Early detection of extrahepatic bile-duct carcinomas in the nonicteric stage by using MRCP followed by EUS

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Endoscopic Ultrasound in the Diagnosis of Extrahepatic Cholangiocarcinoma: What Do We Know in 2023?

Extrahepatic cholangiocarcinoma (CCA) is a rare and aggressive type of cancer, presenting as a mass or as a biliary stricture. This review summarizes the utility of endoscopic ultrasound (EUS) in the detection, staging, and determination of the differential diagnosis, especially when no cause of bile duct dilatation is revealed by cross-sectional imaging. The EUS detection rate for distal CCAs is higher than that for the proximal CCAs. The accuracy of T staging varies between 60 and 80%, and vascular involvement is correctly assessed by conventional EUS. EUS-tissue acquisition from the primary tumors is reserved for unresectable or metastatic CCA, especially in distal strictures or mass CCAs. For proximal lesions, EUS could be performed as an adjunctive to ERCP sampling when the latter is inconclusive. EUS is not appropriate for assessing the malignant features of lymph nodes in CCAs. Lymph node EUS-tissue acquisition should be performed only if it changes the surgical decision. Perhaps the development of EUS-fine needle biopsy and the detection of molecular genetic alteration will increase the diagnostic yield in CCAs.

Interventional gastroenterology in oncology

Cancer is one of the foremost health problems worldwide and is among the leading causes of death in the United States. Gastrointestinal tract cancers account for almost one third of the cancer-related mortality globally, making it one of the deadliest groups of cancers. Early diagnosis and prompt management are key to preventing cancer-related morbidity and mortality. With advancements in technology and endoscopic techniques, endoscopy has become the core in diagnosis and management of gastrointestinal tract cancers. In this extensive review, the authors discuss the role endoscopy plays in early detection, diagnosis, and management of esophageal, gastric, colorectal, pancreatic, ampullary, biliary tract, and small intestinal cancers.

SONOGRAPHIC CRITERIA IN THE DIFFERENTIAL DIAGNOSIS OF OBSTRUCTIVE ICTERUS

The article presents the review of the literature data covering the most common causes of obstructive jaundice, methods for its differential diagnosis, as well as sonographic criteria for making a diagnosis. Based on the review, it was found that in practical surgery, ultrasound has a number of advantages in the differential diagnosis of obstructive jaundice. Sonography is an affordable, non-invasive method with high information content, allowing to make a diagnosis in the shortest possible time. The main reliable sonographic criteria for the obstructive genesis of icterus is prestenotic dilatation of the bile ducts. However, since the interpretation of ultrasound results is subjective and depends on the qualifications of the ultrasound specialist, verification of sonographic information by other research methods is necessary.

Test performance and predictors of accuracy of endoscopic ultrasound-guided fine-needle aspiration for diagnosing biliary strictures or masses

Background and study aims  Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has emerged as an important method for obtaining a preoperative tissue diagnosis for suspected cholangiocarcinoma. However, doubts remain about test sensitivity. This study assessed the value and limitations of EUS-FNA in clinical practice. Patients and methods  Patients undergoing EUS-FNA for biliary strictures/masses at a UK tertiary referral center from 2005 to 2014 were prospectively enrolled. Data on EUS-FNA findings, histology, and endoscopy and patient outcomes were collected to evaluate test performance and identify factors predictive of an inaccurate diagnostic result. Results  Ninety-seven patients underwent a total of 112 EUS-FNA procedures. Overall test sensitivity for an initial EUS-FNA for suspected cholangiocarcinoma was 75 % (95 % CI 64 %-84 %), with specificity 100 % (95 % CI 85 %-100 %) and negative predictive value 0.62 (95 % CI 0.47-0.75). Hilar lesions, the presence of a biliary stent, and a diagnosis of PSC were significantly independently associated with an inaccurate result. For the most difficult cases, repeat sampling and use of the Papanicolaou cytopathology grading scale led to an increase in test sensitivity from 17 % to 100 % ( P  = 0.015) with no loss of specificity. Conclusions  EUS-FNA was found to be a useful method for obtaining a preoperative tissue diagnosis for patients with suspected cholangiocarcinoma. This study identified markers that can reduce test accuracy and measures that can improve test performance of EUS-FNA.

ACR Appropriateness Criteria® Jaundice

Jaundice is the end result of myriad causes, which makes the role of imaging in this setting particularly challenging. In the United States, the most common causes of all types of jaundice fall into four categories including hepatitis, alcoholic liver disease, blockage of the common bile duct by a gallstone or tumor, and toxic reaction to a drug or medicinal herb. Clinically, differentiating between the various potential etiologies of jaundice requires a detailed history, targeted physical examination, and pertinent laboratory studies, the results of which allow the physician to categorize the type of jaundice into mechanical or nonmechanical causes. Imaging modalities used to evaluate the jaundiced patient (all etiologies) include abdominal ultrasound (US), CT, MR cholangiopancreatography, endoscopic retrograde cholangiopancreatography and endoscopic US. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Identification of a serum biomarker panel for the differential diagnosis of cholangiocarcinoma and primary sclerosing cholangitis

The non-invasive differentiation of malignant and benign biliary disease is a clinical challenge. Carbohydrate antigen 19-9 (CA19-9), leucine-rich α2-glycoprotein (LRG1), interleukin 6 (IL6), pyruvate kinase M2 (PKM2), cytokeratin 19 fragment (CYFRA21.1) and mucin 5AC (MUC5AC) have reported utility for differentiating cholangiocarcinoma (CCA) from benign biliary disease. Herein, serum levels of these markers were tested in 66 cases of CCA and 62 cases of primary sclerosing cholangitis (PSC) and compared with markers of liver function and inflammation. Markers panels were assessed for their ability to discriminate malignant and benign disease. Several of the markers were also assessed in pre-diagnosis biliary tract cancer (BTC) samples with performances evaluated at different times prior to diagnosis. We show that LRG1 and IL6 were unable to accurately distinguish CCA from PSC, whereas CA19-9, PKM2, CYFRA21.1 and MUC5AC were significantly elevated in malignancy. Area under the receiver operating characteristic curves for these individual markers ranged from 0.73–0.84, with the best single marker (PKM2) providing 61% sensitivity at 90% specificity. A panel combining PKM2, CYFRA21.1 and MUC5AC gave 76% sensitivity at 90% specificity, which increased to 82% sensitivity by adding gamma-glutamyltransferase (GGT). In the pre-diagnosis setting, LRG1, IL6 and PKM2 were poor predictors of BTC, whilst CA19-9 and C-reactive protein were elevated up to 2 years before diagnosis. In conclusion, LRG1, IL6 and PKM2 were not useful for early detection of BTC, whilst a model combining PKM2, CYFRA21.1, MUC5AC and GGT was beneficial in differentiating malignant from benign biliary disease, warranting validation in a prospective trial.

Novel biomarkers and endoscopic techniques for diagnosing pancreaticobiliary malignancy

The UK incidence of pancreatic ductal adenocarcinoma is 9 per 100,000 population, and biliary tract cancer occurs at a rate of 1–2 per 100,000. The incidence of both cancers is increasing annually and these tumours continue to be diagnosed late and at an advanced stage, limiting options for curative treatment. Population-based screening programmes do not exist for these cancers, and diagnosis currently is dependent on symptom recognition, but often symptoms are not present until the disease is advanced. Recently, a number of promising blood and urine biomarkers have been described for pancreaticobiliary malignancy and are summarised in this review. Novel endoscopic techniques such as single-operator cholangioscopy and confocal endomicroscopy have been used in some centres to enhance standard endoscopic diagnostic techniques and are also evaluated in this review.

[The efficacy of endoscopic endosonography in diagnosis of benign and malignant stenoses of common bile duct]

AIM

To define criteria and to estimate diagnostic significance of endosonography in differential diagnosis of benign and malignant stenoses of common bile duct.

MATERIAL AND METHODS

We presented the results of survey and treatment of 57 patients with benign and malignant stenoses of common bile duct. The technique of endosonography is described. We have formulated major criteria of differential diagnostics of tumoral and non-tumoral lesion of extrahepatic bile ducts. Comparative analysis of endosonography, ultrasound, computed tomography and magnetic resonance cholangiopancreatography was performed.

RESULTS

Sensitivity, specificity and accuracy of endosonography in diagnosis of stenosis cause is 97.7%, 100% and 98.2% respectively. So it exceeds the efficacy of other diagnostic X-ray methods. In modern surgical clinic endosonography should be mandatory performed. It is necessary for final diagnostics of cause of common bile duct stenosis especially in case of its low location.

Risk factors of biliary intervention by imaging after living donor liver transplantation

AIM: To determine the risk factors of biliary intervention using magnetic resonance cholangiopancreatography (MRCP) after living donor liver transplantation (LDLT).

METHODS: We retrospectively enrolled 196 patients who underwent right lobe LDLT between 2006 and 2010 at a single liver transplantation center. Direct duct-to-duct biliary anastomosis was performed in all 196 patients. MRCP images routinely taken 1 mo after LDLT were analyzed to identify risk factors for biliary intervention during follow-up, such as retrograde cholangiopancreatography or percutaneous transhepatic biliary drainage. Two experienced radiologists evaluated the MRCP findings, including the anastomosis site angle on three-dimensional images, the length of the filling defect on maximum intensity projection, bile duct dilatation, biliary stricture, and leakage.

RESULTS: Eighty-nine patients underwent biliary intervention during follow-up. The anastomosis site angle [hazard ratio (HR) = 0.48; 95% confidence interval (CI), 0.30-0.75, P < 0.001], a filling defect in the anastomosis site (HR = 2.18, 95%CI: 1.41-3.38, P = 0.001), and biliary leakage (HR = 2.52, 95%CI: 1.02-6.20, P = 0.048) on MRCP were identified in the multivariate analysis as significant risk factors for biliary intervention during follow-up. Moreover, a narrower anastomosis site angle (i.e., below the median angle of 113.3°) was associated with earlier biliary intervention (38.5 ± 4.2 mo vs 62. 1 ± 4.1 mo, P < 0.001). Kaplan-Meier analysis comparing biliary intervention-free survival according to the anastomosis site angle revealed that lower survival was associated with a narrower anastomosis site angle (36.3% vs 62.0%, P < 0.001).

CONCLUSION: The biliary anastomosis site angle in MRCP after LDLT may be associated with the need for biliary intervention.

Perioperative Management of Hilar Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is the most common primary tumor of the biliary tract although it accounts for only 2 % of all human malignancies. We herein review hilar cholangiocarcinoma including its risk factors, the main classification systems for tumors, current surgical management of the disease, and the role chemotherapy and liver transplantation may play in selected patients.

METHODS

We performed a comprehensive literature search using PubMed, Medline, and the Cochrane library for the period 1980-2015 using the following MeSH terms: "hilar cholangiocarcinoma", "biliary cancer", and "cholangiocarcinoma". Only recent studies that were published in English and in peer reviewed journals were included.

FINDINGS

Hilar cholangiocarcinoma is a disease of advanced age with an unclear etiology, most frequently found in Southeast Asia and relatively rare in Western countries. The best chance of long-term survival and potential cure is surgical resection with negative surgical margins, but many patients are unresectable due to locally advanced or metastatic disease at diagnosis. As a result of recent efforts, new methods of management have been identified for these patients, including preoperative portal vein embolism and biliary drainage, neoadjuvant chemotherapy with subsequent transplantation, and chemoradiation therapy.

CONCLUSION

Current management of hilar cholangiocarcinoma depends on extent of the tumor at presentation and includes surgical resection, liver transplantation, portal vein embolization, and chemoradiation therapy. Our understanding of hilar cholangiocarcinoma has improved in recent years and further research offers hope to improve the outcome in patients with these rare tumors.

Early detection of metachronous bile duct cancer in Lynch syndrome: report of a case

Lynch syndrome is an autosomal dominant disease associated with a high incidence of colorectal, endometrial, stomach, ovarian, pancreatic, ureter and renal pelvis, bile duct and brain tumors. The syndrome can also include sebaceous gland adenomas and keratoacanthomas, and carcinoma of the small bowel. The lifetime risk for bile duct cancer in patients with Lynch syndrome is approximately 2 %. The present report describes a case of Lynch syndrome with metachronous bile duct cancer diagnosed at an early stage. The patient was a 73-year-old Japanese male who underwent a successful left lobectomy of the liver, and there was no sign of recurrence for 2 years postoperative. However, this patient harbored a germline mutation in MLH1, which prompted diagnostic examinations for noncolorectal tumors when a periodic surveillance blood examination showed abnormal values of hepatobiliary enzymes. Although most patients with bile duct cancer are diagnosed at an advanced stage, the bile duct cancer was diagnosed at an early stage in the present patient due to the observation of the gene mutation and the preceding liver tumor. This case illustrates the importance of continuous surveillance for extracolonic tumors, including bile duct cancer, in patients with Lynch syndrome.

Multimodal treatment strategies for advanced hilar cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common primary malignancy of the liver arising from malignant transformation and growth of biliary ductal epithelium. Approximately 50-70 % of CCAs arise at the hilar plate of the biliary tree, which are termed hilar cholangiocarcinoma (HC). Various staging systems are currently employed to classify HCs and determine resectability. Depending on the pre-operative staging, the mainstays of treatment include surgery, chemotherapy, radiation therapy, and photodynamic therapy. Surgical resection offers the only chance for cure of HC and achieving an R0 resection has demonstrated improved overall survival. However, obtaining longitudinal and radial surgical margins that are free of tumor can be difficult and frequently requires extensive resections, particularly for advanced HCs. Pre-operative interventions may be necessary to prepare patients for major hepatic resections, including endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, and portal vein embolization. Multimodal therapy that combines chemotherapy with external beam radiation, stereotactic body radiation therapy, bile duct brachytherapy, and/or photodynamic therapy are all possible strategies for advanced HC prior to resection. Orthotopic liver transplantation is another therapeutic option that can achieve complete extirpation of locally advanced HC in judiciously selected patients following standardized neoadjuvant protocols.

Novel diagnostic and prognostic biomarkers in biliary tract cancer

INTRODUCTION

The worldwide incidence of biliary tract carcinoma (BTC, tumours of the bile ducts and gall-bladder) continues to rise, with the only potentially curative treatment remaining surgical resection or transplantation, possible in only a minority of patients. Late presentation and a paucity of effective treatments mandate the development of techniques for early lesion detection.

AREAS COVERED

This article reviews currently available biomarkers for the diagnosis and prognosis of BTC, as well as recently published studies describing novel serum, bile and urinary biomarkers.

EXPERT OPINION

The incorporation of novel analysis techniques, such as digital image analysis and fluorescence in situ hybridization, into existing management algorithms enhances the accuracy of brush cytology taken at the time of therapeutic endoscopy. However, a key goal is the discovery of reliable non-invasive biomarkers with high sensitivity and specificity. Recent advances in gene sequencing and expression, clonal evolution and tumour heterogeneity in other cancers should advance understanding of BTC tumour biology and facilitate biomarker discovery.

Novel endoscopic approaches in the diagnosis and management of biliary strictures

Indeterminate bilary strictures present the clinician with a wide differential diagnosis. Histological confirmation is usually required for treatment, but tissue acquisition remains challenging. Novel developments in endoscopic technology, such as single operator cholangioscopy and confocal endomicroscopy, have led to improvements in diagnostic accuracy in recent years. In patients with non-resectable malignant biliary obstruction, effective biliary decompression improves symptoms and enables patients to undergo palliative therapies. Improvements in endoscopic techniques, biliary stents and the development of local ablative techniques have led to further improvements in stent patency and survival in these patients. In this article, we review emerging diagnostic and therapeutic techniques for the endoscopic management of indeterminate biliary strictures.

For biliary dilatation, a negative endosonography needs additional image studies in weight loss suggesting malignancy

BACKGROUND AND AIM

Biliary dilatation frequently raises concerns about the possibility of pancreatobiliary diseases. This study assessed the etiologic yield of endosonography (EUS) in this situation.

METHODS

A retrospective review was completed with 163 consecutive patients who had undergone EUS for a dilated common bile duct (CBD) without definite pathology on ultrasonography.

RESULTS

Binary logistic regression analysis disclosed that malignancy was positively related to weight loss and was inversely related to abdominal pain; nevertheless, choledocholithiasis was positively related to fever and elevated carbohydrate antigen 19-9 (p < 0.05). The accuracy of EUS was 95.1 % (155/163) for overall cause of biliary dilatation, 100 % (73/73) for no pathological finding, 96.3 % (26/27) for ampullary cancer, 84.6 % (11/13) for pancreatic cancer, 40.0 % (2/5) for CBD cancer, and 92.6 % (25/27) for choledocholithiasis, respectively. The accuracy of EUS decreased in the presence of malignancy (86.7 %, 39/45 vs. 98.3 %, 116/118, p = 0.006). EUS missed three CBD cancers, two pancreatic cancers, and one ampullary cancer; however, the diagnosis was rescued by computed tomography in two pancreatic cancers and one CBD cancer.

CONCLUSIONS

EUS is accurate in patients with fever suggestive of choledocholithiasis. However, a negative EUS finding should call for additional image studies in patients with weight loss suggestive of malignancy.

Current endoscopic approach to indeterminate biliary strictures

Biliary strictures are considered indeterminate when basic work-up, including transabdominal imaging and endoscopic retrograde cholangiopancreatography with routine cytologic brushing, are non-diagnostic. Indeterminate biliary strictures can easily be mischaracterized which may dramatically affect patient’s outcome. Early and accurate diagnosis of malignancy impacts not only a patient’s candidacy for surgery, but also potential timely targeted chemotherapies. A significant portion of patients with indeterminate biliary strictures have benign disease and accurate diagnosis is, thus, paramount to avoid unnecessary surgery. Current sampling strategies have suboptimal accuracy for the diagnosis of malignancy. Emerging data on other diagnostic modalities, such as ancillary cytology techniques, single operator cholangioscopy, and endoscopic ultrasonography-guided fine needle aspiration, revealed promising results with much improved sensitivity.

Management of perihilar cholangiocarcinoma in the era of multimodal therapy

Perihilar cholangiocarcinoma (CCA) is the second most common primary malignant tumor of the liver. In the USA, there are approximately 3000 cases of CCA diagnosed annually, with approximately 50-70% of these tumors arising at the hilar plate of the biliary tree. Risk factors include advanced age, male gender, primary sclerosing cholangitis, choledochal cysts, cholelithiasis, parasitic infection, inflammatory bowel disease, cirrhosis and chronic pancreatitis. Patients typically present with jaundice, abdominal pain, pruritus and weight loss. The mainstays of treatment include surgery, chemotherapy, radiation therapy and photodynamic therapy. Specific preoperative interventions for patients with perihilar CCA include endoscopic retrograde cholangiopancreatography, percutanteous transhepatic cholangiography and portal vein embolization. Surgical resection offers the only chance for curative therapy in perihilar CCA. R0 resection is of utmost importance and has been linked to improved survival. Major hepatic resection is needed to achieve both longitudinal and radial margins negative for tumor. Fractionated stereotactic body radiotherapy has shown promising results in CCA. Perihilar CCA typically presents with advanced disease, and many patients receive systemic therapy; however, the response to current regimens is limited. Orthotopic liver transplantation offers complete resection of locally advanced tumors in select patient groups.

Endoscopic diagnosis of biliary tract disease

PURPOSE OF REVIEW

Endoscopic diagnosis of biliary disease is challenging due to difficulties in access, visualization, and sampling. Recent advances in endoscopic technology, ancillary diagnostic methods, and our understanding of autoimmune pancreatitis (AIP) and IgG4-related cholangitis (IRC) have led to improvements in the endoscopic diagnosis of pancreaticobiliary disease.

RECENT FINDINGS

Single-operator cholangioscopy overcomes several of the limitations of mother-baby cholangioscopy enhancing the diagnostic accuracy in indeterminate pancreaticobiliary disease. Probe-based confocal laser endomicroscopy has been recently shown to provide a significantly higher accuracy for the diagnosis of malignant biliary strictures than achieved by endoscopic retrograde cholangiopancreatogram and standard tissue acquisition, and has the potential to develop into a useful adjunct method of cholangioscopy. Fluorescence in-situ hybridization increases the sensitivity of routine brush cytology without compromising specificity in patients with indeterminate biliary strictures. The diagnosis of AIP/IRC remains challenging. The recently published international consensus criteria for AIP have included data on the potential diagnostic utility of endoscopic retrograde pancreatogram and endoscopic ampullary biopsies.

SUMMARY

Recent technical advances as well as ancillary diagnostic methods have improved the diagnostic accuracy of conventional endoscopic techniques. Future refinement of endoscopic methods may further improve diagnostic approaches to biliary disease.

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.

Endoscopic ultrasound in the papilla and the periampullary region

Endoscopic ultrasound (EUS) provides relevant information when an ampullary or periampullary tumor is suspected. Early detection, T and N staging and Fine Needle Aspiration plus cithologic confirmation, are some of the expected benefits. Exclusion of benign findings like choledocholithiasis or chronic pancreatitis is also important. A correct understanding of the complex ampullary and periampullary anatomy is needed. Knowledge of the individual clinical history and other previous diagnostic images all contribute to a successful EUS examination. Radial and lineal EUS images are uniquely detailed and, at the moment, it seems to be the best way to exclude or confirm malignant or benign findings. We propose a procedural algorithm, including EUS, for suspected ampullary or periampullary tumors. This review summarizes the vast amount of information to be found spread in the literature, and recognizes this small anatomic area as the origin for a clinical entity with proper clinical presentation, proper imaging and proper therapeutic resolutions. The benefits of performing EUS for its study are highlighted.

Endoscopic tumor treatment in the bile duct

There is little information in the literature on endoscopic tumor treatment in the bile duct with a curative intention. This article reports on the few cases published and on the authors' own experience with endoscopic retrograde and percutaneous transhepatic cholangioscopic treatment of tumors in the biliary system.