What is the current state-of-the-art imaging for detection and staging of cholangiocarcinoma?

Atlas for Cholangioscopy and Cholecystoscopy: A Primer for Diagnostic and Therapeutic Endoscopy in the Biliary Tree and Gallbladder

Percutaneous endoscopy of the biliary system (cholangioscopy) and gallbladder (cholecystoscopy) has significantly impacted diagnostic and therapeutic approaches to many diseases in interventional radiology, overcoming previous challenges related to scope size and rigidity. The current endoscopes offer enhanced maneuverability within narrow tubular structures such as bile ducts. Before endoscopy, reliance on 2D imaging modalities limited real-time visualization during percutaneous procedures. Percutaneous endoscopy provides 3D perspectives, enabling a better appreciation of normal structures, targeted biopsy of lesions, and accurate deployment of therapeutic interventions. This review aims to explore percutaneous endoscopic findings across various biliary and gallbladder pathologies.

Exploiting the Potential of Photon-Counting CT in Abdominal Imaging

ABSTRACT

Photon-counting computed tomography (PCCT) imaging uses a new detector technology to provide added information beyond what can already be obtained with current CT and MR technologies. This review provides an overview of PCCT of the abdomen and focuses specifically on applications that benefit the most from this new imaging technique. We describe the requirements for a successful abdominal PCCT acquisition and the challenges for clinical translation. The review highlights work done within the last year with an emphasis on new protocols that have been tested in clinical practice. Applications of PCCT include imaging of cystic lesions, sources of bleeding, and cancers. Photon-counting CT is positioned to move beyond detection of disease to better quantitative staging of disease and measurement of treatment response.

Detection of Human Cholangiocarcinoma Markers in Serum Using Infrared Spectroscopy

Simple Summary

Cholangiocarcinoma is a form of liver cancer that is found, predominantly, in Thailand. Due to the non-specific symptoms and laboratory investigation, it is difficult to rule out cholangiocarcinoma from other liver conditions. Here, we demonstrate the development of a diagnostic tool for cholangiocarcinoma, based on the ATR-FTIR analyses of sera, coupled with multivariate analyses and machine learning tools to obtain a better specificity. The innovative approach that shows highly promising results for this otherwise difficult to diagnose cancer.

Abstract

Cholangiocarcinoma (CCA) is a malignancy of the bile duct epithelium. Opisthorchis viverrini infection is a known high-risk factor for CCA and in found, predominantly, in Northeast Thailand. The silent disease development and ineffective diagnosis have led to late-stage detection and reduction in the survival rate. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) is currently being explored as a diagnostic tool in medicine. In this study, we apply ATR-FTIR to discriminate CCA sera from hepatocellular carcinoma (HCC), biliary disease (BD) and healthy donors using a multivariate analysis. Spectral markers differing from healthy ones are observed in the collagen band at 1284, 1339 and 1035 cm⁻¹, the phosphate band (vsPO2−) at 1073 cm⁻¹, the polysaccharides band at 1152 cm⁻¹ and 1747 cm⁻¹ of lipid ester carbonyl. A Principal Component Analysis (PCA) shows discrimination between CCA and healthy sera using the 1400–1000 cm⁻¹ region and the combined 1800—1700 + 1400–1000 cm⁻¹ region. Partial Least Square-Discriminant Analysis (PLS-DA) scores plots in four of five regions investigated, namely, the 1400–1000 cm⁻¹, 1800–1000 cm⁻¹, 3000–2800 + 1800–1000 cm⁻¹ and 1800–1700 + 1400–1000 cm⁻¹ regions, show discrimination between sera from CCA and healthy volunteers. It was not possible to separate CCA from HCC and BD by PCA and PLS-DA. CCA spectral modelling is established using the PLS-DA, Support Vector Machine (SVM), Random Forest (RF) and Neural Network (NN). The best model is the NN, which achieved a sensitivity of 80–100% and a specificity between 83 and 100% for CCA, depending on the spectral window used to model the spectra. This study demonstrates the potential of ATR-FTIR spectroscopy and spectral modelling as an additional tool to discriminate CCA from other conditions.

Clinical practice guidelines for the management of biliary tract cancers 2019: The 3rd English edition

BACKGROUND

The Japanese Society of Hepato-Biliary-Pancreatic Surgery launched the clinical practice guidelines for the management of biliary tract cancers (cholangiocarcinoma, gallbladder cancer, and ampullary cancer) in 2007, then published the 2nd version in 2014.

METHODS

In this 3rd version, clinical questions (CQs) were proposed on six topics. The recommendation, grade for recommendation, and statement for each CQ were discussed and finalized by an evidence-based approach. Recommendations were graded as Grade 1 (strong) or Grade 2 (weak) according to the concepts of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

The 31 CQs covered the six topics: (a) prophylactic treatment, (b) diagnosis, (c) biliary drainage, (d) surgical treatment, (e) chemotherapy, and (f) radiation therapy. In the 31 CQs, 14 recommendations were rated strong and 14 recommendations weak. The remaining three CQs had no recommendation. Each CQ includes a statement of how the recommendations were graded.

CONCLUSIONS

This latest guideline provides recommendations for important clinical aspects based on evidence. Future collaboration with the cancer registry will be key for assessing the guidelines and establishing new evidence.

Intrahepatic cholangiocarcinoma: pathogenesis, current staging, and radiological findings

To this date, it is a major oncological challenge to optimally diagnose, stage, and manage intrahepatic cholangiocarcinoma (ICC). Imaging can not only diagnose and stage ICC, but it can also guide management. Hence, imaging is indispensable in the management of ICC. In this article, we review the pathology, epidemiology, genetics, clinical presentation, staging, pathology, radiology, and treatment of ICC.

Pancreatoscopy: An update

Per-oral pancreatoscopy (POPS) is an endoscopic procedure to visualize the main pancreatic duct. POPS specifically has the advantage of direct visualization of the pancreatic duct, allowing tissue acquisition and directed therapies such as stones lithotripsy. The aim of this review is to analyze and summarize the literature around pancreatoscopy. Pancreatoscopy consists of the classic technique of the mother-baby method in which a mini-endoscope is passed through the accessory channel of the therapeutic duodenoscope. Pancreatoscopy has two primary indications for diagnostic purpose. First, it is used for visualization and histological diagnosis of intraductal papillary mucinous neoplasms. In these cases, POPS is very useful to assess the extent of malignancy and for the study of the intraductal papillary mucinous neoplasm in order to guide the surgery resection margins. Second, it is used to determine pancreatic duct strictures, particularly important in cases of chronic pancreatitis, which is associated with both benign and malignant strictures. Therefore POPS allows differentiation between benign and malignant disease and allows mapping the extent of the tumor prior to surgical resection. Also tissue sampling is possible, but it can be technically difficult because of the limited maneuverability of the biopsy forceps in the pancreatic ducts. Pancreatoscopy can also be used for therapeutic purposes, such as pancreatoscopy-guided lithotripsy in chronic painful pancreatitis with pancreatic duct stones. The available data for the moment suggests that, in selected patients, pancreatoscopy has an important and promising role to play in the diagnosis of indeterminate pancreatic duct strictures and the mapping of main pancreatic duct intraductal papillary mucinous neoplasms. However, further studies are necessary to elucidate and validate the pancreatoscopy role in the therapeutic algorithm of chronic pancreatitis.

Differentiating peripheral cholangiocarcinoma in stages T1N0M0 and T2N0M0 from hepatic hypovascular nodules using dynamic contrast-enhanced MRI

Because cholangiocarcinoma shows no specific clinical signs or symptoms and presents with non-specific biological and tumor markers in the early stages, MRI findings often lack typical features before this lesion becomes symptomatic and might be mistaken for other liver lesions. An evaluation of relevant radiological findings in nodular cholangiocarcinoma (≤3 cm) in stages T1N0M0 and T2N0M0 is urgently needed. In our study, we compared two groups of liver hypovascular nodules and found that a distinct margin and enhanced area/nodule size >2/3 in the delayed phase were more frequently observed in cholangiocarcinoma cases than in metastatic nodule cases in which markedly high signal intensity on T2WI was common (p < 0.05). The results also revealed that in the both the portal and delayed phases, an enhanced area/nodule size >2/3 favored cholangiocarcinoma, whereas the presence of regional markedly higher SI on T2WI favored benign nodules. Furthermore, signs of peripheral washout in the delayed phase only appeared in cholangiocarcinoma cases.

Cholangiocarcinoma

Biliary tract cancer accounts for <1% of all cancers and affects chiefly an elderly population, with predominance in men. We distinguish cholangiocarcinoma (intrahepatic, hilar and distal) and gallbladder cancer, with different pathogenesis and prognosis. The treatment is based on surgery (whenever possible), radiotherapy in selected cases, and chemotherapy. The standard cytotoxic treatment for advanced/metastatic disease is represented by the combination of gemcitabine and cisplatin, whereas fluoropyrimidines are generally administered in second line setting. At the present time, no biologic drug demonstrated a clear efficacy in this cancer, although the molecular characterisation could provide a promising basis for experimental treatments. A good supportive care and an early palliative care are warranted in most patients and should be delivered as a part of a global approach.

Application of Contrast-Enhanced Sonography for Diagnosis of Space-Occupying Lesions in the Extrahepatic Bile Duct: Comparison With Conventional Sonography and Contrast-Enhanced Computed Tomography

OBJECTIVES

To investigate the application of contrast-enhanced sonography compared with conventional sonography and contrast-enhanced computed tomography (CT) for diagnosis of space-occupying lesions in the extrahepatic bile duct.

METHODS

Seventy-two patients with pathologic diagnoses of space-occupying lesions in the extrahepatic bile duct were retrospectively recruited. All patients underwent conventional sonography, contrast-enhanced sonography, and contrast-enhanced CT. The sensitivity, specificity, and diagnostic accuracy were compared.

RESULTS

Among the 72 patients, 11 cases were benign, and 61 were malignant. The diagnostic accuracy rates for conventional sonography, contrast-enhanced sonography, and contrast-enhanced CT were 66.67% (48 of 72), 90.28% (65 of 72), and 88.89% (64 of 72), respectively. The Youden index showed that contrast-enhanced sonography (0.811) was comparable with contrast-enhanced CT (0.720) and better than conventional sonography (0.159). There were significant differences in accuracy between conventional and contrast-enhanced sonography (P= .001) and conventional sonography and contrast-enhanced CT (P = .001); however, there was no significant difference between contrast-enhanced sonography and contrast-enhanced CT (P = .785). There were significant differences in sensitivity between conventional and contrast-enhanced sonography (P= .006) and conventional sonography and contrast-enhanced CT (P = .006) but no significant difference between contrast-enhanced sonography and contrast-enhanced CT (P > .99). There were no significant differences in specificity among the techniques (P > .05). There was a significant difference in the number of lesions with clear boundaries displayed: 16 on conventional sonography and 56 on contrast-enhanced sonography (P = .006).

CONCLUSIONS

Contrast-enhanced sonography can show the dynamic blood supply in space-occupying pathologic regions of the extrahepatic bile duct. The diagnostic accuracy of contrast-enhanced sonography in the extrahepatic bile duct was higher than that of conventional sonography and comparable with that of contrast-enhanced CT. Therefore, contrast-enhanced sonography may be a promising imaging technique for diagnosis of space-occupying lesions in the extrahepatic bile duct.

Hilar cholangiocarcinoma: Cross sectional evaluation of disease spectrum

Although hilar cholangiocarcinoma is relatively rare, it can be diagnosed on imaging by identifying its typical pattern. In most cases, the tumor appears to be centered on the right or left hepatic duct with involvement of the ipsilateral portal vein, atrophy of hepatic lobe on that side, and invasion of adjacent liver parenchyma. Multi-detector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP) are commonly used imaging modalities to assess the longitudinal and horizontal spread of tumor.

Clinical practice guidelines for the management of biliary tract cancers 2015: the 2nd English edition

BACKGROUND

The Japanese Society of Hepato-Biliary-Pancreatic Surgery launched the clinical practice guidelines for the management of biliary tract and ampullary carcinomas in 2008. Novel treatment modalities and handling of clinical issues have been proposed after the publication. New approaches for editing clinical guidelines, such as the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, also have been introduced for better and clearer grading of recommendations.

METHODS

Clinical questions (CQs) were proposed in seven topics. Recommendation, grade of recommendation and statement for each CQ were discussed and finalized by evidence-based approach. Recommendation was graded to grade 1 (strong) and 2 (weak) according to the concept of GRADE system.

RESULTS

The 29 CQs covered seven topics: (1) prophylactic treatment, (2) diagnosis, (3) biliary drainage, (4) surgical treatment, (5) chemotherapy, (6) radiation therapy, and (7) pathology. In 27 CQs, 19 recommendations were rated strong and 11 recommendations weak. Each CQ included the statement of how the recommendation was graded.

CONCLUSIONS

This guideline provides recommendation for important clinical aspects based on evidence. Future collaboration with cancer registry will be a key for assessment of the guidelines and establishment of new evidence. Free full-text articles and a mobile application of this guideline are available via http://www.jshbps.jp/en/guideline/biliary-tract2.html.

Adult bile duct strictures: role of MR imaging and MR cholangiopancreatography in characterization

Bile duct strictures in adults are secondary to a wide spectrum of benign and malignant pathologic conditions. Benign causes of bile duct strictures include iatrogenic causes, acute or chronic pancreatitis, choledocholithiasis, primary sclerosing cholangitis, IgG4-related sclerosing cholangitis, liver transplantation, recurrent pyogenic cholangitis, Mirizzi syndrome, acquired immunodeficiency syndrome cholangiopathy, and sphincter of Oddi dysfunction. Malignant causes include cholangiocarcinoma, pancreatic adenocarcinoma, and periampullary carcinomas. Rare causes include biliary inflammatory pseudotumor, gallbladder carcinoma, hepatocellular carcinoma, metastases to bile ducts, and extrinsic bile duct compression secondary to periportal or peripancreatic lymphadenopathy. Contrast material-enhanced magnetic resonance (MR) imaging with MR cholangiopancreatography is extremely helpful in the noninvasive evaluation of patients with obstructive jaundice, an obstructive pattern of liver function, or incidentally detected biliary duct dilatation. Some of these conditions may show characteristic findings at MR imaging-MR cholangiopancreatography that help in making a definitive diagnosis. Although endoscopic retrograde cholangiopancreatography with tissue biopsy or surgery is needed for the definitive diagnosis of many of these strictures, certain MR imaging characteristics of the narrowed segment (eg, thickened wall, long-segment involvement, asymmetry, indistinct outer margin, luminal irregularity, hyperenhancement relative to the liver parenchyma) may favor a malignant cause. Awareness of the various causes of bile duct strictures in adults and familiarity with their appearances at MR imaging-MR cholangiopancreatography are important for accurate diagnosis and optimal patient management.

Selective internal radiotherapy (SIRT) versus transarterial chemoembolization (TACE) for the treatment of intrahepatic cholangiocellular carcinoma (CCC): study protocol for a randomized controlled trial

Background

Cholangiocellular carcinoma is the second most common primary liver cancer after hepatocellular carcinoma. Over the last 30 years, the incidence of intrahepatic cholangiocellular carcinoma has risen continuously worldwide. Meanwhile, the intrahepatic cholangiocellular carcinoma has become more common than the extrahepatic growth type and currently accounts for 10-15% of all primary hepatic malignancies. Intrahepatic cholangiocellular carcinoma is typically diagnosed in advanced stages due to late clinical symptoms and an absence of classic risk factors. A late diagnosis precludes curative surgical resection. There is evidence that transarterial chemoembolization leads to better local tumor control and prolongs survival compared to systemic chemotherapy. New data indicates that selective internal radiotherapy, also referred to as radioembolization, provides promising results for treating intrahepatic cholangiocellular carcinoma.

Methods/Design

This pilot study is a randomized, controlled, single center, phase II trial. Twenty-four patients with intrahepatic cholangiocellular carcinoma will be randomized in a 1:1 ratio to receive either chemoembolization or radioembolization. Randomization will be stratified according to tumor load. Progression-free survival is the primary endpoint; overall survival and time to progression are secondary endpoints. To evaluate treatment success, patients will receive contrast enhanced magnetic resonance imaging every 3 months.

Discussion

Currently, chemoembolization is routinely performed in many centers instead of systemic chemotherapy for treating intrahepatic cholangiocellular carcinoma confined to the liver. Recently, radioembolization has been increasingly applied to cholangiocellular carcinoma as second line therapy after TACE failure or even as an alternative first line therapy. Nonetheless, no randomized studies have compared radioembolization and chemoembolization. Considering all this background information, we recognized a strong need for a randomized controlled trial (RCT) to compare the two treatments. Therefore, the present protocol describes the design of a RCT that compares SIRT and TACE as the first line therapy for inoperable CCC confined to the liver.

Trial registration

ClinicalTrials.gov, Identifier: NCT01798147, registered 16^th of February 2013.

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.

Imaging of malignancies of the biliary tract- an update

Malignancies of the biliary tract include cholangiocarcinoma, gallbladder cancers and carcinoma of the ampulla of Vater. Biliary tract adenocarcinomas are the second most common primary hepatobiliary cancer. Due to their slow growing nature, non-specific and late symptomatology, these malignancies are often diagnosed in advanced stages with poor prognosis. Apart from incidental discovery of gall bladder carcinoma upon cholecystectomy, early stage biliary tract cancers are now detected with computed tomography (CT) and magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP). Accurate characterization and staging of these indolent cancers will determine outcome as majority of the patients’ are inoperable at the time of presentation. Ultrasound is useful for initial evaluation of the biliary tract and gallbladder masses and in determining the next suitable modality for further evaluation. Multimodality imaging plays an integral role in the management of the biliary tract malignancies. The imaging techniques most useful are MRI with MRCP, endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound (EUS) and positron emission tomography (PET). In this review we will discuss epidemiology and the role of imaging in detection, characterization and management of the biliary tract malignancies under the three broad categories of cholangiocarcinomas (intra- and extrahepatic), gallbladder cancers and ampullary carcinomas.

Magnetic resonance evaluations of biliary malignancy and condition at high-risk for biliary malignancy: Current status

Tumors of the biliary tree are relatively rare; but their incidence is rising worldwide. There are several known risk factors for bile duct cancers, and these are seem to be associated with chronic inflammation of the biliary epithelium. Herein, 2 risk factors have been discussed, primary sclerosing cholangitis and reflux of pancreatic juice into the bile duct, as seen in such as an abnormal union of the pancreatic-biliary junction because magnetic resonance imaging (MRI) is used widely and effectively in the diagnosis of these diseases. When biliary disease is suspected, MRI can often help differentiate between benignity and malignancy, stage tumors, select surgical candidates and guide surgical planning. MRI has many advantages over other modalities. Therefore, MRI is a reliable noninvasive imaging tool for diagnosis and pre-surgical evaluation of bile duct tumors. Nowadays remarkable technical advances in magnetic resonance technology have expanded the clinical applications of MRI in case of biliary diseases. In this article, it is also discussed how recent developments in MRI contributes to the diagnosis of the bile duct cancer and the evaluation of patients with risk factors affecting bile duct cancer.

Role of positron emission tomography-computed tomography in gastrointestinal malignancies

Positron emission tomography (PET) has proved itself to be valuable in the evaluation of patients with a wide array of gastrointestinal (GI) malignancies. Subsequent development of fusion imaging with PET and computed tomography (PET-CT) scanners has significantly advanced the capabilities of imaging by combining the functional data of the(18)F-labeled glucose analogue fluorodeoxyglucose (FDG) with the conventional anatomic data provided by CT. This article reviews the evolving role of FDG PET-CT imaging in the initial assessment and monitoring of GI tumors. Specific applications are discussed, and normal variants and benign findings frequently encountered during PET-CT of the GI tract are reviewed.

Current management of cholangiocarcinoma

Cholangiocarcinoma is the second most common primary hepatobiliary malignancy after hepatocellular carcinoma and remains among the most difficult management problems faced by surgeons. Curative surgery is achieved in only 25% to 30% of patients. Local tumor extent, such as portal vein invasion and hepatic lobar atrophy, does not preclude resection. Long-term survival has been seen only in patients who underwent extensive liver resections, suggesting that bile-duct excision alone is less effective. The majority of patients have unresectable disease, with 20% to 30% incidence of distant metastasis at presentation. Unresectable patients should be referred for nonsurgical biliary decompression, and in potential curative resection candidates the use of biliary stents should be reduced. Liver transplantation provides the option of wide resection margins, expanding the indication of surgical intervention for selected patients who otherwise are not surgical candidates due to lack of functional hepatic reserve.

Intrahepatic mass-forming cholangiocarcinoma: enhancement patterns on gadoxetic acid-enhanced MR images

PURPOSE

To evaluate the enhancement patterns of intrahepatic mass-forming cholangiocarcinomas (IMCCs) with emphasis on the hepatobiliary phase (HBP) of gadoxetic acid-enhanced magnetic resonance (MR) imaging.

MATERIALS AND METHODS

This retrospective study was institutional review board approved, and the requirement for informed consent was waived. Fifty patients (41 men, nine women; mean age, 62.3 years; range, 44-76 years) with IMCC underwent unenhanced and gadoxetic acid-enhanced T1- and T2-weighted MR imaging including dynamic phase and hepatobiliary phase imaging between May 2008 and December 2010. Signal intensity and enhancement patterns of lesions were compared with those of the liver parenchyma in each phase. Conspicuity and margin sharpness of lesions on dynamic phase and HBP images were rated on a 4- or 5-point scale and compared by using the Wilcoxon signed-rank test. Percentage of relative enhancement was compared among pathologic subgroups by using the unpaired Student t test.

RESULTS

On dynamic phase images, 29 of 48 (60%) lesions showed a thin peripheral rim with centripetal or gradual progression. On HBP images, 48 of 50 (96%) IMCCs were hypointense, and two of 50 (4%) were hyperintense. Subjective ratings of conspicuity and margin sharpness were significantly higher on HBP (median scores, 5 and 4, respectively) (P < .001) than on the dynamic phase (median scores, 4 and 3, respectively) images (P < .001). Additional daughter nodules were found in five patients and intrahepatic metastasis was found in one. Percentage of relative enhancement on HBP images was significantly higher in moderately differentiated (66.4% ± 42.1) than in poorly differentiated (36.84% ± 21.5) tumors (P = .039) and in patients without (59.7% ± 28.8) than in those with (24.9% ± 14.7) (P = .036) lymph node metastasis.

CONCLUSION

The most prevalent enhancement pattern on gadoxetic acid-enhanced MR images of IMCCs was a thin peripheral rim with internal heterogeneous enhancement during the dynamic phase. HBP images showed increased lesion conspicuity and better delineation of daughter nodules and intrahepatic metastasis, which may aid in the diagnosis of IMCC.

Update of cholangioscopy and biliary strictures

Cholangioscopy remains another modality in the investigation of biliary strictures. At cholangioscopy, the “tumour vessel” sign is considered a specific sign for malignancy. Through its ability to not only visualise mucosa, but to take targeted biopsies, it has a greater accuracy, sensitivity and specificity for malignant strictures than endoscopic retrograde cholangiopancreatography guided cytopathological acquisition. Cholangioscopy however, is time consuming and costly, requires greater technical expertise, and should be reserved for the investigation of undifferentiated strictures after standard investigations have failed.

Case report: Cholangiocarcinoma in a choledochal cyst

Cholangiocarcinoma is a dreaded complication of unresected choledochal cysts, with an incidence approaching 20-30% in early adulthood. The risk of cholangiocarcinoma remains high where an internal drainage procedure has been performed and the cyst has been partially resected or left unresected. We report a case of cholangiocarcinoma occurring in an unresected choledochal cyst following a drainage procedure in infancy and highlight the role of PET/CT in its diagnosis.

Cholangiocarcinoma--controversies and challenges

Cholangiocarcinomas are a diverse group of tumors that are presumed to originate from the biliary tract epithelium either within the liver or the biliary tract. These cancers are often difficult to diagnose, their pathogenesis is poorly understood, and their dismal prognosis has resulted in a nihilistic approach to their management. The two major clinical phenotypes are intrahepatic, mass-forming tumors and large ductal tumors. Among the ductal cancers, lesions at the liver hilum are most prevalent. The risk factors, clinical presentation, natural history and management of these two types of cholangiocarcinoma are distinct. Efforts to improve outcomes for patients with these diseases are affected by several challenges to effective management. For example, designations based on anatomical characteristics have been inconsistently applied, which has confounded analysis of epidemiological trends and assessment of risk factors. The evaluation of therapeutic options, particularly systemic therapies, has been limited by a lack of appreciation of the different phenotypes. Controversies exist regarding the appropriate workup and choice of management approach. However, new and emerging tools for improved diagnosis, expanded indications for surgical approaches, an emerging role for locoregional and intrabiliary therapies and improved systemic therapies provide optimism and hope for improved outcomes in the future.

Mesothelin as a potential therapeutic target in human cholangiocarcinoma

Background: Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the two most common primary liver cancers, yet there have been no significant advances in effective therapeutics. Mesothelin has been reported as a new therapeutic target in various types of cancer. Here, we investigated the expression of mesothelin in liver cancer and its potential role as a novel therapeutic target for immunotherapy.

Methods: HCC and CCA specimens were examined by immunohistochemistry for mesothelin expression. Protein expression was assessed by immunoblotting and flow cytometry. The SS1P immunotoxin targeting mesothelin was evaluated in the well-established CCA cell lines HuCCT1, HuH-28, KMBC, KMCH, Mz-ChA-1 and OZ.

Results: We showed strong immunochemical mesothelin staining in 33% of the surgically resected CCA specimens and 3 of 6 CCA cell lines (OZ, KMBC and KMCH). No mesothelin staining was found in HCC or normal liver tissue. Mesothelin was primarily localized to the cellular plasma membrane and the mature form (molecular weight, ~40 kDa) was expressed at a high level in CCA tissues. Moreover, 22% of CCA specimens had a high mesothelin expression level which was comparable to the CCA cell line models. Interestingly, SS1P showed very high and specific growth inhibition when added to mesothelin-expressing CCA cells with IC₅₀ values ranging from 0.5 to 11 ng/mL.

Conclusions: Mesothelin is overexpressed in one-third of CCA tissues. SS1P targeting mesothelin reveals a remarkable single agent activity against CCA in vitro. These findings indicate a potential for SS1P in the immunotherapeutic treatment of CCA.

Signet ring cell carcinoma of the extrahepatic bile duct

Most tumors affecting the extrahepatic bile duct are adenocarcinomas; the other histologic types occur only rarely. We herein report the extremely rare case of signet ring cell carcinoma (SRCC) originating from the extrahepatic bile duct. A 55-year-old man was hospitalized for jaundice and pruritus. Computed tomography and positron emission tomography suggested the presence of distal extrahepatic bile-duct cancer. He underwent a pylorus preserving pancreaticoduodenectomy. A histologic study confirmed a signet ring cell neoplasm of the distal common bile duct. Because the upper resection margin was invaded by the tumor, he received postoperative concurrent chemoradiotherapy and four cycles of chemotherapy. The patient has survived with no evidence of recurrence for 2 years. This is the second case of primary SRCC of the distal extrahepatic bile duct reported in the literature; further reports of cases are warranted to determine the nature of SRCC in the extrahepatic bile duct.

Cholangiocarcinoma: has there been any progress?

Cholangiocarcinoma is the second most common primary hepatic tumour after hepatocellular carcinoma. Primary sclerosing cholangitis is one of the most commonly recognized risk factors for cholangiocarcinoma; however, approximately 90% of patients have no identifiable risk factors. Extrahepatic type is its most common presentation. Cholangiocarcinoma is considered to be a devastating disease, with a poor survival rate and few therapeutic options. Although surgical resection has been considered the best treatment option for localized cholangiocarcinoma, local recurrences of this cancer are very common, and imply persistent micro-metastatic disease in lymph nodes or at surgical margins, even after extended surgical resection. Consequently, the five year survival rate after attempted curative resection is only 20% to 40%. Early studies of liver transplantation for cholangiocarcinoma did not show a survival benefit and, currently, this tumour is considered to be an absolute contraindication for liver transplantation in most transplant centres worldwide. Recently, neoadjuvant chemoradiation in combination with liver transplantation for highly selected patients with cholangiocarcinoma has shown impressive results, with five-year survival rates at approximately 76% to 82%--similar to other standard indications for liver transplantation, such as hepatocellular carcinoma or hepatitis C-induced cirrhosis. However, this success of liver transplantation applies to only a subset of patients and most of the data originated from a single centre. Wider application of this strategy, especially for patients with potentially resectable disease, will require validation by other centres.

Synchronous development of HCC and CCC in the same subsegment of the liver in a patient with type C liver cirrhosis

As a result of having undergone computed tomography (CT), a 75-year-old woman with type-C liver cirrhosiswas shown to have two tumors on the ventral and dorsal sides of subsegment 3 (S3). The tumor on the ventral side was diagnosed as a classic hepatocellular carcinoma (HCC), while that on the dorsal side was considered atypical for a HCC. Although the indocyanine green (ICG) findings indicated poor hepatic reserve, the prothrombin time (PT) was relatively good. An operation was performed in February 2007; however, this resulted in exploratory laparotomy. Dynamic CT performed 12 mo after the operation revealed that the tumor on the dorsal side of S3 had apparently increased. The marginal portion of the tumor was shown to be in the early and parenchymal phases, while the internal portion was found to have grown only slightly in the delayed phase. We diagnosed this tumor as a cholangiocellular carcinoma (CCC). S3 subsegmentectomy was performed in April 2008. The tumor on the ventral side was pathologically diagnosed as a moderately differentiated HCC, and that on the dorsal side was diagnosed as a CCC. We can therefore report a rare case of synchronous development of HCC and CCC in the same subsegment of the liver in a patient with type-C liver cirrhosis. We also add a literature review for all the reported cases published in Japan and around the world, and summarize the features of double cancer exhibiting both HCC and CCC.

Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009

Several advances in diagnosis, treatment and palliation of cholangiocarcinoma (CC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. CC is a relatively rare tumor and the main risk factors are: chronic inflammation, genetic predisposition and congenital abnormalities of the biliary tree. While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down. The only curative treatment for CC is surgical resection with negative margins. Liver transplantation has been proposed only for selected patients with hilar CC that cannot be resected who have no metastatic disease after a period of neoadjuvant chemo-radiation therapy. Magnetic resonance imaging/magnetic resonance cholangiopancreatography, positron emission tomography scan, endoscopic ultrasound and computed tomography scans are the most frequently used modalities for diagnosis and tumor staging. Adjuvant therapy, palliative chemotherapy and radiotherapy have been relatively ineffective for inoperable CC. For most of these patients biliary stenting provides effective palliation. Photodynamic therapy is an emerging palliative treatment that seems to provide pain relief, improve biliary patency and increase survival. The clinical utility of other emerging therapies such as transarterial chemoembolization, hepatic arterial chemoinfusion and high intensity intraductal ultrasound needs further study.

MR imaging findings of early bile duct cancer

PURPOSE

To retrospectively evaluate the MR imaging features of early bile duct cancer and to correlate them with the clinicopathologic findings.

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board, and informed consent was waived. Seventeen patients with surgically proven early bile duct cancer who had undergone preoperative MR cholangiopancreatography with gadolinium-enhanced MR imaging, were included in this study. Two, experienced radiologists evaluated the MR images in consensus regarding the following findings: tumor number and morphology; signal intensity of the tumor; sharpness of the outer border of the bile duct wall; enhancement pattern of the tumor; and the presence of enlarged peribiliary lymph nodes. Another radiologist measured the SNR of the tumor and bile duct wall on gadolinium-enhanced MRI during the dynamic phases to evaluate the tumor enhancement degree.

RESULTS

In all patients, MR imaging demonstrated single or multiple intraluminal bile duct masses showing a sharply defined outer margin. The most common enhancement pattern of the biliary lesions showed heterogeneous amorphous enhancement or heterogeneous enhancement with central, dot-like structures or vascular structures (76.5%, 13/17 patients). The difference of SNR between bile duct and tumor was greatest in the equilibrium phase (P < 0.05).

CONCLUSION

MRCP combined with dynamic contrast-enhanced MRI can be useful for detecting early bile duct cancers. Common MR findings of early bile duct cancer include one or more inhomogeneously enhancing intraductal masses with clear outer margins and preservation of the bile duct wall.

Cholangiocarcinoma: current and novel imaging techniques

The radiologic manifestations of cholangiocarcinomas are extremely diverse, since these tumors vary greatly in location, growth pattern, and histologic type. Familiarity with the imaging manifestations of cholangiocarcinomas is important for accurate detection and characterization of these tumors and assessment of resectability. Advances in imaging techniques have led to the availability of an array of modalities that, used independently or in combination, can aid in the accurate diagnosis and evaluation of cholangiocarcinomas in preparation for advanced surgical procedures and treatment planning. Response to novel targeted therapies can also be assessed with newer imaging tools. Hence, knowledge of current and emerging imaging applications is essential for correct diagnosis and appropriate management of these tumors.

Current status of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a rare primary liver cancer with a global increasing trend in recent years. Symptoms tend to be vague and insidious in development, often are diagnosed at an advanced stage when only palliative approaches can be used with a median survival rate of months. Comparing with HCC, ICC tends to spread to lymph nodes early, and is rarely limited to the regional lymph nodes, with a frequent postoperative recurrence. Surgery is the only choice of curative therapy for ICC, but recently no consensus has been established for operation. Thus, more data from multiple centers and more cases are needed. Generally speaking, current adjunctive therapy cannot clearly improve survival. Further research is needed to find more effective radio- and chemotherapeutic regimens.

Hilar cholangiocarcinoma: MRI/MRCP in staging and treatment planning

The role of MR imaging in hilar cholangiocarcinoma is to confirm/reach a diagnosis and to assess resectability. Hilar cholangiocarcinoma shows the same signal intensity pattern of peripheral tumors both on T1- and T2-weighted images. On magnetic resonance cholangiopancreatography (MRCP) images, hilar cholangiocarcinoma appears as a moderately irregular thickening of the bile duct wall (5 mm) with symmetric upstream dilation of the intrahepatic bile ducts. The aim of preoperative investigation in Klatskin tumors typically requires the evaluation of the level of biliary obstruction, the intrahepatic tumor spread, and the vascular involvement; it also needs to show any atrophy-hypertrophy complex. Because of its intrinsic high tissue contrast and multiplanar capability, MR imaging and MRCP are able to detect and preoperatively assess patients with cholangiocarcinoma, investigating all involved structures such as bile ducts, vessels and hepatic parenchyma. The main reason for surgical/imaging discrepancy is represented by the microscopic diffusion along the mucosa and in the perineural space.

Primary Cancer of the Liver and Biliary Duct

F-18-FDG PET and PET/CT are useful for staging, predicting the prognosis, and evaluating recurrence and treatment response in hepatocellular carcinomas (HCCs) and cholangiocarcinomas. Increased F-18-FDG uptake within tumors could be a surrogate marker of aggressive behavior and poor clinical outcome, despite high false-negative rates in detecting primary intrahepatic low-grade HCCs and periductal-infiltrating cholangiocarcinomas. Dualtracer PET or PET/CT using carbon-11-acetate and F-18-FDG will increase diagnostic performance in HCC.

Cholangiocarcinoma

Cholangiocarcinoma is a primary hepatic malignancy originating from bile duct epithelium. It is the second most common primary hepatic neoplasia, and its incidence has increased within the last 3 decades. Although several risk factors have been identified, especially chronic biliary tract inflammation, most patients with cholangiocarcinoma have no identifiable risk factors. Recent developments in radiologic and molecular diagnostic methods have helped in the diagnosis of this disease. The only curative therapy is surgical resection or liver transplantation. For patients with advanced stage disease, survival remains limited. With growing understanding of the molecular and cellular etiology of this disease, new targeted therapies are being developed.

The multidisciplinary management of gastrointestinal cancer. Biliary tract cancers: from pathogenesis to endoscopic treatment

Cholangiocarcinoma is the second most common hepatobiliary tumour. Even if it is a rare tumour, its incidence is increasing over these last decades, probably due in part to a better knowledge of the disease and to an improvement of the diagnosis. Accurate diagnosis and staging are key steps to determine the appropriate treatment. The only curative treatment of this cancer is surgical resection. To date, no neoadjuvant or adjuvant treatments have ever proved any survival benefit, and are not recommended outside clinical trials. Liver transplantation (with or without neoadjuvant treatment) can be an option for highly selected cases. Unfortunately, these tumours are generally diagnosed at an advanced stage or are unresectable. For most of these patients, palliative therapeutic options exist and are in further development, based on multimodal promising combinations including chemotherapy, targeted agents, radiation, endoscopic stenting and photodynamic treatment.