Retrospective study.

CONCLUSIONS

The presence or absence of a biliary stent, whether plastic or metal, does not have an impact on the diagnostic yield or technical difficulty of EUS-FNA.

Best practices in endoscopic ultrasound-guided fine-needle aspiration

Over the past 2 decades, endoscopic ultrasound-guided fine-needle aspiration has evolved to become an indispensable tool for tissue acquisition in patients with gastrointestinal tumors. The technique is useful for biopsy of mucosal and submucosal lesions in which prior endoscopic biopsies have been nondiagnostic; to sample peri-intestinal structures such as lymph nodes; and to sample masses in the pancreas, liver, adrenal glands, gallbladder, and bile duct. Also, with the advent of neoadjuvant therapies for diseases such as pancreatic cancer, most patients require a tissue diagnosis before initiating treatment. This review provides a perspective on technical issues that are key for best practices in endoscopic ultrasound-guided fine-needle aspiration.

How can we get the best results with endoscopic ultrasound-guided fine needle aspiration?

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has evolved to become an indispensable tool for tissue acquisition. While the overall diagnostic accuracy of EUS-FNA is greater than 90% for lung cancer staging, it is lower for pancreatic mass lesions. Several factors such as location of the tumor, disease characteristics and procedural techniques determine the outcomes of EUS-FNA. In this review we evaluate the various technical factors that are keys to attaining optimal procedural outcomes.

Interobserver agreement in contrast harmonic endoscopic ultrasound

BACKGROUND AND AIM

Contrast harmonic endoscopic ultrasound (CH-EUS) was recently introduced to clinical practice; its reproducibility among endosonographers is unknown. Our aim was to assess the interobserver agreement (IA) in CH-EUS.

METHODS

Fifteen endosonographers (eight experienced and seven non-experienced) from 11 Italian EUS centers evaluated 80 video-cases (40 solid pancreatic lesions, 20 pancreatic cystic lesions and 20 submucosal lesions) of CH-EUS, according to the degree of enhancement, the pattern of distribution and the washout of the contrast agent. IA within each group and between the two groups of observers was assessed with the Fleiss kappa statistic.

RESULTS

Overall IA was moderate for the uptake and fair for the pattern of distribution and the washout. In solid pancreatic lesions, IA was moderate for the uptake and fair for the pattern and the washout. In cystic pancreatic lesions, IA was uniformly moderate for the assessment of uptake, slight for the pattern and fair for the washout. In submucosal tumors, IA was substantial for the uptake, slight for the pattern and fair for the washout. Non-experienced endosonographers demonstrated, in most cases, comparable IA with the experienced ones.

CONCLUSIONS

Interobserver agreement among endosonographers for CH EUS was satisfactory. In particular, overall IA varied from slight to substantial, being fair in the majority of cases. Inherent structural features of the lesions, as well as technical differences between the variables assessed, could have accounted for the fluctuation of the results. Outcomes of IA were reproducible between experienced and non-experienced endosonographers.

Clinical impact of K-ras mutation analysis in EUS-guided FNA specimens from pancreatic masses

BACKGROUND

EUS-guided FNA (EUS-FNA) is considered optimal for differentially diagnosing pancreatic masses. However, the sensitivity of EUS-FNA ranges from 65% to 95%, respectively, which requires improvement.

OBJECTIVE

To evaluate clinical impact of K-ras mutation analysis in EUS-FNA specimens from pancreatic masses.

DESIGN

Prospective registration, single-center study.

SETTING

Tertiary referral center.

PATIENTS

This study involved 394 consecutive patients with pancreatic masses (307 pancreatic ductal adenocarcinomas [PDACs], 47 pancreatic inflammatory lesions, and 40 other types of tumors) who underwent EUS-FNA and analysis of K-ras mutations.

INTERVENTION

EUS-FNA, Cycleave polymerase chain reaction.

MAIN OUTCOME MEASUREMENTS

Improvement of the diagnostic accuracy by K-ras mutation analysis; absence of K-ras mutations in non-PDAC masses.

RESULTS

K-ras mutations were detected in 266 of 307 PDAC aspirates (87%) and in 3 of 87 non-PDAC masses (3%). K-ras mutations were detected in 18 of 39 patients (46%) who remained cytohistopathologically undiagnosed. The sensitivity, specificity, positive and negative predictive values, and accuracy of cytohistopathological and K-ras mutation analyses alone were 87%, 100%, 100%, 54%, and 89%, respectively, and, when combined, were 93%, 100%, 100%, 68%, and 94%, respectively. Adding K-ras mutation analysis to standard cytohistopathological assessment increased the sensitivity and accuracy of EUS-FNA by 6% (P < .001) and 5% (P < .001), respectively.

LIMITATIONS

Single-center study.

CONCLUSIONS

K-ras mutation analysis may be helpful in patients with suspected PDAC yet inconclusive EUS-FNA findings. K-ras mutations were extremely rare in pancreatic inflammation and other pancreatic tumors.

Endoscopic ultrasound elastography

Endoscopic ultrasound (EUS) is a reference technique for diagnosing and staging several different diseases. EUS-guided biopsies and fine needle aspirations are used to improve diagnostic performance of cases where a definitive diagnosis cannot be obtained through conventional EUS. However, EUS-guided tissue sampling requires experience and is associated with a low but not negligible risk of complications. EUS elastography is a non-invasive method that can be used in combination with conventional EUS and has the potential for improving the diagnostic accuracy and reducing the need for EUS-guided tissue sampling in several situations. Elastography measures tissue stiffness by evaluating changes in the EUS image before and after the application of slight pressure to the target tissue by the ultrasonography probe. Pathologic processes such as cancerization and fibrosis alter tissue elasticity and therefore induce changes in elastographic appearance. Qualitative elastography depicts tissue stiffness using different colors, whereas quantitative elastography renders numerical results expressed as a strain ratio or hue histogram mean. EUS elastography has been proven to differentiate between benign and malignant solid pancreatic masses, as well as between benign and malignant lymph nodes with a high accuracy. Studies have also demonstrated that the early changes of chronic pancreatitis can be distinguished from normal pancreatic tissues under EUS elastography. In this article, we review the technical aspects and current clinical applications of qualitative and quantitative EUS elastography and emphasize the potential additional indications that need to be evaluated in future clinical studies.

Endoscopic ultrasound image enhancement elastography

Endoscopic ultrasound (EUS) represents an advance in the diagnosis and staging of several diseases. EUS-guided fine-needle aspiration is useful, but technically demanding, and can be associated with complications. Elastography emerges as a useful tool that is based on the knowledge that some diseases, like cancer, lead to a modification in tissue stiffness. Elastography evaluates the elastic properties of tissues and compares images obtained before and after compression to target tissues; differentiating benign from malignant lesions. This article reviews theoretical aspects and the methodology of EUS elastography. Clinical applications, mainly in pancreatic diseases and lymph nodes, are analyzed.

EUS-guided FNA of solid pancreas tumors

Although endoscopic ultrasonography (EUS) is considered superior to MRI and CT in detecting pancreatic masses, it is the ability to target and place a needle into suspicious lesions that has made EUS indispensible in the evaluation of patients with solid pancreatic tumors. Endoscopic ultrasound-guided-fine-needle aspiration (EUS-FNA) is an accurate and safe technique to confirm the diagnosis of pancreatic cancer. EUS-FNA is now the principal technique applied to obtain the diagnosis of malignancy. We have designed this article to address a number of the key technical aspects of EUS-FNA of solid pancreatic masses.

The role of endoscopic ultrasonography in the diagnosis and management of pancreatic cancer

EUS with FNA is highly sensitive and specific for diagnosing pancreatic cancer. However, in certain situations, such as in patients with chronic pancreatitis, this high sensitivity and specificity can significantly diminish. The use of new technology, such as EUS elastography, CE-EUS, and gene mutations detection in FNA specimens, can help to differentiate chronic pancreatitis from pancreatic cancer. EUS has evolved from a diagnostic procedure to a therapeutic intervention in pancreatic cancer. EUS-guided fiducial insertion and EUS-guided delivery of antitumor agents, in addition to celiac plexus neurolysis, are the main therapeutic applications of EUS in pancreatic cancer.

EUS-guided FNA for diagnosis of solid pancreatic neoplasms: a meta-analysis

BACKGROUND

Preoperative diagnosis of solid pancreatic lesions remains challenging despite advancement in imaging technologies. EUS has the benefit of being a minimally invasive, well-tolerated procedure, although results are operator-dependent. The addition of FNA (EUS-guided FNA) provides samples for cytopathologic analysis, a major advantage over other imaging techniques.

OBJECTIVE

To determine the diagnostic accuracy of EUS-FNA for pancreatic cancer.

DESIGN

This is a meta-analysis of published studies assessing the diagnostic capability of EUS-FNA. Relevant studies were identified via MEDLINE and were included if they used a reference standard of definitive surgical histology or clinical follow-up of at least 6 months.

MAIN OUTCOME MEASUREMENTS

Data from selected studies were analyzed by using test accuracy meta-analysis software, providing a pooled value for sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curve. Cytology results were classified as inadequate, benign, atypical, suspicious, or malignant. Predefined subgroup analysis was performed.

RESULTS

Thirty-three studies published between 1997 and 2009 were included, with a total number of 4984 patients. The pooled sensitivity for malignant cytology was 85% (95% confidence interval [CI], 84-86), and pooled specificity was 98% (95% CI, 0.97-0.99). If atypical and suspicious cytology results were included to determine true neoplasms, the sensitivity increased to 91% (95% CI, 90-92); however, the specificity was reduced to 94% (95% CI, 93-96). The diagnostic accuracy of EUS-FNA was enhanced in prospective, multicenter studies.

LIMITATION

Publication bias was not a significant determinant of pooled accuracy.

CONCLUSION

This meta-analysis demonstrates that EUS-FNA is a highly accurate diagnostic test for solid neoplasms of the pancreas and should be considered when algorithms for investigating solid pancreatic lesions are being planned.

Efficacy of endoscopic ultrasound guided fine needle aspiration in patients with solid pancreatic neoplasms

BACKGROUND/AIM

Endosonography is a distinct method for evaluating the structural lesions of the gastrointestinal (GI) tract, particularly the pancreatobilliary region. This procedure has made a fundamental change in the diagnosis of pancreatic mass lesion through providing fine needle aspiration. This study aims at evaluating the results and efficacy of endoscopic ultrasound fine needle aspiration (EUS-FNA) in patients with pancreatic solid mass.

PATIENTS AND METHODS

The present study is an observational, prospective case series nature, evaluated patients with pancreatic solid mass referred to Imam Khomeini educational hospital in Tehran for a duration of one year since November 2010. In order to determine the false negative cases, the patients were followed-up from 6 to 12 months.

RESULTS

EUS-FNA was conducted on all 53 patients without any complication. The majority of patients included in the study were males (68%) and 81% of patients had a mass in the head of pancreas. The result of cytopathology revealed 36 adenocarcinomas (68%), 7 other malignancies (13%), benign lesions (6%) and 7 non-diagnostic cases (13%). The frequency of non-diagnostic results was significantly high in masses smaller than 3 cm (6 vs. 1, P < 0.002). Patients with non-diagnostic result were younger than those with malignant cytopathology (52 ± 7.5 vs. 66 ± 7.5 years, P < 0.001).. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this procedure concerning Adenocarcinoma were 88%, 100%, 100%, 70% and 90%, respectively.

CONCLUSION

EUS - FNA is an effective and safe procedure in histopathologic diagnosis of pancreatic tumors. This procedure is useful in all pancreatic mass cases including resectable and non-resectable ones.

Unusual, metastatic, or neuroendocrine tumor of the pancreas: a diagnosis with endoscopic ultrasound-guided fine-needle aspiration and immunohistochemistry

BACKGROUND/AIM

To determine the yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in combination with immunostains in diagnosing unusual solid pancreatic masses (USPM) in comparison with pancreatic adenocarcinoma (ACP).

PATIENTS AND METHODS

All EUS-FNA of solid pancreatic masses performed with a 22-gauge needle were included. Data on clinical presentations, mass characteristics, presence of pancreatitis, yield of tissue, and final diagnosis were compared between the two groups. On site cytopathology was provided and additional passes were requested to perform immunostains.

RESULTS

Two hundred and twenty-nine cases with either adenocarcinoma or USPM were included. The median age of the cohort was 65 years. ACP (210/229, 92%) accounted for the majority of the cases. The USPM included neuroendocrine (NET) masses (n=13), metastatic renal carcinoma (n=3), metastatic melanoma (n=1), lymphoma (n=1), and malignant fibrous histiocytoma (n=1). Subjects with ACP were significantly more likely to present with loss of weight (P=0.02) or obstructive jaundice (P<0.001). Subjects with ACP were more likely to have suspicious/atypical FNA biopsy results as compared with USPM (10% vs 0%). The sensitivity of EUS-FNA with immunostains was 93% in ACP as compared with 100% in USPM. Diagnostic accuracy was higher in USPM as compared with ACP (100% vs 93%).

CONCLUSIONS

EUS-FNA using a 22-gauge needle with immunostains has excellent diagnostic yield in patients with USPMs, which is comparable if not superior to the yield in pancreatic adenocarcinoma.

Efficacy of an artificial neural network-based approach to endoscopic ultrasound elastography in diagnosis of focal pancreatic masses

BACKGROUND & AIMS

By using strain assessment, real-time endoscopic ultrasound (EUS) elastography provides additional information about a lesion's characteristics in the pancreas. We assessed the accuracy of real-time EUS elastography in focal pancreatic lesions using computer-aided diagnosis by artificial neural network analysis.

METHODS

We performed a prospective, blinded, multicentric study at of 258 patients (774 recordings from EUS elastography) who were diagnosed with chronic pancreatitis (n = 47) or pancreatic adenocarcinoma (n = 211) from 13 tertiary academic medical centers in Europe (the European EUS Elastography Multicentric Study Group). We used postprocessing software analysis to compute individual frames of elastography movies recorded by retrieving hue histogram data from a dynamic sequence of EUS elastography into a numeric matrix. The data then were analyzed in an extended neural network analysis, to automatically differentiate benign from malignant patterns.

RESULTS

The neural computing approach had 91.14% training accuracy (95% confidence interval [CI], 89.87%-92.42%) and 84.27% testing accuracy (95% CI, 83.09%-85.44%). These results were obtained using the 10-fold cross-validation technique. The statistical analysis of the classification process showed a sensitivity of 87.59%, a specificity of 82.94%, a positive predictive value of 96.25%, and a negative predictive value of 57.22%. Moreover, the corresponding area under the receiver operating characteristic curve was 0.94 (95% CI, 0.91%-0.97%), which was significantly higher than the values obtained by simple mean hue histogram analysis, for which the area under the receiver operating characteristic was 0.85.

CONCLUSIONS

Use of the artificial intelligence methodology via artificial neural networks supports the medical decision process, providing fast and accurate diagnoses.

[Elastography in the evaluation of chronic pancreatitis]

Endoscopic ultrasound (EUS) has become an essential tool in the evaluation of pancreatic disease and can be considered the technique of choice for the diagnosis and staging of chronic pancreatitis (CP) and pancreatic cancer (PC). However, EUS has certain limitations, especially in the evaluation of patients with solid pancreatic masses (in the differential diagnosis of CP and PC). Furthermore there is variability in the EUS diagnostic criteria for CP. EUS-guided elastography is emerging as a highly useful tool in this setting. This modality has shown high diagnostic accuracy in the differential diagnosis of solid pancreatic masses, including differentiation between CP and PC. EUS-guided elastography has also been found to be useful in the diagnosis of CP, and can even classify patients according to the severity of their disease.

EUS-FNA with rescue fluorescence in situ hybridization for the diagnosis of pancreatic carcinoma in patients with inconclusive on-site cytopathology results

BACKGROUND

Detection of chromosomal abnormalities by fluorescence in situ hybridization (FISH) analysis has not been well-studied in FNA samples of pancreatic masses. Selective use of FISH in patients with inconclusive on-site cytopathology results may improve the sensitivity of EUS for malignancy.

OBJECTIVE

To determine the sensitivity and specificity of FISH analysis in patients with inconclusive on-site cytopathology results.

DESIGN

Consecutive patients with suspected pancreatic malignancy, nonrandomized cohort study. Final diagnosis was based on either surgical biopsy or disease progression on extended follow-up or death.

SETTING

Academic center, tertiary-care referral cancer center.

PATIENTS

A total of 212 EUS examinations were performed in 206 patients for solid pancreatic lesions over a 24-month period (January 2009-December 2010). FISH analysis was done for 69 patients with inconclusive or nonavailable on-site cytology results.

INTERVENTION

EUS-guided FNA (EUS-FNA) of solid pancreatic masses with cytology and FISH analysis for polysomy of chromosomes 3, 7, and 17 and deletion of 9p21.

MAIN OUTCOME MEASUREMENTS

Sensitivity/specificity of cytology, FISH, and a composite of cytology and FISH.

RESULTS

Patients with positive on-site cytology (110), neuroendocrine tumors (22), insufficient follow-up (1), FISH not obtained (3), and renal cancer with pancreatic metastasis (1) were excluded. Sixty-nine patients comprised the study cohort, 54 with malignancy and 15 with benign disease. Sensitivity for malignancy of cytology, FISH analysis, and the combination were 61%, 74%, and 85%, respectively (P = .009). FISH detected an additional 13 cases of pancreatic adenocarcinoma missed by cytology. There was no false-positive FISH analysis in 15 patients with benign disease. No major complications occurred from EUS-FNA.

LIMITATIONS

Single center, selected patients underwent FISH analysis, limited number of patients with benign disease.

CONCLUSION

In patients with suspected pancreatic cancer, FISH analysis can detect additional cases missed by cytology without compromising specificity. FISH analysis to detect polysomy of chromosomes 3, 7, and 17 and deletion of 9p21 should be considered when cytology is negative for malignancy in patients with a known pancreatic mass.

Effect of dedicated and supervised training on achieving competence in EUS-FNA of solid pancreatic lesions

BACKGROUND AND AIM

The diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been suggested as a benchmark of quality performance in EUS. However, there is paucity of data on the training requirement for competency in EUS-FNA of the pancreas. KO commenced the service without prior formal training in EUS-FNA. A formally trained colleague (MN) who underwent a fellowship in the same unit was appointed to a substantive post in 2007. The aims of the study were to assess if a dedicated training program in pancreaticobiliary (PB) EUS-FNA of solid lesions: (1) produced better results at the outset of independent practice than produced at the initiation of service without formal training and (2) produced results comparable with those of an experienced endosonographer.

MATERIAL AND METHODS

This is a retrospective review comparing the first 80 consecutive cases at the onset of practice of operator KO1 (2003/2004) and MN (2007/2008) as well as consecutive cases of operator KO2 (2007/2008) in the same time frame as the initial cases of operator MN.

RESULTS

There was a significant difference in EUS-FNA sensitivity for pancreatic malignancy between operator KO1 (56%) and operator MN (77%) p < 0.05. There was no significant difference in test performance between operator KO2 (82%) and MN (77%) (p > 0.05).

CONCLUSION

Our data show that formal training in PB EUS produces test performance at the outset of independent practice that is comparable with an experienced endosonographer, in line with the published standards for EUS-FNA of the pancreas and significantly better than that achieved without training.

EUS elastography combined with the strain ratio of tissue elasticity for diagnosis of solid pancreatic masses

BACKGROUND

Recently, the usefulness of endoscopic ultrasound (EUS) elastography has been reported for the diagnosis of pancreatic lesions. In the present study, we retrospectively assessed EUS elastography as a diagnostic tool by evaluating tissue elasticity distribution and elasticity semiquantification, using the strain ratio (SR) of tissue elasticity, in patients with pancreatic masses.

METHODS

One hundred and nine patients who underwent EUS elastography between September 2006 and May 2009 were retrospectively evaluated. The final diagnosis was chronic pancreatitis (CP) in 20 patients [6 with non-mass-forming pancreatitis, 7 with mass-forming pancreatitis (MFP), and 7 with autoimmune pancreatitis (AIP)], pancreatic cancer (PC) in 72, pancreatic neuroendocrine tumor (PNET) in 9, and normal pancreas in 8. The tissue elasticity distribution calculation was performed in real time, and the results were represented in color in fundamental B-mode imaging. In addition, we performed quantification using the SR (non-mass area/mass area).

RESULTS

Elastography for all PC patients showed intense blue coloration, indicating malignant lesions. In contrast, MFP presented with a mixed coloration pattern of green, yellow, and low-intensity blue. Normal controls showed an even distribution of green to red. The mean SR was 23.66 ± 12.65 for MFP and 39.08 ± 20.54 for PC (P < 0.05).

CONCLUSIONS

Endoscopic ultrasound elastography is a promising diagnostic tool for defining the tissue characteristics of pancreatic masses. In addition, semiquantitative analysis of elasticity using the SR may allow the differentiation of MFP from PC.

Role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis of solid pancreatic masses

Since it was developed in 1992, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been widely used and has been adapted for gastrointestinal and perigastrointestinal lesions. A medical literature review to evaluate the role of EUS-FNA for diagnosis of solid pancreatic masses showed a 78-95% sensitivity, 75-100% specificity, 98-100% positive predictive value, 46-80% negative predictive value and a 78-95% accuracy. The reported complication rates of EUS-FNA for pancreatic solid masses were 0-2%, although the criteria for complications varied among the studies. Because of its high diagnostic yield and low complication rate, EUS-FNA is cost-effective and widely applicable for the diagnosis of solid pancreatic masses, and is the best initial and the preferred secondary method compared with other biopsy techniques, such as endoscopic retrograde cholangiopancreatography-guided biopsy, computed tomography/ultrasound-FNA and surgery. Although EUS-FNA is 'a nearly perfected procedure,' controversy remains, such as the most suitable diameter of the needle, the appropriate number of needle passes and the necessity of on-site cytopathological evaluation. Recently investigators reported that using molecular analysis of EUS-FNA samples can achieve a higher diagnostic efficacy. Further research is encouraged to optimize the EUS-FNA procedure to reach its maximum diagnostic yield for solid pancreatic masses.

A prediction rule for estimating pancreatic cancer risk in chronic pancreatitis patients with focal pancreatic mass lesions with prior negative EUS-FNA cytology

OBJECTIVE

Considerable false-negative endoscopic ultrasound guided fine needle aspiration (EUS-FNA) findings exist in chronic pancreatitis patients with focal pancreatic mass lesions. Our aim was to develop a prediction rule to stratify risk for pancreatic cancer in chronic pancreatitis patients with focal pancreatic mass lesions with prior negative EUS-FNA cytology.

MATERIAL AND METHODS

A total of 138 eligible consecutive patients were identified from three hospitals between January 2000 and May 2008. A final diagnosis of pancreatic mass lesions was confirmed histologically or verified by a follow-up of at least 12 months. A prediction rule was developed from a logistic regression model by using a regression coefficient-based scoring method, and then internally validated by using bootstrapping.

RESULTS

The rate of pancreatic cancer in the cohort was 18.1%. The prediction rule, which was scored from 0 to 10 points, comprised five variables: sex, mass location, mass number, direct bilirubin, and CA 19-9. Among the 87.7% of patients with low-risk scores (≤ 3), the risk of pancreatic cancer was 13.2%; by comparison, this risk was 52.9% (p < 0.001) among the 12.3% of patients with high-risk scores (> 3). If further invasive tests were used for patients with high risk, 36% of patients with pancreatic cancer would not be missed. The prediction rule had good discrimination (area under the receiver operating characteristic curve, 0.72) and calibration (p = 0.96).

CONCLUSIONS

The prediction rule can provide available risk stratification for pancreatic cancer in chronic pancreatitis patients with focal mass lesions with prior negative EUS-FNA cytology. Application of risk stratification may improve clinical decision making.

Molecular endoscopic ultrasound for diagnosis of pancreatic cancer

Endoscopic ultrasound-guided fine needle aspiration-biopsy is a safe and effective technique in diagnosing and staging of pancreatic ductal adenocarcinoma. However its predictive negative value does not exceed 50% to 60%. Unfortunately, the majority of pancreatic cancer patients have a metastatic and/or a locally advanced disease (i.e., not eligible for curative resection) which explains the limited access to pancreatic tissue specimens. Endoscopic ultrasound-guided fine needle aspiration-biopsy is the most widely used approach for cytological and histological material sampling in these situations used in up to two thirds of patients with pancreatic cancer. Based on this unique material, we and others developed strategies to improve the differential diagnosis between carcinoma and inflammatory pancreatic lesions by analysis of KRAS oncogene mutation, microRNA expression and methylation, as well as mRNA expression using both qRT-PCR and Low Density Array Taqman analysis. Indeed, differentiating pancreatic cancer from pseudotumoral chronic pancreatitis remains very difficult in current clinical practice, and endoscopic ultrasound-guided fine needle aspiration-biopsy analysis proved to be very helpful. In this review, we will compile the clinical and molecular advantages of using endoscopic ultrasound-guided fine needle aspiration-biopsy in managing pancreatic cancer.

[A rare tumor-like lesion of the pancreatic head with bile duct obstruction]

Tumors of the pancreatic head commonly consist of carcinomas whereas other entities are rare exceptions. Extrapulmonary sarcoidosis is well-known but is extremely rare when detected as a mass in the pancreatic head. In general the diagnosis of sarcoidosis requires histologic examination with verification of non-caseous, epithelioid cell-like granulomas. Systemic therapy consists of steroids when the patient exhibits symptoms or in the case of progression of the disease. However, in some cases extended abdominal resections are also required to confirm the diagnosis and/or to treat symptoms.

Plectin-1 as a novel biomarker for pancreatic cancer

PURPOSE

We are in great need of specific biomarkers to detect pancreatic ductal adenocarcinoma (PDAC) at an early stage, ideally before invasion. Plectin-1 (Plec1) was recently identified as one such biomarker. However, its suitability as a specific biomarker for human pancreatic cancer, and its usability as an imaging target, remain to be assessed.

EXPERIMENTAL DESIGN

Specimens of human PDAC, chronic pancreatitis, and normal pancreata were evaluated by immunohistochemistry and Western blot analysis. To validate Plec1 as an imaging target, Plec1-targeting peptides (tPTP) were used as a contrast agent for single photon emission computed tomography in an orthotopic and liver metastasis murine model of PDAC.

RESULTS

Plec1 expression was noted to be positive in all PDACs but negative in benign tissues. Plec1 expression increases during pancreatic carcinogenesis. It was found to be misexpressed in only 0% to 3.85% of early PDAC precursor lesions (PanIN I/II) but in 60% of PanIN III lesions. Plec1 expression was further noted to be retained in all metastatic foci assayed and clearly highlighted these metastatic deposits in lymph nodes, liver, and peritoneum. In vivo imaging using tPTP specifically highlighted the primary and metastatic tumors. Biodistribution studies performed after imaging show that the primary pancreatic tumors and liver metastases retained 1.9- to 2.9-fold of tPTP over normal pancreas and 1.7-fold over normal liver.

CONCLUSIONS

Plec1 is the first biomarker to identify primary and metastatic PDAC by imaging and may also detect preinvasive PanIN III lesions. Strategies designed to image Plec1 could therefore improve detection and staging.

Staining for p53 and Ki-67 increases the sensitivity of EUS-FNA to detect pancreatic malignancy

AIM: To investigate whether tumor marker staining can improve the sensitivity of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to diagnose pancreatic malignancy.

METHODS: Patients who underwent EUS-FNA were retrospectively identified. Each EUS-FNA specimen was evaluated by routine cytology and stained for tumor markers p53, Ki-67, carcinoembryonic antigen (CEA) and CA19-9. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and positive and negative likelihood ratios (PLR and NLR) were calculated in order to evaluate the performance of each test to detect malignancy.

RESULTS: Sixty-one specimens had complete sets of stains, yielding 49 and 12 specimens from pancreatic adenocarcinomas and benign pancreatic lesions due to pancreatitis, respectively. Cytology alone had sensitivity and specificity of 41% and 100% to detect malignancy, respectively. In 46% of the specimens, routine cytology alone was deemed indeterminate. The addition of either p53 or Ki-67 increased the sensitivity to 51% and 53%, respectively, with perfect specificity, PPV and PLR (100%, 100% and infinite). Both stains in combination increased the sensitivity to 57%. While additional staining with CEA and CA19-9 further increased the sensitivity to 86%, the specificity, PPV and PLR were significantly reduced (at minimum 42%, 84% and 1, respectively). Markers in all combinations performed poorly as a negative test (NPV 26% to 47%, and NLR 0.27 and 0.70).

CONCLUSION: Immunohistochemical staining for p53 and Ki-67 can improve the sensitivity of EUS-FNA to diagnose pancreatic adenocarcinoma.