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

Differential diagnosis of pancreatic cancer from normal tissue with digital imaging processing and pattern recognition based on a support vector machine of EUS images

BACKGROUND

EUS can detect morphologic abnormalities of pancreatic cancer with high sensitivity but with limited specificity.

OBJECTIVE

To develop a classification model for differential diagnosis of pancreatic cancer by using a digital imaging processing (DIP) technique to analyze EUS images of the pancreas.

DESIGN

A retrospective, controlled, single-center design was used.

SETTING

The study took place at the Second Military Medical University, Shanghai, China.

PATIENTS

There were 153 pancreatic cancer and 63 noncancer patients in this study.

INTERVENTION

All patients underwent EUS-guided FNA and pathologic analysis.

MAIN OUTCOME MEASUREMENTS

EUS images were obtained and correlated with cytologic findings after FNA. Texture features were extracted from the region of interest, and multifractal dimension vectors were introduced in the feature selection to the frame of the M-band wavelet transform. The sequential forward selection process was used for a better combination of features. By using the area under the receiver operating characteristic curve and other texture features based on separability criteria, a predictive model was built, trained, and validated according to the support vector machine theory.

RESULTS

From 67 frequently used texture features, 20 better features were selected, resulting in a classification accuracy of 99.07% after being added to 9 other features. A predictive model was then built and trained. After 50 random tests, the average accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of pancreatic cancer were 97.98 ± 1.23%, 94.32 ± 0.03%, 99.45 ± 0.01%, 98.65 ± 0.02%, and 97.77 ± 0.01%, respectively.

LIMITATIONS

The limitations of this study include the small sample size and that the support vector machine was not performed in real time.

CONCLUSION

The classification of EUS images for differentiating pancreatic cancer from normal tissue by DIP is quite useful. Further refinements of such a model could increase the accuracy of EUS diagnosis of tumors.

What is the role of endotherapy in chronic pancreatitis?

Chronic pancreatitis (CP) can have debilitating clinical course due to chronic abdominal pain, malnutrition and related complications. Medical, endoscopic and surgical treatment of CP should aim at control of symptoms, prevention of progression of the disease and correction of complications. Endoscopic management plays a specific role in carefully selected patients as primary interventional therapy when medical measures fail or in high-risk surgical candidates. Endotherapy for CP is utilized also as a bridge to surgery or to assess potential response to pancreatic surgery. In this review we address the role of endotherapy for the relief of obstruction of the pancreatic duct (PD) and bile duct, closure of PD leaks and drainage of pseudocysts in the setting of CP. In addition, endotherapy for relief of pancreatic pain by endoscopic ultrasound-guided celiac plexus block for CP is discussed.

Combined contrast-enhanced power Doppler and real-time sonoelastography performed during EUS, used in the differential diagnosis of focal pancreatic masses (with videos)

BACKGROUND

Contrast-enhanced power Doppler (CEPD) and real-time sonoelastography (RTSE) performed during EUS were previously described to be useful for the differential diagnosis between chronic pseudotumoral pancreatitis and pancreatic cancer.

OBJECTIVE

To prospectively assess the accuracy of the combination of CEPD and RTSE to differentiate pancreatic focal masses.

DESIGN

Cross-sectional feasibility study.

SETTING

A tertiary-care academic referral center.

PATIENTS

The study group included 54 patients with chronic pancreatitis (n = 21) and pancreatic adenocarcinoma (n = 33).

INTERVENTIONS

Both imaging methods (CEPD and RTSE) were performed sequentially during the same EUS examination. Power Doppler mode examination was performed after intravenous injection of a second-generation contrast agent (2.4 mL of SonoVue), and the data were digitally recorded, comprising both the early arterial phase and venous/late phase. Three 10-second sonoelastographic videos were also digitally recorded that included the focal mass and the surrounding pancreatic parenchyma. Postprocessing analyses based on specially designed software were used to analyze the CEPD and RTSE videos. A power Doppler vascularity index was used to characterize CEPD videos, the values being averaged during a 10-second video in the venous phase. Hue histogram analysis was used to characterize RTSE videos, with the mean hue histogram values being also averaged during a 10-second video.

MAIN OUTCOME MEASUREMENTS

To differentiate chronic pancreatitis and pancreatic cancer.

RESULTS

The sensitivity, specificity, and accuracy of combined information provided by CEPD and RTSE to differentiate hypovascular hard masses suggestive of pancreatic carcinoma were 75.8%, 95.2%, and 83.3%, respectively, with a positive predictive value and negative predictive value of 96.2% and 71.4%, respectively.

LIMITATION

A single-center, average size of study population.

CONCLUSIONS

A combination of CEPD and RTSE performed during EUS seems to be a promising method that allows characterization and differentiation of focal pancreatic masses.

Current status of molecular markers for early detection of sporadic pancreatic cancer

Pancreatic cancer (PC) is a highly lethal malignancy with near 100% mortality. This is in part due to the fact that most patients present with metastatic or locally advanced disease at the time of diagnosis. Significantly, in nearly 95% of PC patients there is neither an associated family history of PC nor of diseases known to be associated with an increased risk of PC. These groups of patients who comprise the bulk of PC cases are termed as "sporadic PC" in contrast to the familial PC cases that comprise only about 5% of all PCs. Given the insidious onset of the malignancy and its extreme resistance to chemo and radiotherapy, an abundance of research in recent years has focused on identifying biomarkers for the early detection of PC, specifically aiming at the sporadic PC cohort. However, while several studies have established that asymptomatic individuals with a positive family history of PC and those with certain heritable syndromes are candidates for PC screening, the role of screening in identifying sporadic PC is still an unsettled question. The present review attempts to assess this critical question by investigating the recent advances made in molecular markers with potential use in the early diagnosis of sporadic PC - the largest cohort of PC cases worldwide. It also outlines a novel yet simple risk factor based stratification system that could be potentially employed by clinicians to identify those individuals who are at an elevated risk for the development of sporadic PC and therefore candidates for screening.

Quantitative endoscopic ultrasound elastography: an accurate method for the differentiation of solid pancreatic masses

BACKGROUND & AIMS

Qualitative endoscopic ultrasound (EUS) elastography is an accurate but subjective tool for the differential diagnosis of solid pancreatic masses. Second-generation EUS elastography allows quantitative analysis of tissue stiffness. We evaluated the accuracy of quantitative, second-generation EUS elastography in the differential diagnosis of solid pancreatic masses.

METHODS

The study included 86 consecutive patients who underwent EUS for the evaluation of solid pancreatic masses. EUS elastography was performed with the linear Pentax EUS and the Hitachi EUB900. Representative areas from the mass (A) and soft reference areas (B) were analyzed. The result of the elastographic evaluation was defined by the quotient B/A (strain ratio). Final diagnosis was based on histology of surgical specimens and cytology of EUS-fine-needle aspiration samples. The diagnostic accuracy of EUS elastography in detecting malignancy was calculated using receiver operating curve analysis.

RESULTS

The mean size of the pancreatic masses was 31.4 ± 12.3 mm. The final diagnoses were pancreatic adenocarcinoma (n = 49), inflammatory mass (n = 27), malignant neuroendocrine tumor (n = 6), metastatic oat-cell lung cancer (n = 2), pancreatic lymphoma (n = 1), and pancreatic solid pseudopapillary tumor (n = 1). The strain ratio was significantly higher among patients with pancreatic malignant tumors compared with those with inflammatory masses. The sensitivity and specificity of strain ratio for detecting pancreatic malignancies were 100% and 92.9%, respectively (area under the receiver operating curve, 0.983).

CONCLUSIONS

Quantitative, second-generation EUS elastography is useful for differential diagnosis of solid pancreatic masses. It allows for a quantitative and objective evaluation of tissue stiffness, which indicates the malignant or benign nature of the pancreatic lesion.

Endoscopic ultrasound in chronic pancreatitis: Where are we now?

Endoscopic ultrasonography (EUS) is well suited for assessment of the pancreas due to its high resolution and the proximity of the transducer to the pancreas, avoiding air in the gut. Evaluation of chronic pancreatitis (CP) was an early target for EUS, initially just for diagnosis but later for therapeutic purposes. The diagnosis of CP is still accomplished using the standard scoring based on nine criteria, all considered to be of equal value. For diagnosis of any CP, at least three or four criteria must be fulfilled, but for diagnosis of severe CP at least six criteria are necessary. The Rosemont classification, more restrictive, aims to standardize the criteria and assigns different values to different features, but requires further validation. EUS-fine needle aspiration (EUS-FNA) is less advisable for diagnosis of diffuse CP due to its potential side effects. Elastography and contrast-enhanced EUS are orientation in differentiating a focal pancreatic mass in a parenchyma with features of CP, but they cannot replace EUS-FNA. The usefulness of EUS-guided celiac block for painful CP is still being debated with regard to the best technique and the indications. EUS-guided drainage of pseudocysts is preferred in non-bulging pseudocysts or in the presence of portal hypertension. EUS-guided drainage of the main pancreatic duct should be reserved for cases in which endoscopic retrograde cholangiopancreatography has failed owing to difficult cannulation of the papilla or difficult endotherapy. It should be performed only by highly skilled endoscopists, due to the high rate of complications.

Role of endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of solid pancreatic and peripancreatic lesions: is onsite cytopathology necessary?

OBJECTIVES

The reported median diagnostic yield from endoscopic ultrasound (EUS) fine-needle aspiration (FNA) cytology is 78% (range 39-93%). The aim of this study is to describe a single-centre experience in the diagnostic work-up of solid pancreatic and peripancreatic masses without the benefit of an onsite cytopathologist.

METHODS

In a consecutive series of 429 EUS examinations performed over a 12-month period by a single operator, 108 were on non-cystic pancreatic or biliary lesions. Data were collected prospectively and the accuracy of FNA was assessed retrospectively using either surgery or repeat imaging as the benchmark in the presence or absence of malignancy.

RESULTS

Of the 108 FNAs, 102 (94%) were diagnostic, four were falsely negative (FN) and two were atypical and considered equivocal. There were 78 pancreatic lesions, of which 65 were true positives (TP), 11 true negatives (TN) and two FN, giving an overall accuracy of 97% (76/78). Of nine periampullary lesions, two were TP, six were TN and one was FN, giving an overall accuracy of 89% (8/9). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of EUS-FNA for pancreatic and periampullary lesions combined were 96%, 100%, 100% [95% confidence interval (CI) 95-100%], 85% (95% CI 62-97%) and 97%, respectively. There were 21 bile duct lesions, of which 10 were TP, eight TN, two atypical and one FN, giving an overall accuracy of 86% (18/21). The sensitivity, specificity, PPV, NPV and accuracy of EUS-FNA for biliary lesions were 91%, 100%, 100% (95% CI 69-100%), 91% (95% CI 59-100%) and 95%, respectively.

CONCLUSIONS

The diagnostic accuracy of EUS-FNA for pancreatic lesions in our series was 97% and the PPV for the three subgroups of lesion type was 100%; these figures are comparable with the best rates reported in the literature, despite the absence of onsite cytopathology. These rates are potentially a direct result of high-volume practice, dedicated endosonography and cytopathology. These results show that it is possible to achieve high rates of accuracy in places where logistical issues make it impossible to maintain a cytopathologist in the endoscopy suite. In addition, our results contribute to the limited, collective global experience on the effectiveness of EUS-FNA in periampullary and biliary lesions.

Contrast harmonic echo-endoscopic ultrasound improves accuracy in diagnosis of solid pancreatic masses

BACKGROUND & AIMS

Contrast harmonic echo (CHE) has been developed for endoscopic ultrasound (EUS). This new technique detects echo signals from microbubbles in vessels with very slow flow, without artifacts. We assessed whether CHE-EUS increases the accuracy of diagnosis of pancreatic solid lesions.

METHODS

At a tertiary-care EUS center, we examined 90 patients who were suspected of having pancreatic solid neoplasm. Radial and linear echoendoscopes were used with dedicated software for CHE. Sonovue (Bracco International BV, Amsterdam, The Netherlands) uptake, pattern, and washout were studied; data were compared for pancreatic lesions and adjacent parenchyma. The final diagnosis was obtained based on results of surgical pathology and/or EUS-fine needle aspiration (FNA) analyses.

RESULTS

The finding of a hypoenhancing mass with an inhomogeneous pattern was a sensitive and accurate identifier of patients with adenocarcinoma (96% and 82%, respectively) (49 of 51 patients with primary pancreatic adenocarcinoma had a hypoenhancing mass that was inhomogeneous and had fast washout). This finding was more accurate in diagnosis than the finding of a hypoechoic lesion using standard EUS (P < .000). Hyperenhancement specifically excluded adenocarcinoma (98%), although sensitivity was low (39%). Of neuroendocrine tumors, 11 of 13 were non-hypo-enhancing (9 hyperenhancing, 2 isoenhancing). Interestingly, CHE-EUS allowed detection of small lesions in 7 patients who had uncertain standard EUS findings because of biliary stents (n = 5) or chronic pancreatitis (n = 2). Targeted EUS-FNA was performed on these lesions.

CONCLUSIONS

Detection of a hypoenhancing and inhomogeneous mass accurately identified patients with pancreatic adenocarcinoma. CHE-EUS increased the detection of malignant lesions in difficult cases (patients with chronic pancreatitis or biliary stents) and helped guide EUS-FNA. A hyperenhancing pattern could be used to rule out adenocarcinoma.

Incidence of benign disease in patients that underwent resection for presumed pancreatic cancer diagnosed by endoscopic ultrasonography (EUS) and fine-needle aspiration (FNA)

INTRODUCTION

The lack of accurate markers makes preoperative differentiation between pancreatic cancer and non-malignant head lesions clinically challenging. In this study, we investigated the incidence of benign disease in patients that underwent resection for presumed pancreatic cancer diagnosed by EUS and EUS-guided FNA.

METHODS

Medical records of consecutive patients who underwent pancreaticoduodenectomy at Duke University were reviewed. Demographics, clinicopathologic characteristics, preoperative imaging, EUS, EUS-guided FNA, and postoperative outcomes were analyzed.

RESULTS

Seven percent of the total 494 patients studied were found to have benign disease on postoperative pathology. Fifty-nine percent of these patients with benign disease underwent preoperative EUS. EUS was positive for a head mass in 70%, demonstrated enlarged lymph nodes in 27%, and showed signs concerning for vascular invasion in 13%. FNA was suspicious or indeterminate for cancer in 63% of patients. Postoperative complications occurred in 47% and one patient died after surgery. The overall pancreatic leak rate was 15%.

CONCLUSIONS

Even with aggressive use of preoperative evaluation, there is still a small subset of patients where malignancy cannot be excluded without pancreaticoduodenectomy.

Absence of a dilated duct predicts benign disease in suspected pancreas cancer: a simple clinical rule

BACKGROUND

Pancreatic cancer can be difficult to diagnose. Fine-needle aspiration (FNA) biopsies may be negative even when malignancy is present.

AIMS

To identify endosonographic features predictive of malignancy that will separate patients into high- and low-risk groups, in whom a negative FNA effectively rules out malignancy.

METHODS

Patients presenting for endoscopic ultrasound (EUS) evaluation for suspected pancreatic mass were prospectively enrolled. If a mass or abnormal lymph nodes were present, sampling via fine-needle aspiration (FNA) was performed. The characteristics of patients with cancer were compared to the characteristics of patients without cancer using Chi-square testing and t-tests.

RESULTS

Seventy-three patients were enrolled. Thirty-three patients had cancer and 40 had benign disease. On multivariate analysis, only vascular or organ invasion and dilation of the pancreatic duct (PD) were significantly associated with cancer. PD dilation was examined as a stand-alone feature. The presence of a dilated PD placed patients into a group with a 65% prevalence of malignancy. In the non-dilated PD group, the prevalence of malignancy was only 17%, and in this group, the negative predictive value of FNA was 100%, compared to an NPV of 73% in the entire cohort.

CONCLUSIONS

The most significant negative predictive endosonographic finding in patients with suspected pancreatic cancer is a non-dilated PD. If a patient with suspected pancreatic cancer does not have a dilated PD and the FNA is negative for malignancy, the likelihood of cancer is low.

Incidence and characteristics of chronic and lymphoplasmacytic sclerosing pancreatitis in patients scheduled to undergo a pancreatoduodenectomy

BACKGROUND

The determination of the exact nature of a pancreatic head mass in a patient scheduled to undergo a pancreatoduodenectomy can be very difficult. This is important as patients who suffer from benign disease such as pancreatitis do not always require surgery. The aim of the present study was to analyse the incidence of pancreatitis and the signs and symptoms associated with these tumours mistaken for pancreatic cancer and the diagnostic procedures performed.

METHODS

A consecutive group of patients who underwent a pancreatoduodenectomy between 1992 and 2005 with histopathologically proven pancreatic adenocarcinoma (PCA) and pancreatitis were analysed.

RESULTS

The incidence of pancreatitis after pancreatoduodenectomy is 63 out of 639 patients who underwent a pancreaticoduodenectomy (9.9%). Of these patients, 24 patients (38%) had lymphoplasmacytic sclerosing pancreatitis (LPSP) and 31 patients (49%) had focal chronic pancreatitis. Eight patients (13%) had an intermediate form with characteristics of both. Pancreatic adenocarcinoma occurred in 227 patients (36%). The presence of pancreatitis without a discrete mass on endoscopic ultrasonography (EUS) seemed to have clinical relevance with a positive likelihood ratio of 5.1. Mortality after resection was nil in both groups.

CONCLUSION

The incidence of pancreatitis is 9.9% for patients scheduled to undergo a pancreatoduodenectomy. Of these patients, 38% had LPSP, 13% had a intermediate form and 49% had focal chronic pancreatitis. The determination of the exact nature of a pancreatic head mass remains difficult.

Periductal hypoechoic sign: an endosonographic finding associated with pancreatic malignancy

BACKGROUND

Despite advances in imaging, differentiating benign from malignant causes of pancreatic duct dilation is difficult.

OBJECTIVE

The aim of our study was to assess the accuracy of the periductal hypoechoic sign (PHS), defined as patchy hypoechoic areas adjacent to a dilated pancreatic duct, for the diagnosis of pancreatic malignancy.

DESIGN

Single-center, retrospective analysis.

SETTING

Tertiary care university hospital.

PATIENTS

All patients who underwent EUS from 2006 to 2008 for evaluation of pancreatic pathology were identified. Those with pancreatic duct dilation of 4 mm or more in the head of the pancreas or 3 mm or more in the body or tail were included. Digitally recorded EUS images were analyzed for PHS by 1 endoscopist blinded to final results. The final diagnosis was based on pathology results or clinical follow-up.

RESULTS

During the study period, 84 of 427 patients who underwent EUS for pancreas pathology had dilated pancreatic ducts. Of these, 42 patients had benign disease and 42 had pancreatic malignancy. The PHS was noted in 31 (73.8%) of 42 patients with malignancy compared with 6 (14.3%) of 42 patients with benign disease (P < .001). The PHS had a sensitivity of 73.8%, a specificity of 85.7%, and an accuracy of 79.8% for the diagnosis of pancreatic malignancy. After adjusting for age, patients with the PHS were 17 times more likely to have a malignancy (odds ratio 16.66; 95% CI, 5.01-55.44). Pancreatic duct diameter or dilation of both bile and pancreatic ducts were not predictive of malignancy.

LIMITATION

A retrospective design.

CONCLUSIONS

The PHS was an accurate and independent predictor of pancreatic malignancy in patients with a dilated pancreatic duct.

EUS elastography for the characterization of solid pancreatic masses

BACKGROUND

Differential diagnosis of solid pancreatic masses remains a challenge. EUS elastography, by analyzing tissue stiffness of the mass, may be of help in this setting.

OBJECTIVE

To evaluate the different elastographic patterns of solid pancreatic masses and the diagnostic accuracy of EUS elastography for malignancy.

DESIGN

Prospective, consecutive, descriptive study with a second blind evaluation of elastographic patterns for concordance analysis and use of a well-defined reference method for calculation of diagnostic accuracy.

PATIENTS

This study involved 130 consecutive patients with solid pancreatic masses and 20 controls with normal pancreases.

INTERVENTION

EUS elastography was performed by using a linear Pentax echoendoscope and Hitachi EUB-8500 US.

MAIN OUTCOME MEASUREMENTS

Elastographic patterns of solid pancreatic masses and accuracy of the technique for malignancy.

RESULTS

Mean (SD) size of the masses was 30.9 (12.5) mm. The final diagnosis was malignant tumor in 78 patients, inflammatory mass in 42 patients, and neuroendocrine tumor in 10 patients. Four elastographic patterns were described, with a high concordance among 2 blinded investigators. A green-predominant pattern, either homogeneous or heterogeneous, excluded malignancy with a high accuracy. On the contrary, a blue-predominant pattern, either homogeneous or heterogeneous, supported the diagnosis of malignant tumor. Sensitivity, specificity, positive and negative predictive values, and overall accuracy of EUS elastography for diagnosis of malignancy were 100%, 85.5%, 90.7%, 100%, and 94.0%, respectively.

LIMITATION

Single-center study.

CONCLUSION

EUS elastography is a useful tool for differential diagnosis of solid pancreatic masses. It provides specific patterns supporting the benign or malignant nature of the disease.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA): experience of an academic centre in the USA

OBJECTIVES

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has become widely accepted as an effective modality for obtaining tissue for primary diagnosis and staging. We have been using EUS-FNA since July 2001 and herein we summarize our experience over a 5-year period.

METHODS

A computer-based search for in-house EUS-FNA was performed in the pathology database from July 2001 to October 2006. To calculate the sensitivity, specificity and accuracy of EUS-FNA, the cytology diagnosis was compared with the surgical follow-up.

RESULTS

A total of 951 EUS-FNAs were performed during the study period and included 279 pancreatic solid lesions, 186 pancreatic cyst lesions, 249 lymph node aspirations, 111 gastrointestinal (GI) tract submucosal lesions, and 126 miscellaneous lesions. EUS-FNA had a very high sensitivity and accuracy for solid pancreatic lesions (94.7 and 97.7%, respectively), low sensitivity and accuracy but high specificity (47, 64.8 and 95%, respectively) for cystic lesions. Cyst fluid carcinoembryonic (CEA) levels were significantly higher in mucinous neoplasms than non-neoplastic cysts. EUS-FNA also had very high sensitivity and specificity for detecting metastatic carcinoma in lymph nodes (95 and 100%, respectively). GI submucosal spindle cell tumours were further classified with immunohistochemical stains performed either on a cell block or a core biopsy obtained via EUS guidance.

CONCLUSIONS

EUS-FNA has a very high sensitivity and accuracy for pancreatic solid lesions, but the sensitivity for cystic lesions is generally low. Cyst fluid chemical analysis for CEA is helpful, but the overlap between mucinous neoplasm and non-neoplastic cysts is significant. Recognizing GI contamination is important and immunohistochemical stains are useful for GI submucosal spindle cell lesions.

Endoscopic ultrasound-guided fine-needle aspiration biopsy and trucut biopsy in gastroenterology - An overview

Endoscopic ultrasound (EUS)-guided biopsies are reliable, safe and effective techniques in obtaining samples for cytological or histological examinations either as a primary procedure or in cases where other biopsy techniques have failed. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA), as well as endoscopic ultrasound-guided trucut biopsy (EUS-TCB), has proven to be of significant value in the diagnostic evaluation of benign and malignant diseases, as well as in staging of the malignant tumours of the gastrointestinal tract and of adjacent organs. The diagnostic yield of EUS-guided biopsies depends on site, size and characteristics of target tissues as well as technical and procedural factors (type of needle, biopsy technique and material processing). Other weighting factors include expertise, training and interaction between the endosonographer and cytopathologist. Rapid on-site cytological evaluation has proven to be successful in optimising the diagnostic efficiency of EUS-FNA. A sensible alternative is to collect specimens for histological and immunohistochemical investigations in addition to the cytological smears. EUS-FNA using a 22-gauge needle is successful in harvesting core biopsies in approximately three out of four cases. Therefore, the use of 19-gauge needles for EUS-FNA or EUS-TCB may only be necessary in selected cases. The reproducibility of cytopathological diagnosis among pathologists with special experience in assessing material obtained by EUS-guided biopsies is very high. False-positive diagnosis of malignancy in EUS-guided biopsy is rare. False-negative diagnosis appears with variable frequency depending on the target tissue, technical factors and expertise of the endosonographer and cytopathologist. There are numerous challenges and pitfalls in the differential diagnostic classification of benign and malignant lesions. These problems are related to the characteristics of samples obtained by EUS-guided biopsy, as well as to the multiple diagnoses with similar or overlapping cytological or histological characteristics. The high prognostic and therapeutic relevance of the cytopathological diagnoses resulting from EUS-guided biopsy calls for a shared responsibility of an endosonographer and a cytopathologist.

EUS-guided FNA of solid pancreatic masses: high yield of 2 passes with combined histologic-cytologic analysis

BACKGROUND

EUS-guided FNA (EUS-FNA) is an established tissue-acquisition technique, with most studies concentrating on cytologic analyses of specimens, with only few data existing on histologic assessment.

OBJECTIVE

To assess the sensitivity of a combined analysis of histologic followed by cytologic tissue diagnosis.

DESIGN

A retrospective 3-center study.

METHODS

In consecutive patients undergoing FNA of solid pancreatic masses, core specimens were harvested for histology; residual tissue was examined cytologically. Only unequivocally positive results were regarded as malignant. Criterion standards were positive results from EUS-FNA or other histologic findings, or, if negative, clinical follow-up data (minimum 12 months).

RESULTS

Among 192 patients (110 men; mean age 63 years) with mostly pancreatic-head masses (72.4%), overall, adequate tissue was obtained in 98.9% of all cases, with a mean of 1.88 needle passes and an overall sensitivity of 82.9% (95% CI, 76.0%-88.5%). Histology and subsequent cytology provided adequate tissue and sensitivities of 86.5% and 60%, and 92.7% and 68.1%, respectively. Excluding cases with inadequate specimens, sensitivities rose by 4% to 10%. Histology showed a trend for superiority over cytology only in characterizing nonadenocarcinoma tumor types. No differences in sensitivity were found between the centers involved.

LIMITATIONS

Retrospective design, different processing of cytologic specimens.

CONCLUSIONS

At EUS-FNA in pancreatic masses, combined histologic-cytologic analysis achieved a sensitivity of more than 80%, despite a low number of needle passes and may thus save time. Histology alone did not reach higher sensitivity than cytology. In particular situations, eg, rare tumors, histology may still be required.

EUS/EUS-FNA for suspected pancreatic cancer: influence of chronic pancreatitis and clinical presentation with or without obstructive jaundice on performance characteristics

BACKGROUND

The clinical utility of EUS-FNA is debated in patients with obstructive jaundice (ObJ) because of a very high pretest probability of pancreatobiliary malignancy (PBM) and biliary stent-induced inflammation that can potentially confound EUS-FNA diagnosis. EUS-FNA also has lower accuracy in patients with underlying chronic pancreatitis (CP).

OBJECTIVE

Our purpose was to determine the clinical value of EUS-FNA for PBM diagnosis based on clinical presentation and presence of CP.

DESIGN

Retrospective analysis of prospective database.

SETTING

University hospital.

PATIENTS

Patients who underwent EUS-FNA from 2002 to 2006 for suspected PBM based on (1) ObJ with biliary stricture or a mass lesion or (2) abnormal pancreatic imaging by CT/MRI: a focal pancreatic "mass" lesion; dilated pancreatic duct +/- common bile duct; or an enlarged head of pancreas.

INTERVENTIONS

EUS was performed with a radial echoendoscope followed by a linear echoendoscope if a focal pancreatic lesion was identified. Fine-needle aspirates were assessed immediately by an attending cytopathologist.

MAIN OUTCOME MEASUREMENTS

(1) Prevalence of cancer and (2) performance characteristics of EUS-FNA.

RESULTS

PBM was diagnosed in 73.9% of patients with ObJ and biliary stricture or pancreatic mass, in 49.6% of patients with pancreatic mass, and in 7.0% of patients with an enlarged head of pancreas or dilated pancreatic duct +/- common bile duct. The prevalence of PBM was lower in all 3 presentations with associated CP. Both CP and presentation with ObJ lowered performance characteristics of EUS-FNA, but CP did so only in the subset of patients with ObJ. All except 1 false-negative diagnoses were due to cytologic misinterpretation.

LIMITATION

Retrospective design.

CONCLUSION

Among patients with suspected PBM, the accuracy of EUS-FNA is significantly lower only in a subset of patients with ObJ with underlying CP, largely as a result of difficulty in cytologic interpretation.

Predictors of malignancy and recommended follow-up in patients with negative endoscopic ultrasound-guided fine-needle aspiration of suspected pancreatic lesions

BACKGROUND

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) can characterize and diagnose pancreatic lesions as malignant, but cannot definitively rule out the presence of malignancy. Outcome data regarding the length of follow-up in patients with negative or nondiagnostic EUS-FNA of pancreatic lesions are not well-established.

OBJECTIVE

To determine the long-term outcome and provide follow-up guidance for patients with negative EUS-FNA diagnosis of suspected pancreatic lesions based on imaging predictors.

METHODS

A retrospective review of patients undergoing EUS-FNA for suspected pancreatic lesions, but with negative or nondiagnostic FNA results was conducted at a tertiary care referral medical centre. Patient demographics, EUS imaging characteristics and follow-up data were examined.

RESULTS

Seventeen of 55 patients (30.9%) with negative/nondiagnostic FNA were subsequently diagnosed with pancreatic malignancy. The risk of cancer was significantly higher for patients who had associated lymph nodes on EUS (P<0.001) and vascular involvement on EUS (P=0.001). The mean time to diagnosis in the group with falsenegative EUS-FNA diagnosis was 66 days. The true-negative EUSFNA patients were followed for a mean of 403 days after negative EUS-FNA results without the development of malignancy.

CONCLUSION

For patients undergoing EUS-FNA for a suspected pancreatic lesion, a negative or nondiagnostic FNA does not provide conclusive evidence for the absence of cancer. Patients for whom vascular invasion and lymphadenopathy are detected on EUS are more likely to have a true malignant lesion and should be followed closely. When a patient has been monitored for six months or more with no cancer being diagnosed, there appears to be much less chance that a pancreatic malignancy is present.

Endoscopic ultrasound in the evaluation of radiologic abnormalities of the liver and biliary tree

Gastroenterologists increasingly find themselves in the un-enviable position of having to choose the optimal radiographic test to visualize the biliary tree and the liver. This dilemma is compounded by the rapid evolution of the available technologies and their ever-increasing resolution capabilities. Endoscopic ultrasound (EUS) has shown itself to be equally capable of providing detailed imaging of the biliary tree and of surrounding structures; its potential for evaluating liver lesions is just now being realized. EUS-fine needle aspiration (FNA) may supplant some of the existing technologies as it offers a way to sample masses, strictures, lymph nodes, and now certain segments of the liver and periportal regions. This review takes an in-depth look at the role of EUS in evaluating bile duct dilatation, suspected choledocholithiasis, biliary strictures, and polyps and masses of the gallbladder. It also reviews the literature on the exciting and rapidly evolving role of EUS-FNA evaluation of occult, metastatic, and primary hepato-cellular malignancies, as well as periportal lesions. Technologies such as EUS elastography may completely obviate FNA of liver lesions.

Role of endoscopic ultrasound in pancreatic cancer

Pancreatic cancer (PC) is the fourth most common cause of cancer deaths in Western societies. It is an aggressive tumor with an overall 5-year survival rate of less than 5%. Surgical resection offers the only possibility of cure and long-term survival for patients suffering from PC; however, unfortunately, fewer than 20% of patients suffering from PC have disease that is amendable to surgical resection. Therefore, it is important to accurately diagnose and stage these patients to enable optimal treatment of their disease. The imaging modalities involved in the diagnosis and staging of PC include multidetector CT scanning, endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreaticography and MRI. The roles and relative importance of these imaging modalities have changed over the last few decades and continue to change owing to the rapid technological advances in medical imaging, but these investigations continue to be complementary. EUS was first introduced in the mid-1980s in Japan and Germany and has quickly gained acceptance. Its widespread use in the last decade has revolutionized the management of pancreatic disease as it simultaneously provides primary diagnostic and staging information, as well as enabling tissue biopsy. This article discusses the potential benefits and drawbacks of EUS in the primary diagnosis, staging and assessment of resectability, and EUS-guided fine-needle aspiration in PC. Difficult diagnostic scenarios and pitfalls are also discussed. A suggested management algorithm for patients with suspected PC is also presented.

Screening of high-risk families for pancreatic cancer

PURPOSE OF REVIEW

To discuss how to recognise and manage high-risk individuals.

RECENT FINDINGS

Publication of initial results of screening for pancreatic cancer from US centres. Several masses and premalignant lesions have been detected, but the detection of the first pancreatic cancer through an organised study of screening has yet to be published. There has been progress in risk stratification; the role of diabetes in predisposing for cancer has been characterised and molecular modalities have been published which could be used in conjunction with imaging in a screening programme. A mutation in the palladin gene was found to segregate with the disease in a family with a clear predisposition for pancreatic cancer, though this has yet to be found in other such kindreds.

SUMMARY

Significant challenges remain to be solved in screening for early pancreatic cancer. Risk stratification needs to be improved and high-risk patients included in research-based screening programmes. It will be impossible to confirm that screening can detect cancers early enough for curative treatment until the results of these prospective studies become available.

Pancreatic cytopathology: a practical approach and review

CONTEXT

Pancreatic cytopathology plays an important role in the diagnosis and management of patients with solid and cystic lesions of the pancreas.

OBJECTIVE

To serve as a practical guide to pancreatic cytopathology for the practicing pathologist. Data Sources.-A comprehensive assessment of the medical literature was performed.

CONCLUSIONS

We review pancreatic cytopathology, with specific discussions of its role in patient management, specimen types and specimen processing, specific diagnostic criteria, and the use of ancillary testing and advanced techniques.

Preoperative tissue diagnosis for tumours of the pancreas

BACKGROUND

Preoperative biopsy of pancreatic lesions suspected of malignancy is controversial.

METHODS

A systematic Medline literature search was carried out. Diagnostic studies reporting quantitative preoperative pancreatic biopsy data were evaluated.

RESULTS

The analysis included 53 studies, mostly of a retrospective nature. Despite acceptable rates for sensitivity and specificity, the negative predictive value of percutaneous and endoscopic ultrasonography-guided biopsies was 60-70 per cent. Biopsy results were considered to be essential for directing non-surgical therapy in advanced disease. However, they were of limited value in planning the treatment of resectable solid or cystic tumours, or focal lesions in the setting of chronic pancreatitis.

CONCLUSIONS

Biopsy of suspected pancreatic malignancies with systemic spread or local irresectability is indicated for planning palliative or neoadjuvant therapy. Preoperative biopsy of potentially resectable pancreatic tumours is not generally advisable, as malignancy cannot be ruled out with adequate reliability.

Endoscopic ultrasound guided fine needle aspiration of solid pancreatic lesions: Performance and outcomes

BACKGROUND AND AIM

We report our single-centre experience with endoscopic ultrasound guided fine needle aspiration (EUS-FNA) of solid pancreatic lesions with regard to clinical utility, diagnostic accuracy and safety.

METHODS

We prospectively reviewed data on 100 consecutive EUS-FNA procedures performed in 93 patients (54 men, mean age 60.6 +/- 12.9 years) for evaluation of solid pancreatic lesions. Final diagnosis was based on a composite standard: histologic evidence at surgery, or non-equivocal malignant cytology on FNA and follow-up. The operating characteristics of EUS-FNA were determined.

RESULTS

The location of the lesions was pancreatic head in 73% of cases, the body in 20% and the tail in 7%. Mean lesion size was 35.1 +/- 12.9 mm. The final diagnosis revealed malignancy in 87 cases, including adenocarcinomas (80.5%), neuroendocrine tumours (11.5%), lymphomas (3.4%) and other types (4.6%). The FNA findings were: 82% interpreted as malignant cytology, 1% as suspicious for neoplasia, 1% as atypical, 7% as benign process and 9% as non-diagnostic. No false-positive results were observed. There was a false-negative rate of 5%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.3%, 100%, 100%, 72.2% and 95%, respectively. In 23 (88.5%) of 26 aspirated lymph nodes malignancy was found. Minor complications occurred in two patients.

CONCLUSIONS

Our experience confirms that EUS-FNA in patients with suspected solid pancreatic lesions is safe and has a high diagnostic accuracy. This technique should be considered the preferred test when a cytological diagnosis of a pancreatic mass lesion is required.

Role of endoscopic ultrasound in the diagnosis and staging of pancreatic cancer

Early diagnosis of pancreatic cancer remains a difficult task, and multiple imaging tests have been proposed over the years. The aim of this review is to describe the current role of endoscopic ultrasound (EUS) for the diagnosis and staging of patients with pancreatic cancer. A detailed search of MEDLINE between 1980 and 2007 was performed using the following keywords: pancreatic cancer, endoscopic ultrasound, diagnosis, and staging. References of the selected articles were also browsed and consulted. Despite progress made with other imaging methods, EUS is still considered to be superior for the detection of clinically suspected lesions, especially if the results of other cross-sectional imaging modalities are equivocal. The major advantage of EUS is the high negative predictive value that approaches 100%, indicating that the absence of a focal mass reliably excludes pancreatic cancer. The introduction of EUS-guided fine needle aspiration allows a preoperative diagnosis in patients with resectable cancer, as well as a confirmation of diagnosis before chemoradiotherapy for those that are not. This comprehensive review highlighted the diagnostic capabilities of EUS including the newest refinements such as contrast-enhanced EUS, EUS elastography, and 3-dimensional EUS. The place of EUS-guided biopsy is also emphasized, including the addition of molecular marker techniques.

Neural network analysis of dynamic sequences of EUS elastography used for the differential diagnosis of chronic pancreatitis and pancreatic cancer

BACKGROUND

EUS elastography is a newly developed imaging procedure that characterizes the differences of hardness and strain between diseased and normal tissue.

OBJECTIVE

To assess the accuracy of real-time EUS elastography in pancreatic lesions.

DESIGN

Cross-sectional feasibility study.

PATIENTS

The study group included, in total, 68 patients with normal pancreas (N = 22), chronic pancreatitis (N = 11), pancreatic adenocarcinoma (N = 32), and pancreatic neuroendocrine tumors (N = 3). A subgroup analysis of 43 cases with focal pancreatic masses was also performed.

INTERVENTIONS

A postprocessing software analysis was used to examine the EUS elastography movies by calculating hue histograms of each individual image, data that were further subjected to an extended neural network analysis to differentiate benign from malignant patterns.

MAIN OUTCOME MEASUREMENTS

To differentiate normal pancreas, chronic pancreatitis, pancreatic cancer, and neuroendocrine tumors.

RESULTS

Based on a cutoff of 175 for the mean hue histogram values recorded on the region of interest, the sensitivity, specificity, and accuracy of differentiation of benign and malignant masses were 91.4%, 87.9%, and 89.7%, respectively. The positive and negative predictive values were 88.9% and 90.6%, respectively. Multilayer perceptron neural networks with both one and two hidden layers of neurons (3-layer perceptron and 4-layer perceptron) were trained to learn how to classify cases as benign or malignant, and yielded an excellent testing performance of 95% on average, together with a high training performance that equaled 97% on average.

LIMITATION

A lack of the surgical standard in all cases.

CONCLUSIONS

EUS elastography is a promising method that allows characterization and differentiation of normal pancreas, chronic pancreatitis, and pancreatic cancer. The currently developed methodology, based on artificial neural network processing of EUS elastography digitalized movies, enabled an optimal prediction of the types of pancreatic lesions. Future multicentric, randomized studies with adequate power will have to establish the clinical impact of this procedure for the differential diagnosis of focal pancreatic masses.

Immunostaining as an adjunct to cytology for diagnosis of pancreatic adenocarcinoma

BACKGROUND & AIMS

Serial analysis of gene expression has helped identify several proteins that are expressed differentially in pancreatic cancer and are highly sensitive and specific for pancreatic adenocarcinoma. We evaluated if the diagnostic accuracy of pancreatic cancer from endoscopic ultrasound (EUS)-fine-needle aspiration (FNA) can be improved by combined evaluation of cytology and immunostaining with these markers.

METHODS

This study involved the use of archived specimens from patients treated at Saint Louis University Hospital from 2002 to 2006. We identified 5 protein markers that appeared most promising from published literature. We sequentially evaluated immunostaining with these markers in (1) surgical resection specimens, (2) cell blocks from EUS-FNA, and (3) direct smears of EUS-FN aspirates. Finally, we performed a combined evaluation of cytology and immunostaining in direct smears that were difficult to interpret and required a second consultative cytologic opinion.

RESULTS

In resection specimens, the majority of pancreatic adenocarcinomas expressed all 5 markers but fascin, maspin, and carcinoembryonic antigen-related cell adhesion molecule 6 also were expressed abnormally in normal pancreata and in chronic pancreatitis. Further evaluation therefore was limited to the other 2 markers: mesothelin and 14-3-3sigma. It was feasible and useful to perform immunostaining in cell blocks and direct smear for diagnosing pancreatic cancer. In cases requiring a second cytologic consultation, a combined evaluation of cytologic morphology and immunostaining had 90% accuracy for a pancreatic adenocarcinoma diagnosis.

CONCLUSIONS

In conclusion, immunostaining with newer protein markers is feasible in EUS-FNA specimens and can assist cytopathologists in diagnosing pancreatic cancer. Among the currently available protein immunomarkers, a combination of mesothelin and 14-3-3sigma seems most promising, but needs to be validated in prospective studies before routine clinical use.

Diagnostic ascertainment of suspicious pancreatic mass: a threshold analysis

BACKGROUND & AIMS

It is frequently difficult to differentiate between a benign and malignant pancreatic mass. The aim of this study was to assess the parameters that affect the decision to perform surgery on a suspicious pancreatic head lesion.

METHODS

A cost-benefit analysis, using decision tree and threshold analysis, accumulates costs and quality-adjusted life years in patients undergoing pancreaticoduodenectomy or expectant management. The threshold value is defined as the diagnostic probability for pancreatic cancer when the cost-benefit relationships of pancreaticoduodenectomy or expectant management are equal.

RESULTS

For a localized pancreatic head lesion, the threshold probability of cancer is 43%. Any higher probability of pancreatic cancer makes pancreaticoduodenectomy the preferred treatment option. Within a range of $20,000 to $80,000 spent on surgery, the threshold in favor of Whipple procedure remains relatively low at 40% to 65%. A reduced quality of life after surgery weighs against surgery and raises its threshold. Varying quality of life between 100% and 80% changes the threshold between 31% and 67%. The threshold also is increased in younger patients because of the potentially more dire consequences of unnecessary surgery in instances of long life expectancy.

CONCLUSIONS

Even if diagnostic certainty cannot be achieved, it frequently is beneficial to perform surgery despite the risk of subjecting the occasional patient with benign pancreatic head lesion to an unnecessary pancreaticoduodenectomy.

Digital image analysis of EUS images accurately differentiates pancreatic cancer from chronic pancreatitis and normal tissue

BACKGROUND

Concomitant changes of chronic pancreatitis markedly degrade the performance of EUS in diagnosing pancreatic adenocarcinoma (PC). Digital image analysis (DIA) of the spatial distribution of pixels in a US image has been used as an effective approach to tissue characterization.

OBJECTIVE

We applied the techniques of DIA to EUS images of the pancreas to develop a classification model capable of differentiating pancreatic adenocarcinoma from non-neoplastic tissue.

DESIGN

Representative regions of interest were digitally selected in EUS images of 3 groups of patients with normal pancreas (group I), chronic pancreatitis (group II), and pancreatic adenocarcinoma (group III). Texture analyses were then performed by using image analysis software. Principal component analysis (PCA) was used for data reduction, and, later, a neural-network-based predictive model was built, trained, and validated.

SETTING

Tertiary academic medical center.

PATIENTS

Patients undergoing EUS of the pancreas.

RESULTS

A total of 110, 99, and 110 regions of interest in groups I, II, III, respectively, were available for analysis. For each region, a total of 256 statistical parameters were extracted. Eleven parameters were subsequently retained by PCA. A neural network model was built, trained by using these parameters as input variables for prediction of PC, and then validated in the remainder of the data set. This model was very accurate in classifying PC with an area under the receiver operating characteristic curve of 0.93.

LIMITATION

Exploratory study with a small number of patients.

CONCLUSIONS

DIA of EUS images is accurate in differentiating PC from chronic inflammation and normal tissue. With the potential availability of real-time application, DIA can develop into a useful clinical diagnostic tool in pancreatic diseases and in certain situations may obviate EUS-guided FNA.

Prospective pilot evaluation of a new needle prototype for endoscopic ultrasonography-guided fine-needle aspiration: comparison of cytology and histology yield

OBJECTIVES

Endoscopic ultrasonography (EUS) with the adjunct of EUS-guided fine needle aspiration has become an important diagnostic modality in gastroenterologic oncology. EUS-guided fine needle aspiration mainly relies on cytology; data are scarce that compare cytology and histology. While testing a 22-gauge prototype needle, we prospectively compared the yield for both.

METHODS

Forty-two consecutive patients (27 male, 15 female; mean age 59.2 years, range: 17-90 years) were included. In each patient we aimed to make two needle passes, and if the material acquired appeared insufficient macroscopically (no in-room cytopathology was available), further passes were done. The material was sent for cytological and histological assessment.

RESULTS

A median number of two passes (range: 2-3) were uneventfully performed for pancreatic lesions (n=30), mediastinal and other lymph nodes/masses (n=8) and various other lesions (n=4) and yielded adequate material for cytology, histology or at least one of the two investigations in 62, 67 and 74% of patients, respectively. No false positive results were found (specificity 100%). Sensitivities were 58.6 and 65.5%, respectively, for cytology and histology alone; combined assessment increased sensitivity to 79.3%. When adjusted values were calculated, based only on those cases with adequate material, sensitivity was 89.5% for cytology and 85.7% for histology, and increased to 100% with combined assessment.

CONCLUSION

The new needle achieves sensitivities similar to those previously reported with no significant differences in sensitivity between cytology and histology. More effective tissue acquisition methods must be sought to improve overall results.

The role of endoscopic ultrasound in biliary strictures

The role of endoscopic ultrasound (EUS) in the diagnosis of biliary strictures is well established, and emerging evidence suggests it may also play a therapeutic role. Differentiating between benign and malignant causes of biliary strictures can be challenging, but EUS can aid in their diagnosis and may predict resectability. The diagnostic yield of EUS combined with fine-needle aspiration (FNA) is excellent, especially in distal bile duct strictures, and far surpasses endoscopic retrograde cholangiopancreatography (ERCP) with brushings. Intraductal ultrasound may add to the diagnostic sensitivity of ERCP with brushings when no mass is seen on cross-sectional imaging or EUS, or when EUS with FNA is negative and suspicion of cancer persists. EUS-guided cholangiography is an emerging technique that may aid biliary decompression when ERCP has failed or is not possible; however, new therapeutic echoendoscopes or accessories are needed before the use of this technique can become more widespread.

Value of repeat endoscopic ultrasound-guided fine needle aspiration for suspected pancreatic cancer

BACKGROUND AND AIMS

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a safe and accurate technique for diagnosing pancreatic cancer. The value of repeat EUS-FNA in patients with high clinical suspicion for pancreatic cancer after an inconclusive index study is unknown. Our aims were to determine the yield and success of repeat EUS-FNA and the reasons for failure of initial EUS-FNA.

METHODS

This was a retrospective analysis of prospectively collected data in a tertiary University based referral center for pancreatico-biliary disorders. All patients who underwent more then one EUS-FNA for evaluation of suspected pancreatic cancer over a five and a half year period were included in this analysis.

RESULTS

Of the 547 procedures performed on 517 patients, 24 (4.6%) patients underwent 51 repeat EUS-FNA procedures. Initial EUS-FNA was atypical/suspicious in 10 (41.6%), benign in 10 (41.6%), malignant in two (8.3%), and failed/indeterminate in two (8.3%) patients. Eight of 10 (80%) patients with atypical/suspicious findings at initial EUS-FNA were diagnosed with malignancy on repeat EUS-FNA. Of the 10 patients with benign findings at initial EUS-FNA, repeat study diagnosed two (20%) with malignancy and the rest were confirmed benign on long-term follow up (average 530 days, SD 369 days). Of the two patients with indeterminate findings at initial EUS-FNA, repeat study diagnosed one patient with malignant disease and the other with benign disease that was confirmed by long-term follow up. Of the two patients diagnosed with neoplastic disease at initial EUS-FNA, repeat EUS-FNA with immunostains downgraded both to chronic pancreatitis. Repeat EUS-FNA facilitated determination of the true status of disease in 20 of 24 patients (accuracy 84%). Suspected reasons for failed initial EUS-FNA were: coexisting pancreatitis (n = 10; 42%), technical difficulty due to scope positioning in uncinate lesion/sedation failure (n = 4; 16.7%), difficult cytology (partly cystic, extensive necrosis, well-differentiated adenocarcinoma) (n = 4; 16.7%), presence of ascites or collaterals (n = 3; 12.5%), pathologist's interobserver variation (n = 2; 8.33%), and unknown reason in one patient.

CONCLUSION

Repeat EUS-FNA is warranted in patients with high clinical suspicion for pancreatic cancer despite indeterminate or negative findings at initial EUS-FNA.

Pancreatic ductal adenocarcinoma: ultrasound, computed tomography, and magnetic resonance imaging features

The technologies of computed tomography, magnetic resonance, and ultrasound (transabdominal and endoscopic) have advanced considerably in recent years, having a major impact on the management of pancreatic cancer, guiding surgery for the potential of cure, and avoiding needless surgery in those patients who are unresectable. Knowledge of how these modalities should be utilized, how they can be optimized, and the appearance of ductal adenocarcinoma on each modality are crucial for them to be used effectively and accurately.

Efficacy of endoscopic ultrasound in characterizing mass lesions in chronic pancreatitis

BACKGROUND AND GOALS

The aim of this study is to determine the influence of endoscopic ultrasound (EUS) in the detection of chronic pancreatitis and identification of pancreatic masses suspected by other radiographic imaging modalities in such a clinical background.

METHODS

Retrospective analysis was performed on 105 consecutive pancreatic EUS examinations in an 18-month period at a single tertiary care referral center. Analysis included 75 patients with a suspected pancreatic mass by computerized axial tomography, magnetic resonance imaging, ultrasound, or endoscopic retrograde cholangiopancreotography. All patients underwent EUS examination and if a mass was visualized, fine-needle aspiration biopsy was performed. Patients underwent either surgical exploration or clinical and radiographic follow-up for 6 months to confirm EUS findings.

RESULTS

Chronic pancreatitis was suspected in 53 individuals by clinical or radiographic methods. Using standard EUS parenchymal and ductal criteria, chronic pancreatitis was confirmed in 41 (77%) of patients. In 33 patients with chronic pancreatitis detected by EUS, initial referral was for pancreatic mass. Twenty-eight (85%) patients had an actual mass and the remainder were false-positive clinical findings. Thirty-two percent of pancreatic masses in chronic pancreatitis were found to be malignant adenocarcinoma and the rest were inflammatory in nature. Subset analysis showed EUS-fine-needle aspiration of solid lesions to have a sensitivity and specificity of 87.9% and 100%, respectively. Detection of cystic lesions had a sensitivity and specificity of 88.5% and 100%, respectively.

CONCLUSIONS

EUS is superior to other radiographic modalities in the determination of chronic pancreatitis and detection of mass lesions.

Utility of endoscopic ultrasound in pancreatitis: A review

The close proximity of the endoscopic ultrasound probe to the pancreas results in superior spatial resolution compared to CT scan and MRI. In addition, endoscopic ultrasound (EUS) is a minimally invasive procedure that does not share the relatively high complication rate of ERCP. Due to these advantages, EUS has evolved into an important technique to assess pancreatobiliary disease. This review will discuss the role of EUS in patients with pancreatitis. The indications can be divided into acute pancreatitis and chronic pancreatitis. In acute pancreatitis, EUS is used to determine the etiology; in suspected chronic pancreatitis it is helpful to establish the diagnosis. Lastly, this review will discuss biliary pancreatitis with suspicion for persistent choledocholithiasis.

[Pancreatic incidentalomas. Correct assessment and therapy]

Due to recent advances in CT/MRI technology, incidentalomas of the pancreas are detected with increasing frequency. Pancreatic incidentalomas should be differentiated into solid and cystic tumors. In both subgroups definitive classification of the tumor is often not possible. Operative therapy is recommended in premalignant or malignant pathologies. Thus solid incidentalomas should be resected independently of their size, if the patient is without serious comorbidities. In case of cystic incidentalomas, benign cystic lesions should be excluded as far as possible. Otherwise they should be resected if their size is >or=2 cm. In case of IPMN with specific risk factors, resection is recommended when the tumor size exceeds 1 cm.

A clinical and economic evaluation of endoscopic ultrasound for patients at risk for familial pancreatic adenocarcinoma

BACKGROUND AND AIMS

Approximately 10% of pancreatic adenocarcinoma is familial. Approximately 50% of 1st-degree relatives (FDRs) have endoscopic ultrasound (EUS) findings of chronic pancreatitis. We modeled the natural history of these patients to compare 4 management strategies.

METHODS

We performed a systematic review, and created a Markov model for 45-year-old male FDRs, with findings of chronic pancreatitis on screening EUS. We compared 4 strategies: doing nothing, prophylactic total pancreatectomy (PTP), annual surveillance by EUS, and annual surveillance with EUS and fine needle aspiration (EUS/FNA). Outcomes incorporated mortality, quality of life, procedural complications, and costs.

RESULTS

In the Do Nothing strategy, the lifetime risk of cancer was 20%. Doing nothing provided the greatest remaining years of life, the lowest cost, and the greatest remaining quality-adjusted life years (QALYs). PTP provided the fewest remaining years of life, and the fewest remaining QALYs. Screening with EUS provided nearly identical results to PTP, and screening with EUS/FNA provided intermediate results between PTP and doing nothing. PTP provided the longest life expectancy if the lifetime risk of pancreatic cancer was at least 46%, and provided the most QALYs if the risk was at least 68%.

CONCLUSIONS

FDRs from familial pancreatic cancer kindreds, who have EUS findings of chronic pancreatitis, have increased risk for cancer, but their precise risk is unknown. Without the ability to further quantify that risk, the most effective strategy is to do nothing.

Endoscopic ultrasound-fine needle aspiration (EUS-FNA) for pancreatic lesions: effectiveness in clinical practice

BACKGROUND

Diagnosis of pancreatic masses is often difficult. Endoscopic ultrasound-fine needle aspiration has been proposed as the best single-step strategy.

AIMS

To prospectively evaluate feasibility, effectiveness and safety of endoscopic ultrasound-fine needle aspiration of pancreatic masses in a consecutive study of unselected patients.

METHODS

Two hundred ninety-three patients were enrolled in two referral Hospitals in Northern Italy. All patients were referred either due to the presence of imaging test abnormalities (suspected or evident masses, or features indirectly suggesting the presence of a mass) or due to clinical or biochemical findings suggesting pancreatic cancer in the absence of positive imaging. All patients underwent linear array endoscopic ultrasound and, when indicated, fine needle aspiration. All procedures were recorded prospectively. The final diagnosis was established at the end of follow-up or when the patients underwent surgery or died.

RESULTS

Fine needle aspiration was indicated in 246 of 293 cases (84%), considered technically feasible in 232 of 246 cases (94%) and gave adequate samples for histopathological diagnosis in 204 of 232 cases (88%). Endoscopic ultrasound sensitivity, specificity and accuracy were 79, 60 and 72%, respectively; the corresponding figures for endoscopic ultrasound-fine needle aspiration were 80, 86 and 82%. There was good agreement with final diagnosis for endoscopic ultrasound-fine needle aspiration (kappa 0.673, 95%CI 0.592-0.753), greater than that for endoscopic ultrasound alone (kappa 0.515, 95%CI 0.425-0.605). There was one case of intracystic haemorrhage and one case of transient hyperthermia (0.3%).

CONCLUSIONS

Endoscopic ultrasound-fine needle aspiration of pancreatic masses seems to be feasible, effective and safe in this consecutive study of patients.

Intraductal US in evaluation of biliary strictures without a mass lesion on CT scan or magnetic resonance imaging: significance of focal wall thickening and extrinsic compression at the stricture site

BACKGROUND AND OBJECTIVE

The clinical utility of intraductal US (IDUS) for evaluating biliary strictures has been limited because of a lack of easily recognized morphologic criteria to distinguish benign and malignant strictures. We studied the clinical value of 2 easily assessed IDUS findings: wall thickness and extrinsic compression at the stricture site.

DESIGN AND SETTING

A retrospective, single-center study.

PATIENTS AND METHODS

Forty-five patients without an identifiable mass on CT/magnetic resonance imaging, who underwent ERCP/IDUS for evaluation of biliary strictures were studied. IDUS pictures were reviewed specifically to measure wall thickness and to look for extrinsic compression at the stricture site.

MAIN OUTCOME MEASUREMENTS AND RESULTS

The mean age of the patients was 64.2+/-13.3 years. Thirty patients had jaundice at presentation, and in 15 patients a stricture was suspected on imaging. The mean length of biliary strictures was 15.1+/-7.8 mm. Strictures were distal (distal common bile duct) in 25 patients and proximal (mid/proximal common bile duct or common hepatic duct) in 20 patients. Fourteen strictures were finally diagnosed to be malignant. Strictures in 20 patients were caused by extrinsic compression, and tissue diagnosis was readily obtained by EUS-FNA in all these patients. Of 25 strictures without extrinsic compression, 6 were malignant (wall thickness 9-16 mm) and 19 were benign (wall thickness<or=9 mm). Bile duct wall thickness<or=7 mm at the stricture site, in the absence of extrinsic compression, had a negative predictive value of 100% for excluding malignancy in this cohort.

LIMITATIONS

Retrospective study and relatively small number of patients.

CONCLUSIONS

Evaluation of wall thickness and the presence of extrinsic compression at the site of biliary strictures by IDUS can help in further management of these patients.

Pancreatoscopy: present and future role

Current imaging modalities do not allow for direct access to the pancreatic duct. Because of this limitation, diagnosis and assessment of pancreatic diseases require radiographic imaging and cytologic analysis. Although many of these techniques have excellent specificity for the detection of pancreatic cancer, they offer no therapeutic capabilities and are relatively poor in early detection of cancer and in differentiating chronic pancreatitis from malignancy, particularly when the conditions coexist. Currently available cholangioscopes are too large to access the pancreatic duct without sphincterotomy or balloon dilation, increasing the risk of instrumentation trauma to the pancreas. Novel, dedicated pancreatoscopes have recently been developed and are under investigation in clinical trials. Preliminary evidence suggests that these new technologies allow for direct visualization of the pancreatic ducts, with the potential for forceps biopsy in suspected malignancy and endotherapy for pancreatic calculi. Future and ongoing clinical trials will better define the utility and roles of these new endoscopy tools.

Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound for diagnosis of chronic pancreatitis

The diagnosis of chronic pancreatitis is based on altered pancreatic morphology and function. A spectrum of disease exists, and milder forms of disease may be missed by CT but demonstrated by endoscopic retrograde cholangiopancreatography (ERCP) or endoscopic ultrasound (EUS). The accuracy of ERCP and EUS for diagnosis of "minimal change" or "early" chronic pancreatitis is controversial, particularly when the results from these imaging procedures are discordant with each other or with tests of pancreatic function; in some cases ERCP and EUS should be considered indeterminate for diagnosis. This review discusses recent data concerning the accuracy of ERCP and EUS for diagnosis of chronic pancreatitis, the use of EUS fine-needle aspiration for differential diagnosis of pancreatic masses, and the use of EUS and EUS-guided TruCut biopsy for diagnosis of autoimmune pancreatitis.

Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a benign, IgG4-related, fibroinflammatory form of chronic pancreatitis that can mimic pancreatic ductal adenocarcinoma both clinically and radiographically. Laboratory studies typically demonstrate elevated serum IgG4 levels and imaging studies reveal a diffusely or focally enlarged pancreas with associated diffuse or focal narrowing of the pancreatic duct. The pathologic features include periductal lymphoplasmacytic inflammation, obliterative phlebitis, and abundant IgG4-positive plasma cells. The treatment of choice for AIP is steroid therapy. Diagnostic criteria for AIP have been proposed that incorporate histologic, radiographic, serologic, and clinical information.

Endoscopic ultrasound: a meta-analysis of test performance in suspected biliary obstruction

BACKGROUND & AIMS

Endoscopic ultrasound (EUS) achieves high-resolution images of the bile duct and pancreas, while avoiding the risks of ERCP (endoscopic retrograde cholangiopancreatography). It appears comparable to MRCP (magnetic resonance cholangiopancreatography), although its use is less widely disseminated. We aimed to summarize EUS test performance in suspected biliary disease with meta-analysis.

METHODS

MEDLINE search (January 1987-September 2006), selected reference lists, external experts, and manual search of abstracts were used. Studies permitting (re)construction of 2 x 2 tables for EUS versus a gold standard were used. Random-effects models were used to estimate pooled sensitivity and specificity after adjusting for a number of potential confounders. Summary receiver operating characteristic analysis, with the sensitivity corresponding to the point on the receiver operating characteristic curve where sensitivity equals specificity (Q*) and area under the curve, was performed. The effects of sample size, quality, disease prevalence and spectrum, pancreatitis, echoendoscope type, and EUS era on diagnostic performance were assessed. Performance regarding presence of obstruction, choledocholithiasis, and malignancy was analyzed.

RESULTS

Thirty-six eligible, non-overlapping studies met inclusion criteria (3532 subjects). EUS had a high overall pooled sensitivity (88%; 95% confidence interval, 85%-91%) and specificity (90%; 87%-93%) for biliary obstruction (area under the curve = 0.97; Q* = 0.92). EUS had higher sensitivity (89%; 87%-91%) and specificity (94%; 91%-96%) for choledocholithiasis than for malignancy (sensitivity, 78%; 69%-85%; specificity, 84%; 78%-91%). Smaller studies and ones mainly studying patients with suspected strictures were associated with lower test performance.

CONCLUSIONS

There is excellent overall accuracy for EUS in diagnosing choledocholithiasis, with less impressive results for malignancy (when fine-needle aspiration is not used).

Accurate discrimination of pancreatic ductal adenocarcinoma and chronic pancreatitis using multimarker expression data and samples obtained by minimally invasive fine needle aspiration

To augment cytological diagnosis of pancreatic ductal adenocarcinoma (PDAC) in tissue samples obtained by minimally invasive endoscopic ultrasound-guided fine needle aspiration, we investigated whether a small set of molecular markers could accurately distinguish PDAC from chronic pancreatitis (CP). Expression levels of 29 genes were first determined by quantitative real-time RT-PCR in a training set of tissues in which the final diagnosis was PDAC (n=20) or CP (n=10). Using receiver operator characteristic curve analysis, we determined that the single gene with the highest diagnostic accuracy for discrimination of CP vs. PDAC in the training study was urokinase plasminogen activator receptor (UPAR; AUC value = 0.895, 95% CI=0.728-0.976). In the set of test tissues (n=14), the accuracy of UPAR decreased to 79%. However, we observed that the addition of 6 genes (EPCAM2, MAL2, CEA5, CEA6, MSLN and TRIM29; referred to as the 6-gene classifier) to UPAR resulted in high accuracy in both training and testing sets. Excluding 3 samples (out of 44; 7%) for which results of the UPAR/6-gene classifier were "undefined," the accuracy of the UPAR/6-gene classifier was 100% in training samples (n=29), 92% in 12 test samples (p=0.004 that results were randomly generated; p=0.046 that the UPAR/6-gene classifier was comparable to UPAR alone; chi2 test), 100% in 3 samples for which the initial cytological diagnosis was "suspicious" and 98% (40/41) overall. Our results provide evidence that molecular marker expression data can be used to augment cytological analysis.