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

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.

Clinical Outcomes of Robotic Resection for Perihilar Cholangiocarcinoma: A First, Multicenter, Trans-Atlantic, Expert-Center, Collaborative Study

INTRODUCTION

Perihilar cholangiocarcinoma is a difficult cancer to treat with frequent vascular invasion, local recurrence, and poor survival. Due to the need for biliary anastomosis and potential vascular resection, the standard approach is an open operation. Suboptimal outcomes after laparoscopic resection had been sporadically reported by high-volume centers. In this first, Trans-Atlantic, multicenter study, we report our outcomes of robotic resection for perihilar cholangiocarcinoma. This is the largest study of its kind in the Western hemisphere.

METHODS

Between 2016 and 2023, we prospectively followed patients undergoing robotic resection for perihilar cholangiocarcinoma at three, high-volume, robotic, liver-surgery centers.

RESULTS

Thirty-eight patients underwent perihilar cholangiocarcinoma utilizing the robotic technique; Klatskin type-3 was the most common. The median age was 72 years, and 82% of the patients underwent preoperative biliary drainage. Median operative time was 481 minutes with a median estimated blood loss of 200 mL. The number of harvested lymph nodes was seven, and 11 (28%) patients yielded positive lymph nodes. Three patients required vascular reconstruction; 18% of patients had >1 biliary anastomosis. R0 resection margins were achieved in 82% of patients. Clavien-Dindo Grade ≥3 complications were seen in 16% of patients. The length of stay was 6 days. Five patients had an unplanned readmission within 30 days. One patient died within 30 days. With a median follow-up of 15 months, 68% of patients are alive without disease, 13% recurred, and 19% died.

CONCLUSIONS

Application of the robotic platform for perihilar cholangiocarcinoma is safe and feasible with acceptable short-term clinical and oncological outcomes.

The contribution of new methods in cytology for increasing sensitivity in the diagnosis of extrahepatic bile duct lesions

The aim of this review is to provide a comprehensive analysis of the existing literature pertaining to cytology of extrahepatic bile ducts. A search using the keywords "biliary brush cytology" was conducted in the PubMed database, with a focus on recent articles. The inclusion criteria primarily encompassed publications addressing problematic biliary stenosis. Emphasis was placed on identifying articles that explored innovative or less-utilized examination techniques aimed at enhancing the sensitivity of cytological examination. This review presents a comprehensive overview of the various types of materials used in sampling and the corresponding sampling methods. Additionally, it explores cytological and cytogenetic techniques, such as fluorescence in situ hybridization (FISH) and genetic methods (miRNA, NGS, cfDNA). These techniques possess the potential to improve the accuracy of diagnosing bile duct tumors, although their sensitivity varies. Furthermore, their utilization can facilitate early therapy, which plays a crucial role in patient prognosis. Each examination is always dependent on the quality and quantity of material delivered. A higher sensitivity of these examinations can be achieved by combining biliary cytology and other complementary methods.

Subserosal Layer and/or Pancreatic Invasion Based on Anatomical Features as a Novel Prognostic Indicator in Patients with Distal Cholangiocarcinoma

The American Joint Committee on Cancer (AJCC) 8th edition T-staging system for distal cholangiocarcinoma (DCC) proposes classification according to the depth of invasion (DOI); nevertheless, DOI measurement is complex and irreproducible. This study focused on the fibromuscular layer and evaluated whether the presence or absence of penetrating fibromuscular invasion of DCC contributes to recurrence and prognosis. In total, 55 patients pathologically diagnosed with DCC who underwent surgical resection from 2002 to 2022 were clinicopathologically examined. Subserosal layer and/or pancreatic (SS/Panc) invasion, defined as penetration of the fibromuscular layer and invasion of the subserosal layer or pancreas by the cancer, was assessed with other clinicopathological prognostic factors to investigate recurrence and prognostic factors. According to the AJCC 8th edition, there were 11 T1, 28 T2, and 16 T3 cases, with 44 (80%) cases of SS/Panc invasion. The DOI was not significantly different for both recurrence and prognostic factors. In the multivariate analysis, only SS/Panc was identified as an independent factor for prognosis (hazard ratio: 16.1; 95% confidence interval: 2.1-118.8, p = 0.006). In conclusion, while the determination of DOI in DCC does not accurately reflect recurrence and prognosis, the presence of SS/Panc invasion may contribute to the T-staging system.

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.

Evolution of the Targeted Therapy Landscape for Cholangiocarcinoma: Is Cholangiocarcinoma the 'NSCLC' of GI Oncology?

In the past two decades, molecular targeted therapy has revolutionized the treatment landscape of several malignancies. Lethal malignancies such as non-small cell lung cancer (NSCLC) have become a model for precision-matched immune- and gene-targeted therapies. Multiple small subgroups of NSCLC defined by their genomic aberrations are now recognized; remarkably, taken together, almost 70% of NSCLCs now have a druggable anomaly. Cholangiocarcinoma (CCA) is a rare tumor with a poor prognosis. Novel molecular alterations have been recently identified in patients with CCA, and the potential for targeted therapy is being realized. In 2019, a fibroblast growth factor receptor 2 (FGFR2) inhibitor, pemigatinib, was the first approved targeted therapy for patients with locally advanced or metastatic intrahepatic CCA who had FGFR2 gene fusions or rearrangement. More regulatory approvals for matched targeted therapies as second-line or subsequent treatments in advanced CCA followed, including additional drugs that target FGFR2 gene fusion/rearrangement. Recent tumor-agnostic approvals include (but are not limited to) drugs that target mutations/rearrangements in the following genes and are hence applicable to CCA: isocitrate dehydrogenase 1 (IDH1); neurotrophic tropomyosin-receptor kinase (NTRK); the V600E mutation of the BRAF gene (BRAFV600E); and high tumor mutational burden, high microsatellite instability, and gene mismatch repair-deficient (TMB-H/MSI-H/dMMR) tumors. Ongoing trials investigate HER2, RET, and non-BRAFV600E mutations in CCA and improvements in the efficacy and safety of new targeted treatments. This review aims to present the current status of molecularly matched targeted therapy for advanced CCA.

Contemporary advances in the endoscopic management of cholangiocarcinoma: a review of accomplished milestones and prospective opportunities

INTRODUCTION

Cholangiocarcinoma, a primary malignancy of epithelial cells of the bile ducts, has been shown to have increasing incidence rates globally. Many of the current advances aim to improve the accuracy of differentiation between benign biliary strictures and cholangiocarcinoma, which include endoscopic techniques, devices, image processing, and the use of genomic sequencing in acquired specimens.

AREAS COVERED

In this review, the authors explore the historical timeline of changes leading to modern management of cholangiocarcinoma, with special emphasis on endoscopic modalities and novel therapeutic interventions. The authors also expand on the strengths and shortcomings of endoscopic diagnostics and techniques in biliary drainage and finally discuss potential areas to focus for future research and development.

EXPERT OPINION

Despite the advances in diagnosis and management of cholangiocarcinoma, there remain multiple tasks that are still awaiting to be completed. Next-generation sequencing in the diagnosis of cholangiocarcinoma needs to be further tested, validated, and easily obtainable. Other innovative diagnostic modalities, such as the use of artificial intelligence in cholangioscopy, may provide an effective complementary modality to existing techniques. A consensus on biliary drainage needs to be defined and account for longevity and patient convenience.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

In vivo detection of bile duct pre-cancer with endoscopic light scattering spectroscopy

Bile duct cancer is the second most common primary liver cancer, with most diagnoses occurring in the advanced stages. This leads to a poor survival rate, which means a technique capable of reliably detecting pre-cancer in the bile duct is urgently required. Unfortunately, radiological imaging lacks adequate accuracy for distinguishing dysplastic and benign biliary ducts, while endoscopic techniques, which can directly assess the bile duct lining, often suffer from insufficient sampling. Here, we report an endoscopic optical light scattering technique for clinical evaluation of the malignant potential of the bile duct. This technique employs an ultraminiature spatial gating fiber optic probe compatible with cholangioscopes and endoscopic retrograde cholangiopancreatography (ERCP) catheters. The probe allowed us to investigate the internal cellular composition of the bile duct epithelium with light scattering spectroscopy (LSS) and phenotypic properties of the underlying connective tissue with diffuse reflectance spectroscopy (DRS). In a pilot in vivo double-blind prospective study involving 29 patients undergoing routine ERCP procedures, the technique detected malignant transformation with 97% accuracy, showing that biliary duct pre-cancer can be reliably identified in vivo non-invasively.

Locoregional Approaches in Cholangiocarcinoma Treatment

Cholangiocarcinoma (CCA) is a rare hepatic malignant tumor with poor prognosis due to late detection and anatomic factors limiting the applicability of surgical resection. Without surgical resection, palliation is the most common approach. In non-surgical cases contained within the liver, locoregional therapies provide the best chance for increased survival and disease control. The most common methods, transarterial chemoembolization and transarterial radioembolization, target tumors by embolizing their blood supply and limiting the tumor's ability to metabolize. Other treatments induce direct damage via thermal ablation to tumor tissue to mediate their anti-tumor efficacy. Recent studies have begun to explore roles for these therapies outside their previous role of palliation. This review will outline the mechanisms of each of these treatments, along with their effects on overall survival, while comparing these to non-locoregional therapies.

Novel Mathematical Diagnostic Analysis of Malignant Biliary Stenosis Using Magnetic Resonance Cholangiography in Patients Undergoing Pancreaticoduodenectomy

BACKGROUND/AIM

A novel mathematical diagnostic analysis using Fourier transform (FT) algorithm of the extrahepatic bile duct (BD) using magnetic resonance-cholangiography (MRC) was performed to evaluate irregularities of the bile duct lumen indicating BD cancer (BDC) extension compared to pancreatic head malignancies controls.

PATIENTS AND METHODS

BD lumen was automatically traced, and a 2D-diagram cross-section was measured and a FT-based integrated-power-spectral-density-function value (FTV) of both diameter and area (mm ²  and mm ⁴ /Hz) was calculated for cancerous and non-cancerous parts utilizing a computer workstation.

RESULTS

FT analysis that was achieved in 59 patients consisted of BDC in 31, pancreatic cancer with biliary stenosis (PC) in 10 and pancreatic neoplasm without stenosis (PN) in 18. FTV-diameter and -area of non-tumorous proximal BD were larger compared to tumor involving BD (p<0.01), and those of the entire BD in BDCs were significantly larger than those in PN (p<0.01). FTV-diameter and -area in proximal BDC-positive were smaller than those in BDC-negative (p<0.05). BDC part was significantly discriminated by the cutoff value (286 mm ² Hz ^-1  in diameter and 10,311 mm ⁴ Hz ^-1 in area) compared to PC and diagnostic accuracy was over 70% (p<0.01).

CONCLUSION

Novel mathematical MRC FT-analysis is promising for differentiating between BDC and PC with biliary stenosis and can be utilized as an objective diagnostic tool in the future.

Screening for hilar biliary invasion in ampullary cancer patients

BACKGROUND

The treatment for ampullary cancer is pancreatoduodenectomy or local ampullectomy. However, effective methods for the preoperative investigation of hilar biliary invasion in ampullary cancer patients have not yet been identified.

AIM

To determine the necessity of and an appropriate method for investigating hilar biliary invasion of ampullary cancer.

METHODS

Among 43 ampullary cancer patients, 34 underwent endoscopic treatment (n = 9) or surgery (n = 25). The use of imaging findings (thickening and enhancement of the bile duct wall on contrast-enhanced computed tomography, irregularity on endoscopic retrograde cholangiography, thickening of the entire bile duct wall on intraductal ultrasonography (IDUS), and partial thickening of the bile duct wall on IDUS) and biliary biopsy results for diagnosing hilar biliary invasion of ampullary cancer was compared.

RESULTS

Hilar invasion was not observed in every patient. Among the patients who did not undergo biliary stent insertion, the combination of partial thickening of the bile duct wall on IDUS and biliary biopsy results showed the highest accuracy (100%) for diagnosing hilar biliary invasion. However, each imaging method and biliary biopsy yielded some false-positive results.

CONCLUSION

Although some false-positive results were obtained with each method, the combination of partial thickening of the bile duct wall on IDUS and biliary biopsy results was useful for diagnosing hilar biliary invasion of ampullary cancer. However, hilar invasion of ampullary cancer is rare; therefore, the investigation of hilar biliary invasion of ampullary cancer might be unnecessary.

Clinical impact of a novel device delivery system in the diagnosis of bile duct lesions: A single-center experience

BACKGROUND AND AIM

Pathological evaluation is essential for the diagnosis of biliary tract diseases. However, existing evaluation methods have various challenges in terms of operability and diagnostic performance. The present study aimed to evaluate the feasibility, utility, and safety of a novel device delivery system for bile duct biopsy.

METHODS

This study was conducted as a retrospective, descriptive analysis at a single center. Overall, 25 examinations in 14 consecutive patients who underwent transpapillary biopsies for biliary lesions using the novel device delivery system from July to November 2020 were reviewed. Number and time of biopsy, technical success rate, adequate tissue sampling rate, adverse events, and diagnostic performance of bile duct biopsies using the novel device were evaluated. Moreover, negative surgical margins were assessed in patients who underwent surgical resection after mapping biopsy.

RESULTS

The median number of biopsy samples was five (range: 2-13), with a median biopsy time of 11.6 min. The technical success rate was 100% (140/140), with an adequate sampling rate of 82.9% (116/140). These rates did not differ depending on the biopsy site or purpose. There were no serious adverse events related to the procedures. The diagnostic sensitivity, specificity, and accuracy of biliary stricture were 90%, 100%, and 92.3%, respectively. Negative surgical margins were confirmed in all patients undergoing surgical resection, including one patient with a surgical procedure changed based on the results of mapping biopsy.

CONCLUSIONS

The novel device delivery system has potentials in diagnosing biliary tract diseases and determining appropriate treatment strategies.

Novel analysis using magnetic resonance cholangiography for patients with pancreaticobiliary maljunction

PURPOSE

We used a novel diagnostic Fourier transform (FT) algorithm of the entire extrahepatic bile duct (EHBD) measured by magnetic resonance cholangiography (MRC) to evaluate subtle deformation of bile duct lumen, indicating the malignant potential of EHBD, in patients with pancreaticobiliary maljunction (PBMJ) and in a comparative group of controls without PBMJ.

METHODS

From the workstation, the EHBD lumen was traced automatically and a 2D diagram cross section was measured at 0.5 mm-longitudinal intervals. The FT-based integrated power spectral density function value (FTPSDI) of the diameter or area (mm² or mm⁴/Hz) and the phase value distribution entropy (PVDE) were also measured.

RESULTS

There were 16 patients with undilated PBMJ and 7 with dilated PBMJ. The control group comprised 10 patients with a normal bile duct, 20 with bile duct carcinoma (BDC), and 1 with primary sclerosing cholangitis. Both the diameter and area of the dilated bile ducts and the ducts with early- or advanced-stage BDC were significantly greater than those of the normal duct (p < 0.05). The undilated type of PBMJ tended to have a larger FTPSDI diameter than a normal bile duct, which had a smaller diameter than the dilated type of PBMJ or BDC. BDC had a significantly larger FTPSDI diameter (p < 0.05) and the cutoff value for accuracy was 168 mm² Hz^-1.

CONCLUSION

The novel mathematical FTPSDI is a promising indicator of whether preventive EHBD resection is necessary for patients with PBMJ, which can be widely applied in the early diagnosis of other biliary diseases.

Fluoroscopy-guided shaped endobiliary biopsy at endoscopic retrograde cholangiography can accurately diagnose biliary neoplasia: Results from a large cohort

Background and study aims  The sensitivity of using standard endobiliary forceps biopsy to diagnose neoplastic biliary lesions remains low. We have developed a unique biopsy approach, termed fluoroscopy-guided, shaped endobiliary biopsy (FSEB), in which the biopsy forceps are modified to improve diagnostic yield. In this study, we evaluate the diagnostic characteristics of FSEB for endobiliary lesions at endoscopic retrograde cholangiography (ERC). Patients and methods  Consecutive patients undergoing FSEB between 1/2001 and 12/2014 were retrospectively enrolled. The identification of neoplastic lesions with FSEB, was the primary endpoint. The gold standard of neoplasia was histopathology, cytology or surgical histopathology. The benign cases were followed up for one year. Results  A total of 204 patients undergoing 250 biopsy sessions by FSEB were analyzed. Per-patient analysis was performed and FSEB showed 81.1 % sensitivity and 88.2 % accuracy. FSEB detection of proximal biliary lesions was more sensitive (91.1 % vs 73.2 %, P  < 0.01) and accurate (94.9 % vs 82.2 %, P  < 0.01) compared to distal lesions. No complications from FSEB were reported. Conclusions  FSEB shows high accuracy for diagnosis of neoplasia in biliary strictures, especially for proximal lesions. Future prospective randomized controlled studies are merited to further validate the role of FSEB as the first-line sampling tool for evaluation of biliary neoplasm.

Dilemma of the differential diagnosis of hilar cholangiocarcinoma and benign diseases: a single-center retrospective study

Hilar cholangiocarcinoma (HCCA), which lacks specific clinical manifestations, remains very difficult to distinguish from benign disease. This distinction is further complicated by the complex hilar anatomy. We conducted the present study to evaluate the differential diagnosis of these conditions. Sixty-five patients underwent resection surgery for suspected HCCA between January 2011 and October 2018. Institutional Review Board of Shengjing hospital agreed this study and all participants sign an informed consent document prior to participation in a research study. Following a postoperative pathology analysis, all patients were divided into two groups: malignant group (54 patients with HCCA) and benign group (11 cases with benign lesions). Compared with the benign group, the malignant group had a significantly higher median age and serum CA19-9, CEA, ALT, BILT and BILD levels (P < 0.05). In contrast, the groups did not differ significantly in terms of the sex distribution, clinical manifestations, serum levels of AST and ALKP, and imaging findings. In a receiver operating characteristic curve analysis, we identified a CA19-9 cutoff point of 233.15 U/ml for the differential diagnosis and CEA cutoff point of 2.98 ng/ml for the differential diagnosis. The differential diagnosis of HCCA and benign hilar lesions remains difficult. However, we found that patients with HCCA tended to have an older age at onset and higher serum levels of CA19-9, CEA, BILT, ALT and BILD. Furthermore, patients with a serum CA19-9 level >233.15 U/ml and CEA level >2.98 ng/ml are more likely to have malignant disease.

Efficacy and Safety of Apatinib Treatment for Advanced Cholangiocarcinoma After Failed Gemcitabine-Based Chemotherapy: An Open-Label Phase II Prospective Study

Purpose

As a novel small-molecule vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor (VEGFR2-TKI), Methylsulfonic apatinib (apatinib) exhibits a specific antitumor effect in various solid tumors via inhibition of angiogenesis. The present study was performed to evaluate the clinical efficacy and safety of apatinib in the treatment of advanced cholangiocarcinoma after failed gemcitabine-based chemotherapy.

Patients and Methods

This was a prospective open-label phase II trial (NCT03521219). A total of 32 patients, in whom gemcitabine-based first-line chemotherapy for advanced intrahepatic cholangiocarcinoma had failed, were consecutively enrolled in a prospective, open, exploratory, and single-center clinical trial from November 2017 to November 2018. They were treated with apatinib mesylate second-line monotherapy (orally, 500 mg per day for a cycle of 28 days) until progressive disease or unacceptable toxicity. Using Response Evaluation Criteria in Solid Tumor version 1.1 (RECIST 1.1) and the Common Terminology Criteria for Adverse Events version 4.0 (NCI-CTCAE 4.0), the efficacy and adverse were evaluated, respectively. Kaplan-Meier method was used for survival analysis.

Results

Twenty-six patients were enrolled in full analysis set. At the end of follow-up, two patients were lost to follow-up, 24 of 26 patients in FAS were included in efficacy analyses. For the efficacy analysis set, the objective response rate (ORR) was 20.8% [95% confidence interval (CI): 9.24-40.47%] and the disease control rate (DCR) was 62.5% (95% CI: 112.86-387.14 days). One patient (4%) showed complete response (CR), 4 patients (17%) showed partial response (PR), 10 patients (41.7%) stable disease (SD), and 9 patients (37.5%) had progressive disease (PD). Meanwhile, apatinib therapy achieved the median progression-free survival PFS was 95 days (95% CI: 79.70-154.34 days), and the median OS was 250 days (95% CI: 112.86-387.14 days). Furthermore, univariate analysis revealed that age and tumor's anatomic location significantly affected PFS (P < 0.05). The most common clinically adverse events (AEs) included myelosuppression (69.2%), hypertension (57.7%), proteinuria (46.2%). The AEs were mild, mainly in grade 1 or 2, and no toxicity-induced death occurred.

Conclusion

Apatinib monotherapy is an effective and promising regimen for treating patients with advanced cholangiocarcinoma who experienced failure of gemcitabine-based chemotherapy.

Diagnostic Process Using Endoscopy for Biliary Strictures: A Narrative Review

The diagnostic process for biliary strictures remains challenging in some cases. A broad differential diagnosis exists for indeterminate biliary strictures, including benign or malignant lesions. The diagnosis of indeterminate biliary strictures requires a combination of physical examination, laboratory testing, imaging modalities, and endoscopic procedures. Despite the progress of less invasive imaging modalities such as transabdominal ultrasonography, computed tomography, and magnetic resonance imaging, endoscopy plays an essential role in the accurate diagnosis, including the histological diagnosis. Imaging findings and brush cytology and/or forceps biopsy under fluoroscopic guidance with endoscopic retrograde cholangiopancreatography (ERCP) are widely used as the gold standard for the diagnosis of biliary strictures. However, ERCP cannot provide an intraluminal view of the biliary lesion, and its outcomes are not satisfactory. Recently, peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound (EUS), and EUS-guided fine-needle aspiration have been reported as useful for indeterminate biliary strictures. Appropriate endoscopic modalities need to be selected according to the patient's condition, the lesion, and the expertise of the endoscopist. The aim of this review article is to discuss the diagnostic process for indeterminate biliary strictures using endoscopy.

Extrahepatic cholangiocarcinoma: Current status of endoscopic approach and additional therapies

The prognosis of patients with advanced or unresectable extrahepatic cholangiocarcinoma is poor. More than 50% of patients with jaundice are inoperable at the time of first diagnosis. Endoscopic treatment in patients with obstructive jaundice ensures bile duct drainage in preoperative or palliative settings. Relief of symptoms (pain, pruritus, jaundice) and improvement in quality of life are the aims of palliative therapy. Stent implantation by endoscopic retrograde cholangiopancreatography is generally preferred for long-term palliation. There is a vast variety of plastic and metal stents, covered or uncovered. The stent choice depends on the expected length of survival, quality of life, costs and physician expertise. This review will provide the framework for the endoscopic minimally invasive therapy in extrahepatic cholangiocarcinoma. Moreover, additional therapies, such as brachytherapy, photodynamic therapy, radiofrequency ablation, chemotherapy, molecular-targeted therapy and/or immunotherapy by the endoscopic approach, are the nonsurgical methods associated with survival improvement rate and/or local symptom palliation.

Targeted therapies for extrahepatic cholangiocarcinoma: preclinical and clinical development and prospects for the clinic

Introduction: Until recently, cholangiocarcinoma (CCA) was a largely overlooked disease, and among CCAs, extrahepatic CCA (eCCA) was even more neglected. Despite the growing impact of molecularly targeted therapies and immunotherapy, prognosis of eCCA is dismal. Therefore, unraveling the complex molecular landscape of eCCA has become an urgent need. Deep phenotyping studies have revealed that eCCA is a heterogeneous tumor, harboring specific alterations categorizable into four classes, 'Mesenchymal', 'Proliferation', 'Immune', 'Metabolic'. Molecular alterations convey the activation of several pro-oncogenic pathways, where either actionable drivers or outcome predictors can be identified.Areas covered: We offer insights on perturbed pathways, molecular profiling, and actionable targets in eCCA and present a perspective on the potential stepping-stones to future progress. A systematic literature search in PubMed/ClinicalTrials.gov websites was performed by authors from different disciplines according to their specific topic knowledge to identify the newest and most relevant advances in precision medicine of eCCA.Expert opinion: eCCA is a distinct entity with unique features in terms of molecular classes, oncogenic drivers, and tumor microenvironment. Since more prevalent mutations are currently undruggable, and immunotherapy can be offered only to a minority of patients, international collaborations are instrumental to improve the understanding of the molecular underpins of this disease.

Role of Endoscopic Procedures in the Diagnosis of IgG4-Related Pancreatobiliary Disease

The emergence of the disease entity of glucocorticoid-responsive systemic immunoglobulin G4 (IgG4)-related pancreatobiliary disease has generated substantial attention among the international gastroenterology society. IgG4-related pancreatobiliary disease includes type 1 autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC). The typical manifestations of IgG4-related pancreatobiliary disease are cholestatic liver dysfunction, obstructive jaundice, and weight loss, although it may present with no clinical symptoms. Since it mimics tumors on imaging, AIP/IgG4-SC may often be misdiagnosed as pancreatic or biliary cancer. The endoscopic armamentarium for the diagnosis of IgG4-related pancreatobiliary disease includes endoscopic ultrasonography, intraductal ultrasonography, endoscopic retrograde cholangiopancreatography, and cholangioscopy. The role of endoscopic tissue acquisition is two-fold in the diagnosis of IgG4-related pancreatobiliary disease: exclusion of cancer and procurement of histopathological proof for diagnosis of AIP/IgG4-SC, which can also be achieved by adding the immunohistochemistry for IgG4. Our review article addresses the role of various endoscopic examinations in diagnosing IgG4-related pancreatobiliary disease, focusing on the differentiation of this condition from pancreatobiliary malingnancies.

Peroral Cholangioscopy-Guided Forceps Mapping Biopsy for Evaluation of the Lateral Extension of Biliary Tract Cancer

Background: Peroral cholangioscopy (POCS)-guided forceps mapping biopsy (FMB) is a method for the accurate preoperative identification of the extent of the disease of biliary tract cancer (BTC). However, the diagnostic value of POCS-FMB is still uncertain. Objectives: We evaluated the diagnostic utility of POCS-FMB for the identification of lateral extension—superficial intraductal spread longitudinally and continuously from the main lesion—of BTC. Methods: In the retrospective study, patients who received POCS-FMB and surgery for curative resection of BTC between September 2016 and August 2019 at our medical institution were enrolled. The diagnostic accuracy of POCS-FMB for the identification of lateral extension of BTC was evaluated. Furthermore, we also evaluated the factors affecting the diagnostic accuracy of POCS-FMB. Results: A total of 23 patients with BTC were enrolled, and 24 procedures of POCS-FMB from 96 sites of biliary tracts were performed. The sensitivity, specificity, and accuracy of POCS-FMB were 53.8%, 63.9%, and 63.1%, respectively. In the multivariate logistic regression analyses, the biopsy from the bifurcation of biliary tracts was a significant factor affecting the diagnostic accuracy of POCS-FMB (odds ratio 3.538, 95%; confidence interval 1.151–10.875, p = 0.027). Conclusions: The diagnostic accuracy of POCS-FMB for the identification of lateral extension of BTC was insufficient. The biopsy from the bifurcation of biliary tracts was a positive factor affecting the diagnostic accuracy of POCS-FMB.

Circulating Tumor DNA in Biliary Tract Cancer: Current Evidence and Future Perspectives

Peripheral blood of cancer patients "physiologically" presents cells and cellular components deriving from primary or metastatic sites, including circulating tumor cells (CTCs), circulating free DNA (cfDNA) and exosomes containing proteins, lipids and nucleic acids. The term circulating tumor DNA (ctDNA) indicates the part of cfDNA which derives from primary tumors and/or metastatic sites, carrying tumor-specific genetic or epigenetic alterations. Analysis of ctDNA has enormous potential applications in all stages of cancer management, including earlier diagnosis of cancer, identification of driver alterations, monitoring of treatment response and detection of resistance mechanisms. Thus, ctDNA has the potential to profoundly change current clinical practice, by moving from tissue to peripheral blood as a source of information. Herein, we review current literature regarding the potential role for ctDNA in biliary tract cancer (BTC) patients, with a particular focus on state-of-the-art techniques and future perspectives of this highly aggressive disease.

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.

Genotyping of circulating tumor DNA in cholangiocarcinoma reveals diagnostic and prognostic information

Diagnosis of Cholangiocarcinoma (CCA) is difficult, thus a noninvasive approach towards (i) assessing and (ii) monitoring the tumor-specific mutational profile is desirable to improve diagnosis and tailor treatment. Tumor tissue and corresponding ctDNA samples were collected from patients with CCA prior to and during chemotherapy and were subjected to deep sequencing of 15 genes frequently mutated in CCA. A set of ctDNA samples was also submitted for 710 gene oncopanel sequencing to identify progression signatures. The blood/tissue concordance was 74% overall and 92% for intrahepatic tumors only. Variant allele frequency (VAF) in ctDNA correlated with tumor load and in the group of intrahepatic CCA with PFS. 63% of therapy naive patients had their mutational profile changed during chemotherapy. A set of 76 potential progression driver genes was identified among 710 candidates. The molecular landscape of CCA is accessible via ctDNA. This could be helpful to facilitate diagnosis and personalize and adapt therapeutic strategies.

Cholangiocarcinoma

Cholangiocarcinoma is a rare malignancy and accounts for 2% of all malignancies. Incidence is on the increase in the Western world. Cholangiocarcinoma arises from the malignant growth of the epithelial lining of the bile ducts and can be found all along the biliary tree. It can be classified into subtypes based on location: intrahepatic (arising from the intrahepatic biliary tract in the hepatic parenchyma), perihilar (at the hilum of the liver involving the biliary confluence) and distal (extrahepatic, often in the head of the pancreas). Margin status and locoregional lymph node metastases are the most important determinants of postsurgical outcomes.

Periampullary Metastases from Breast Cancer: A Case Report and Literature Review

We presented a metastatic breast cancer case who was afflicted with obstructive jaundice caused by an ampullary neoplasm. Since jaundice due to periampullary metastasis from breast cancer was a rare entity, a literature review of similar cases through the PubMed database was done. A total of 23 additional cases were found. Among these 24 cases, 5 presented with periampullary metastasis synchronously with the diagnosis of breast cancer, while 19 had metachronous periampullary metastasis with an interval ranging between 1.3 and 23 years from the initial diagnosis of breast cancer to the emergence of jaundice. It is intriguing to establish a differential diagnosis for common bile tract stricture prior to tissue biopsy, even with diagnostic workups including serum tumor markers, MRI plus MRCP, ERCP with intraductal brushing, and endoscopic ultrasound, in that the clinical, radiological, and endoscopic findings of metastatic lesions overlapped extensively with those found with primary periampullary malignancies. An immunohistochemical portfolio including cytokeratin7/20 (CK7/20), homeobox protein CDX2, human epidermal growth factor receptor 2 (HER2/neu), estrogen receptor alfa (ERα), progesterone receptor (PgR), mammaglobin, gross cystic disease fluid protein-15 (GCDFP-15), and transacting T-cell-specific transcription factor (GATA-3) was helpful for differential diagnosis among cases with ambiguous microscopic features.

Rare Collision Tumor of the Biliary Tract

Malignancies of the gallbladder are uncommon in the developed world. Collision tumors are also extremely rare neoplastic phenomena. Given their scarcity, there are no guidelines for treatment, and prognosis is based on the more aggressive tumor type. We present a patient with a collision tumor consisting of signet-ring cholangiocarcinoma and large-cell neuroendocrine gallbladder carcinoma of the biliary tract, and we review the literature pertaining to biliary tract collision tumors and their management.

Factors Impacting the Performance Characteristics of Bile Duct Brushings: A Clinico-Cytopathologic Analysis of 253 Patients

Context.—

Literature on factors impacting bile duct brushings (BDBs) performance characteristics remain limited.

Objective.—

To capture the current state of daily practice with BDB sign-out.

Design.—

Two hundred fifty-three of 444 BDBs signed out by more than 7 cytopathologists, with histopathologic and/or clinical follow-up of at least 18 months, were examined.

Results.—

One hundred thirty-five of 253 BDBs (53%) had histologically confirmed malignancies, 22 (9%) had cancer-related deaths, and 96 (38%) were benign. Cytologic diagnoses in the 444 BDBs were nondiagnostic (11 [2.5%]), negative (284 [64%]), atypical (62 [13.9%]), suspicious (34 [7.7%]), and malignant (53 [11.9%]). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of malignancy detection were 35%, 100%, 100%, 58%, and 66%, respectively. When atypical, suspicious, and malignant (ASM) categories were combined, sensitivity increased (58%), specificity and PPV dropped (97%), and accuracy increased (73%). Carcinoma type (bile-duct versus pancreatic-ductal) had no effect on accuracy (P = .60) or diagnostic class (P = .84), nor did time of performance (first 7.5 versus latter 7.5 years, P = .13). Interestingly, ThinPrep + cell block (n = 41) had higher sensitivity (61%) and lower specificity (80%) than ThinPrep only (versus 51% and 100%, respectively). Sensitivity and specificity were higher (47% and 100%) in nonstented than stented specimens (59% and 97%). Relative risk of malignancy for “suspicious” (2.30) and “atypical” (2.28) categories was lower but not very different from that of “malignant” category (2.41).

Conclusions.—

Bile duct brushings had fairly low sensitivity but high specificity and PPV with no false positives. Sensitivity almost doubled and specificity dipped minimally when ASM categories were combined, highlighting the need for better classification criteria for atypical/suspicious cases. Higher specificity, PPV, NPV, and accuracy but lower sensitivity in stented BDBs suggest that they be called malignant only when evidence is overwhelmingly convincing.

The Impact of Intraoperative Re-Resection of a Positive Bile Duct Margin on Clinical Outcomes for Hilar Cholangiocarcinoma

BACKGROUND

The impact of re-resection of a positive intraoperative bile duct margin on clinical outcomes for resectable hilar cholangiocarcinoma (HCCA) remains controversial. We sought to define the impact of re-resection of an initially positive frozen-section bile duct margin on outcomes of patients undergoing surgery for HCCA.

METHODS

Patients who underwent curative-intent resection for HCCA between 2000 and 2014 were identified at 10 hepatobiliary centers. Short- and long-term outcomes were analyzed among patients stratified by margin status.

RESULTS

Among 215 (83.7%) patients who underwent frozen-section evaluation of the bile duct, 80 (37.2%) patients had a positive (R1) ductal margin, 58 (72.5%) underwent re-resection, and 29 ultimately had a secondary negative margin (secondary R0). There was no difference in morbidity, 30-day mortality, and length of stay among patients who had primary R0, secondary R0, and R1 resection (all p > 0.10). Median and 5-year survival were 22.3 months and 23.3%, respectively, among patients who had a primary R0 resection compared with 18.5 months and 7.9%, respectively, for patients with an R1 resection (p = 0.08). In contrast, among patients who had a secondary R0 margin with re-resection of the bile duct margin, median and 5-year survival were 30.6 months and 44.3%, respectively, which was comparable to patients with a primary R0 margin (p = 0.804). On multivariable analysis, R1 margin resection was associated with decreased survival (R1: hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.0-1.7; p = 0.027), but secondary R0 resection was associated with comparable long-term outcomes as primary R0 resection (HR 0.9, 95% CI 0.4-2.3; p = 0.829).

CONCLUSIONS

Additional resection of a positive frozen-section ductal margin to achieve R0 resection was associated with improved long-term outcomes following curative-intent resection of HCCA.

In vitro detection of cholangiocarcinoma cells using a fluorescent protein-expressing oncolytic herpes virus

Pathological confirmation is desired prior to high-risk surgery for suspected perihilar cholangiocarcinoma (PHC), but preoperative tissue diagnosis is limited by poor sensitivity of available techniques. This study aimed to validate whether a tumor-specific enhanced green fluorescent protein (eGFP)-expressing oncolytic virus could be used for cholangiocarcinoma (CC) cell detection. Extrahepatic CC cell lines SK-ChA-1, EGI-1, TFK-1 and control cells (primary human liver cells) were exposed to the oncolytic herpes simplex type 1 virus NV1066 for up to 24 h in adherent culture. The technique was validated for cells in suspension and cultured cells that had been exposed to crude patient bile. Optimal incubation time of the CC cells with NV1066 at a multiplicity of infection of 0.1 was determined at 6-8 h, yielding 15% eGFP-expressing cells, as measured by flow cytometry. Cells were able to survive 2-h crude bile exposure and remained capable of producing eGFP following NV1066 infection. Detection of malignant cells was possible at the highest dilution tested (10 CC cells among 2 × 10⁵ control cells), though hampered by non-target cell autofluorescence. The technique was not applicable to cells in suspension due to insufficient eGFP production. Accordingly, as yet the technique is not suitable for standardized clinical diagnostics in PHC.

Transhepatic Hilar Approach for Perihilar Cholangiocarcinoma: Significance of Early Judgment of Resectability and Safe Vascular Reconstruction

In the most common surgical procedure for perihilar cholangiocarcinoma, the margin status of the proximal bile duct is determined at the final step. Our procedure, the transhepatic hilar approach, confirms a cancer-negative margin status of the proximal bile duct first. We first performed a partial hepatic parenchymal transection to expose the hilar plate, and then transected the proximal bile duct to confirm margin status. Then, divisions of the hepatic artery and portal vein of the future resected liver are performed, followed by the residual hepatic parenchymal transection. The transhepatic hilar approach offers a wide surgical field for safe resection and reconstruction of the portal vein in the middle of the hepatectomy. We reviewed 23 patients with perihilar cholangiocarcinoma who underwent major hepatectomy using our procedure from 2011 to 2015. A combined vascular resection and reconstruction was carried out in 14 patients (60.9%). R0 resection was achieved in 17 patients (73.9%), and the overall 3-year survival rate was 52.9% (median survival time 52.4 months). The transhepatic hilar approach is useful and practicable regardless of local tumor extension, enabling us to determine tumor resectability and perform safe resection and reconstruction of the portal vein early in the operation.

[Primary Biliary Mucosa-associated Lymphoid Tissue Lymphoma Mimicking Hilar Cholangiocarcinoma]

Primary biliary mucosa-associated lymphoid tissue (MALT) lymphoma is extremely rare. We report a case of primary biliary MALT lymphoma with obstructive jaundice diagnosed by endoscopic biopsy, without surgical intervention. Obstructive jaundice was relieved by endoscopic drainage and endoscopic biopsy was done simultaneously during endoscopic retrograde cholangiopancreatography. Unnecessary surgical intervention can be avoided after pathological confirmation of lymphoma. The patient received radiotherapy, and is alive without any evidence of recurrence or biliary obstruction. Diagnosis of primary biliary lymphoma is very difficult because of its low prevalence. However, it should always be considered as a differential diagnosis, since when an accurate diagnosis is made, unnecessary surgical intervention can be avoided.

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.

[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.

Two cases of immunoglobulin G4-related sclerosing cholangitis in which transabdominal ultrasonography was useful in diagnosis and follow-up observation

Immunoglobulin G4-related disease (IgG4-RD) represents a group of disorders that share features of inflammation, plasma cell infiltrates, and fibrosis. Sclerosing cholangitis is a disorder involving inflammation, scarring, and destruction of the bile ducts. IgG4-related sclerosing cholangitis (IgG4-SC) has been proposed as a bile duct lesion associated with IgG4-RD. This disease entity can be distinguished from other types of sclerosing cholangitis and classified into four types based upon the region of strictures revealed by cholangiography. Here, we present two cases in which the finding of bile duct wall thickening visualized with transabdominal ultrasonography was useful in the diagnosis of patients with IgG4-SC. At present, transabdominal ultrasonography is not included in the diagnostic algorithm for IgG4-SC. We are certain that detailed observation of the bile duct wall with transabdominal ultrasonography can make a significant contribution to the diagnosis of IgG4-SC. Furthermore, we propose that transabdominal ultrasonography may be useful in following clinical improvement in cases where a steroid trial is the best option for treatment. Both cases emphasize the practicality of transabdominal ultrasonography in the diagnosis and follow-up observation of IgG4-SC.

Endoscopic diagnosis of cholangiocarcinoma: From endoscopic retrograde cholangiography to bile proteomics

Cholangiocarcinoma (CCA) is the second most common primary liver cancer. In clinical practice, the diagnosis remains challenging and often requires endoscopic approaches. Endoscopic retrograde and percutaneous transhepatic cholangiography are the first-line endoscopic procedures for the evaluation of indeterminate bile duct strictures. Tissue acquisition via brush cytology and forceps biopsies allows the cytological and/or histological confirmation of the disease. Due to the low sensitivity of these techniques, repetitive examinations and/or alternative approaches are required. Cholangioscopy, endoscopic and intraductal ultrasound and confocal laser endomicroscopy are additional methods which can be applied for the diagnosis of CCA. Particularly, new experimental approaches like bile and urine proteomic analyses show promising results which have to be evaluated prospectively for further integration in diagnostic algorithms.

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.

Imaging bile duct tumors: pathologic concepts, classification, and early tumor detection

Cholangiocarcinoma is the most common primary malignancy of the bile ducts which has several predisposing factors such as hepatolithiasis and primary sclerosing cholangitis, and can develop from precancerous conditions such as biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct. As surgical resection of early stage cholangiocarcinoma or precancerous lesions may provide better prognosis, early detection of those lesions is very important. Imaging studies play important roles in the diagnosis of bile duct tumors followed by appropriate management. Indeed, not only diagnosis of cholangiocarcinoma but also appropriate categorization of bile duct tumors based on their morphologic features and location on cross-sectional imaging studies, including computed tomography and magnetic resonance imaging, is important to predict their biologic behaviors, and choose relevant treatment strategies. We herein review the classification system of the bile duct tumors with their radiologic and pathologic findings as well as role of imaging in the early detection of bile duct tumors.

Hilar cholangiocarcinoma: diagnosis, treatment options, and management

Hilar cholangiocarcinoma (HC) is a rare disease with a poor prognosis which typically presents in the 6(th) decade of life. Of the 3,000 cases seen annually in the United States, less than one half of these tumors are resectable. A variety of risk factors have been associated with HC, most notably primary sclerosing cholangitis (PSC), biliary stone disease and parasitic liver disease. Patients typically present with abdominal pain, pruritis, weight loss, and jaundice. Computed topography (CT), magnetic resonance imaging (MRI), and ultrasound (US) are used to characterize biliary lesions. Endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) assess local ductal extent of the tumor while allowing for therapeutic biliary drainage. MRCP has demonstrated similar efficacies to PTC and ERCP in identifying anatomic extension of tumors with less complications. Treatment consists of surgery, radiation, chemotherapy and photodynamic therapy. Biliary drainage of the future liver remnant should be performed to decrease bilirubin levels thereby facilitating future liver hypertrophy. Standard therapy consists of surgical margin-negative (R0) resection with extrahepatic bile duct resection, hepatectomy and en bloc lymphadenectomy. Local resection should not be undertaken. Lymph node invasion, tumor grade and negative margins are important prognostic indicators. In instances where curative resection is not possible, liver transplantation has demonstrated acceptable outcomes in highly selected patients. Despite the limited data, chemotherapy is indicated for patients with unresectable tumors and adequate functional status. Five-year survival after surgical resection of HC ranges from 10% to 40% however, recurrence can be as high as 50-70% even after R0 resection. Due to the complexity of this disease, a multi-disciplinary approach with multimodal treatment is recommended for this complex disease.