The clinical utility of endoscopic ultrasound-guided fine-needle aspiration in the diagnosis and staging of pancreatic carcinoma

Cytotechnologists and on-site evaluation of adequacy

While fine needle aspiration (FNA) is certainly not a new biopsy technique, recent developments in advanced imaging techniques, molecular testing, and targeted therapies have coincided with a rapid increase in the number of FNA procedures being performed. Concurrently, the demand for on-site evaluation of adequacy (OSEA) has also increased, outstripping the capacity of available cytopathologists at some institutions. Among the several alternatives to cytopathologist-performed OSEA, cytotechnologist-attended OSEA stands out because it preserves the representation of the pathology service at the time of the procedure. Herein, we review the current literature about OSEA and the necessity of cytotechnologists to expand access of this useful pathology service to a broader patient population. We also examine how cytotechnologists are likely to fit into the emerging practice of telecytology.

The role of K-ras gene mutation analysis in EUS-guided FNA cytology specimens for the differential diagnosis of pancreatic solid masses: a meta-analysis of prospective studies

BACKGROUND

Differential diagnosis of pancreatic solid masses with EUS-guided FNA (EUS-FNA) is still challenging in about 15% of cases. Mutation of the K-ras gene is present in over 75% of pancreatic adenocarcinomas (PADC).

OBJECTIVE

To assess the accuracy of K-ras gene mutation analysis for diagnosing PADC.

DESIGN

We systematically searched the electronic databases for relevant studies published. Data from selected studies underwent meta-analysis by use of a bivariate model providing a pooled value for sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curve.

SETTING

Meta-analysis of 8 prospective studies.

PATIENTS

Total of 931 patients undergoing EUS-FNA for diagnosis of pancreatic solid masses.

INTERVENTION

K-ras mutation analysis.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy of K-ras mutation analysis and of combined diagnostic strategy by using EUS-FNA and K-ras mutation analysis in the diagnosis of PADC.

RESULTS

The pooled sensitivity of EUS-FNA for the differential diagnosis of PADC was 80.6%, and the specificity was 97%. Estimated sensitivity and specificity were 76.8% and 93.3% for K-ras gene analysis, respectively, and 88.7% and 92% for combined EUS-FNA plus K-ras mutation analysis. Overall, K-ras mutation testing applied to cases that were inconclusive by EUS-FNA reduced the false-negative rate by 55.6%, with a false-positive rate of 10.7%. Not repeating EUS-FNA in cases in which mutation testing of the K-ras gene is inconclusive would reduce the repeat-biopsy rate from 12.5% to 6.8%.

LIMITATIONS

Small number of studies and between-study heterogeneity.

CONCLUSION

K-ras mutation analysis can be useful in the diagnostic work-up of pancreatic masses, in particular when tissue obtained by EUS-FNA is insufficient, and the diagnosis inconclusive.

Feasibility and yield of a novel 22-gauge histology EUS needle in patients with pancreatic masses: a multicenter prospective cohort study

BACKGROUND

The option of obtaining tissue samples for histological examination during endoscopic ultrasound (EUS) has theoretical and practical advantages over cytology alone. The aim of this study was to evaluate the feasibility, yield, and diagnostic accuracy of a new EUS 22-G fine-needle biopsy (FNB) device in patients with solid pancreatic masses in a multicenter, prospective study.

METHODS

All consecutive patients who underwent EUS-guided fine-needle biopsy (EUS-FNB) using a newly developed 22-G FNB needle between September 2010 and October 2010 were enrolled in the study. The EUS-FNB technique was standardized among the participating endoscopists. Only a single needle pass was performed.

RESULTS

A total of 61 patients (35 males, mean age 64.2 ± 12.4 years) with solid pancreatic masses with a mean size of 32.4 ± 8.5 mm (range 13-90 mm) participated. EUS-FNB was performed through the duodenum in 35 cases (57.4 %) and was technically feasible in all but one of the 61 (98.4 %) patients without complications. Tissue samples for histological examination were obtained from 55 patients (90.2 %) and were deemed adequate in 54 of the cases (88.5 %). The diagnoses established by EUS-FNB were adenocarcinoma (39 patients), neuroendocrine tumors (5), chronic focal pancreatitis (5), sarcoma (2), lymphoma (1), acinar cellular tumor (1), and pancreatic metastasis from renal cell carcinoma (1). In an intention-to-treat (ITT) analysis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the histologic diagnosis of a pancreatic mass were 87.5, 100, 100, 41.7, and 88.5 %, respectively.

CONCLUSIONS

EUS-FNB was technically feasible in 98 % of patients with a solid pancreatic mass. A suitable sample for histological evaluation was obtained in 88.5 % of the cases after only one single needle pass. The apparently low negative predictive value is likely to be improved by increasing the number of needle passes.

Technical Advances in Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition for Pancreatic Cancers: How Can We Get the Best Results with EUS-Guided Fine Needle Aspiration?

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is one of the least invasive and most effective modality in diagnosing pancreatic adenocarcinoma in solid pancreatic lesions, with a higher diagnostic accuracy than cystic tumors. EUS-FNA has been shown to detect tumors less than 3 mm, due to high spatial resolution allowing the detection of very small lesions and vascular invasion, particularly in the pancreatic head and neck, which may not be detected on transverse computed tomography. Furthermore, this minimally invasive procedure is often ideal in the endoscopic procurement of tissue in patients with unresectable tumors. While EUS-FNA has been increasingly used as a diagnostic tool, most studies have collectively looked at all primary pancreatic solid lesions, including lymphomas and pancreatic neuroendocrine neoplasms, whereas very few studies have examined the diagnostic utility of EUS-FNA of pancreatic ductal carcinoma only. As with any novel and advanced endoscopic procedure that may incorporate several practices and approaches, endoscopists have adopted diverse techniques to improve the tissue procurement practice and increase diagnostic accuracy. In this article, we present a review of literature to date and discuss currently practiced EUS-FNA technique, including indications, technical details, equipment, patient selection, and diagnostic accuracy.

Performance characteristics of endoscopic ultrasound in the staging of pancreatic cancer: a meta-analysis

CONTEXT

The optimal approach to pre-operative imaging assessment of pancreatic cancer is unknown.

OBJECTIVE

The aim of this meta-analysis was to assess accuracy and performance characteristics of EUS in determining nodal staging, vascular invasion, and prediction of resectability of pancreatic cancer. A secondary aim was to perform head to head comparison of performance characteristics between EUS and CT for nodal staging, vascular invasion and resectability.

DESIGN

Data from EUS studies were pooled according to bivariate generalized random effects model. Pooled estimates for CT were obtained from studies which performed head to head comparison between EUS and CT.

PATIENTS

Patients with pancreatic cancer undergoing pre-operative imaging assessment.

INTERVENTION

EUS.

MAIN OUTCOME MEASURE

Pooled sensitivity, specificity, positive and negative predictive values of EUS for nodal staging, vascular invasion and resectability.

RESULTS

Forty-nine studies were considered of which 29 met inclusion criteria with a total of 1,330 patients. Pooled summary estimates for EUS-nodal staging were 69% for sensitivity and 81% for specificity. For vascular invasion, sensitivity was 85% and specificity was 91%. The sensitivity and specificity for resectability was 90% and 86%, respectively. CT scan showed lower sensitivity than EUS for nodal staging (24% vs. 58%) and vascular invasion (58% vs. 86%); however, the specificities for nodal staging (88% vs. 85%) and vascular invasion (95% vs. 93%) were comparable in studies where both imaging techniques were performed. The sensitivity and specificity of CT in determining resectability (90% and 69%) was similar to that of EUS (87% and 89%).

CONCLUSIONS

EUS is an accurate pre-operative tool in the assessment of nodal staging, vascular invasion and resectability in patients with pancreatic cancer.

Endoscopic ultrasound-guided fine needle aspiration as a diagnostic and staging tool for rectal and perirectal lesions-an institutional experience

The role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in evaluating lesions adjacent to the upper gastrointestinal tract wall is well established. However, this tool is underused in evaluating rectal and perirectal lesions, possibly due to insufficient experience and underrecognized value of this procedure. In this study, we report our institutional experience with EUS-FNA as a diagnostic and staging tool for rectal and perirectal lesions. A retrospective chart review was performed and a cohort of 38 patients who underwent rectal EUS-FNA (41 specimens) at our institution between January 2002 and July 2012 was retrieved. The cytology diagnoses were compared with the concurrent or follow-up histologic and clinical diagnoses. Among the total 41 cases, rectal EUS-FNA was performed as a diagnostic procedure in 22 (54%) and a staging procedure in 19 (46%) cases. On cytology examination, 18 cases (44%) were diagnosed as malignant; 1 (2%), as atypical/suspicious for malignancy; 3 (7%), as benign neoplastic; 13 (32%), as nonneoplastic; and 6 (15%), as nondiagnostic cases. Concurrent or follow-up histologic diagnoses were available in 20 cases (48%), 19 of them had concordant cytological/histologic findings (10 benign, 9 malignant). One perirectal lymph node with negative cytology diagnosis was found to be positive on histologic examination, probably due to sampling error on cytology. The sensitivity and specificity of EUS-FNA for detecting malignant rectal/perirectal lesions in this study were 91% and 100%, respectively. Endoscopic ultrasound-guided fine needle aspiration is a useful diagnostic tool for rectal/perirectal lesions; it confirms or excludes malignancy for lesions with high or low clinical suspicions. It serves as a reliable staging method to identify patients for proper clinical management.

Rarity of severe bleeding and perforation in endoscopic ultrasound-guided fine needle aspiration for submucosal tumors

BACKGROUND

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an established procedure for the pathological diagnosis of gastrointestinal submucosal tumors (SMTs). Although bleeding and perforation are potentially severe complications of EUS-FNA, the incidences and severities of these complications have not yet been fully evaluated because of their relative rarity.

AIM

The purpose of this study was to evaluate the incidences and mortality of severe bleeding and perforation in patients who underwent EUS-FNA for SMTs.

METHODS

The records of 1,135 consecutive patients who underwent EUS-FNA for SMTs at 219 hospitals, with low- to high-volume, were reviewed using a Japanese nationwide administrative database.

RESULTS

Of the targeted lesions 73.5% were located in the stomach, 13.4% in the esophagus, 8.2% in the duodenum, and 4.9% at other sites. Five patients (0.44%) experienced severe bleeding requiring red blood cell transfusion or endoscopic treatment, with none experiencing perforation. Only one patient (0.09%) died in-hospital within 30 days of EUS-FNA (0.09%), with death not associated with bleeding or perforation.

CONCLUSIONS

EUS-FNA is safe in evaluating SMTs, with low risks of bleeding and perforation.

Evaluating comparative effectiveness with observational data: endoscopic ultrasound and survival in pancreatic cancer

BACKGROUND

A previous observational study reported that endoscopic ultrasound (EUS) is associated with improved survival in older patients with pancreatic cancer. The objective of this study was to reevaluate this association using different statistical methods to control for confounding and selection bias.

METHODS

Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data (1992-2007) was used to identify patients with locoregional pancreatic cancer. Two-year survival in patients who did and did not receive EUS was compared by using standard Cox proportional hazards models, propensity score methodology, and instrumental variable analysis.

RESULTS

EUS was associated with improved survival in both unadjusted (hazard ratio [HR] = 0.67, 95% confidence interval [CI] = 0.63-0.72) and standard regression analyses (HR = 0.78, 95% CI = 0.73-0.84) which controlled for age, sex, race, marital status, tumor stage, SEER region, Charlson comorbidity, year of diagnosis, education, preoperative biliary stenting, chemotherapy, radiation, and pancreatic resection. Propensity score adjustment, matching, and stratification did not attenuate this survival benefit. In an instrumental variable analysis, the survival benefit was no longer observed (HR = 1.00, 95% CI = 0.73-1.36).

CONCLUSIONS

These results demonstrate the need to exercise caution in using administrative data to infer causal mortality benefits with diagnostic and/or treatment interventions in cancer research.

Clinical controversies in endoscopic ultrasound

The field of diagnostic and therapeutic endoscopic ultrasound (EUS) is growing rapidly. Although EUS has enhanced our ability to diagnose and treat a wide variety of GI conditions, there are many controversial issues regarding the appropriate application of EUS techniques. In this review we discuss five controversial topics in EUS: the utility of EUS in staging of esophageal and gastric cancer; selection of appropriate needle gauge for fine needle aspiration (FNA); use of the stylet in FNA; and the emerging role of contrast agents in endoscopic ultrasound.

Skeletal muscle metastases from pancreatic carcinoma-a case report and review of literature

With an overall mortality approaching nearly 100 %, pancreatic cancer is still a challenging disease. A major proportion of pancreatic cancers are still diagnosed at the locally advanced or metastatic stage. Tumors originating from tail region present very late due to the absence of specific symptoms and signs. The usual sites of metastases are the liver, peritoneum and lungs, with occasional reports of metastases in other sites. There are very few documented cases of gastrointestinal cancers manifesting as metastases to muscle. This is a report on a case of pancreatic cancer presenting as metastases to skeletal muscle and multiple other viscera and review of literature for pancreatic cancer metastases.

Current status on the diagnosis and evaluation of pancreatic tumor in Asia with particular emphasis on the role of endoscopic ultrasound

In Asia, the incidence of pancreatic cancer in some countries has been increasing. Owing to most cases being diagnosed late, prognosis for pancreatic cancer remains dismal. It is clear that the future for pancreatic cancer lies in early detection. While the possible presence of pancreatic masses is often first raised by non-invasive abdominal imaging, such as computerized tomography and magnetic resonance imaging, smaller lesions and locoregional lymph node metastases are often not detectable by these means. Endoscopic ultrasonography (EUS) offers a higher sensitivity (93-100%) for detection of small potentially curable pancreatic masses than other existing imaging modalities. It is also recommended for the evaluation of portal vein confluence, portal vein, celiac axis, and superior mesentric artery origin, and exclusion of resectability. Due to the closer proximity of EUS to the target structure, and lower rate of needle tract seeding, EUS-guided fine-needle aspiration of pancreatic mass is considered the most suitable tissue acquisition technique. Lastly, EUS also enables the performance of endoscopic interventions. Its performance can be further enhanced with newer techniques, including contrast-enhanced ultrasound and elastrography. It is anticipated that in the near future, molecular technologies may make it possible to detect microscopic amounts of cancer in tissue or blood, predict relapse and survival after therapy, as well as determine optimal therapy.

The presence of a cytopathologist increases the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration cytology for pancreatic adenocarcinoma: a meta-analysis

OBJECTIVE

A meta-analysis has not been previously performed to evaluate critically the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solely pancreatic ductal adenocarcinoma and address factors that have an impact on variability of accuracy. The aim of this study was to determine whether the presence of a cytopathologist, variability of the reference standard and other sources of heterogeneity significantly impacts diagnostic accuracy.

METHODS

We conducted a comprehensive search to identify studies, in which the pooled sensitivity, specificity, likelihood ratios for a positive or negative test (LR+, LR-) and summary receiver-operating curves (SROC) could be determined for EUS-FNA of the pancreas for ductal adenocarcinoma using clinical follow-up, and/or surgical biopsy or excision as the reference standard.

RESULTS

We included 34 distinct studies (3644 patients) in which EUS-FNA for a solid pancreatic mass was evaluated. The pooled sensitivity and specificity for EUS-FNA for pancreatic ductal adenocarcinoma was 88.6% [95% confidence interval (CI): 87.2-89.9] and 99.3% (95% CI: 98.7-99.7), respectively. The LR+ and LR- were 33.46 (95% CI: 20.76-53.91) and 0.11 (95% CI: 0.08-0.16), respectively. The meta-regression model showed rapid on-site evaluation (ROSE) (P = 0.001) remained a significant determinant of EUS-FNA accuracy after correcting for study population number and reference standard.

CONCLUSION

EUS-FNA is an effective modality for diagnosing pancreatic ductal adencarcinoma in solid pancreatic lesions, with an increased diagnostic accuracy when using on-site cytopathology evaluation.

A prospective, randomized trial comparing 25-gauge and 22-gauge needles for endoscopic ultrasound-guided fine needle aspiration of pancreatic masses

OBJECTIVES

Endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is widely performed for pancreatic masses. The 25-gauge needle (25G) might be easier to be manipulated and expected to be associated with fewer complications since it is thinner and more flexible than the 22-gauge needle (22G) although obtaining adequate specimens is questioned. In this randomized trial, the authors tried to compare prospectively 25G and 22G in diagnostic accuracy, manipulability from the operator's viewpoint and procedure-related complications.

MATERIAL AND METHODS

A total of 188 consecutive patients undergoing EUS-FNA for solid or cystic pancreatic masses were consecutively enrolled and 94 patients were randomized to either 25G or 22G group, respectively.

RESULTS

Baseline characteristics were similar except that more masses of 25G group were located in the head or uncinate process of pancreas than those from 22G group. Although there was no difference in diagnostic accuracy (89.4% vs. 88.3% with p = 0.82), 25G was easier to be manipulated (p = 0.004) and related with fewer procedure-related complications (10.6% vs. 3.2% with p = 0.004).

CONCLUSIONS

25G can be chosen in preference to 22G when performing pancreatic EUS-FNA because 25G was significantly superior to 22G in terms of manipulability and complications although both were effective for accurate diagnosis.

False-negative rate of endoscopic ultrasound-guided fine-needle aspiration for pancreatic solid and cystic lesions with matched surgical resections as the gold standard: one institution's experience

BACKGROUND

The diagnosis of pancreatic tumors is often complicated because of sampling and interpretive challenges. The current study was performed to determine the rates, types, and causes of diagnostic discrepancies.

METHODS

The authors retrospectively reviewed cytology cases from 2004 to 2010 using matched surgical resection cases as the gold standard.

RESULTS

A total of 733 cases were divided into 3 categories: 1) positive or suspicious (290 cases); 2) negative or atypical (403 cases); and 3) unsatisfactory (40 cases). Of these cases, 101 fine-needle aspiration (FNA) cases had matched surgical resections including 58 positive diagnoses, 39 negative diagnoses, and 4 unsatisfactory diagnoses. All 19 discrepant cases represented false-negative diagnoses without any false-positive cases noted, which included 2 cases with interpretive errors (10%) and 17 cases with sampling errors (90%). All matched cytology cases were divided into 5 subgroups based on the type of lesion or type of error and were analyzed for sensitivity and specificity. The sampling error rate in cystic lesions (8 of 24; 33%) was significantly higher than that in solid lesions (9 of 73; 12%). The false-negative rate in the interpretive error group (3%) was significantly lower than that in the sampling error group (23%).

CONCLUSIONS

The results of the current study confirm that pancreatic endoscopic ultrasound-guided FNA diagnosis has a very low false-positive rate but a relatively high false-negative rate using matched surgical resections as the gold standard. The major cause of a false-negative cytology diagnosis is sampling error and the rate of sampling error in cystic lesions is significantly higher than that in solid lesions.

Prognostic value of K-ras mutation status and subtypes in endoscopic ultrasound-guided fine-needle aspiration specimens from patients with unresectable pancreatic cancer

BACKGROUND

Although recent reports indicate that K-ras mutation status is a biomarker that acts as a prognostic factor, only a few analyses of K-ras mutation subtypes have been published. In addition, there are no reports that analyze overall survival and prognostic factors according to K-ras mutation status and subtypes in only unresectable pancreatic cancer (PC) determined from tissues obtained by endoscopic ultrasound-guided fine-needle aspiration.

METHODS

We retrospectively analyzed 242 patients who were diagnosed as having unresectable PC with available histological diagnosis. Clinical data collected included sex, age, Eastern Cooperative Oncology Group performance status, carbohydrate antigen (CA) 19-9, primary tumor location, stage (local or metastatic) according to TNM staging, first-line chemotherapy, K-ras mutation status and subtypes (G12D, G12V, and G12R), and overall survival. We analyzed the negative prognostic factors for reduced overall survival in unresectable PC patients using these data.

RESULTS

From multivariate analysis, CA19-9 ≥1000 U/ml (hazard ratio [HR] 1.78, 95 % confidence interval [CI] 1.28-2.46, P < 0.01), metastatic stage (HR 2.26, 95 % CI 1.58-3.24, P < 0.01), and mutant-K-ras (HR 1.76, 95 % CI 1.03-3.01, P = 0.04) were negative prognostic factors, indicating a reduced survival. Among the patients who had K-ras mutation subtypes, CA19-9 ≥1000 U/ml (HR 1.65, 95 % CI 1.12-2.37, P < 0.01), metastatic stage (HR 2.12, 95 % CI 1.44-3.14, P < 0.01), and the presence of the G12D or G12R mutations (HR 1.60, 95 % CI 1.11-2.28) were negative prognostic factors for overall survival.

CONCLUSIONS

K-ras mutation status and subtypes may be associated with survival duration in pancreatic cancer patients.

Rapid on-site evaluation by endosonographer during endoscopic ultrasound-guided fine needle aspiration for pancreatic solid masses

BACKGROUND AND AIM

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an established diagnostic method for patients with suspected pancreatic ductal carcinoma. Rapid on-site evaluation (ROSE) has been reported to improve the accuracy. However, an on-site cytopathologist is not routinely available in many institutions. One of the solutions may be ROSE by endosonographer. The aim was to examine whether diagnostic accuracy increases through ROSE by endosonographer using our cytological criteria.

METHODS

Patients who underwent EUS-FNA of solid pancreatic masses from January 2006 to August 2009 (n = 53, period 1) and September 2009 to April 2011 (n = 85, period 2) were retrospectively identified. Before initiating ROSE at the start of period 2, two endosonographers underwent training for cytological interpretation, which was focused on four cytological features of pancreatic ductal carcinoma: anisonucleosis, nuclear membrane irregularity, overlapping, and enlargement. During EUS-FNA in period 2, endosonographers classified the Diff-Quik smears under three atypical grades and evaluated the adequacy. All diagnoses were made by one pathologist without knowledge of clinical information.

RESULTS

The rate of "inconclusive" diagnoses, interpreted as "suspicious," "atypical," and "inadequate for diagnosis" was reduced from 26.4% in period 1 to 8.2% in period 2 (P = 0.004). Moreover, diagnostic accuracy was increased from 69.2% in period 1 to 91.8% in period 2 (P < 0.001).

CONCLUSIONS

This cytological grading system used in ROSE by endosonographers is invaluable for the diagnosis of pancreatic solid masses.

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.

One- and two-step self-expandable metal stent placement for distal malignant biliary obstruction: a propensity analysis

BACKGROUND

Although self-expandable metal stents (SEMS) are widely used for distal malignant biliary obstruction, one-step SEMS (direct placement without a prior plastic stent) and two-step SEMS (placement at second endoscopic retrograde cholangiopancreatography [ERCP] following plastic stent placement) have not been fully compared.

METHODS

In this multicenter retrospective study, patients were included who underwent first-time endoscopic SEMS placement between September 1994 and December 2010. We compared the one-step and two-step strategies using a propensity analysis.

RESULTS

In total, 370 patients were identified and one-step SEMS was performed in 59 patients. After adjustment using propensity scores, the median times to dysfunction were 116 and 219 days, respectively, for one-step and two-step SEMS (P = 0.058). Stent migration was more frequently observed in one-step SEMS as compared with two-step SEMS (25 vs. 11 %, P = 0.031). In one-step SEMS, the number of days of hospitalization associated with first-time SEMS placement was shorter compared with that in two-step SEMS (21 vs. 30 days, P = 0.001), and the total costs of SEMS-related interventions within 6 months were lower (6510 and 8100 USD, P = 0.004). The pathological diagnosis rates for pancreatic and biliary tract cancer at initial ERCP were 52 and 61 %. After failed diagnosis at initial ERCP, pathological diagnosis rates for pancreatic cancer were 32 versus 76 % (P = 0.005) by repeated ERCP versus endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA).

CONCLUSIONS

One-step SEMS was associated with increased stent migration, despite having potential cost-effectiveness. The additional yield of pathological diagnosis at repeated ERCP was low compared with that yielded by EUS-guided FNA.

Effectiveness of combined endoscopic ultrasound-guided fine-needle aspiration biopsy and stenting in patients with suspected pancreatic cancer

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) can be coupled with endoscopic retrograde cholangiopancreatography in the same setting when biliary and/or duodenal stenting are required.

AIMS

Our aim was to examine the effectiveness of EUS-FNA combined with stenting during the same session in patients with pancreatic cancer.

METHODS

Consecutive patients referred for EUS-FNA of a pancreatic mass with symptoms of biliary (±upper digestive) obstruction were included. Consecutive patients undergoing biliary and/or duodenal stenting without EUS-FNA during the same period were used as controls. Procedure-related complications were the primary outcome measure. Duration of the procedure, ability to achieve biliary/duodenal stenting, the yield of EUS-FNA, and clinical outcomes were evaluated.

RESULTS

A total of 122 patients underwent combined EUS-FNA and stenting and 68 underwent stenting alone (control group). In the combined group, histological proof of cancer was obtained in 88.52% at first EUS-FNA and 95.08% after a second EUS-FNA. Biliary stent placement was successful in 97.5 and 98% in the combined and the control groups, respectively. There was no statistical difference between the groups for length of stay after endoscopy and for procedure-related mortality and morbidity within 30 days. The median time from endoscopy to chemotherapy in the combined group was 12 days.

CONCLUSION

Combined EUS-FNA and biliary and/or duodenal stenting is feasible in almost all patients with suspected pancreatic cancer, with no additional hazard and a high histological yield.

Diagnostic endoscopic ultrasonography: Assessment of safety and prevention of complications

Endoscopic ultrasonography (EUS) has gained wide acceptance as an important, minimally invasive diagnostic tool in gastroenterology, pulmonology, visceral surgery and oncology. This review focuses on data regarding risks and complications of non-interventional diagnostic EUS and EUS-guided fine-needle biopsy (EUS-FNB). Measures to improve the safety of EUS und EUS-FNB will be discussed. Due to the specific mechanical properties of echoendoscopes in EUS, there is a low but noteworthy risk of perforation. To minimize this risk, endoscopists should be familiar with the specific features of their equipment and their patients’ specific anatomical situations (e.g., tumor stenosis, diverticula). Most diagnostic EUS complications occur during EUS-FNB. Pain, acute pancreatitis, infection and bleeding are the primary adverse effects, occurring in 1% to 2% of patients. Only a few cases of needle tract seeding and peritoneal dissemination have been reported. The mortality associated with EUS and EUS-FNB is 0.02%. The risks associated with EUS-FNB are affected by endoscopist experience and target lesion. EUS-FNB of cystic lesions is associated with an increased risk of infection and hemorrhage. Peri-interventional antibiotics are recommended to prevent cyst infection. Adequate education and training, as well consideration of contraindications, are essential to minimize the risks of EUS and EUS-FNB. Restricting EUS-FNB only to patients in whom the cytopathological results may be expected to change the course of management is the best way of reducing the number of complications.

Diagnosis of autoimmune pancreatitis by EUS-FNA by using a 22-gauge needle based on the International Consensus Diagnostic Criteria

BACKGROUND

It is controversial whether EUS-guided FNA by using 22-gauge (G) needles is useful for the diagnosis or evaluation of autoimmune pancreatitis (AIP).

OBJECTIVE

To evaluate the usefulness of EUS-FNA by 22-G needles for the histopathological diagnosis of AIP.

DESIGN

A retrospective study.

SETTING

Single academic center.

PATIENTS

A total of 273 patients, including 25 with AIP, underwent EUS-FNA and histological examinations.

RESULTS

EUS-FNA by using 22-G needles provided adequate tissue samples for histopathological evaluation because more than 10 high-power fields were available for evaluation in 20 of 25 patients (80%). The mean immunoglobulin G4-positive plasma cell count was 13.7/high-power field. Obliterative phlebitis was observed in 10 of 25 patients (40%). In the context of the International Consensus Diagnostic Criteria for AIP, 14 and 6 of 25 patients were judged to have level 1 (positive for 3 or 4 items) and level 2 (positive for 2 items) histological findings, respectively, meaning that 20 of 25 patients were suggested to have lymphoplasmacytic sclerosing pancreatitis based on the International Consensus Diagnostic Criteria. The diagnosis in 1 patient was type 2 AIP because a granulocytic epithelial lesion was identified in this patient.

LIMITATIONS

A retrospective study with a small number of patients.

CONCLUSIONS

The results of this study suggest that EUS-FNA by using 22-G needles provides tissue samples adequate for histopathological evaluation and greatly contributes to the histological diagnosis of AIP.

Simultaneous functional photoacoustic and ultrasonic endoscopy of internal organs in vivo

At present, clinicians routinely apply ultrasound endoscopy in a variety of interventional procedures that provide treatment solutions for diseased organs. Ultrasound endoscopy not only produces high-resolution images, but also is safe for clinical use and broadly applicable. However, for soft tissue imaging, its mechanical wave-based image contrast fundamentally limits its ability to provide physiologically specific functional information. By contrast, photoacoustic endoscopy possesses a unique combination of functional optical contrast and high spatial resolution at clinically relevant depths, ideal for imaging soft tissues. With these attributes, photoacoustic endoscopy can overcome the current limitations of ultrasound endoscopy. Moreover, the benefits of photoacoustic imaging do not come at the expense of existing ultrasound functions; photoacoustic endoscopy systems are inherently compatible with ultrasound imaging, thereby enabling multimodality imaging with complementary contrast. Here we present simultaneous photoacoustic and ultrasonic dual-mode endoscopy and show its ability to image internal organs in vivo, thus illustrating its potential clinical application.

Endoscopic-ultrasound-guided fine-needle aspiration and the role of the cytopathologist in solid pancreatic lesion diagnosis

Endoscopic ultrasound (EUS) is the most sensitive imaging modality for solid pancreatic lesions. The specificity, however, is low (about 75%). It can be increased to 100% with an accuracy of 95% by the addition of fine-needle aspiration (FNA). Cytopathology plays an important role. The final diagnosis is based upon the correlation of clinical, EUS, and cytologic features. A close interaction with the cytopathologist is required in improving the diagnostic yield. In this paper, we present an overview of the role of EUS-guided FNA and importance of close interaction with the cytopathologist. Day to day examples of different solid pancreatic lesions have been presented at the end.

Prospective randomized controlled study comparing cell block method and conventional smear method for pancreatic juice cytology

AIM

  To elucidate the diagnostic efficacy of the cell block (CB) method by comparing it with that of conventional smear cytology for pancreatic juice obtained by endoscopic retrograde cholangiopancreatography (ERCP) in a randomized controlled trial fashion.

METHODS

  A total of 170 patients with pancreatic lesions suspicious of being malignant who underwent pancreatic juice collection without giving secretin under ERCP were enrolled in this study. After sampling, the pancreatic juice was randomized to the CB method (n = 85) or to smear cytology (n = 85). CB sections were subjected to hematoxylin-eosin, periodic acid Schiff-Alcian blue, and immunohistochemical stains. Both Papanicolaou stain and Giemsa stain were used for smear cytology.

RESULTS

  The final diagnosis was malignancy in 54 patients: pancreatic cancer, 45; intraductal papillary-mucinous carcinoma, six; and endocrine tumor, three. The number of patients with a cytological borderline malignancy in the CB group (3.5%) was significantly smaller than that in the smear group (27.1%) (P < 0.001). The diagnostic accuracy of the CB method and that of smear cytology were 76.5% (65/85) and 74.1% (63/85), respectively (P = 0.72), and their respective sensitivities were 50% (14/28) and 38.5% (10/26) (P = 0.39). The sensitivity of the CB method (88.9%) was better than that of smear cytology (42.9%) for invasive ductal carcinoma in the pancreas head (P = 0.048).

CONCLUSIONS

  The CB method using immunostaining for pancreatic juice cytology showed a much lower rate of equivocal borderline malignancy and a tendency for a higher diagnostic yield compared with smear cytology. Its diagnostic sensitivity, however, was not satisfactory except for pancreatic-head cancer.

Does on-site adequacy evaluation reduce the nondiagnostic rate in endoscopic ultrasound-guided fine-needle aspiration of pancreatic lesions?

BACKGROUND

This retrospective study compared the nondiagnostic rate for endoscopic ultrasound-guided (EUS) fine-needle aspiration (FNA) of pancreatic lesions in 2 settings: 1 with and 1 without on-site evaluation.

METHODS

The authors reviewed 381 consecutive cases and divided them into groups with and without on-site adequacy evaluation. For the group with on-site evaluation, cytopathology personnel prepared and evaluated Diff-Quik-stained direct smears and rinsed the remaining material in CytoLyt solution (Cytyc Corporation, Marlborough, Mass). The group without on-site evaluation was divided into 2 subgroups: the clinical team either prepared an air-dried smear for each FNA pass and then rinsed the remaining material in CytoLyt, or the entire sample was rinsed in CytoLyt. The cytologic diagnoses were reviewed and the nondiagnostic rates for each group were calculated.

RESULTS

On-site evaluation was provided for 167 cases with a nondiagnostic rate of 25.8% (43 of 167 cases). On-site evaluation was not provided for 214 cases with a nondiagnostic rate of 24.3% (52 of 214 cases). The nondiagnostic rate for the subgroup with air-dried smears prepared by the clinical team was 25.6% (43 of 168 cases) and that for the subgroup with the entire sample rinsed in CytoLyt was 19.6% (9 of 46 cases). There were no significant statistical differences in nondiagnostic rates noted among the different groups or subgroups.

CONCLUSIONS

The results of the current study indicate that when experienced operators perform EUS FNA of pancreatic lesions, on-site adequacy evaluation offers no benefit in reducing the nondiagnostic rate. Optimizing visualization of the sampled material by omitting the preparation of direct smears and rinsing the entire sample in liquid-based media demonstrated a trend toward improving the diagnostic rate.

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.

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 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.

Does cytotechnician training influence the accuracy of EUS-guided fine-needle aspiration of pancreatic masses?

BACKGROUND/AIM

The presence of on-site cytopathologists improves the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of pancreatic masses; however, on-site cytopathologists are not available to all endoscopic units. We hypothesized that experienced cytotechnicians can accurately assess whether an on-site pancreatic mass fine needle aspiration specimen is adequate. The aim of this study was to evaluate the effect of formal cytotechnician training on the diagnostic accuracy of EUS-FNA of pancreatic masses.

METHODS

Single-centre, prospective study. The cytotechnician made an on-site assessment of specimen adequacy with immediate evaluation of smears over a 12-month period (pre-training period) then over another 12-month period (post-training period), with a year's intermediate training when the cytopathologist and the cytotechnician worked together in the room. The gold standard used to establish the final diagnosis was based on a non-equivocal fine needle aspiration biopsy reviewed by the same expert cytopathologist. The main outcome measurements were the cytotechnician diagnostic accuracy before and after the training period.

RESULTS

A total of 107 patients were enrolled in the pre-training period. Cytotechnician in-room adequacy was 68.2% (73/107). The diagnostic accuracy was 74.8%. The adequacy for the blind-review pathologist was 93.4% (100/107), significantly higher (p=0.008) than the cytotechnician's results. During the post-training period, 95 EUS-FNA were performed and reviewed. Cytotechnician in-room adequacy was 87.4% (83/95). The diagnostic accuracy was 90.5%. The adequacy for the blinded pathologist was 95.8% (91/95), not significantly different from the cytotechnician (p=0.23).

CONCLUSIONS

An adequate training period with an expert pathologist significantly improves the cytotechnician skill in terms of judging adequacy and diagnostic accuracy.

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.

Distinctive endoscopic ultrasound features of isolated pancreatic tuberculosis and requirements for biliary stenting

BACKGROUND & AIMS

There are insufficient data about the appearance of isolated pancreatic tuberculosis on endoscopic ultrasound (EUS). The safety and efficacy of antitubercular therapy (ATT) in patients with pancreatic tuberculosis with cholestasis are also relatively unknown.

METHODS

We evaluated 6 patients with isolated pancreatic head tuberculosis retrospectively and compared their EUS findings with those of 25 patients with pancreatic head adenocarcinoma.

RESULTS

There was no difference in the EUS appearance between the 2 diseases. The mean diameter of the common bile duct was significantly greater in patients with pancreatic adenocarcinoma. The pancreatic duct was dilated in 20 of 25 patients with pancreatic adenocarcinoma (80%), whereas it was dilated in only 1 of 6 patients with pancreatic tuberculosis (16.6%) (P < .05). All 6 patients with pancreatic tuberculosis had a resolution of their cholestatic symptoms within 4 weeks of starting ATT alone. None of these patients required biliary stenting.

CONCLUSIONS

None of the EUS features of a mass lesion caused by pancreatic tuberculosis are distinctive. Once diagnosed, these patients can be successfully treated with ATT without needing biliary stenting.

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.

Direct histological processing of EUS biopsies enables rapid molecular biomarker analysis for interventional pancreatic cancer trials

OBJECTIVE

Current practice to diagnose pancreatic cancer is accomplished by endoscopic ultrasound guided fine needle aspiration (EUS-FNA) using a cytological approach. This method is time consuming and often fails to provide suitable specimens for modern molecular analyses. Here, we compare the cytological approach with direct formalin fixation of pancreatic EUS-FNA micro-cores and evaluate the potential to perform molecular biomarker analysis on these specimen.

METHODS

130 specimens obtained by EUS-FNA with a 22G needle were processed by the standard cytological approach and compared to a separate cohort of 130 specimens that were immediately formalin fixed to preserve micro-cores of tissue prior to routine histological processing.

RESULTS

We found that direct formalin fixation significantly shortened the time required for diagnosis from 3.6 days to 2.9 days (p<0.05) by reducing the average time (140 vs 33 min/case) and number of slides (9.65 vs 4.67 slides/case) for histopathological processing. Specificity and sensitivity yielded comparable results between the two approaches (82.3% vs 77% and 90.9% vs 100%). Importantly, EUS-FNA histology preserved the tumour tissue architecture with neoplastic glands embedded in stroma in 67.89% of diagnostic cases compared to 27.55% with the standard cytological approach (p < 0.001). Furthermore, micro-core samples were suitable for molecular studies including the immunohistochemical detection of intranuclear Hes1 in malignant cells, and the laser-capture microdissection-mediated measurement of Gli-1 mRNA in tumour stromal myofibroblasts.

CONCLUSIONS

Direct formalin fixation of pancreatic EUS-FNA micro-cores demonstrates superiority regarding diagnostic delay, costs, and specimen suitability for molecular studies. We advocate this approach for future investigational trials in pancreatic cancer patients.

Endoscopic ultrasonography-guided fine needle aspiration biopsy using 22-gauge needle in diagnosis of autoimmune pancreatitis

BACKGROUNDS

The effectiveness of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has not been fully evaluated in the diagnosis of autoimmune pancreatitis (AIP).

AIM

To evaluate the effectiveness of EUS-FNA using 22-gauge needles in the diagnosis of AIP.

METHODS

EUS-FNA was examined in 85 patients with pancreatic mass, including 64 patients with pancreatic cancer and 21 patients with AIP. We investigated ability of EUS-FNA using 22-gauge needle for the differential diagnosis between AIP and pancreatic cancer. We also compared the factors concerning FNA procedures (number of needle passes, size of lesion, device, and amount of obtained pancreatic tissue) between two diseases.

RESULTS

Tissues obtained from 21 patients with AIP, although none of them demonstrated histology suspicious for malignancy, did not show histological evidence definitive for AIP. The amount of obtained pancreatic tissue was almost equal between two diseases in each pancreatic location. Sensitivity, specificity, overall accuracy, and negative predictive value of histological diagnosis of pancreatic cancer were 92.2%, 100%, 94.1%, and 80.8%, respectively.

CONCLUSION

EUS-FNA using 22-gauge needle distinguished benign from malignant pancreatic mass with >90% of accuracy, regardless of the location. Hence, it was helpful for the clinical diagnosis of AIP, however not providing satisfactory samples for the histological diagnosis of AIP.

EUS elastography for the differentiation of benign and malignant lymph nodes: a meta-analysis

BACKGROUND

EUS elastography is a new technique for differentiating benign and malignant lymph nodes (LNs) by describing the mechanical property of the target tissue.

OBJECTIVE

To assess the accuracy of EUS elastography by pooling data of existing trials.

DESIGN

Seven studies involving 368 patients with 431 LNs were included. Meta-analysis was performed. Pooling was conducted in a fixed-effect model or a random-effect model.

PATIENTS

This study involved 368 patients.

INTERVENTION

EUS elastography.

MAIN OUTCOME MEASUREMENTS

Meta-analysis and meta-regression analysis.

RESULTS

The pooled sensitivity of EUS elastography for the differential diagnosis of benign and malignant LNs was 88% (95% confidence interval [CI] 0.83-0.92), and the specificity was 85% (95% CI, 0.79-0.89). The area under the curve under summary receiver operating characteristic (SROC) was 0.9456. The pooled positive likelihood ratio was 5.68 (95% CI, 2.86-11.28), and the negative likelihood ratio was 0.15 (95% CI, 0.10-0.21). The subgroup analysis by excluding the outliers provided a sensitivity of 85% (95% CI, 0.79-0.90) and a specificity of 91% (95% CI, 0.85-0.95) for the differential diagnosis of benign and malignant LNs. The area under the curve under SROC was 0.9421.

LIMITATIONS

A small number of studies met inclusion criteria.

CONCLUSION

EUS elastography is a promising, noninvasive method for differential diagnosis of malignant LNs and may prove to be a valuable supplemental method to EUS-guided FNA.

Clinical impact of EUS-guided Trucut biopsy results on decision making for patients with gastric subepithelial tumors ≥ 2 cm in diameter

BACKGROUND

Preoperative pathologic diagnosis of a gastric subepithelial tumor (SET) may improve clinical decision making. However, the clinical impact of EUS-guided Trucut biopsy (EUS-TCB) data on decision making in patients with a gastric SET has not been assessed.

OBJECTIVE

To evaluate the impact of EUS-TCB information on the clinical management of patients with a gastric SET.

DESIGN

Retrospective review of prospectively collected data.

SETTING

Tertiary referral center.

PATIENTS

Sixty-five patients with gastric SETs 2 cm or larger in diameter.

INTERVENTION

EUS-TCB.

MAIN OUTCOME MEASUREMENTS

The number of patients for whom treatment plans were changed because of EUS-TCB results.

RESULTS

Nine SETs were not punctured by the TCB needle because of technical problems, and we were unable to obtain adequate subepithelial tissue from 19 SETs. Treatment plans were changed for 18 of 65 patients (27.7%). The changes were avoiding unnecessary resection (7 benign SETs ≥ 3 cm in diameter), scheduling for definitive treatment (6 GI stromal tumors and 1 carcinoid tumor), and modifying the surgical field (3 large GI stromal tumors and 1 carcinoma). When we assessed treatment plans relative to tumor location, we found that avoiding unnecessary resection was associated with the presence of cardiac SETs.

LIMITATIONS

Retrospective study with a small number of patients.

CONCLUSIONS

EUS-TCB changed or influenced management decisions in 18 of 65 patients (27.7%) with gastric SETs. Patients could receive proper and tailored surgery, medical treatment, or surveillance according to size and location of SETs with EUS-TCB.

An electronic radial scanning echoendoscope is superior to a mechanical radial scanning echoendoscope in ultrasound image quality for gastrointestinal tract and pancreaticobiliary lesions

PURPOSE

To objectively compare the electronic radial scanning echoendoscope (ER-ES) with the mechanical radial scanning echoendoscope (MR-ES) in the quality of endoscopic ultrasonography (EUS) images of gastrointestinal tract and pancreaticobiliary lesions.

METHODS

Studied were 56 patients: 20 with gastric cancer, 20 with gallbladder lesions, and 16 with intraductal papillary-mucinous neoplasms of the pancreas (IPMN). They were subjected to EUS, half of them using the ER-ES, and the other half using the MR-ES. EUS images thus obtained were evaluated concerning four items in patients with gastric cancer and those with gallbladder lesions, and three items in patients with IPMN. Six endosonographers blindly assessed two EUS images per patient on a visual analogue scale. In each of the three groups of patients, the evaluators' median scores for the ER-ES and MR-ES for each item were compared.

RESULTS

The median scores for the ER-ES were significantly higher than those for the MR-ES in all items in patients with gastric cancer and those with IPMN, and in one item in patients with gallbladder lesions.

CONCLUSION

The ER-ES is certainly superior to the MR-ES in the quality of EUS images of gastrointestinal tract and pancreaticobiliary lesions.

Endoscopic ultrasound staging and guided fine needle aspiration biopsy in patients with resectable pancreatic malignancies: a single-center prospective experience

BACKGROUND

Endoscopic ultrasound staging and guided fine needle aspiration biopsy (EUS-FNA) is a highly accurate diagnostic method, useful in characterizing pancreatic lesions, obtaining definitive tissue diagnosis in patients with suspected pancreatic lesions, and providing accurate locoregional staging that enhances diagnostic certainty and evaluation of appropriateness of surgical intervention. The aims of this study were to evaluate the preoperative contribution of EUS staging and EUS-FNA in patients with suspected resectable pancreatic malignancies.

PATIENTS AND METHODS

A prospective study was conducted in a tertiary referral center. During a 54-month period, a total of 103 consecutive patients were prospectively evaluated with EUS and EUS-FNA. Enrolled in the study were patients with resectable pancreatic lesions, who underwent surgery.

RESULTS

The overall operating characteristics of EUSFNA were sensitivity 96.7%, specificity 90.0%, positive predictive value 98.9%, negative predictive value 75.0%, and diagnostic accuracy 96.1%.

CONCLUSION

EUS and EUS-FNA have a high accuracy and positive predictive value in the preoperative determination of resectability in pancreatic cancer.

Influence of on-site cytopathology evaluation on the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solid pancreatic masses

OBJECTIVES

The aim of this study was to evaluate the influence of on-site cytopathological evaluation on the diagnostic yield of endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) for the differential diagnosis of solid pancreatic masses in an unselected series of consecutive patients.

METHODS

Patients undergoing EUS-guided FNA of solid pancreatic lesions over a 2-year study period were included. Samples were either evaluated on site by a cytopathologist or processed by the endoscopist and sent to the pathology department for evaluation. Diagnostic accuracy for malignancy, number of needle passes, adequate-specimen collection rate, cytological diagnosis, and final diagnosis, and complication rate according to the presence or absence of on-site cytopathologist were evaluated.

RESULTS

A total of 182 patients were included. An on-site cytopathologist was available in 95 cases (52.2%). There was no difference between groups in terms of age, sex, location, and size of the lesions. A significantly higher number of needle passes was performed when an on-site cytopathologist was not available (3.5±1.0 vs. 2.0±0.7; P<0.001). The presence of an on-site cytopathologist was associated with a significantly lower number of inadequate samples (1.0 vs. 12.6%, P=0.002), and a significantly higher diagnostic sensitivity (96.2 vs. 78.2%; P=0.002) and overall accuracy (96.8 vs. 86.2%; P=0.013) for malignancy. Three patients developed complications (two acute pancreatitis, one local bleeding), all of them belonging to the group without on-site cytopathology.

CONCLUSIONS

On-site cytopathological evaluation improves the diagnostic yield of EUS-guided FNA for the cytological diagnosis of solid pancreatic masses. This is associated with a significantly lower number of inadequate samples and a lower number of needle passes.

False-positive EUS-guided FNA cytology for solid pancreatic lesions

BACKGROUND

The currently accepted paradigm is that the false-positive (FP) rate for EUS-guided fine-needle aspiration (EUS-FNA) cytologic analysis of a pancreatic lesion is less than 1%.

OBJECTIVE

To assess the FP rate of EUS-FNA in patients who underwent surgical resection for presumed pancreatic cancer.

DESIGN

Retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

This study involved 367 patients with solid pancreatic lesions in whom EUS-FNA cytology results were interpreted as positive or suspicious for malignancy, which resulted in subsequent surgical resection.

INTERVENTION

Surgical resection.

MAIN OUTCOME MEASUREMENTS

The FP diagnosis was defined as EUS-FNA cytology specimens being reported as "positive" or "suspicious for malignancy" but that were later proven to be benign on surgical pathology.

RESULTS

The FP rate for EUS-FNA was 4 of 367 (1.1%) when only "positive" cytology findings were interpreted as malignant and 14 of 367 (3.8%) when both suspicious and positive cytology findings were interpreted as malignant. Among the 4 cases falsely interpreted as positive, 1 was falsely diagnosed cytologically as a neuroendocrine tumor and 3 as adenocarcinomas. All FP specimens showed chronic pancreatitis on surgical pathology. The incidence of discordance between cytology and surgical pathology did not change over time (2000-2006: 8/188 [4.3%] vs 2007-2010: 6/179 [3.4%]; P = .79).

LIMITATIONS

Retrospective study at a single center.

CONCLUSION

In a retrospective cohort trial, the FP rate for EUS-FNA of solid pancreatic lesions was 1.1%. Findings of the current study are in line with previous studies that have evaluated the FP cytology rates with EUS-FNA of solid lesions. FP cases transpired primarily as a result of cytologic misinterpretation in the setting of chronic pancreatitis.

A comparative study of endoscopic ultrasound guided fine needle aspiration with and without a stylet

BACKGROUND

Despite lack of evidence, use of a stylet during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is assumed to improve the quality and diagnostic yield of specimens.

AIM

The purpose of this study was to compare EUS-FNA specimens obtained with stylet (S+) and without stylet (S-) for: (i) cellularity, contamination, adequacy, and amount of blood and (ii) diagnostic yield of malignancy.

METHODS

Patients who underwent EUS-FNA of solid lesions by two experienced endosonographers at a tertiary referral center using a 22-gauge FNA needle with suction were included. Stylet was used for all EUS-FNA procedures performed between January 2006 and September 2007 and no stylet was used between October 2007 and April 2009 allowing comparison between the two techniques. Cytology slides were retrieved, de-identified and evaluated by two experienced cytopathologists blinded to FNA technique. Slides were evaluated for cellularity, degree of contamination, adequacy, amount of blood and cytologic diagnosis. Fisher's exact and unpaired t-test were used for comparative analysis.

RESULTS

A total of 162 patients with 228 lesions were included. FNA of 106 and 122 lesions each was performed in the S+ and S- groups, respectively. FNA sites included pancreas [41 (18%)], lymph node [125 (55%)], liver [20 (9%)], adrenal [21 (9%)] and others [21 (9%)]. No significant differences in the cellularity (P=0.37), contamination (P=0.18), significant blood (P=0.42) and adequacy of specimen (P=0.45) were found between S+ and S- specimens. There was no statistically significant difference in the diagnostic yield of malignant lesions (P=0.48).

CONCLUSIONS

The use of stylet during FNA does not appear to confer any advantage with regards to the adequacy of specimen or diagnostic yield of malignancy.

Mucin expression pattern in pancreatic diseases: findings from EUS-guided fine-needle aspiration biopsies

OBJECTIVES

Alterations in mucin (MUC) glycosylation and expression have been described in cancer. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) can provide material for molecular biology analysis. This study assessed the feasibility of evaluating MUC expression from material obtained by EUS-FNA and studied the profile of MUC expression in benign and malignant pancreatic lesions.

METHODS

A total of 90 patients with solid or cystic pancreatic lesions underwent FNA. The aspirated material was used for cytological analysis and RNA extraction to assess the expression pattern of MUCs by reverse transcription-PCR with primers specific for the MUC1, MUC2, MUC3, MUC4, MUC5A, MUC5B, MUC6, and MUC7 genes.

RESULTS

RNA extraction was successful in 81% of the biopsies. The prevalences of MUC1, MUC2, MUC4, and MUC7 in ductal adenocarcinoma were 57.7, 51.4, 18.9, and 73.0%, respectively. Fifty percent of benign lesions and neuroendocrine tumors (NETs), and 63% of intraductal papillary mucinous neoplasms (IPMNs) were positive for MUC1. Twenty-five percent of benign lesions, 86% of NETs, and 47% of IPMNs were positive for MUC2. Of NETs, 50% were positive for MUC1, and 14% were positive for MUC7. None of the benign lesions or NETs expressed MUC4. MUC7 expression was highly significant for adenocarcinoma (P=0.007) and borderline for IPMN (P=0.05). MUC7 was expressed in 37.5% of chronic pancreatitis cases.

CONCLUSIONS

RNA can be extracted from samples obtained under EUS-FNA. MUC7 could serve as a potential biological marker to identify malignant lesions, especially pancreatic adenocarcinoma.

Current status of diagnostic endoscopic ultrasonography in the evaluation of pancreatic mass lesions

Endoscopic ultrasonography (EUS) is currently well established as a diagnostic method for the evaluation of pancreatic mass lesions. Diagnostic EUS might be divided into two broad categories; it is an imaging method, and also a device for obtaining cytopathology and histopathology. EUS as an imaging method has seen the introduction of newer intravenous contrast agents that enable the characterization of the pancreatic masses. EUS elastography enables real-time graphical representation of differential tissue hardness within a lesion. Contrast-enhanced EUS and/or elastography provide information additional to the fundamental images, leading to more accurate diagnosis. EUS-guided fine needle aspiration (EUS-FNA) has been shown to be a highly accurate method for distinguishing benign from malignant pancreatic masses. Several investigators have reported the usefulness of EUS-FNA samples obtained from pancreatic masses for genetic analysis, e.g. p53, K-ras. Genetic analysis of EUS-FNA samples to characterize chemo-sensitivity has recently been attempted in patients with unresectable pancreatic cancers. Although further improvement of EUS technology is desired to render it an even more convenient and reliable procedure, EUS at its current level of advancement is of proven utility in the diagnosis of pancreatic masses.

Endoscopic ultrasonography-guided fine needle aspiration biopsy in a patient with prior Billroth II gastrectomy

Endoscopic ultrasonography-guided fine needle aspiration biopsy (EUS-FNA) is a safe and accurate procedure for the diagnosis of pancreatic lesions. However, in general, surgically altered anatomy excluding Billroth I gastrectomy is considered a relative contraindication to EUS-FNA. Herein, we described a successful case of EUS-FNA in a patient with prior Billroth II gastrectomy. A 78-year-old man, who had previously undergone Billroth II gastrectomy for duodenal ulcer, undertook EUS-FNA using a curved linear echoendoscope. An echoendoscope was advanced into the duodenum and EUS-FNA could be carried out using a 22-gauge needle without procedure-related adverse event.

Histological diagnosis by EUS-guided fine-needle aspiration biopsy in pancreatic solid masses without on-site cytopathologist: a single-center experience

There are few reports on the histological diagnostic ability of endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) in a large-series of pancreatic masses. In the present study therefore we retrospectively evaluated the histological diagnostic ability of EUS-FNA in pancreatic masses without on-site cytopathologist. In 355 patients with pancreatic solid masses, EUS-FNA was carried out. EUS-FNA histology showed accuracy, 90.7%; sensitivity, 89.5%; specificity, 95.6%; positive predict value, 98.8%; negative predict value, 68.8% by intention-to-treat analysis. Except for 10 with inadequate materials, EUS-FNA histology showed accuracy, 93.3%; sensitivity, 91.8%; specificity, 100%; positive predict value, 100%; negative predict value, 77.6%. The mean number of puncture was 2.88 (range 1 to 8). There was two (0.6%) procedure-related bleeding. In conclusion, diagnostic ability of EUS-FNA by histological materials was similar to previous literature on the EUS-FNA without on-site cytopathologist.

Endoscopic ultrasonography findings in autoimmune pancreatitis

Endoscopic ultrasonography is an established diagnostic tool for pancreatic masses and chronic pancreatitis. In recent years there has been a growing interest in the worldwide medical community in autoimmune pancreatitis (AIP), a form of chronic pancreatitis caused by an autoimmune process. This paper reviews the current available literature about the endoscopic ultrasonographic findings of AIP and the role of this imaging technique in the management of this protean disease.