Grasp or brush for biliary sampling at endoscopic retrograde cholangiography? A blinded randomized controlled trial

The Catheter Flushing Method Shows a Similar Diagnostic Yield to the Conventional Method in Brushing Cytology for Biliary Strictures

Background/Objectives: Endobiliary brushing is usually performed in the diagnosis of indeterminate biliary strictures; however, in this setting, brush cytology is limited by a low diagnostic yield and sensitivity. Here, we compared the catheter flushing method (CFM) with the conventional cytologic method (CCM) in terms of cellularity and diagnostic performance. Methods: Endobiliary brushings were obtained during endoscopic retrograde cholangiopancreatography (ERCP) from patients with biliary strictures enrolled at six tertiary hospitals. Additionally, the CFM was performed after brushing. Using liquid-based cytologic preparations of samples, we assessed the diagnostic performance of the CCM using Pap staining and the CFM using methionyl-transfer RNA synthetase 1 (MARS1) immunofluorescence staining. Results: From a total of 399 patients (malignant, 253; benign, 146), 374 CCM samples and 361 CFM samples contained adequate cells, with no significant difference in diagnostic yield (93.7% vs. 90.5%, respectively; p = 0.088). The sensitivity of the CFM (90.3%) was significantly higher than that of the CCM (75.1%; p < 0.001), with no significant difference in accuracy between methods (81.2% vs. 82.6%, respectively; p = 0.608). Conclusions: The diagnostic yield of the CFM was comparable to that of the CCM. Additionally, the diagnostic performance of the CFM was comparable to that of the CCM. These findings indicate that the CFM could be an additional brush cytology method for sample collection in patients with indeterminate biliary strictures. Incorporating both the CCM and CFM might be expected to improve the diagnostic yield of brush cytology in the biliary strictures. Further prospective comparative studies between the CCM and CFM using the same staining method are needed to validate these findings.

Molecular diagnosis of pancreatobiliary tract cancer by detecting mutations and methylation changes in bile samples

BACKGROUND

Patients with pancreatobiliary tract cancer usually have a poor clinical outcome, with a 5-year overall survival rate below 20%. This is mainly associated with the late diagnosis. In addition, the standard-of-care for patients with malignant biliary stenosis involves a major surgery, the Whipple procedure. An accurate preoperative diagnosis, including differentiation from benign diseases, is critical to avoid unnecessary treatment. Here we developed BileScreen, a sensitive detection modality for the diagnosis of pancreatobiliary tract cancer based on massively parallel sequencing mutation and methylation changes in bile samples.

METHODS

A total of 338 patients, from five hospitals in China, with pancreatobiliary system disorders were enrolled in this study between November 2018 and October 2020, and 259 were included for the analysis of BileScreen. We profiled 23 gene mutations and 44 genes with methylation modifications in parallel from bile samples, and set up a model for the detection of malignancy based on multi-level biomarkers.

FINDINGS

We applied the BileScreen assay in a training cohort (n = 104) to set up the model and algorithm. The model was further evaluated in a validation cohort (n = 105), resulting in 92% sensitivity and 98% specificity. The performance of BileScreen was further assessed in a prospective test cohort (n = 50) of patients diagnosed with suspicious or negative pathology by endoscopic retrograde cholangiopancreatography and were confirmed in follow-up. BileScreen yielded 90% sensitivity and 80% specificity, and outcompeted serum carbohydrate antigen 19-9 in detecting pancreatobiliary tract cancer in all three cohorts, especially in terms of specificity.

INTERPRETATION

Taken together, BileScreen has the ability to interrogate mutations and methylation changes in bile samples in parallel, thus rendering it a potentially sensitive detection method to help in the diagnosis of pancreatobiliary tract cancer in a safe, convenient and less-invasive manner.

FUNDING

This study was supported by the Capital's Funds for Health Improvement and Research (2020-2-4025 to S.H.), the National Natural Science Foundation of China (81972311 to H.Z.), CAMS Innovation Fund for Medical Sciences (CIFMS) (2017-12M-4-002 to H.Z.), the CAMS Innovation Fund for Medical Sciences(CIFMS) (2021-I2M-1-066 to CJQ), the Non-profit Central Research Institution Fund of Chinese Academy of Medical Sciences (2019PT310026 to H.Z.) and Sanming Project of Medicine in Shenzhen (SZSM202011010 to H.Z.).

High Diagnostic Yield of Endoscopic Retrograde Cholangiopancreatography Brush Cytology for Indeterminate Strictures

Background

Endoscopic retrograde cholangiopancreatography (ERCP) brush cytology is used frequently for sampling indeterminate biliary strictures. Studies have demonstrated that the diagnostic yield of brush cytology for malignant strictures is estimated to be 6%-70%. With improved diagnostic tools, sampling techniques and specimen processing, the yield of ERCP brush cytology may be higher. This study aimed to assess the yield of brush cytology and determine factors associated with a positive diagnosis.

Methods

This was a cohort study of patients who underwent ERCP brush cytology from October 2017 to May 2020. Patient demographics, clinical, procedural and pathological data were collected using chart review. Sampling data were captured up to 3 months post-index ERCP to capture repeat brushings, biopsies or surgical resections. Outcomes included the diagnostic yield, true/false positive values and true/false negative values of malignancy detection using ERCP brush cytology.

Results

A total of 126 patients underwent a brush cytology, 58% were male and 79% had a stricture in the extrahepatic region. Ninety-three patients were diagnosed with a malignancy, of which 78 had positive brush cytology results and 15 had a negative brush cytology result. The diagnostic yield, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 84%, 83%, 97%, 99%, 68% and 87% respectively.

Conclusion

ERCP brush cytology performed using updated sampling technique is associated with high diagnostic yield. This allows for earlier malignancy diagnosis, timely treatment and decreased need for further investigation.

Brush Cytology, Forceps Biopsy, or Endoscopic Ultrasound-Guided Sampling for Diagnosis of Bile Duct Cancer: A Meta-Analysis

Endoscopic sampling is essential for tissue diagnosis of cholangiocarcinoma (CCA). To evaluate and compare the diagnostic sensitivities of endoscopic retrograde cholangiopancreatography-guided brush cytology biopsy, and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with CCA. A comprehensive literature search through multiple databases was conducted for articles published between January 1995 and August 2020. The pooled rates of sensitivity for the diagnosis of CCA and of adverse events were compared among brushing, biopsy, brushing & biopsy, and EUS-FNA. In total, 1123 patients with CCA (32 studies), 719 patients (20 studies), 358 patients (13 studies), and 422 patients (17 studies) were tested by brushing, biopsy, brushing & biopsy, and EUS-FNA, respectively. The pooled diagnostic sensitivity was 56.0% (95% confidence interval (CI) 48.8-63.1%, I2 = 83.0%) with brushing, 67.0% (95% CI 60.2-73.5%, I2 = 72.5%) with biopsy, 70.7% (95% CI 64.1-76.8%, I2 = 42.7%) with brushing & biopsy, and 73.6% (95% CI 64.7-81.5%, I2 = 74.7%) with EUS-FNA. The diagnostic sensitivity was significantly lower for brushing than for biopsy, brushing & biopsy, or EUS-FNA. No significant difference was noted in diagnostic sensitivities among biopsy, brushing & biopsy, and EUS-FNA. Adverse events were comparable between the groups. Intraductal biopsy, brushing & biopsy, and EUS-FNA had comparable efficacy and safety for the diagnosis of CCA. Brushing was the least sensitive diagnostic tool compared with intraductal biopsy or EUS-FNA. Given the modest diagnostic sensitivities of intraductal biopsy and EUS-FNA in the diagnosis of CCA, further studies for complementing these techniques with biomarkers may be needed.

Challenging biliary strictures: pathophysiological features, differential diagnosis, diagnostic algorithms, and new clinically relevant biomarkers - part 1

It is frequently challenging to make the correct diagnosis in patients with biliary strictures. This is particularly important as errors may have disastrous consequences. Benign-appearing strictures treated with stents may later be revealed to be malignant and unnecessary surgery for benign strictures carries a high morbidity rate. In the first part of the review, the essential information that clinicians need to know about diseases responsible for biliary strictures is presented, with a focus on the most recent data. Then, the characteristics and pitfalls of the methods used to make the diagnosis are summarized. These include serum biomarkers, imaging studies, and endoscopic modalities. As tissue diagnosis is the only 100% specific tool, it is described in detail, including techniques for tissue acquisition and their yields, how to prepare samples, and what to expect from the pathologist. Tricks to increase diagnostic yields are described. Clues are then presented for the differential diagnosis between primary and secondary sclerosing cholangitis, IgG4-related sclerosing cholangitis, cholangiocarcinoma, pancreatic cancer, autoimmune pancreatitis, and less frequent diseases. Finally, algorithms that will help to achieve the correct diagnosis are proposed.

Endoscopic Perspective in Cholangiocarcinoma Diagnostic Process

Cholangiocarcinoma is a malignancy arising from the epithelial lining of the intrahepatic or extrahepatic biliary tract. Timely diagnosis is challenging due to its silent clinical course. As reliable laboratory markers are lacking, diagnostic imaging plays a pivotal role. While cross-sectional imaging studies are usually conclusive for intrahepatic lesions, endoscopy plays an essential role in cases of extrahepatic tumors. Rational utilization of different diagnostic methods based on available evidence is needed. This article focuses on the diagnostic role of advanced biliary endoscopy, including endoscopic retrograde cholangiopancreatography, cholangioscopy, endoscopic ultrasonography, and intraductal sonography.

Outcomes of Different Methods for Analysis of Biliary Brush Cytology and of Factors Associated with Positive Diagnosis in an Age-Dependent Retrospective Review

Background and Aims

Brush cytology during endoscopic retrograde cholangiopancreatography (ERCP) is the most frequently used strategy for obtaining a tissue sample from an indeterminate biliary stricture. A recent study reported that age is a factor associated with positive yields, but further analysis of how age influences the results was lacking. We aimed to evaluate clinical effectiveness of biliary cytology and prognostic factors for a positive outcome, especially age.

Methods

This study was a single-center, retrospective, clinical study of 77 consecutive patients who underwent brush cytology during ERCP to obtain a diagnosis of an indeterminate biliary stricture. We compared 2 routine cytology techniques: A (smear); B (centrifugation of the cytological material collected and the cut-off brush + cell block when sufficient amount of material was available). The data were collected aiming to compare the accuracy of the different techniques used and the prognostic factors affecting the outcome, with a particular focus on age. The yield for brush cytology was compared with the gold standard defined as either definitive histology or the long-term clinical course.

Results

The overall accuracy of the 2 used methods was 75.3%. Sensitivity was 52.5%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 66.1%. Although not statistically significant, there was a trend toward accuracy for method B compared with method A (80.4 vs. 65.4%; p = 0.153). Multiple logistic regression analysis showed that younger age was the only independent prognostic factor associated with a positive diagnosis (OR 0.95; 95% CI 0.90-0.99; p = 0.039). Receiver operating characteristic curves for age yielded an area under the curve value of 68.2%. On the basis of the Youden index, 69 years was found to be the optimal cutoff for age.

Conclusions

In this series, the accuracy of routine biliary brush cytology was not equal for all methods and ages; in particular, younger patients (below 69 years) tended to have a higher probability of a correct diagnosis.

Polarized release of hepatic microRNAs into bile and serum in response to cellular injury and impaired liver function

BACKGROUND & AIMS

Extracellular microRNAs (miRNAs) in serum and bile are currently under intense investigation for biomarker purposes in liver disease. However, the directions and pathways by which miRNAs are released from hepatic cells remains largely unknown. Here, we investigated the release of hepatocyte and cholangiocyte-derived miRNAs (HDmiRs and CDmiRs) into blood and bile during various (patho)physiological hepatic conditions.

METHODS

MiRNA release was analysed using longitudinally collected tissue and paired bile and serum samples (n = 124) that were obtained from liver transplant recipients during follow-up.

RESULTS

Cell-type specificity of HDmiRs and CDmiRs was confirmed in liver and common bile duct biopsies (P < 0.001). Analysis of paired bile and serum samples showed up to 20-times higher miRNA-levels in bile compared to serum (P < 0.0001). Fractionation of bile showed the majority of miRNAs being present in the unpelletable supernatant, where protein conjunctions protect miRNAs against degradation (P < 0.0001). During episodes of liver injury and histologically proven rejection in liver transplant recipients, relative HDmiR-levels in bile decreased while its levels in serum increased (P ≤ 0.015). Simultaneously, relative CDmiR-levels in bile significantly increased, while their levels in serum decreased. Related to liver excretory function, a strong positive correlation was observed between HDmiR-122 levels and bilirubin excretion into bile (R = 0.694, P < 0.0001), whereas CDmiRs showed an inverse correlation (P < 0.05).

CONCLUSION

During impaired excretory function and injury, the liver shows polarized release of extracellular HDmiRs and CDmiRs. This sheds new light on the biology of hepatic miRNA release which is relevant for the interpretation of hepatic miRNAs as biomarkers.

Transpapillary biliary biopsy for malignant biliary strictures: comparison between cholangiocarcinoma and pancreatic cancer

BACKGROUND

Tissue sampling for biliary stricture is important for differential diagnosis and further treatment. This study aims to assess the differences of transpapillary biliary biopsy for malignant biliary strictures between cholangiocarcinoma and pancreatic cancer.

METHODS

From January 2010 to December 2013, we retrospectively studied 79 patients who suffered from biliary strictures and received transpapillary forceps biopsy after sphincterotomy for tissue sampling. The diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of forceps biopsy were calculated in all cases for both cholangiocarcinoma and pancreatic cancer patients. Possible factors that distinguish malignant strictures from benign strictures and which could affect the accuracy of tissue sampling were analyzed.

RESULTS

There are 65 malignant and 14 benign biliary stricture patients enrolled. The malignant group has a significantly higher serum bilirubin level than the benign group, but age, clinical presentation, level of serum carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, and alkaline phosphatase are not. The sensitivity, specificity, PPV, and NPV of forceps biopsy for biliary stricture are 53.85, 100, 100, and 31.82%, respectively. The cholangiocarcinoma group has a higher sensitivity (73.53 versus 29.17%, p < 0.001), older age, lower CA 19-9 level, and more common hepatic duct strictures than the pancreatic group. The age, serum CEA, CA 19-9 and the alkaline phosphatase level, serum bilirubin level >10 mg/dL, tissue sampling ≧3 are not significant factors affecting diagnostic accuracy in forceps biopsy for pancreatobiliary strictures. There is neither major bleeding nor perforation in our study.

CONCLUSIONS

Transpapillary forceps biopsy of biliary strictures after sphincterotomy for tissue sampling is safe and a significantly higher sensitive method in cholangiocarcinoma but not in pancreatic cancer.

Triple modality testing by endoscopic retrograde cholangiopancreatography for the diagnosis of cholangiocarcinoma

OBJECTIVES

Brush cytology has a low sensitivity for the diagnosis of cholangiocarcinoma. This study aimed to compare the standard approach (brush cytology) with a triple modality approach utilizing brush cytology, forceps biopsy and fluorescence in situ hybridization in terms of sensitivity and specificity for the diagnosis of cholangiocarcinoma.

METHODS

In a retrospective study at a single academic center, 50 patients underwent triple modality testing. Additionally, 61 patients underwent brush cytology alone. Intervention was endoscopic retrograde cholangiopancreatography with brush cytology, fluorescence in situ hybridization, and forceps biopsy. The main outcome measures included sensitivity, specificity, positive predictive value and negative predictive value.

RESULTS

Overall, 50 patients underwent triple tissue sampling, and 61 patients underwent brush cytology alone. Twenty-two patients were eventually diagnosed with cholangiocarcinoma. Brush cytology had a sensitivity of 42%, specificity of 100%, positive predictive value of 100% and negative predictive value of 88%. Triple tissue sampling had an overall sensitivity of 82%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 87%. Within the triple test group, brush cytology had a sensitivity of 27%, forceps biopsy had a sensitivity of 50%, and fluorescence in situ hybridization analysis had a sensitivity of 59%.

CONCLUSIONS

A triple modality approach results in a marked increase in sensitivity for the diagnosis of cholangiocarcinoma compared with single modality testing such as brush cytology and should be considered in the evaluation of indeterminate or suspicious biliary strictures.

Bile proteome in health and disease

The study of bile proteins could improve the understanding of physiological processes involved in the regulation of the hepato-biliary system. Researchers have tried for years to investigate the bile proteome but, until recently, only a few tens of proteins were known. The advent of proteomics, availing of large-scale analytical devices paired with potent bioinformatic resources, lately allowed the identification of thousands of proteins in bile. Nevertheless, the knowledge of their role in the hepato-biliary system still represents almost a "blank page in the book of physiology." In this review, we first guide the reader through the historical phases of the analysis of bile protein content, emphasizing the recent progresses achieved through the use of proteomic techniques. Thereafter, we deeply explore the involvement of bile proteins in health and disease, with a particular focus on the discovery of biomarkers for biliary tract malignancies.

Comparison of brush and basket cytology in differential diagnosis of bile duct stricture at endoscopic retrograde cholangiopancreatography

BACKGROUND

A previous report has identified a significantly higher sensitivity of cancer detection for dedicated grasping basket than brushing at endoscopic retrograde cholangiopancreatography (ERCP). This study aimed to compare the diagnostic accuracy of Geenen brush and Dormia basket cytology in the differential diagnosis of bile duct stricture.

METHOD

The current study enrolled one hundred and fourteen patients who underwent ERCP with both Geenen brush and Dormia basket cytology for the differential diagnosis of bile duct stricture at our institution between January 2008 and December 2012.

RESULTS

We adopted sequential performances of cytologic samplings by using initial Geenen brush and subsequent Dormia basket cytology in 59 patients and initial Dormia basket and subsequent Geenen brush cytology in 55 patients. Presampling balloon dilatations and biliary stentings for the stricture were performed in 17 (14.9%) and 107 patients (93.9%), respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of Geenen brush cytology for the diagnosis of malignant bile duct stricture were 75.0%, 100.0%, 100.0%, 66.7% and 83.3%, respectively, and those of Dormia basket cytology were 64.5%, 100.0%, 100.0%, 58.5% and 76.3%, respectively (P=0.347 and 0.827 for sensitivity and accuracy, respectively). The good and excellent cellular yields (≥grade 2) were obtained by Geenen brush and Dormia basket cytology in 88 (77.2%) and 79 (69.3%) patients, respectively.

CONCLUSION

The sensitivity, specificity and accuracy of biliary sampling with a Dormia basket are comparable to those with conventional Geenen brush cytology in the detection of malignant bile duct stricture.

Brushing cytology of the biliary tract: bile juice from the ERCP sheath tube provides cell-rich smear samples

OBJECTIVES

To improve the diagnostic accuracy of bile smear cytology, we assessed two cell-yielding procedures.

STUDY DESIGN

One hundred and forty-one patients with biliary stricture underwent endoscopic retrograde cholangiopancreatography (ERCP) and conventional brush sampling. The cytologist cut the brush head off the support wire, centrifuged it directly in tissue culture medium for 1 min at 3,000 rpm, centrifuged the medium again and then smeared the cell pellet onto slides. The remaining sheath tube was then cut into 12-cm segments, which were centrifuged in a centrifuge tube for 1 min at 3,000 rpm, collected and submitted for cytospin preparation.

RESULTS

The final histopathological diagnoses based on surgery, biopsy or clinical progression were evaluated for sensitivity, specificity and accuracy. Using conventional smears alone, the sensitivity, specificity and accuracy in patients with biliary stricture were 66.1, 80.7 and 68.8%, respectively. For conventional smears, brush washing and sheath tube contents together, the sensitivity improved to 73.9%, specificity to 100% and accuracy to 78.7%. In the patients with bile duct carcinoma, the sensitivity, specificity and accuracy were 87.3, 100 and 90.7%, respectively.

CONCLUSION

Superior diagnostic accuracy was achieved when conventional smear procedures were combined with the two new procedures.

An integrated approach for comparative proteomic analysis of human bile reveals overexpressed cancer-associated proteins in malignant biliary stenosis

Proteomics is a key tool in the identification of new bile biomarkers for differentiating malignant and nonmalignant biliary stenoses. Unfortunately, the complexity of bile and the presence of molecules interfering with protein analysis represent an obstacle for quantitative proteomic studies in bile samples. The simultaneous need to introduce purification steps and minimize the use of pre-fractionation methods inevitably leads to protein loss and limited quantifications. This dramatically reduces the chance of identifying new potential biomarkers. In the present study, we included differential centrifugation as a preliminary step in a quantitative proteomic workflow involving iTRAQ labeling, peptide fractionation by OFFGEL electrophoresis and LC-MS/MS, to compare protein expression in bile samples collected from patients with malignant or nonmalignant biliary stenoses. A total of 1267 proteins were identified, including a set of 322 newly described bile proteins, mainly belonging to high-density cellular fractions. The subsequent comparative analysis led to a 5-fold increase in the number of quantified proteins over previously published studies and highlighted 104 proteins overexpressed in malignant samples. Finally, immunoblot verifications performed on a cohort of 8 malignant (pancreatic adenocarcinoma, n=4; cholangiocarcinoma, n=4) and 5 nonmalignant samples (chronic pancreatitis, n=3; biliary stones, n=2) confirmed the results of proteomic analysis for three proteins: olfactomedin-4, syntenin-2 and Ras-related C3 botulinum toxin substrate 1. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge.

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

BACKGROUND AND AIM

There is a paucity of data on the cell block (CB) method for bile cytology. We compared the diagnostic efficacy of the CB method with that of conventional smear cytology for bile obtained by endoscopic retrograde cholangiopancreatography (ERCP) in a randomized controlled trial manner.

METHODS

A total of 137 patients with biliary tract lesions suspicious of malignancy who had undergone bile collection under ERCP were recruited to this study. After sampling, the bile was randomized to the CB method (n = 69) or to smear cytology (n = 68). CB sections were prepared using the sodium alginate method and subjected to hematoxylin-eosin, Alcian blue-periodic acid-Schiff stain, and immunohistochemical stains. Both Papanicolaou and Giemsa stains were used for smear cytology.

RESULTS

The final diagnosis was malignancy in 94 patients: bile duct cancer, 42; pancreatic head cancer, 34; gallbladder cancer, 16; and ampullary cancer, two. The diagnostic accuracy of the CB method and that of smear cytology were 64% and 53%, respectively (P = 0.20). The sensitivity of the CB method (53%) was significantly better than that of smear cytology (28%; P = 0.014). Their respective sensitivities were 80% and 31% (P = 0.002) for bile duct cancer, 20% and 15% (P = 1.0) for pancreatic head cancer, and 30% and 67% (P = 0.30) for gallbladder cancer.

CONCLUSION

The CB method for bile cytology showed a higher diagnostic yield than smear cytology. Its diagnostic sensitivity was satisfactory in cases of bile duct cancer.

Bile carcinoembryonic cell adhesion molecule 6 (CEAM6) as a biomarker of malignant biliary stenoses

Differentiating malignant from nonmalignant biliary stenoses is challenging. This could be facilitated by the measurement of cancer biomarkers in bile. We aimed at (i) identifying new cancer biomarkers by comparative proteomic analysis of bile collected from patients with a malignant or benign biliary stenosis (exploratory phase) and (ii) verifying the accuracy of the newly identified potential biomarkers for discriminating malignant versus nonmalignant biliary stenoses in a larger group of patients (confirmation phase). Overall, 66 proteins were found overexpressed (ratio>1.5) in at least one cancer condition using proteomic analysis and 7 proteins were increased in all malignant/nonmalignant disease comparisons. Preliminary screening by immunoblot highlighted carcinoembryonic cell adhesion molecule 6 (CEAM6), a cell surface protein overexpressed in many human cancers, as an interesting candidate biomarker. ELISA subsequently confirmed CEAM6 as a potential bile biomarker for distinguishing malignant from benign biliary stenoses with a receiver operating characteristic (ROC) area under the curve (AUC) of 0.92 (specificity 83%, sensitivity 93%, positive predictive value 93%, and negative predictive value 83%). No significant difference in serum CEAM6 level was found between malignant and nonmalignant samples. Combining bile CEAM6 and serum CA19-9 in a panel further improved diagnostic accuracy for malignant stenoses (AUC 0.96, specificity 83%, sensitivity 97%, positive predictive value 93%, and negative predictive value 91%). CEAM6 measurement in bile could be clinically useful to discriminate between malignant and nonmalignant causes of biliary stenosis. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge.

Sampling at ERCP for cyto- and histopathologicical examination

Sampling at ERCP may be performed at the level of the papilla or of the biliopancreatic ducts. Samples collected at the level of the biliopancreatic ducts allow for diagnosing malignancy with a specificity close to 100% but present a moderate sensitivity in most studies. In this article, the different aspects of sampling at ERCP are discussed, and a special focus is placed on the means that are routinely available to the endoscopist for obtaining a high sensitivity for the diagnosis of malignancy.

Intraductal aspiration: a promising new tissue-sampling technique for the diagnosis of suspected malignant biliary strictures

BACKGROUND

Brushing is the most commonly used technique for biliary sampling at ERCP, despite its limited sensitivity.

OBJECTIVE

To evaluate intraductal aspiration (IDA) as a new combined endoscopic technique for cytodiagnosis, its cellular adequacy, diagnostic accuracy for cancer detection, feasibility, and safety.

DESIGN

Prospective, observational study.

SETTING

Single tertiary referral center.

MAIN OUTCOME MEASUREMENTS

IDA cellular adequacy, diagnostic accuracy for cancer detection, feasibility, and safety.

PATIENTS AND METHODS

From April 2009 to September 2010, 42 consecutive patients with suspected malignant biliary stricture underwent ERCP, with tissue sampling obtained with IDA. IDA included performance of standard brushing in all patients. After standard brushing, to perform IDA, we removed the brush from its catheter and used the tip of the catheter as a scraping device. The tip was scraped back and forth across the stricture at least 10 times. The catheter and a suction line were connected to a specimen trap to obtain intraductal aspiration of fluids and samplings.

RESULTS

Our cytopathologists found adequate cellular yield in 39 of the 42 IDA samples (92.8%) versus 15 of the 42 brushing samples (35.7%) (P < .001). IDA showed a significantly higher sensitivity than brushing (89% vs 78% for adequate samples and 89% vs 37% for all samples) and provided significantly superior cellular adequacy (92.8% vs 35.7%).

LIMITATIONS

Observational study, small number of patients.

CONCLUSIONS

IDA significantly improves brushing cellular adequacy and has high sensitivity for cancer detection. It was also safe, simple, rapid, and applicable during routine diagnostic ERCP, with no additional costs.

Diagnostic value of dynamic contrast-enhanced magnetic resonance imaging in the evaluation of the biliary obstruction

Purpose. In this study, our purpose was to investigate the diagnostic efficacy of the dynamic contrast-enhanced magnetic resonance imaging (MRI) method in the patients with bile duct obstruction. Materials and Methods. 108 consecutive patients (53 men, 55 women, mean age; 55.77 ± 14.62, range 18–86 years) were included in this study. All the patients underwent conventional upper abdomen MRI using intravenous contrast material (Gd-DTPA) and MRCP in 1.5 Tesla MRI scanner. MRCP images were evaluated together with the T1 and T2w images, and both biliary ducts and surrounding tissues were examined for possible pathologies that may cause obstruction. Results. MRI/MRCP findings compared with final diagnoses, MRI/MRCP in the demonstration of bile duct obstruction sensitivity 96%, the specificity 100%, and accuracy 96.3%, in the detection of presence and level of obstruction, the sensitivity 96.7%, specificity 100%, and accuracy 97.2%, in the diagnosis of choledocholithiasis, the sensitivity 82.3%, specificity 96%, and accuracy 91.7%, and in the determination of the character of the stenosis, sensitivity 95.6%, specificity 91.3%, and accuracy 94.5% were found. Conclusion. The combination of dynamic contrast-enhanced MRI and MRCP techniques in patients with suspected biliary obstruction gives the detailed information about the presence of obstruction, location, and causes and is a highly specific and sensitive method.

Combined brush cytology and stent placement in a single session for presumed malignant biliary stricture

BACKGROUND AND AIM

  Biliary stricture may be benign or malignant and causes obstructive jaundice. Brush cytology is a simple technique for diagnosing the cause of biliary stricture; however, its sensitivity has been reported to be low. A technique that comprises diagnosing the cause of stricture with a satisfactory sensitivity and relieving jaundice is required. This study was designed to evaluate the diagnostic performance of brush cytology and the feasibility of the subsequent stent placement in a single endoscopic retrograde cholangiopancreatography (ERCP) session performed for presumed malignant biliary strictures.

METHODS

  Data were collected by reviewing the medical records of 100 consecutive patients with suspected malignant biliary stricture who underwent brush cytology followed by stent placement at our center. Diagnostic performance of brush cytology, completion rate of the whole procedures comprising brush cytology and stent placement, and complications were evaluated.

RESULT

  Sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of brush cytology were 83%, 100%, 100%, 33% and 84%, respectively. Biliary stent was successfully inserted for all patients (100%) subsequent to brush cytology in a single ERCP session. Eight patients (8%) had complications.

CONCLUSION

  Brush cytology was performed with much higher sensitivity of 83% than those of previous reports and the subsequent stent placement was successfully completed in all cases. For presumed malignant biliary stricture, brush cytology should be selected as an initial attempt because this technique is simple and enables subsequent stent placement in a single ERCP session.

Endoscopic diagnosis of extrahepatic bile duct carcinoma: Advances and current limitations

The accurate diagnosis of extrahepatic bile duct carcinoma is difficult, even now. When ultrasonography (US) shows dilatation of the bile duct, magnetic resonance cholangiopancreatography followed by endoscopic US (EUS) is the next step. When US or EUS shows localized bile duct wall thickening, endoscopic retrograde cholangiopancreatography should be conducted with intraductal US (IDUS) and forceps biopsy. Fluorescence in situ hybridization increases the sensitivity of brush cytology with similar specificity. In patients with papillary type bile duct carcinoma, three biopsies are sufficient. In patients with nodular or infiltrating-type bile duct carcinoma, multiple biopsies are warranted, and IDUS can compensate for the limitations of biopsies. In preoperative staging, the combination of dynamic multi-detector low computed tomography (MDCT) and IDUS is useful for evaluating vascular invasion and cancer depth infiltration. However, assessment of lymph nodes metastases is difficult. In resectable cases, assessment of longitudinal cancer spread is important. The combination of IDUS and MDCT is useful for revealing submucosal cancer extension, which is common in hilar cholangiocarcinoma. To estimate the mucosal extension, which is common in extrahepatic bile duct carcinoma, the combination of IDUS and cholangioscopy is required. The utility of current peroral cholangioscopy is limited by the maneuverability of the “baby scope”. A new baby scope (10 Fr), called “SpyGlass” has potential, if the image quality can be improved. Since extrahepatic bile duct carcinoma is common in the Far East, many researchers in Japan and Korea contributed these studies, especially, in the evaluation of longitudinal cancer extension.

Malignant biliary stenosis: conventional cytology versus DNA image cytometry

BACKGROUND

The aim of this study is to evaluate the utility of image cytometry (ICM)-DNA analysis on cytological brush specimens in improving the sensitivity and diagnostic accuracy for biliary neoplasias.

METHODS

A total of 71 patients with 89 samples of biliary tree brushing from a stenosis were included in this prospective study. Conventional cytology (CC) and DNA ploidy using ICM of the brushing were performed. Benign or malignant findings were confirmed by surgical exploration or a clinical follow-up of at least 12 months.

RESULTS

Diagnosis was confirmed by clinical follow-up in 44 cases and surgical investigation or histology in 41 cases. A definitive diagnosis of the smears resulted in 40 malignant and 49 benign diagnoses. The sensitivity was 0.666 for CC and 0.658 for ICM, and the specificity was 0.920 and 0.937, respectively. The positive predictive value (PPV) was 0.866 for CC and 0.900 for ICM. McNemar's test did not reveal a significant difference between CC and ICM (P=0.803). Agreement of the two methods was found in 73 samples, raising specificity to 0.998 but not sensitivity (0.725).

CONCLUSIONS

ICM-DNA seems not to improve significantly the PPV and NPV for detecting neoplasias of the biliary tract compared to CC. Nevertheless a clinical advantage can be seen in the agreement of the two methods in diagnosing dysplasia or cancer, since it did not show false positive results.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of cholangiocarcinoma

Cholangiocarcinomas (CCAs) are rare malignancies that arise from the biliary epithelium. Intrahepatic CCAs usually present as mass lesions that are asymptomatic or cause nonspecific systemic symptoms such as fatigue, fever, and weight loss. Hilar and extrahepatic tumors most commonly present with jaundice, though cholangitis also can be seen. Tumor markers such as carbohydrate antigen 19-9 and carcinoembryonic antigen have been used to diagnose CCA, but these are nonspecific and may be elevated in infection, inflammation, or any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) has been used for the diagnosis and management of CCA for many years. This article summarizes the data regarding the application of ERCP in the diagnosis and management of CCA.

Proteomic analysis of human bile and potential applications for cancer diagnosis

Bile is a body fluid produced by the liver and drained by biliary ducts into the duodenum. It has two major functions: first, it contains bile acids, which are critical for the digestion of fats, and second, it is an excretory pathway for many endogenous and exogenous compounds. Proteomic analysis of bile is particularly difficult since this fluid contains high concentrations of various substances that strongly interfere with protein separation and identification techniques. Furthermore, owing to its deep location in the body, bile must be collected by surgical or endoscopic procedures. However, as was speculated for other body fluids, bile appears to be a promising sample for the discovery of disease biomarkers leaking from proximal tissues: the liver, pancreas or biliary tree. The interest in clinical proteomics was demonstrated by two studies that identified in bile potential biomarkers for two deadly and difficult to diagnose neoplasms, pancreatic cancer and cholangiocarcinoma.