Impact of endoscopic ultrasound-guided fine needle biopsy for diagnosis of pancreatic masses

The diagnostic utility of methylthioadenosine phosphorylase immunohistochemistry for pancreatic ductal adenocarcinoma in FNA and small biopsy specimens

BACKGROUND

Accurate diagnosis of pancreatic lesions by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) or fine-needle biopsy can be challenging. Although surrogate immunohistochemical markers for genetic alterations associated with pancreatic ductal adenocarcinoma (PDAC) have been identified, they have modest sensitivity. Biallelic loss of CDKN2A occurs in up to 46% of PDACs, and methylthioadenosine phosphorylase (MTAP) immunohistochemistry (IHC) has been identified as a reliable surrogate marker for this alteration. The current study evaluates the utility of MTAP IHC for the diagnosis of PDAC.

METHODS

In total, 136 cases of EUS-FNA cell block or core biopsy targeting solid pancreatic masses were identified. MTAP IHC was performed and evaluated for complete loss of expression in neoplastic cells. These results were correlated with available clinical next-generation sequencing that was performed on a subset of cases.

RESULTS

Complete loss of MTAP expression was identified in 23 of 80 (29%) PDACs. A subset of cases classified as suspicious (4 of 21) and atypical (4 of 22) showed MTAP loss. All morphologically indeterminate cases with MTAP loss were confirmed as PDAC on resection/additional sampling. No benign samples (n = 13) showed loss of MTAP. In samples that had available clinical next-generation sequencing data (n = 13), copy number loss of CDKN2A was detected in all cases that had loss of MTAP expression (n = 4).

CONCLUSIONS

Loss of MTAP was identified in approximately 30% of PDAC small biopsy specimens. As loss of MTAP expression is not expected in nonneoplastic cells, and these findings suggest that MTAP IHC can support a diagnosis of PDAC in small biopsy samples.

Rapid on-site evaluation improves the sensitivity of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for solid pancreatic lesions irrespective of technique: A single-centre experience

OBJECTIVE

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the first-line technique for the sampling of pancreatic lesions. Many factors can influence the diagnostic performance of this procedure, including the use of rapid on-site evaluation (ROSE). The primary aim of this study was to compare the adequacy, diagnostic yield, accuracy, sensitivity and specificity of EUS-FNA for solid pancreatic lesions before and after the introduction of ROSE.

METHODS

This retrospective single-centre study evaluated all consecutive patients who underwent EUS-FNA for suspicious, solid pancreatic masses from April 2012 to March 2015. We compared the findings of EUS-FNA procedures performed during the first and second years following the adoption of ROSE ("ROSE1" and "ROSE2", respectively) to those performed the year before ROSE introduction (the "pre-ROSE" group).

RESULTS

Ninety-one consecutive patients with a total of 93 pancreatic lesions were enrolled. For the pre-ROSE, ROSE1 and ROSE2 groups, the adequacy rates were 96.2%, 96.6% and 100%, the diagnostic yield values were 76.9%, 89.7% and 92.1% and accuracy values were 69.2%, 86.2% and 89.5% (p = NS). Sensitivity for malignancy improved from 63.7% in the pre-ROSE group to 91.7% and 91.2% in the post-ROSE groups (p < 0.05). Specificity for malignancy was 100% in all groups.

CONCLUSIONS

ROSE can improve the diagnostic performance of EUS-FNA for solid pancreatic lesions, although only sensitivity reached statistical significance.

Approach to Pancreatic Head Mass in the Background of Chronic Pancreatitis

Chronic pancreatitis (CP) is a known risk factor for pancreatic cancer. CP may present with an inflammatory mass, and differentiation from pancreatic cancer is often difficult. Clinical suspicion of malignancy dictates a need for further evaluation for underlying pancreatic cancer. Imaging modalities remain the mainstay of evaluation for a mass in background CP; however, they have their shortcomings. Endoscopic ultrasound (EUS) has become the go-to investigation. Adjunct modalities such as contrast-harmonic EUS and EUS elastography, as well as EUS-guided sampling using newer-generation needles are useful in differentiating inflammatory from malignant masses in the pancreas. Paraduodenal pancreatitis and autoimmune pancreatitis often masquerade as pancreatic cancer. In this narrative review, we discuss the various modalities used to differentiate inflammatory from malignant masses of the pancreas.

The diagnostic performance of combined conventional cytology with smears and cell block preparation obtained from endoscopic ultrasound-guided fine needle aspiration for intra-abdominal mass lesions

BACKGROUND/AIM

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the primary method for tissue acquisition of intra-abdominal masses. However, the main limitation of cytology alone is the lack of tissue architecture and inadequate samples. This study aimed to evaluate the diagnostic performance of combined conventional cytology and cell block preparation obtained from EUS-FNA of intra-abdominal masses without Rapid On-site Evaluation (ROSE).

METHODS

Cytologic smears and cell block slides of 166 patients undergoing EUS-FNA during 2010-2015 were reviewed by an experienced cytopathologist blinded to clinical data.

RESULTS

125 patients had neoplastic lesions. Pancreatic adenocarcinoma was the most common etiology (35.5%), followed by lymph node metastasis (27.7%). The mean mass size was 2.5±1.3 cm. The mean number of passes was 1.9±1.28. Tissue adequacy for conventional cytology and cell block preparation was 78.9% and 78.1%, respectively. Factors associated with tissue adequacy were assessed. For cytology, lesions of > 2.1 cm, masses in the pancreatic body or tail, malignancy, and pancreatic cancer were positively associated with adequate cellularity. For cell block preparation, lesions of > 3 cm and malignancy were associated with increased tissue adequacy. The conventional cytology alone had a sensitivity of 68.5%, a specificity of 95.7%, and an area under the receiver operating characteristics (AUROC) of 0.821. The cell block preparation alone had a sensitivity of 65.4%, a specificity of 96%, and an AUROC of 0.807. The combined conventional cytology and cell block preparation performed significantly better than either method alone (p<0.05), as demonstrated by an increased AUROC of 0.853. Furthermore, cell block detected malignancy in 9.3% of cases where the cytologic smears failed to identify malignant cells.

CONCLUSIONS

The combined conventional cytology and cell block preparation increased the diagnostic accuracy of EUS-FNA compared to either method alone. This approach should be implemented in routine practice, especially where ROSE is unavailable.

Comprehensive review of diagnostic modalities for early chronic pancreatitis

Chronic pancreatitis (CP) is a progressive condition caused by several factors and characterised by pancreatic fibrosis and dysfunction. However, CP is difficult to diagnose at an early stage. Various advanced methods including endoscopic ultrasound based elastography and confocal laser endomicroscopy have been used to diagnose early CP, although no unified diagnostic standards have been established. In the past, the diagnosis was mainly based on imaging, and no comprehensive evaluations were performed. This review describes and compares the advantages and limitations of the traditional and latest diagnostic modalities and suggests guidelines for the standardisation of the methods used to diagnose early CP.

The level of agreement between rapid-on-site evaluation of endoscopic ultrasound fine needle aspirate and surgical histological diagnosis in gastrointestinal lesions

OBJECTIVE

Endoscopic ultrasound (EUS) is the main tool for biopsy via fine needle aspiration (FNA) from gastrointestinal (GI) lesions including pancreatic, upper gastrointestinal, and adjacent lesions. The variable diagnostic yield and delay until the final pathological results can affect treatment planning and cause patient anxiety. We aimed to assess the agreement of rapid on-site evaluation (ROSE) of EUS-FNA with the surgical histological diagnosis of patients who underwent resection.

METHOD

A retrospective study was performed including all patients 18 years or older who underwent EUS-FNA with ROSE for GI lesions. For patients who underwent surgical resection, the correlation between ROSE and the surgical histological diagnosis was evaluated with the kappa coefficient.

RESULTS

Overall, 73 patients who underwent EUS-FNA with ROSE were included, of whom 22 (30.1%) had curative resection. The final pathological diagnosis from surgery showed 17 malignant and 5 benign lesions. Among the benign lesions, ROSE correctly identified 2 (diagnostic accuracy of 40%), while among the malignant lesions, ROSE correctly identified 14 (diagnostic accuracy of 82.4%), yielding a fair kappa coefficient of 0.366 (95% CI 0.035-0.697). When classifying the lesions as either malignant vs benign or suspicious of malignancy, the kappa coefficient increased to 0.58 (95% CI 0.180-0.975) for the subgroup of pancreatic lesions, with diagnostic accuracy of 81.2% for the malignant category.

CONCLUSIONS

A high level of agreement for malignancy was found between FNA-EUS with ROSE and the final surgical histological diagnosis. ROSE can be used as an adjuvant diagnostic tool to optimise patient management and decrease delay-related anxiety.

Does ProCore Fine-Needle Biopsy Really Improve the Clinical Outcome of Endoscopic Ultrasound-Guided Sampling of Pancreatic Masses?

INTRODUCTION

Fine-needle biopsy (FNB) has been suggested to provide better histological samples as compared to endoscopic ultrasound fine-needle aspiration (EUS-FNA). However, studies comparing EUS-FNA and EUS-FNB for pancreatic lesions reported contrasting results. The aim of this study was to compare the clinical performance of EUS-FNA versus EUS-FNB with the ProCore needle for the investigation of pancreatic lesions.

METHODS

We reviewed all patients undergoing EUS for the investigation of pancreatic lesions from August 2012 to September 2018. From August 2012 to January 2015, all procedures were performed with standard needles, whereas from February 2015 to September 2018, the use of ProCore needles had been introduced. Data on diagnostic accuracy, number of needle passes, and/or adverse events were collected.

RESULTS

Three hundred twenty-four patients were retrospectively evaluated: 190 (58.6%) underwent EUS-FNA and 134 (41.4%) EUS-FNB. Both EUS-FNA and EUS-FNB showed high diagnostic accuracy for malignancy (94% [95% CI: 89-97%] vs. 94% [95% CI: 89-98%]). Notably, there were no differences between EUS-FNA and EUS-FNB in terms of sensitivity, specificity, positive and negative likelihood ratio, histological core tissue retrieval, adverse events, or number of needle passes. However, subgroup analysis noted a higher diagnostic accuracy for 25G EUS-FNB as compared to 25G EUS-FNA (85.7 vs. 55.5%; *p = 0.023).

CONCLUSION

EUS-FNB with the ProCore needle is safe and feasible in pancreatic lesions. The ProCore needle did not provide any advantage in terms of diagnostic accuracy, sensitivity, specificity, positive and/or negative likelihood ratio, or acquisition of the core specimen; therefore, its routine application is not supported.

Comparison of EUS-guided conventional smear and liquid-based cytology in pancreatic lesions: A systematic review and meta-analysis

Background and study aims  Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) has limitations of inadequate sampling and false-negative results for malignancy. It has been performed using conventional smear (CS) cytology with rapid on-site evaluation (ROSE) with reasonable diagnostic accuracy. An alternative to ROSE is liquid-based cytology (LBC). Commonly used LBC techniques include precipitation-based (SurePath™) and filtration-based (ThinPrep ^® , CellPrep ^® ). Data regarding the diagnostic efficacy of LBC compared with CS are limited. Methods  Multiple databases were searched through March 2020 to identify studies reporting diagnostic yield of EUS-guided CS and LBC in pancreatic lesions. Pooled diagnostic odds and rates of performance for the cytologic diagnoses of benign, suspicious, and malignant lesions were calculated. Diagnostic efficacy was evaluated by pooled rates of accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results  Nine studies with a total of 1308 patients were included in our final analysis. Pooled diagnostic odds of CS cytology were 1.69 (CI 1.02-2.79) and 0.39 (CI 0.19-0.8) for malignant lesions when compared to filtration-based and precipitation-based LBC techniques, respectively. For CS, precipitation-based and filtration-based LBC, pooled diagnostic accuracy was 79.7 %, 85.2 %, 77.3 %, sensitivity was 79.2 %, 83.6 %, 68.3 %, and specificity was 99.4 %, 99.5 %, 99.5 %, respectively. Conclusions  The precipitation-based LBC technique (SurePath™) had superior diagnostic odds for malignant pancreatic lesions compared with CS cytology in the absence of ROSE. It showed superior accuracy and sensitivity, but comparable specificity and PPV. Diagnostic odds of CS cytology in the absence of ROSE were superior to the filtration-based LBC technique (ThinPrep ^® , Cellprep ^® ) for diagnosing malignant pancreatic lesions.

Safety and efficacy of endoscopic ultrasound-guided fine needle aspiration for pancreatic masses: A prospective multicenter study

OBJECTIVES

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for solid pancreatic lesions has high diagnostic yield. However, few prospective multicenter studies have been performed. We performed a prospective cohort study to evaluate the efficacy and safety of EUS-FNA for diagnosis of solid pancreatic lesions.

METHODS

This prospective cohort study involved five hospitals in Japan. The primary outcome was sensitivity of EUS-FNA for diagnosing malignant lesions. We also evaluated parameters of diagnostic sufficiency and the safety of EUS-FNA.

RESULTS

In total, 246 patients were enrolled. The absolute values of the parameters evaluated showed no significant differences; however, the percentage changes in the white blood cell counts and C-reactive protein levels after examination were significantly higher, and the percentage change in hemoglobin concentrations was significantly lower. The minor and major complication rates at the time of puncture, 24 h, 7 days and 28 days were 4.1%, 2.8%, 1.6%, and 0.0%, respectively. The true complication rate was 1.2%. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 97.2%, 88.0%, 96.2%, 100%, and 81.4%, respectively.

CONCLUSIONS

EUS-FNA for solid pancreatic lesions has high diagnostic yield and is safe, consistent with previously studies.

Prospective comparison of slow-pull and standard suction techniques of endoscopic ultrasound-guided fine needle aspiration in the diagnosis of solid pancreatic cancer

Background

The usage of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the diagnosis of solid pancreatic cancer is increasing, however mainly retrospective studies are available about the detailed methods of sampling.

Methods

To compare prospectively the diagnostic yield of EUS-FNA samples obtained with slow-pull (SP) and with standard suction technique (SS).

Results

EUS-FNA sampling was diagnostic in 72 of 92 cases (78.3%). Diagnostic yield was 67.4% in the SS and 65.2% in the SP group. The number of smear pairs (1.84 vs. 3.56; p < 0.001) and blood contamination (1.50 vs. 2.19; p < 0.001) were significantly higher in the SS group, which resulted in lower rate of diagnostic samples (41.8% vs. 30.0%; p = 0.003). There was no difference in the cellularity (1.58 vs. 1.37; p = 0.2554), or in the sensitivity and specificity in the identification of malignancy between SP and SS subgroups (69.9, 100% vs. 73.5, 100%). Histological samples were obtained in 60 cases (with SP: 49 cases; with SS: 46 cases). There was no difference in the diagnostic yield of histological samples between the groups (63 and 58.7%).

Conclusion

The diagnostic yield, the cellularity of smears and the rate of acquiring sufficient histological material are similar in the SP and SS group, but due to lower bloodiness and decreased number of slides, the pathological diagnosis is faster and more cost-effective.

Immunohistochemical analysis of IMP3 and p53 expression in endoscopic ultrasound-guided fine needle aspiration and resected specimens of pancreatic diseases

BACKGROUND

Insulin-like growth factor II messenger ribonucleic acid-binding protein 3 (IMP3) is a valuable marker that distinguishes malignant from benign lesions and predicts prognosis.

METHODS

First, we evaluated IMP3 expression in 77 resected specimens of pancreatic ductal adenocarcinoma (PDAC), intraductal papillary mucinous neoplasm (IPMN), and chronic pancreatitis (CP). Eleven PDAC patients preoperatively underwent endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Survival analysis of IMP3 and clinicopathological factors was performed. IMP3 and p53 expression was evaluated in another 127 EUS-FNA samples of solid pancreatic masses to compare the diagnostic value of routine and immunohistochemical staining.

RESULTS

IMP3 expression was detected in 72.3%, 50%, 20%, and 0% of PDAC, malignant IPMN, benign IPMN, and CP, respectively. Evaluation of IMP3 expression in EUS-FNA specimens coincided with that in resected specimens in 10 of 11. IMP3 expression correlated with tumor differentiation in PDAC samples (p = .006) and with poor prognosis through univariate analysis (p = .045). Tumor differentiation and lymph node metastasis were significantly associated with poor prognosis through multivariate analysis. In EUS-FNA specimens, the sensitivity, specificity, and accuracy of cytohistological analysis were 80.8%, 100%, and 85.0%, respectively. IMP3 and p53 expression were detected in 80.8% and 44.9% of malignant and 0% and 5% of benign lesions. Combined with IMP3 immunostaining, the sensitivity, specificity and accuracy of cytohistological analysis significantly increased to 87.9%, 100%, and 90.8% (p = .016), respectively. Meanwhile, p53 staining had no impact on the results.

CONCLUSIONS

IMP3 immunohistochemical staining can improve the diagnostic accuracy of EUS-FNA for malignant pancreatic tumors.

Repeatability and correlations of dynamic contrast enhanced and T2* MRI in patients with advanced pancreatic ductal adenocarcinoma

BACKGROUND

In current oncological practice of pancreatic ductal adenocarcinoma (PDAC), there is a great demand for response predictors and markers for early treatment evaluation. In this study, we investigated the repeatability and the interaction of dynamic contrast enhanced (DCE) and T2* MRI in patients with advanced PDAC to enable for such evaluation using these techniques.

MATERIALS & METHODS

15 PDAC patients underwent two DCE, T2* and anatomical 3 T MRI sessions before start of treatment. Parametric maps were calculated for the transfer constant (K^trans), rate constant (k_ep), extracellular extravascular space (v_e) and perfusion fraction (v_p). Quantitative R2* (1/T2*) maps were obtained from the multi-echo T2* images. Differences between normal and cancerous pancreas were determined using a Wilcoxon matched pairs test. Repeatability was obtained using Bland-Altman analysis and relations between DCE and T2*/R2* were observed by Spearman correlation and voxel-wise binned plots of tumor voxels.

RESULTS

PDAC K^trans (p = 0.007), k_ep (p < 0.001), v_p (p = 0.035) were lower and v_e (p < 0.001) was higher compared to normal pancreas. The coefficient of variation between sessions was 21.8% for K^trans, 9.9% for k_ep, 19.3% for v_e, 18.2% for v_p and 18.7% for R2*. Variation between patients ranged from 20.2% for k_ep to 43.6% for K^trans. In the tumor both K^trans (r = 0.56, p = 0.030) and v_e (r = 0.54, p = 0.037) showed a positive correlation with T2*. Voxel wise analysis showed a steep increase in R2* for tumor voxels with lower K^trans and v_e.

CONCLUSION

We showed good repeatability of DCE and T2* related MRI parameters in advanced PDAC patients. Furthermore, we have illustrated the relation of DCE K^trans and v_e with tissue T2* and R2* indicating substantial value of these parameters for detecting tumor hypoxia in future studies. The results from our study pave the way for further response evaluation studies and patient selection based on DCE and T2* parameters.

1.0T MR-guided percutaneous coaxial cutting needle biopsy in pancreatic lesion diagnosis

BACKGROUND

Pancreatic carcinoma is a common cause of cancer deaths worldwide. Biopsy is often required for the initial diagnosis of pancreatic masses. Biopsy can be performed endoscopically or percutaneously with computed tomography (CT) and ultrasound (US) guidance. MRI offers many inherent advantages over CT and US.

PURPOSE/HYPOTHESIS

To prospectively evaluate the feasibility, accuracy, and safety of MRI-guided percutaneous coaxial cutting needle biopsy of pancreatic lesions using an open 1.0T high-field MR scanner.

STUDY TYPE

Prospective.

POPULATION

Thirty-one patients with 31 pancreatic lesions underwent MR-guided percutaneous coaxial cutting needle biopsy.

FIELD STRENGTH/SEQUENCE

1.0T T₂ WI-TSE PDW-aTSE T₁ WI-TFE.

ASSESSMENT

Final diagnosis was confirmed by surgery and clinical follow-up for at least 12 months. The accuracy, sensitivity, and specificity were calculated. Complications were recorded.

STATISTICAL TESTS

There was no statistical analysis in this study.

RESULTS

The procedure was technically successful and final biopsy samples were adequate for histopathological examination in all patients. Biopsy pathology revealed malignant pancreatic tumor in 25 patients (25/31, 80.6%), and benign pancreatic lesions were present in six patients (6/31, 19.4%). The final diagnosis was pancreatic malignancy in 27 patients and benign disease in four patients, which was confirmed by surgery and clinical follow-up. Two biopsy results were false-negative. The diagnostic accuracy in biopsies was 93.5% (29 of 31). The sensitivity to detect a malignant disease was 92.6% (25 of 27), and the specificity was 100%. All patients tolerated the procedure well; minor peripancreatic hemorrhage was found in two patients after the procedure, and none had major complications either during or after the procedure.

DATA CONCLUSION

MRI-guided percutaneous biopsy of pancreatic lesions using an open 1.0T high-field scanner has high diagnostic accuracy, which is feasible and safe for use in clinical practice.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2018;48:382-388.

Contrast-enhanced endoscopic ultrasound for differential diagnosis of pancreatic cancer: an updated meta-analysis

Aim

We aim to assess the diagnostic value of contrast-enhanced endoscopic ultrasound (CE-EUS) for pancreatic cancer and inflammatory lesions by pooling current evidence.

Materials and Methods

A systematical search of PubMed, Web of Science and the Cochrane Library was performed from inception to January 2016. Two authors independently screened and extracted detailed data from included studies. A random effect model was adopted to estimate the pooled sensitivity, specificity in order to determine the diagnostic ablitity of CE-EUS. Furthermore, we conducted the meta-regression and subgroup analyses to explore possible heterogeneity.

Results

Eighteen eligible studies enrolling 1668 patients were finally included in the study. The pooled sensitivity of CE-EUS for distinguishing pancreatic cancers from solid inflammatory masses was 0.93 (95% CI, 0.91–0.94), and the specificity was 0.88 (95% CI, 0.84–0.90). The area under summary receiver operating characteristic curve yielded 0.97. No publication bias was observed by Deeks’ funnel plot in current meta-analysis.

Conclusions

We provided evidence that CE-EUS is a promising modality for differential diagnosis of pancreatic adenocarcinomas. Further multicenter prospective studies should be carried out to certify its utility.

Accuracy of endoscopic ultrasound-fine needle aspiration of solid lesions over time: Experience from a new endoscopic ultrasound program at a Canadian community hospital

BACKGROUND AND OBJECTIVES

A Canadian Community Hospital launched a new Endoscopic Ultrasound (EUS) Program in 2011. The aim of this study was to report the accuracy of EUS-fine needle aspiration (EUS-FNA) of solid lesions over time as it pertains to cytotechnologists' involvement and learning curves.

METHODS

The electronic medical records of patients that had a EUS from July 2011 to January 2014 were retrospectively reviewed. Only solid lesions with FNA sampling were included in the study. The primary outcome assessed was the accuracy of specimen acquisition for pathological review. The secondary outcome was diagnostic accuracy. Cases were separated by chronological order into thirds for the assessment of learning curves. Cytotechnologists' involvement was correlated to determine its impact on accuracy.

RESULTS

Two hundred and seventy-one EUS-FNA procedures were completed for solid lesions. Cytotechnologists' involvement resulted in a specimen acquisition accuracy of 82.6%, compared with 68.8% without a cytotechnologist (P = 0.009; 95% confidence interval [CI] 3.2%-25.0%). Diagnostic accuracy was 74.2% with a cytotechnologist while 62.4% without a cytotechnologist (P = 0.038; 95% CI 0.3%-23.7%). The specimen acquisition accuracy increased from 73.2% from the first third of cases to 92.3% for the last third with a cytotechnologist (P = 0.004; 95% CI 6%-33.0%). Without a cytotechnologist, the specimen accuracy was 67.6% for the first third while 57.7% for the last third of cases (P = 0.434; 95% CI - 33.9-14.4%). In the multivariable regression analysis, after adjusting for other predictors, a present cytotechnologist (P = 0.022) and lesion size 21 mm-30 mm (P = 0.039) and >30 mm (P = 0.001) were significantly associated with increased specimen acquisition accuracy. Only a present cytotechnologist (P = 0.046) was significantly associated with increased diagnostic accuracy.

INTERPRETATION

Cytotechnologists' involvement significantly improved the accuracy of specimen acquisition. Although accuracy was impacted by a cytotechnologist learning curve, our results highlight the importance of a cytotechnologist being present for EUS-FNA sampling of solid lesions.

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

22-gauge core vs 22-gauge aspiration needle for endoscopic ultrasound-guided sampling of abdominal masses

AIM

To compare the aspiration needle (AN) and core biopsy needle (PC) in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of abdominal masses.

METHODS

Consecutive patients referred for EUS-FNA were included in this prospective single-center trial. Each patient underwent a puncture of the lesion with both standard 22-gauge (G) AN (Echo Tip Ultra; Cook Medical, Bloomington, Indiana, United States) and the novel 22G PC (EchoTip ProCore; Cook Medical, Bloomington, Indiana, United States) in a randomized fashion; histology was attempted in the PC group only. The main study endpoint was the overall diagnostic accuracy, including the contribution of histology to the final diagnosis. Secondary outcome measures included material adequacy, number of needle passes, and complications.

RESULTS

Fifty six consecutive patients (29 men; mean age 68 years) with pancreatic lesions (n = 38), lymphadenopathy (n = 13), submucosal tumors (n = 4), or others lesions (n = 1) underwent EUS-FNA using both of the needles in a randomized order. AN and PC reached similar overall results for diagnostic accuracy (AN: 88.9 vs PC: 96.1, P = 0.25), specimen adequacy (AN: 96.4% vs PC: 91.1%, P = 0.38), mean number of passes (AN: 1.5 vs PC: 1.7, P = 0.14), mean cellularity score (AN: 1.7 vs PC: 1.1, P = 0.058), and complications (none). A diagnosis on the basis of histology was achieved in the PC group in 36 (64.3%) patients, and in 2 of those as the sole modality. In patients with available histology the mean cellularity score was higher for AN (AN: 1.7 vs PC: 1.0, P = 0.034); no other differences were of statistical significance.

CONCLUSION

Both needles achieved high overall diagnostic yields and similar performance characteristics for cytological diagnosis; histological analysis was only possible in 2/3 of cases with the new needle.

Initial experience with a novel EUS-guided core biopsy needle (SharkCore): results of a large North American multicenter study

BACKGROUND AND AIMS

The ability to safely and effectively obtain sufficient tissue for pathologic evaluation by using endoscopic ultrasound (EUS) guidance remains a challenge. Novel designs in EUS needles may provide for improved ability to obtain such core biopsies. The aim of this study was to evaluate the diagnostic yield of core biopsy specimens obtained using a novel EUS needle specifically designed to obtain core biopsies.

PATIENTS AND METHODS

Multicenter retrospective review of all EUS-guided fine-needle biopsies obtained using a novel biopsy needle (SharkCore FNB needle, Medtronic, Dublin, Ireland). Data regarding patient demographics, lesion type/location, technical parameters, and diagnostic yield was obtained.

RESULTS

A total of 250 lesions were biopsied in 226 patients (Median age 66 years; 113 (50 %) male). Median size of all lesions (mm): 26 (2 - 150). Overall, a cytologic diagnosis was rendered in 81 % specimens with a median number of 3 passes. When rapid onsite cytologic evaluation (ROSE) was used, cytologic diagnostic yield was 126/149 (85 %) with a median number of 3 passes; without ROSE, cytologic diagnostic yield was 31/45 (69 %, P = 0.03) with a median number of 3 passes. Overall, a pathologic diagnosis was rendered in 130/147 (88 %) specimens with a median number of 2 passes. Pathologic diagnostic yield for specific lesion types: pancreas 70/81 (86 %), subepithelial lesion 13/15 (87 %), lymph node 26/28 (93 %). Ten patients (10/226, 4 %) experienced adverse events: 4 acute pancreatitis, 5 pain, 1 fever/cholangitis.

CONCLUSIONS

Initial experience with a novel EUS core biopsy needle demonstrates excellent pathologic diagnostic yield with a minimum number of passes.

The Role of Real Time Endoscopic Ultrasound Guided Elastography for Targeting EUS-FNA of Suspicious Pancreatic Masses: A Review of the Literature and A Single Center Experience

BACKGROUND

Endoscopic ultrasound guided elastography is an imaging modality that can be used to evaluate tissue stiffness and to assess solid pancreatic lesions. It can also assist in optimizing the diagnostic yield of endoscopic ultrasound guided fine needle aspiration biopsies.

AIMS

To review the literature on solid pancreatic lesions, the use of EUS guided fine needle aspiration and endoscopic ultrasound guided elastography and to present a single center experience using elastography to direct fine needle aspiration biopsies of solid pancreatic lesions.

METHODS

We present a review of the literature and a single center experience describing the use of EUS guided elastography in directing fine needle aspiration biopsies of solid pancreatic lesions.

RESULTS

Thirteen male veterans with an average age of 62.3 (SD±11.8) years were enrolled in the study. The mean pancreatic mass size on EUS was 5.1×5.2 (SD±4.4×4.5) cm. A total of 13 lesions were identified during elastography. The lesions were most commonly found in the body (n=5), followed by multifocal lesions (n=4), pancreatic head (n=3) and tail (n=1). The seven concerning pancreatic lesions were stratified based on color pattern identified on EUS and EUS-elastography. Three lesions were homogenously blue, and four lesions were heterogeneously blue. The remaining six lesions which were less concerning were predominantly green. Of the three lesions, that were homogenously blue, two were diagnosed as adenocarcinoma (n=2) and chronic pancreatitis (n=1) respectively. Of the four heterogeneously blue lesions two were adenocarcinomas, while the other two represented a large B-cell lymphoma and chronic pancreatitis. Patients whose lesions were characterized as homogenous or heterogeneous green were benign and remained disease free after a median of two years of regular follow up.

LIMITATIONS

Relatively small number of patients studied.

CONCLUSIONS

In our single center experience we found that the use of real time endoscopic ultrasound guided elastography for targeting fine needle aspiration of suspicious pancreatic lesions may be beneficial as an adjunct modality to complement conventional EUS. Larger prospective studies need to be conducted to evaluate the utility of this modality in targeting pancreatic lesions.

Evaluating the Minimal Specimens From Endoscopic Ultrasound-Guided Fine-Needle Aspiration in Pancreatic Masses

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become one of the most useful diagnostic modalities for the diagnosis of pancreatic mass. The aim of this study was to investigate the role of analyzing the minimal specimens obtained by EUS-FNA for the diagnosis of solid masses of pancreas.This study consisted of retrospective and prospective analyses. The retrospective study was performed on 116 patients who underwent EUS-FNA of solid masses for cytological smear, histological analysis, and combined analysis including immunohistochemical (IHC) staining. In the prospective study, 79 patients were enrolled to evaluate the quality and accuracy of EUS-FNA histological analysis and feasibility of IHC staining.The final diagnoses of all patients included pancreatic cancer (n = 126), nonpancreatic cancer (n = 21), other neoplasm (n = 27), and benign lesions (n = 21). In our retrospective study, the combined analysis was more sensitive than cytological analysis alone (P < 0.01). The overall sensitivity of cytology, histology, and combined analysis was 69.8%, 67.2%, and 81.8%, respectively. In the prospective analysis, 64.2% of all punctures were helpful for determining the diagnosis and 40.7% provided sufficient tissue for IHC staining. Histological analysis was helpful for diagnosis in 74.7% of patients. IHC staining was necessary for a definite diagnosis in 11.4% of patients, especially in the cases of nonmalignant pancreatic mass.Histological analysis and IHC study of EUS-FNA specimens was useful for the accurate diagnosis of pancreatic and peripancreatic lesions. Combined analysis showed significantly higher sensitivity than cytology alone because IHC staining was helpful for a diagnosis in some patients.

Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Pancreatic Lesions: A Systematic Review of Technical and Procedural Variables

Endoscopic ultrasound (EUS)-guided tissue acquisition has emerged over the last decade as an invaluable diagnostic tool in approaching the different pancreatic lesions. Given the safety and minimal invasiveness of this approach combined with the high diagnostic yield, it became the standard of care when dealing with different pancreatic pathologies. However, some variables regarding this procedure remain not fully understood. These can influence the diagnostic yield of the procedure and include the presence of the on-site cytopathologist, the type and size of the needle used as well as obtaining aspiration versus core biopsy, the number of passes and the sampling technique, and the role of suction and stylet use among others. We performed a comprehensive literature search using PubMed, Google Scholar, and Embase for studies that assessed these variables. Eligible studies were analyzed using several parameters such as technique and procedure, with the aim of reviewing results from an evidence-based standpoint.

Pancreatic ductal adenocarcinoma and chronic mass-forming pancreatitis: Differentiation with dual-energy MDCT in spectral imaging mode

OBJECTIVE

To investigate the value of dual-energy MDCT in spectral imaging in the differential diagnosis of chronic mass-forming chronic pancreatitis (CMFP) and pancreatic ductal adenocarcinoma (PDAC) during the arterial phase (AP) and the pancreatic parenchymal phase (PP).

MATERIALS AND METHODS

Thirty five consecutive patients with CMFP (n=15) or PDAC (n=20) underwent dual-energy MDCT in spectral imaging during AP and PP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in iodine concentration between the AP and PP, contrast-to-noise ratio (CNR) and the slope K of the spectrum curve were calculated.

RESULTS

Normalized iodine concentrations (NICs) in patients with CMFP differed significantly from those in patients with PDAC during two double phases (mean NIC, 0.26±0.04 mg/mL vs. 0.53±0.02 mg/mL, p=0.0001; 0.07±0.02 mg/mL vs. 0.28±0.04 mg/mL, p=0.0002, respectively). There were significant differences in the value of the slope K of the spectrum curve in two groups during AP and PP (K(CMFP)=3.27±0.70 vs. K(PDAC)=1.35±0.41, P=0.001, and K(CMFP)=3.70±0.17 vs. K(PDAC)=2.16±0.70, p=0.003, respectively). CNRs at low energy levels (40-70 keV) were higher than those at high energy levels (80-40 keV).

CONCLUSION

Individual patient CNR-optimized energy level images and the NIC can be used to improve the sensitivity and the specificity for differentiating CMFP from PDAC by use of dual-energy MDCT in spectral imaging with fast tube voltage switching.

Endoscopic ultrasound: Elastographic lymph node evaluation

Different imaging techniques can bring different information which will contribute to the final diagnosis and further management of the patients. Even from the time of Hippocrates, palpation has been used in order to detect and characterize a body mass. The so-called virtual palpation has now become a reality due to elastography, which is a recently developed technique. Elastography has already been proving its added value as a complementary imaging method, helpful to better characterize and differentiate between benign and malignant masses. The current applications of elastography in lymph nodes (LNs) assessment by endoscopic ultrasonography will be further discussed in this paper, with a review of the literature and future perspectives.

Interobserver agreement of EUS elastography in the evaluation of solid pancreatic lesions

Background and Objectives:

Previous reports assessing the reproducibility of endoscopic ultrasound elastography (EUS-E) in evaluation of solid pancreatic lesions (SPL) involved only experienced endosonographers. We aimed to assess the interobserver agreement (IOA) of EUS-E in the evaluation of SPL by endoscopists with different levels of experience in EUS and EUS-E.

Materials and Methods:

A cross-sectional observational multicenter study was designed and included 11 endoscopists who were divided into four groups: Group A (long experience in EUS and EUS-E); Group B (short experience in EUS and EUS-E); Group C (long experience in EUS and no experience in EUS-E); and Group D (no experience in EUS or EUS-E). The observers independently classified the patterns of 60 video sequences of EUS-E, after a 20-min training session. For each group, we calculated IOA (kappa statistic, κ) of EUS-E and the diagnostic accuracy of EUS-E for pancreatic malignancy, by comparing the pattern of EUS-E indicative of malignancy (heterogeneous or homogenous blue) with the final diagnosis.

Results:

The overall IOA was moderate (κ = 0.42; 95% confidence interval (CI) 0.33-0.52). The IOA of Group A (κ = 0.80; 95% CI 0.65-1.00) was significantly higher than that of Groups B (κ = 0.54; 95%CI 0.40-0.71), C (κ = 0.54; 95%CI 0.39-0.68), and D (κ = 0.28; 95%CI 0.14-0.40). IOA of Groups B and C was not significantly different, but it was significantly higher than that of Group D. The diagnostic accuracy of Group A (area under the curve under summary receiver operating characteristic (AUROC) = 0.83; 95%CI 0.75-0.90) was not significantly different from that of Group B (AUROC = 0.77; 95%CI 0.71-0.83), but it was significantly higher than that of Groups C (AUROC = 0.74; 95%CI 0.67-0.81) and D (AUROC = 0.74; 95%CI 0.67-0.81). No significant difference was seen between Groups B, C, and D for diagnostic accuracy.

Conclusion:

EUS-E is reproducible in the evaluation of SPL, even between endoscopists with no or limited experience in EUS and/or EUS-E. Reproducibility and diagnostic accuracy increase with experience in EUS and EUS-E.

Interobserver agreement of contrast-enhanced harmonic endoscopic ultrasonography in the evaluation of solid pancreatic lesions

BACKGROUND AND STUDY AIMS

Previous reports assessing the reproducibility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) in the evaluation of solid pancreatic lesions (SPLs) involved mainly experienced endosonographers. We aimed to assess the interobserver agreement (IOA) of CH-EUS in the evaluation of SPLs by endoscopists with different levels of experience in EUS and CH-EUS.

PARTICIPANTS AND METHODS

A cross-sectional observational multicenter study was designed and included 11 endoscopists who were divided into four groups according to their experience in EUS and CH-EUS: group A (long experience in EUS and CH-EUS); group B (short experience in EUS and CH-EUS); group C (long experience in EUS and no experience in CH-EUS); and group D (no experience in EUS or CH-EUS). The observers independently classified the patterns of 60 CH-EUS video sequences of 60 SPLs after a 20-minute training session. For each group, we calculated the IOA (kappa statistic, κ) of CH-EUS and the accuracy of CH-EUS for the diagnosis of pancreatic adenocarcinoma by comparing the pattern of CH-EUS indicative of pancreatic adenocarcinoma (hypo-enhanced contrast pattern) with the final diagnosis.

RESULTS

The overall IOA for CH-EUS was fair (κ = 0.32; 95 %CI 0.22 - 0.41). Group A (κ = 0.63; 95 %CI 0.45 - 0.85) had the highest IOA, followed by group C (κ = 0.54; 95 %CI 0.39 - 0.71), group B (κ = 0.38; 95 %CI 0.22 - 0.55), and group D (κ = 0.21; 95 %CI 0.07 - 0.36). The IOA of groups A and C was significantly higher than that of group D. No significant difference was seen between groups A, B, and C or between groups B and D in terms of IOA. Group A (area under the curve under summary receiver operating characteristic [AUROC] = 0.67; 95 %CI 0.58 - 0.75) had the highest accuracy for the diagnosis of pancreatic adenocarcinoma, followed by group C (AUROC = 0.58; 95 %CI 0.50 - 0.65), group B (AUROC = 0.55; 95 %CI 0.48 - 0.63), and group D (AUROC = 0.51; 95 %CI 0.43 - 0.58). The diagnostic accuracy of group A was not significantly different from that of group C, but it was significantly higher than that of groups B and D. No significant difference was seen between groups B, C, and D in terms of diagnostic accuracy.

CONCLUSIONS

CH-EUS is reproducible in the evaluation of SPLs, even between endoscopists with no or limited experience in EUS and/or CH-EUS. Long experience in EUS is a major contributor to the IOA and diagnostic accuracy of CH-EUS.

Endoscopic ultrasound elastography strain histograms in the evaluation of patients with pancreatic masses

AIM: To investigate the accuracy of the strain histogram endoscopic ultrasound (EUS)-based method for the diagnostic differentiation of patients with pancreatic masses.

METHODS: In a prospective single center study, 149 patients were analyzed, 105 with pancreatic masses and 44 controls. Elastography images were recorded using commercially available ultrasound equipment in combination with EUS linear probes. Strain histograms (SHs) were calculated by machine integrated software in regions of interest and mean values of the strain histograms were expressed as Mode 1 (over the mass) and Mode 2 (over an adjacent part of pancreatic tissue, representing the reference area). The ratio between Mode 2 and Mode 1 was calculated later, representing a new variable, the strain histogram ratio. After the final diagnosis was established, two groups of patients were formed: a pancreatic cancer group with positive cytology achieved by fine needle aspiration puncture or histology after surgery (58 patients), and a mass-forming pancreatitis group with negative cytology and follow-up after 3 and 6 mo (47 patients). All statistical analyses were conducted in SPSS 14.0 (SPSS Inc., Chicago, IL, United States).

RESULTS: Results were obtained with software for strain histograms with reversed hue scale (0 represents the hardest tissue structure and 255 the softest). Based on the receiver operating characteristics (ROC) curve coordinates, the cut-off point for Mode 1 was set at the value of 86. Values under the cut-off point indicated the presence of pancreatic malignancy. Mode 1 reached 100% sensitivity and 45% specificity with overall accuracy of 66% (95%CI: 61%-66%) in detection of pancreatic malignant tumors among the patients with pancreatic masses. The positive and negative predictive values were 54% and 100%, respectively. The cut-off for the new calculated variable, the SH ratio, was set at the value 1.153 based on the ROC curve coordinates. Values equal or above the cut-off value were indicative of pancreatic malignancy. The SH ratio reached 98% sensitivity, 50% specificity and an overall accuracy of 69% (95%CI: 63%-70%). The positive and negative predictive values were 92% and 100%, respectively.

CONCLUSION: SH showed high sensitivity in pancreatic malignant tumor detection but disappointingly low specificity. Slight improvements in specificity and accuracy were achieved using the SH ratio.

Specialized clinical cytology may improve the results of EUS (endoscopic ultrasound)-guided fine-needle aspiration (FNA) from pancreatic tumors

BACKGROUND AND STUDY AIMS

A variety of factors (needle type, needle passes, tumor location, cytological assessment, etc.) may influence the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration cytology (EUS-FNAC) from pancreatic tumors. Whereas most published studies report a diagnostic accuracy of > 80 % for EUS-FNAC, the results in routine settings are often considerably lower. This retrospective study aimed to define the effect of switching microscopic assessment from a standard pathology department to a highly specialized institute of cytology.

PATIENTS AND METHODS

A total of 63 patients underwent EUS-FNAC of solid or semisolid pancreatic masses. Specimens of the first consecutive 20 cases (Phase 1) were assessed by the local department of pathology. Then in Phase 2, involving another 43 subsequent cases, a specialized cytology laboratory examined all aspirates. All EUS-FNACs were performed in the same manner, using a 22-gauge needle. After cytological evaluation, all patients either underwent surgery or were followed up for at least 6 months.

RESULTS

Of the tumors, 56 were solid and 7 semisolid; the mean size was 30 mm. Sensitivity (sens.), specificity (spec.), positive predictive value (PPV), and negative predictive value (NPV) of EUS-FNAC were 38.5 % (95 %CI [confidence interval] 13.9 - 68.4 %), 100 % (59.0 - 100 %), 100 % (47.8 - 100 %), and 46.7 % (21.3 - 73.4 %) during Phase 1 versus 91.4 % (95 %CI 76.9 - 98.2 %), 100 % (63.1 - 100 %), 100 % (89.1 - 100 %), and 72.7 % (39.0 - 94.0 %) during Phase 2.

CONCLUSION

These results emphasize the considerable impact of a dedicated cytological evaluation on the results of EUS-FNAC.

Contrast-enhanced harmonic endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of solid pancreatic lesions: a retrospective study

BACKGROUND

The negative predictive value of endoscopic ultrasonography-guided fine needle aspiration for the diagnosis of solid pancreatic lesions remains low, and the biopsy specimens are sometimes inadequate for appropriate pathological diagnosis.

AIMS

To evaluate the usefulness of a novel method of contrast-enhanced harmonic endoscopic ultrasonography-guided fine-needle aspiration for the differential diagnosis and adequate sampling of solid pancreatic lesions.

METHODS

Patients with a diagnosis of solid pancreatic lesions who underwent fine-needle aspiration guided by contrast-enhanced harmonic endoscopic ultrasonography or by endoscopic ultrasonography from October 2010 to July 2013 were retrospectively identified and classified into the CH-EUS or EUS group, respectively. Surgical pathology and/or follow-up results were defined as the final diagnosis. Operating characteristics and adequacy of biopsy specimens by fine-needle aspiration were compared between the two groups.

RESULTS

Operating characteristics for contrast-enhanced harmonic endoscopic ultrasonography-guided fine-needle aspiration in solid pancreatic lesions were as follows: area under the curve = 0.908, sensitivity = 81.6%, specificity = 100%, positive predictive value = 100%, negative predictive value = 74.1%, and accuracy = 87.9%. The percentage of adequate biopsy specimens in the CH-EUS group (96.6%) was greater than that in the EUS group (86.7%).

CONCLUSION

Simultaneous contrast-enhanced harmonic endoscopic ultrasonography during fine-needle aspiration is useful for improving the diagnostic yield and adequate sampling of solid pancreatic lesions.

A feasibility study of full-field optical coherence tomography for rapid evaluation of EUS-guided microbiopsy specimens

BACKGROUND

Rapid on-site evaluation of cytologic specimens is a way of determining the adequacy of fine-needle aspiration (FNA). However, alternatives may be useful when the presence of a cytotechnologist and/or pathologist is not possible.

OBJECTIVE

To evaluate the feasibility of using full-field optical coherence tomography (FFOCT) for FNA specimen quality assessment.

DESIGN

FFOCT images were acquired on gastric, pancreatic, pelvic, and lymph-node formalin-fixed FNA specimens and were compared with histology of the same samples.

SETTING

Pathology suite in a hospital.

PATIENTS

Fourteen patients undergoing gastric, pancreatic, pelvic, or lymph-node EUS-guided FNA biopsy.

INTERVENTIONS

FFOCT imaging on formalin-fixed samples before histologic procedures.

MAIN OUTCOME MEASUREMENTS

FFOCT imaging feasibility and visibility of normal and abnormal features on images.

RESULTS

FFOCT imaging was possible. Blood, mucus, muscle, collagen, and digestive mucosa could be identified as well as abnormal architectural features including infiltrative pancreatic ductal carcinoma and a neuroendocrine neoplasm. Lesions at the individual cell level could not be detected.

LIMITATIONS

The study was performed on a limited number of cases.

CONCLUSION

FFOCT offers rapid, noninvasive, nondestructive imaging of FNA biopsy specimens. In the future, it could be performed in the endoscopy suite to improve detection of satisfactory specimens and obviate the need for rapid on-site evaluation.

High and low negative pressure suction techniques in EUS-guided fine-needle tissue acquisition by using 25-gauge needles: a multicenter, prospective, randomized, controlled trial

BACKGROUND

EUS-guided FNA (EUS-FNA) has a high diagnostic accuracy for pancreatic diseases. However, although most reports have typically focused on cytology, histological tissue quality has rarely been investigated. The effectiveness of EUS-FNA combined with high negative pressure (HNP) suction was recently indicated for tissue acquisition, but has not thus far been tested in a prospective, randomized clinical trial.

OBJECTIVE

To evaluate the adequacy of EUS-FNA with HNP for the histological diagnosis of pancreatic lesions by using 25-gauge needles.

DESIGN

Prospective, single-blind, randomized, controlled crossover trial.

SETTING

Seven tertiary referral centers.

PATIENTS

Patients referred for EUS-FNA of pancreatic solid lesions. From July 2011 to April 2012, 90 patients underwent EUS-FNA of pancreatic solid masses by using normal negative pressure (NNP) and HNP with 2 respective passes. The order of the passes was randomized, and the sample adequacy, quality, and histology were evaluated by a single expert pathologist.

INTERVENTION

EUS-FNA by using NNP and HNP.

MAIN OUTCOME MEASUREMENTS

The adequacy of tissue acquisition and the accuracy of histological diagnoses made by using the EUS-FNA technique with HNP.

RESULTS

We found that 72.2% (65/90) and 90% (81/90) of the specimens obtained using NNP and HNP, respectively, were adequate for histological diagnosis (P = .0003, McNemar test). For 73.3% (66/90) and 82.2% (74/90) of the specimens obtained by using NNP and HNP, respectively, an accurate diagnosis was achieved (P = .06, McNemar test). Pancreatitis developed in 1 patient after this procedure, which subsided with conservative therapy.

LIMITATIONS

This was a single-blinded, crossover study.

CONCLUSION

Biopsy procedures that combine the EUS-FNA with HNP techniques are superior to EUS-FNA with NNP procedures for tissue acquisition. (

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000005939.).

Endoscopic ultrasound-guided fine needle aspiration: How to obtain a core biopsy?

Endoscopic ultrasound (EUS)-guided fine needle aspiration has emerged as the procedure of choice to obtain samples to reach a definitive diagnosis of lesions of the gastrointestinal tract and of adjacent organs. The obtainment of a tissue core biopsy presents several advantages that can substantially contribute to the widespread diffusion of EUS utilization in the community and in countries where cytology expertise may be difficult to be achieved. This article will review the EUS-guided fine needle biopsy techniques developed so far, the clinical results, their limitations as well as their future perspective.

When to puncture, when not to puncture: Pancreatic masses

Endoscopic ultrasound (EUS) has evolved to become a crucial tool for the evaluation of pancreatic diseases, among them solid pancreatic lesions. However, its ability to determine whether a lesion is malignant or not is difficult to establish based only in the endosonographic image. EUS-guided fine needle aspiration (EUS-FNA) allows obtaining a cytological and/or histological sample from pancreatic lesions, with a high overall accuracy and low complication rates. Although the clinical usefulness of EUS-FNA for pancreatic diseases is widely accepted, the indications for tissue diagnosis of pancreatic lesions suspected to be malignant is still controversial. This review highlights the diagnostic accuracy and complications of EUS-FNA, focusing on its current indications.

Can elastography replace fine needle aspiration?

Endoscopic ultrasound (EUS) is one of the best diagnostic methods for diseases of the digestive tract and surrounding organs. Whereas EUS-guided fine needle aspiration (FNA) has been very useful for providing histological confirmation for previously hard to reach lesions, elastography is aiming to obtain a “virtual biopsy” by assessing differences in elasticity between the normal and pathological – usually malignant – tissue. A question that arises is whether EUS-elastography has reached a stage where it might successfully supplant the use of EUS-FNA in some of its clinical indications. The main indications of EUS-guided FNA are listed in this article and published data on the usage of elastography in these settings is reviewed for each one. In some of the indications, a plethora of studies have been published, notably for the evaluation of solid pancreatic masses and lymph nodes, while in others there is little relevant data (submucosal masses, left liver lesions, left adrenal masses), or elastography simply is not suitable as a diagnostic means (cystic lesions). Our conclusion is that elastography is not yet ready to replace EUS-FNA in its indications, but should complement it in various settings, especially for the assessment of lymph nodes. It can only be considered an alternative on a case-by-case basis, in situations where FNA is regarded as a contraindication. Furthermore, it could be used in conjunction with other imaging techniques, such as contrast-enhanced EUS, in order to further improve the accuracy of non-invasive EUS assessment, possibly making the case for a more limited or targeted use of EUS-FNA in selected cases.

Impact of rapid on-site evaluation on the adequacy of endoscopic-ultrasound guided fine-needle aspiration of solid pancreatic lesions: a systematic review and meta-analysis

BACKGROUND

Rapid on-site evaluation (ROSE) has the potential to improve adequacy rates for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solid pancreatic lesions, but its impact is context-dependent. No studies exist that summarize the relationship between ROSE, number of needle passes, and resulting adequacy rates.

AIMS

To analyze data from previous studies to establish if ROSE is associated with improved adequacy rates; to evaluate the relationship between ROSE, number of needle passes, and the resulting adequacy rates of EUS-FNA for solid pancreatic lesions.

METHODS

Systematic review and meta-analysis of studies reporting the adequacy rates for EUS-FNA of solid pancreatic lesions.

RESULTS

The search produced 3822 original studies, of which 70 studies met our inclusion criteria. The overall average adequacy rate was 96.2% (95% confidence interval: 95.5, 96.9). ROSE was associated with a statistically significant improvement of up to 3.5% in adequacy rates. There was heterogeneity in adequacy rates across all subgroups. No association between the assessor type and adequacy rates was found. Studies with ROSE have high per-case adequacy and a relatively high number of needle passes in contrast to non-ROSE studies. ROSE is an effect modifier of the relationship between number of needle passes and adequacy.

CONCLUSIONS

ROSE is associated with up to 3.5% improvement in adequacy rates for EUS-FNA of solid pancreatic lesions. ROSE assessor type has no impact on adequacy rates. ROSE is an effect modifier on the relationship between needle passes and per-case adequacy for EUS-FNA of solid pancreatic lesions.

Significance of the diagnostic categories "atypical" and "suspicious for malignancy" in the cytologic diagnosis of solid pancreatic masses

Endoscopic ultrasound guided (EUS) fine-needle aspiration (FNA) investigation of solid pancreatic lesions has been shown to have good sensitivity and specificity. Many lesions can be definitely classified as benign or malignant but some can only be cytologically classified as "atypical" or "suspicious for malignancy". Risk for malignancy in these indeterminate categories has not been well categorized. The cytology records of four University Medical centers were searched for all EUS guided FNAs of solid pancreatic lesions. All cases with a diagnosis of "atypical", or "suspicious for malignancy" were selected for analysis when histologic biopsy or over 18 months clinical follow-up was available. Two hundred and ninety-two cases with a diagnosis of "atypical" or "suspicious for malignancy" and adequate follow-up were obtained from the combined data of the four institutions. The percentage malignant for the categories "atypical" and "suspicious for malignancy" were 79.2 and 96.3%, respectively. If the category "atypical" was classified as benign and "suspicious for malignancy" was classified as malignant, the resulting positive predictive value was 96.3 (95% CI: 92.6-98.5) and the negative predictive value 20.8 (95% CI: 13.4-30.0). The categories of "atypical" and "suspicious for malignancy" stratify risk for malignancy in a fashion, which may aid in patient counseling and selection of follow-up protocols. Classification of "suspicious for malignancy" as malignant optimizes diagnostic sensitivity and specificity.

Techniques for endoscopic ultrasound-guided fine-needle biopsy

Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the method of choice to obtain samples to reach definitive diagnosis of lesions of the gastrointestinal tract and of adjacent organs, it cannot fully characterize certain neoplasms. The lack of cytology expertise has hindered the dissemination of EUS, limiting its widespread use. The obtainment of a tissue specimen through EUS fine-needle biopsy (EUS-FNB) may overcome the limitations of EUS-FNA. EUS-FNB is expected to move the practice of EUS from cytology to histology, expanding the use of EUS and facilitating targeted therapies and monitoring of treatment response in a more biologically driven manner.

Tips to overcome technical challenges in EUS-guided tissue acquisition

The diagnostic yield of EUS-FNA depends on several factors, such as the experience of the endosonographer, the characteristics of the lesion, the clinical status of the patient, the size and type of needles, the methods of specimen preparation, as well as cytopathologist expertise. The endosonographic technique can be improved when several tips and tricks useful to overcome challenges of FNA are known. Technical challenges of FNA are related to the characteristics of the lesion and its surroundings, sonographic imaging, and limitations related to the needle. Several tips and tricks necessary to overcome them are presented in this review.

Malignancy risk associated with diagnostic categories defined by the Papanicolaou Society of Cytopathology pancreaticobiliary guidelines

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is currently the predominant method for obtaining a preoperative tissue diagnosis for pancreatic lesions suspicious for malignancy. The diagnostic sensitivity and specificity of EUS-FNA are well documented, but malignancy risk associated with the diagnostic categories proposed by the Papanicolaou Society of Cytopathology is poorly defined.

METHODS

The records of the Departments of Pathology at Duke University and the University of Utah were searched for all cases of EUS-FNA performed for the investigation of pancreatic lesions. All cases with follow-up surgical diagnosis or greater than 3 years of clinical follow-up were selected. Cytologic diagnostic categories were "nondiagnostic," "benign," "atypical (not otherwise specified)," "suspicious for malignancy," "neoplasm," and "malignant." Correlation of cytologic diagnosis with surgical and/or clinical follow-up was made and risk of malignancy calculated for each category.

RESULTS

Three hundred seventeen EUS-FNAs with adequate surgical or clinical follow-up were obtained. Risk of malignancy for nondiagnostic specimens was 21%;, benign specimens, 13%; atypical cases, 74%; suspicious for malignancy, 82%; the neoplasm category, 14%; and the malignant category, 97%

CONCLUSIONS

The cytologic categories proposed by the Papanicolaou Society of Cytopathology demonstrate an increasing risk for malignancy extending from benign to malignant. Aspirates designated benign have the lowest risk of malignancy (13%) and aspirates designated malignant the highest (97%). The proposed categorization scheme stratifies risk for malignancy giving useful information to clinicians treating patients with pancreatic lesions.

Autoimmune pancreatitis: role of endoscopy in diagnosis and treatment

This review addresses the role of endoscopy in the diagnosis and treatment of autoimmune pancreatitis (AIP) and provides a diagnostic process for patients with suspected AIP. When should AIP be suspected? When can it be diagnosed without endoscopic examination? Which endoscopic approaches are appropriate in suspected AIP, and when? What are the roles of diagnostic endoscopic retrograde pancreatography, endoscopic biopsies, and IgG4 immunostaining? What is the proper use of the steroid trial in the diagnosis of AIP in patients with indeterminate computed tomography imaging? Should biliary stenting be performed in patients with AIP with obstructive jaundice?

Diagnostic ability and factors affecting accuracy of endoscopic ultrasound-guided fine needle aspiration for pancreatic solid lesions: Japanese large single center experience

BACKGROUND

Several studies have investigated the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for pancreatic lesions, but they have included only limited patient populations. This study aimed to clarify the diagnostic accuracy of EUS-FNA in a large number of pancreatic lesions, and to describe the factors that influence it.

METHODS

From March 1997 to May 2010, 944 consecutive patients who had undergone EUS-FNA for pancreatic solid lesions were evaluated retrospectively. Factors affecting EUS-FNA accuracy were then analyzed.

RESULTS

A total of 996 solid pancreatic lesions were sampled by EUS-FNA. The overall sampling adequacy and diagnostic accuracy of these lesions were 99.3 % (989/996) and 91.8 % (918/996), respectively. The sensitivity and specificity for differentiating malignant from benign lesions were 91.5 % (793/867) and 97.7 % (126/129), respectively. The diagnostic performance was significantly higher when both cytological and cell-block examinations were carried out than with only cytological examination. In multivariate analysis, final diagnosis, location of lesion, lesion size, availability of on-site cytopathological evaluation, and experience of EUS-FNA procedure were independent factors affecting the accuracy of EUS-FNA. On-site cytopathological evaluation and lesion size were found to be the most weighted factors affecting diagnostic accuracy.

CONCLUSIONS

EUS-FNA for pancreatic solid lesions yielded a high accuracy and low complication rate. Both cytological and cell-block preparations and on-site cytopathological evaluation contributed to improve the accuracy. The diagnostic ability of EUS-FNA was less for smaller lesions, and repeated procedures may be needed if malignancy is suspected.

Clinical usefulness of repeated pancreatic juice cytology via endoscopic naso-pancreatic drainage tube in patients with pancreatic cancer

BACKGROUND

Cytological examination of pancreatic juice obtained during endoscopic retrograde cholangiopancreatography (ERCP) is well established, but its sensitivity for pancreatic cancer has not been satisfactory. The aim of this study was to evaluate the usefulness of repeated pancreatic juice cytology (PJC) via the endoscopic naso-pancreatic drainage (ENPD) tube in patients with pancreatic cancer compared with conventional PJC.

METHODS

We retrospectively investigated 139 patients with pancreatic disease. Between April 2004 and November 2007, conventional PJC was performed in 56 patients with pancreatic cancer and 23 with benign pancreatic stricture. Between January 2008 and November 2010, ENPD was used in 40 patients with pancreatic cancer and 20 with benign pancreatic stricture. The ENPD tube was placed into the main pancreatic duct for up to 3 days, and cytological samples of pancreatic juice were collected up to 6 times in total.

RESULTS

Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the ENPD method for pancreatic cancer were 80, 100, 100, 71, and 87 %, respectively, revealing significantly higher sensitivity than the conventional method (p = 0.0001). Sensitivities according to tumor location and size were 90 % (19/21), 69 % (9/13), and 67 % (4/6) in the head, body, and tail of the pancreas, 88 % (7/8), 79 % (19/24), and 75 % (6/8) in tumors with a diameter less than 20 mm including carcinoma in situ, 21-40, and greater than 41 mm, respectively.

CONCLUSIONS

The ENPD method was found to have high diagnostic yield, especially for tumors less than 20 mm or located in the pancreatic head, and might be useful for the diagnosis of early-stage pancreatic cancer.

Optimizing Diagnostic Yield for EUS-Guided Sampling of Solid Pancreatic Lesions: A Technical Review

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a higher diagnostic accuracy for pancreatic cancer than other techniques. This article will review the current advances and considerations for optimizing diagnostic yield for EUS-guided sampling of solid pancreatic lesions. Preprocedural considerations include patient history, confirmation of appropriate indication, review of imaging, method of sedation, experience required by the endoscopist, and access to rapid on-site cytologic evaluation. New EUS imaging techniques that may assist with differential diagnoses include contrast-enhanced harmonic EUS, EUS elastography, and EUS spectrum analysis. FNA techniques vary, and multiple FNA needles are now commercially available; however, neither techniques nor available FNA needles have been definitively compared. The need for suction depends on the lesion, and the need for a stylet is equivocal. No definitive endosonographic finding can predict the optimal number of passes for diagnostic yield. Preparation of good smears and communication with the cytopathologist are essential to optimize yield.

Rapid on-site evaluation increases endoscopic ultrasound-guided fine-needle aspiration adequacy for pancreatic lesions

BACKGROUND

Rapid on-site evaluation (ROSE) has the potential to improve adequacy rates and affect other outcomes; however, there have been few comparative studies to assess the impact of ROSE in the setting of ultrasound-guided endoscopic fine-needle aspiration cytology for pancreatic lesions.

AIMS

To determine whether ROSE improves adequacy rates of endoscopic fine-needle aspiration cytology for pancreatic lesions.

METHODS

Systematic review and meta-analysis of studies reporting a head-to-head comparison of adequacy or diagnostic accuracy (with ROSE vs. without ROSE) at a single site.

RESULTS

ROSE was associated with a statistically significant (p < 0.001) improvement in the adequacy rate (average 10 %, 95 % CI: 5-24 %). The impact of ROSE depends on the per-pass adequacy rate without ROSE. ROSE had no impact on diagnostic yield (p < 0.76).

CONCLUSIONS

ROSE is associated with an improvement in adequacy rates when implemented at sites where the per-case adequacy rate without ROSE is low (<90 %). It is unclear whether the type of assessor (pathologist vs. non-pathologist) has a significant impact on the success rate of ROSE. ROSE has no impact on diagnostic yield. Studies should employ head-to-head comparisons of cohorts with and without ROSE at a single location.