Mimics of cholangiocarcinoma: spectrum of disease

Imaging of Biliary Tree Abnormalities

Pathologic conditions of the biliary system, although common, can be difficult to diagnose clinically. Challenges in biliary imaging include anatomic variants and the dynamic nature of the biliary tract, which can change with age and intervention, blurring the boundaries of normal and abnormal. Choledochal cysts can have numerous appearances and are important to diagnose given the risk of cholangiocarcinoma potentially requiring surgical resection. Choledocholithiasis, the most common cause of biliary dilatation, can be difficult to detect at US and CT, with MRI having the highest sensitivity. However, knowledge of the imaging pitfalls of MRI and MR cholangiopancreatography is crucial to avoid misinterpretation. Newer concepts in biliary tract malignancy include intraductal papillary biliary neoplasms that may develop into cholangiocarcinoma. New paradigms in the classification of cholangiocarcinoma correspond to the wide range of imaging appearances of the disease and have implications for prognosis. Accurately staging cholangiocarcinoma is imperative, given expanding curative options including transplant and more aggressive surgical options. Infections of the biliary tree include acute cholangitis or recurrent pyogenic cholangitis, characterized by obstruction, strictures, and central biliary dilatation. Inflammatory conditions include primary sclerosing cholangitis, which features strictures and fibrosis but can be difficult to differentiate from secondary causes of sclerosing cholangitis, including more recently described entities such as immunoglobulin G4-related sclerosing cholangitis and COVID-19 secondary sclerosing cholangitis. The authors describe a wide variety of benign and malignant biliary tract abnormalities, highlight differentiating features of the cholangitides, provide an approach to interpretation based on the pattern of imaging findings, and discuss pearls and pitfalls of imaging to facilitate accurate diagnosis. ©RSNA, 2024 Supplemental material is available for this article.

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.

Imaging and Clinical Findings of Xanthogranulomatous Inflammatory Disease of Various Abdominal and Pelvic Organs: A Pictorial Essay

Xanthogranulomatous (XG) inflammatory disease is a rare benign disease involving various organs, including the gallbladder, bile duct, pancreas, spleen, stomach, small bowel, colon, appendix, kidney, adrenal gland, urachus, urinary bladder, retroperitoneum, and female genital organs. The imaging features of XG inflammatory disease are nonspecific, usually presenting as a heterogeneous solid or cystic mass. The disease may also extend to adjacent structures. Due to its aggressive nature, it is occasionally misdiagnosed as a malignant neoplasm. Herein, we review the radiological features and clinical manifestations of XG inflammatory diseases in various organs of the abdomen and pelvis.

Magnetic Resonance Cholangiopancreatography (MRCP) Findings in a Patient With AIDS Cholangiopathy and Cryptosporidiosis

AIDS cholangiopathy is a rare condition characterized by intra- and extra-hepatic ductal strictures causing biliary obstruction primarily in individuals with advanced HIV infection and low clusters of differentiation 4 (CD4) count. This case report presents a male patient with a history of HIV, poor adherence to antiretroviral therapy (ART), and chronic cryptosporidiosis infection, who exhibited clinical and radiological findings consistent with advanced immunocompromise and AIDS cholangiopathy. The patient presented with respiratory symptoms, weight loss, renal dysfunction, and elevated liver enzymes. Imaging studies, including ultrasound and magnetic resonance cholangiopancreatography (MRCP), revealed diffuse biliary dilatation and stricturing, indicative of cholangiopathy. Subsequent endoscopic retrograde cholangiopancreatography (ERCP) with stent placement was performed to manage the biliary obstruction. This case highlights the importance of considering AIDS cholangiopathy in HIV patients with poor ART compliance who present with biliary obstruction symptoms or cholestatic liver enzyme abnormalities. Prompt diagnostic evaluation using MRCP or ERCP can aid in confirming the diagnosis and guiding appropriate therapeutic interventions, including endoscopic management and initiation of ART.

Bile Duct Lithiasis Mimicking a Perihilar Cholangiocarcinoma-An Endless Dilemma: A Case Report

Hilar bile duct strictures are mostly caused by malignant lesions. The morphological appearance of perihilar cholangiocarcinomas in various imaging modalities have other malignant and even benign mimics, which pose challenges to an accurate diagnosis and treatment and drive to futile surgery. Herein, we present the case of a 50-year-old woman admitted with jaundice and abdominal pain, elevated bilirubin level, liver function tests and carbohydrate antigen 19-9 level. Magnetic resonance cholangio-pancreatography (MR-CP) and the computed tomography with contrast enhancement revealed a suspected extrahepatic cholangiocarcinoma of the common bile duct. Further spontaneous resolution of the scenario, confirmed by diagnostic assessment, changed the clinical hypothesis in favor of a non-oncological disease. Indeed, the multidisciplinary evaluation supported a diagnosis of transient cholangitis secondary to non-evident intrahepatic lithiasis rather than cholangiocarcinoma. After a 26-month follow-up, the patient was asymptomatic with normal tumor markers and laboratory data. Consecutive MR-CPs showed no suspicion of malignancy. This case report underlines the need for an accurate preoperative assessment in patients with suspected cholangiocarcinoma.

Targeting the Sequences of Circulating Tumor DNA of Cholangiocarcinomas and Its Applications and Limitations in Clinical Practice

Cholangiocarcinoma is a malignant epithelial tumor arising from bile ducts that is frequently fatal. Diagnosis is difficult due to tumor location in the biliary tract. Earlier diagnosis requires less invasive methods of identifying effective biomarkers for cholangiocarcinoma. The present study investigated the genomic profiles of cell-free DNA (cfDNA) and DNA from corresponding primary cholangiocarcinomas using a targeted sequencing panel. Somatic mutations in primary tumor DNA and circulating tumor DNA (ctDNA) were compared and clinical applications of ctDNA validated in patients with cholangiocarcinoma. A comparison of primary tumor DNA and ctDNA identified somatic mutations in patients with early cholangiocarcinomas that showed clinical feasibility for early screening. The predictive value of single-nucleotide variants (SNVs) of preoperative plasma cfDNA positive for somatic mutations of the primary tumor was 42%. The sensitivity and specificity of postoperative plasma SNVs in detecting clinical recurrence were 44% and 45%, respectively. Targetable fibroblast growth factor receptor 2 (FGFR2) and Kirsten rat sarcoma virus (KRAS) mutations were detected in 5% of ctDNA samples from patients with cholangiocarcinoma. These findings showed that genomic profiling of cfDNA was useful in clinical evaluation, although ctDNA had limited ability to detect mutations in cholangiocarcinoma patients. Serial monitoring of ctDNA is important clinically and in assessing real-time molecular aberrations in cholangiocarcinoma patients.

Terminal fucosylation of haptoglobin in cancer-derived exosomes during cholangiocarcinoma progression

Background

Cholangiocarcinoma (CCA) is a silent tumor with a high mortality rate due to the difficulty of early diagnosis and prediction of recurrence even after timely surgery. Serologic cancer biomarkers have been used in clinical practice, but their low specificity and sensitivity have been problematic. In this study, we aimed to identify CCA-specific glycan epitopes that can be used for diagnosis and to elucidate the mechanisms by which glycosylation is altered with tumor progression.

Methods

The serum of patients with various cancers was fractioned into membrane-bound and soluble components using serial ultracentrifugation. Lectin blotting was conducted to evaluate glycosylation. Proteins having altered glycosylation were identified using proteomic analysis and further confirmed using immunoblotting analysis. We performed HPLC, gene analysis, real-time cargo tracking, and immunohistochemistry to determine the origin of CCA glycosylation and its underlying mechanisms. Extracellular vesicles (EV) were isolated from the sera of 62 patients with CCA at different clinical stages and inflammatory conditions and used for glycan analysis to assess their clinical significance.

Results

The results reveal that glycosylation patterns between soluble and membrane-bound fractions differ significantly even when obtained from the same donor. Notably, glycans with α1-3/4 fucose and β1-6GlcNAc branched structures increase specifically in membrane-bound fractions of CCA. Mechanically, it is primarily due to β-haptoglobin (β-Hp) originating from CCA expressing fucosyltransferase-3/4 (FUT 3/4) and N-acetylglucosaminyltransferase-V (MGAT5). Newly synthesized β-Hp is loaded into EVs in early endosomes via a KFERQ-like motif and then secreted from CCA cells to induce tumor progression. In contrast, β-Hp expressed by hepatocytes is secreted in a soluble form that does not affect CCA progression. Moreover, evaluation of EV glycosylation in CCA patients shows that fucosylation level of EV-Hp gradually increases with tumor progression and decreases markedly when the tumors are eliminated by surgery.

Conclusion

This study suggests that terminal fucosylation of Hp in cancer-derived exosomes can be a novel glycan marker for diagnosis and prognosis of CCA. These findings highlight the potential of glycan analysis in different fractions of serum for biomarker discover for other diseases. Further research is needed to understand the role of fucosylated EVs on CCA progression.

Secondary sclerosing cholangitis: mimics of primary sclerosing cholangitis

Sclerosing cholangitis is a chronic cholestatic disease characterized by stricturing, beading, and obliterative fibrosis of the bile ducts. Sclerosing cholangitis is considered primary (PSC) if no underlying etiology is identified or secondary (SSC) if related to another identifiable cause. In this article, we will review the clinical features, pathogenesis, diagnosis, and imaging findings of PSC and SSC, with an emphasis on features that may aid in the distinction of these entities. We will also discuss various etiologies of SSC including recurrent pyogenic cholangitis, other infectious etiologies, ischemic damage, toxic insults, and immunologic, congenital, and miscellaneous causes, highlighting the unique imaging findings and clinical context of each diagnosis.

[Portal Biliopathy Misdiagnosed as Hilar Cholangiocarcinoma]

Portal biliopathy refers to the changes in the bile duct caused by portal vein thrombosis or obstruction. It is assumed to be caused by cavernous transformation due to the development of the venous system surrounding the bile duct, but the exact pathology is still unknown. Biliary morphologic abnormalities of portal biliopathy are discovered incidentally on radiographic images, but it is sometimes difficult to differentiate them from cholangiocarcinoma. Given the poor prognosis of cholangiocarcinoma, a surgical approach can be considered when the diagnosis is uncertain. Herein, we report a case of portal biliopathy with bile ductal wall thickening, which was diagnosed after surgical resection was performed due to the presumed diagnosis of cholangiocarcinoma.

Xanthogranulomatous cholangitis mimicking cholangiocarcinoma: Case report and review of literature

Introduction

Xanthogranulomatous cholangitis is an extremely rare diagnosis and is believed to be an extension of xanthogranulomatous cholecystitis, a benign inflammatory process characterized by lipid-laden foamy macrophages (called “xanthoma cells”) occurring in a background of chronic inflammation consisting of lymphocytes, plasma cells, and eosinophils. Here, we report a case of xanthogranulomatous cholangitis mimicking cholangiocarcinoma.

Case presentation

A 72 year old male with history of recurrent cholangitis had preoperative workup highly suggestive of intrahepatic cholangiocarcinoma. He underwent right hepatectomy and portal lymphadenectomy, with pathology showing xanthogranulomatous cholangitis, with no evidence of malignancy. Interestingly, the patient did not have xanthogranulomatous cholecystitis.

Discussion

We reviewed the current literature on xanthogranulomatous cholangitis, and identified only 14 previously reported cases. In our case series, there were six female and eight male patients. Among the 14 patients, 11 presented to the hospital with jaundice. Twelve patients had preoperative workup concerning for malignancy. The diagnosis of xanthogranulomatous cholangitis was confirmed through pathology in 13 patients, and through endoscopic ultrasound biopsy in one patient. In our review, seven patients had associated xanthogranulomatous cholecystitis, three patients had an isolated case of xanthogranulomatous cholangitis, and four patients had unknown status. Our patient is the fourth case of isolated xanthogranulomatous cholangitis without xanthogranulomatous cholecystitis.

Conclusion

Xanthogranulomatous cholangitis is a very rare phenomenon that can lead to benign strictures of the bile ducts, especially in the setting of recurrent cholangitis. It can mimic malignancies, such as cholangiocarcinoma, and should be considered in the differential diagnosis.

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Xanthogranulomatous cholangitis is an extremely rare inflammatory process.

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It involves lipid-laden macrophages of the bile duct.

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Patients with xanthogranulomatous cholangitis frequently present with jaundice.

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It can mimic malignancies, including bile duct, liver, gallbladder, and pancreatic cancers.

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It should be included in the differential diagnosis of biliary abnormalities

Imaging mimickers of cholangiocarcinoma: a pictorial review

Cholangiocarcinoma (CCA) is the second most common primary hepatobiliary malignancy and presents as three separate morphological subtypes; namely mass-forming, periductal-infiltrating, and intraductal-growing patterns. Each of these subtypes have distinct imaging characteristics, as well as a variety of benign and malignant mimics, making accurate diagnosis of CCA on imaging challenging. Whilst histopathological examination is required to arrive at a definitive diagnosis, it is still important for radiologists to be cognizant of these entities and provide reasonable differential diagnoses, as these potentially have a large impact on patient management. This pictorial essay illustrates the three morphological subtypes of CCA, as well as some important mimics for each subtype, that are encountered in clinical practice.

Integrated prognostication of intrahepatic cholangiocarcinoma by contrast-enhanced computed tomography: the adjunct yield of radiomics

Purpose

To test radiomics for prognostication of intrahepatic mass-forming cholangiocarcinoma (IMCC) and to develop a comprehensive risk model.

Methods

Histologically proven IMCC (representing the full range of stages) were retrospectively analyzed by volume segmentation on baseline hepatic venous phase computed tomography (CT), by two readers with different experience (R1 and R2). Morphological CT features included: tumor size, hepatic satellite lesions, lymph node and distant metastases. Radiomic features (RF) were compared across CT protocols and readers. Univariate analysis against overall survival (OS) warranted ranking and selection of RF into radiomic signature (RSign), which was dichotomized into high and low-risk strata (RSign*). Models without and with RSign* (Model 1 and 2, respectively) were compared.

Results

Among 78 patients (median follow-up 262 days, IQR 73–957), 62/78 (79%) died during the study period, 46/78 (59%) died within 1 year. Up to 10% RF showed variability across CT protocols; 37/108 (34%) RF showed variability due to manual segmentation. RSign stratified OS (univariate: HR 1.37 for R1, HR 1.28 for R2), RSign* was different between readers (R1 0.39; R2 0.57). Model 1 showed AUC 0.71, which increased in Model 2: AUC 0.81 (p < 0.001) and AIC 89 for R1, AUC 0.81 (p = 0.001) and AIC 90.2 for R2.

Conclusion

The use of RF into a unified RSign score stratified OS in patients with IMCC. Dichotomized RSign* classified survival strata, its inclusion in risk models showed adjunct yield. The cut-off value of RSign* was different between readers, suggesting that the use of reference values is hampered by interobserver variability.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-021-03183-9.

Endoscopic Evaluation of Biliary Strictures: Current and Emerging Techniques

The diagnosis of biliary strictures in clinical practice can be challenging. Discriminating between benign and malignant biliary strictures is important to prevent the morbidity and mortality associated with incorrect diagnoses. Missing a malignant biliary stricture may delay surgery, resulting in poor prognostic outcomes. Conversely, it has been demonstrated that approximately 20% of patients who undergo surgery for suspected biliary malignancies have a benign etiology on histopathology. Traditional tissue sampling using endoscopic retrograde cholangiography does not always produce a definitive diagnosis, with a considerable proportion of cases remaining as indeterminate biliary strictures. Recent advances in endoscopic techniques have the potential to improve the diagnostic and prognostic accuracy of biliary strictures.

Cholangiocarcinoma - Part 2, Tumoral and Nontumoral Mimics and Imaging Features Helpful in Differentiation

Each of the 3 morphological subtypes of cholangiocarcinoma has a different set of imaging differentials. Emulators of mass-forming cholangiocarcinoma include other primary and secondary hepatic malignancies, benign tumors and tumor-like mimics such as abscess, hemangioma and confluent hepatic fibrosis. Benign inflammatory biliary strictures constitute the major differential of periductal-infiltrative type and intraductal calculi are the main consideration for intraductal-growth type. CT and MRI are the standard imaging tools for characterization of cholangiocarcinoma and differentiating it from close mimics. Here we will describe the various tumoral and non-tumoral mimics of cholangiocarcinoma and discuss specific imaging features useful in differentiation.

Non-neoplastic cholangiopathies: an algorithmic approach

Cholangiopathies are chronic diseases that affect the bile ducts, comprising a heterogeneous group of progressive and potentially fatal entities. The diagnosis of these diseases is a great challenge for radiologists because of the overlapping of their clinical, biochemical, and imaging findings. Nevertheless, identifying the precise etiology is crucial, given that the therapeutic options are distinct and influence the prognosis of the patient. The purpose of this review article is to discuss some of the non-neoplastic causes of cholangiopathies and to provide a useful diagnostic algorithm.

Early detection of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CC) is a malignant tumor which arises from the biliary epithelium and most cases represent adenocarcinoma. CC can be classified into intrahepatic CC (ICC), perihilar CC, and distal CC, based on the site of anatomic origin. The incidence of ICC is increasing in both Western and Eastern countries, while that of extrahepatic cholangiocarcinoma remains fairly stable. ICC infiltrates into adjacent nerves and lymphatic vessels, resulting in progressive disease with a poor prognosis; thus, early detection of ICC is critical for achieving better outcomes and providing better patient care. However, it is difficult for clinicians to detect an ICC, especially in its early stage. Different from hepatocellular carcinoma, the lack of surveillance system for the high-risk group of CC does not allow for a reliable screening examination. In this context, for early detection and diagnosis of ICC, radiologists need to know predisposing conditions that can lead to the development of ICC, such as chronic biliary or hepatic inflammation, primary sclerosing cholangitis, congenital biliary diseases, and other conditions. In this article, we discuss and illustrate the radiologic features of ICC with special attention to early disease stages and of predisposing conditions of ICC.

Metastasis of ovarian cancer to the bile duct: a case report

Background

Ovarian cancer typically spreads along the peritoneum or metastasizes through the blood or lymphatic stream. The bile duct is an extremely rare site of ovarian cancer-associated metastases.

Case presentation

A 55-year-old female underwent surgery for advanced left ovarian cancer 2 years ago. She was diagnosed with ovarian serous adenocarcinoma with multiple peritoneal metastases. She received chemotherapy for the residual peritoneal metastases. She achieved a clinical complete response and was followed up with imaging examinations for 1 year. She then complained of dark urine, yellowish discoloration of the eyes, and weight loss. Computed tomography showed an approximately 10-mm solid tumor at the hepatic hilum. Simultaneously, multiple peritoneal metastases were detected in the abdominal and pelvic cavity. Intraductal ultrasonography suggested that the hepatic hilum tumor was located in the bile duct wall. Tumor biopsy and brush cytology of the bile duct indicated atypical cells suspicious for carcinoma. After percutaneous transhepatic portal embolization, she underwent right hepatectomy and extrahepatic bile duct resection for the hepato-hilar tumor. The histopathological features were dysplastic cells with hyperchromatic nuclei and no dysplastic cells in the native biliary epithelium. Immunohistochemical staining revealed that the tumor cells were positive for CK-7 and WT-1 and negative for CK-20 and ER. These results suggested that the tumor was a metastasis of the ovarian serous adenocarcinoma.

Conclusion

This may be the first case of ovarian cancer metastasis to the bile duct. While it is extremely rare, ovarian cancer may metastasize to the hepatic duct, mimicking hilar cholangiocarcinoma.

Hepatic involvement in sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. Liver is frequently involved in the pathological process. Wide range of clinical manifestations can be seen: from asymptomatic lesion with normal liver function tests to cirrhosis with portal hypertension. Biopsy plays the key role in diagnosis of the hepatic sarcoidosis. It is essential for morphological diagnosis to exclude other causes of granulomatous liver disease, most often - primary biliary cholangitis. Nowadays there are no standard treatment protocols for patients with hepatic sarcoidosis.

Cholangiocarcinoma in a Resected Biliary Cyst: Importance of Follow-up

Biliary cysts are rare cystic dilatations of the biliary tree. Biliary cysts are positively associated with several significant complications, amongst them, cholangiocarcinoma befalls the most dreadful one. The elevated incidence is 20-30% in the unresected cyst and 0.7% in resected cysts. Magnetic resonance imaging (MRI) scan, magnetic resonance cholangiopancreatography (MRCP) or a contrast-enhanced computed tomography (CECT) is applied for the initial diagnostic study but the ultimate diagnosis ordinarily requires the tissue biopsy. Currently, the sole curative option involves the complete surgical resection of the lesion, with standard chemotherapy and active radiation applied as an alternative for the unresectable tumors. Despite the curative surgery the percentage of eternal recurrence of the tumor indefinitely persists, and effective post-surgical surveillance is reasonably demanded. We report a case of 29-year-old female with local recurrence of cholangiocarcinoma in a previously resected biliary cyst type I. The curative resection of the choledochal cyst only minimizes the considerable risk of the possible development of future cholangiocarcinoma but it does not completely prevent it. The appropriate follow-up for potential patients who have been typically treated for a biliary cyst is unclear. The lethal course of cholangiocarcinoma is believed due to its slow asymptomatic growing phase. Therefore, to adequately screen for malignancy, periodic imaging along with annual liver tests represents a reasonable approach to prevent the possible development of this appalling complication.

Serum cell-free DNA methylation of OPCML and HOXD9 as a biomarker that may aid in differential diagnosis between cholangiocarcinoma and other biliary diseases

BACKGROUND

Cholangiocarcinoma (CCA) is a fatal cancer of the bile duct epithelial cell lining. The misdiagnosis of CCA and other biliary diseases may occur due to the similarity of clinical manifestations and blood tests resulting in inappropriate or delayed treatment. Thus, an accurate and less-invasive method for differentiating CCA from other biliary diseases is inevitable.

METHODS

We quantified methylation of OPCML, HOXA9, and HOXD9 in serum cell-free DNA (cfDNA) of CCA patients and other biliary diseases using methylation-sensitive high-resolution melting (MS-HRM). Their potency as differential biomarkers between CCA and other biliary diseases was also evaluated by using receiver operating characteristic (ROC) curves.

RESULTS

The significant difference of methylation levels of OPCML and HOXD9 was observed in serum cfDNA of CCA compared to other biliary diseases. Assessment of serum cfDNA methylation of OPCML and HOXD9 as differential biomarkers of CCA and other biliary diseases showed the area under curve (AUC) of 0.850 (0.759-0.941) for OPCML which sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 80.00%, 90.00%, 88.88%, 81.81%, and 85.00%, respectively. The AUC of HOXD9 was 0.789 (0.686-0.892) with sensitivity, specificity, PPV, NPV, and accuracy of 67.50%, 90.00%, 87.09%, 73.46%, and 78.75%, respectively. The combined marker between OPCML and HOXD9 showed sensitivity, specificity, PPV, and NPV of 62.50%, 100%, 100%, and 72.72%, respectively, which may be helpful to prevent a misdiagnosis between CCA and other biliary diseases.

CONCLUSIONS

Our findings suggest the application of serum cfDNA methylation of OPCML and HOXD9 for differential diagnosis of CCA and other biliary diseases due to its less invasiveness and clinically practical method which may benefit the patients by preventing the misdiagnosis of CCA and avoiding unnecessary surgical intervention.

Benign Sclerosing and Fibrosing Conditions of the Abdomen and Their Potential Mimics

The process of abnormal reparative or reactive processes in the abdominal cavity, can lead to sclerosis and fibrous deposition. The relatively recent discovery of an IgG4 subgroup of immune mediated sclerosing disease 1,2 has thrown some light on the pathophysiology of these conditions. Firstly, our pictorial review aims to describe imaging findings to enhance the general radiologist's recognition and interpretation of this varied group of benign sclerotic and fibrotic abdominal processes. Secondly, along with the imaging findings, we bring into discussion the potential mimics of these pathologic processes to minimise interpretational errors. Moreover, some of the mimics of these processes are in the spectrum of malignant disease. Most importantly, to ensure a correct diagnosis thorough clinical and histopathological assessment are required to support the imaging findings presented in this review.

A novel nomogram for the prediction of intrahepatic cholangiocarcinoma in patients with intrahepatic lithiasis complicated by imagiologically diagnosed mass

Background

Accurate preoperative diagnosis of intrahepatic cholangiocarcinoma (ICC) among patients with imagiologically intrahepatic lithiasis (IHL) complicated by mass is crucial for timely and effective surgical intervention. The aim of the present study was to develop a nomogram to identify ICC associated with IHL (IHL-ICC).

Patients and methods

Data were obtained from a total of 252 consecutive patients with IHL complicated by mass. Multivariate logistic regression analysis was conducted to identify the clinicopathologic and imagiological characteristics that were potentially associated with ICC. A nomogram was developed based on the results of the multivariate analysis, and the value for prediction of ICC was assessed.

Results

The study revealed six potential predictors for IHL-ICC, including comprehensive imagiological diagnosis, biliary tract operation history, fever, ascites, cancer antigen (CA) 19-9, and carcinoembryonic antigen (CEA). The optimal cutoff value was 3.75 μg/L for serum CEA and 143.15 U/mL for serum CA 19-9. The accuracy of the nomogram in predicting ICC was 78.5%. The Youden index provided a value of 0.348, corresponding to a cutoff of 95 points, with an area under the curve of 0.863.

Conclusion

The nomogram holds promise as a novel and accurate tool in identifying IHL-ICC for hepatectomy, and in the differentiation of benign occupying lesions in IHL patients, resulting in the avoidance of unnecessary surgical resection.

Portal cavernoma cholangiopathy: diagnosis, imaging, and intervention

The term portal cavernoma cholangiopathy refers to the biliary tract abnormalities that accompany extrahepatic portal vein obstruction (EHPVO) and subsequent cavernous transformation of the portal vein. EHPVO is a primary vascular disorder of the portal vein in children and adults manifested by longstanding thrombosis of the main portal vein. Nearly all patients with EHPVO have manifestations of portal cavernoma cholangiopathy, such as extrinsic indentation on the bile duct and mild bile duct narrowing, but the majority are asymptomatic. However, progressive portal cavernoma cholangiopathy may lead to severe complications, including secondary biliary cirrhosis. A spectrum of changes is seen radiologically in the setting of portal cavernoma cholangiopathy, including extrinsic indentation of the bile ducts, bile duct stricturing, bile duct wall thickening, angulation and displacement of the extrahepatic bile duct, cholelithiasis, choledocholithiasis, and hepatolithiasis. Radiologists must be aware of this disorder in order to provide appropriate imaging evaluation and interpretation, to facilitate appropriate treatment and to distinguish this entity from its potential radiologic mimics.

Parasitic and infectious diseases of the biliary tract in migrants and international travelers

In recent years, global and regional crises have led to extraordinary worldwide migration, accompanied by an increase in long-distance travel from Western countries. Both are linked to a rising incidence of rare parasitic and infectious diseases in first world countries, including in the biliary tract. Areas covered: A selective literature research in PubMed was performed to review the most important parasitic and infectious biliary diseases, which are caused by a wide variety of pathogens and may be latent over long periods, with chronic courses leading to cholangitis, hepatic failure or development of cholangiocarcinoma. Parasites such as Ascaris, Fasciola and Clonorchis/Opisthorchis are particularly important and may trigger biliary diseases or predisposition for bacterial superinfections. Viral or protozoal cholangitis is mainly a problem of impaired immunity. Expert commentary: Currently, these entities are still rare in migrants and long-distance travelers. However, a significant increase in Western countries has to be expected. Incidences are most likely underestimated because of protracted clinical latency. Diagnosis depends on the relevant pathogens, the host's immune status and the extent or distribution of biliary obstruction. Modern tomographic methods, ERCP and specific microbiological/parasitological/virological tests are of crucial diagnostic importance. Antimicrobial/antiparasitic/antiviral therapy along with ERCP and interventional sonography/radiology provide effective treatment options.

Inflammatory Myofibroblastic Tumors: Current Update

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate biological potential with a predilection for the lung and abdominopelvic region. IMT represents the neoplastic subset of the family of inflammatory pseudotumors, an umbrella term for spindle cell proliferations of uncertain histogenesis with a variable inflammatory component. IMTs show characteristic fasciitis-like, compact spindle cell and hypocellular fibrous histologic patterns and distinctive molecular features. Imaging findings reflect pathologic features and vary from an ill-defined, infiltrating lesion to a wellcircumscribed, soft tissue mass owing to variable inflammatory, stromal, and myofibroblastic components.

Imaging spectrum of cholangiocarcinoma: role in diagnosis, staging, and posttreatment evaluation

Cholangiocarcinoma, a tumor of biliary epithelium, is increasing in incidence. The imaging appearance, behavior, and treatment of cholangiocarcinoma differ according to its location and morphology. Cholangiocarcinoma is usually classified as intrahepatic, perihilar, or distal. The three morphologies are mass-forming, periductal sclerosing, and intraductal growing. As surgical resection is the only cure, prompt diagnosis and accurate staging is crucial. In staging, vascular involvement, longitudinal spread, and lymphadenopathy are important to assess. The role of liver transplantation for unresectable peripheral cholangiocarcinoma will be discussed. Locoregional therapy can extend survival for those with unresectable intrahepatic tumors. The main risk factors predisposing to cholangiocarcinoma are parasitic infections, primary sclerosing cholangitis, choledochal cysts, and viral hepatitis. Several inflammatory conditions can mimic cholangiocarcinoma, including IgG4 disease, sclerosing cholangitis, Mirizzi's syndrome, and recurrent pyogenic cholangitis. The role of PET in diagnosis and staging will also be discussed. Radiologists play a crucial role in diagnosis, staging, and treatment of this disease.

Sclerosing Cholangitis: Clinicopathologic Features, Imaging Spectrum, and Systemic Approach to Differential Diagnosis

Sclerosing cholangitis is a spectrum of chronic progressive cholestatic liver disease characterized by inflammation, fibrosis, and stricture of the bile ducts, which can be classified as primary and secondary sclerosing cholangitis. Primary sclerosing cholangitis is a chronic progressive liver disease of unknown cause. On the other hand, secondary sclerosing cholangitis has identifiable causes that include immunoglobulin G4-related sclerosing disease, recurrent pyogenic cholangitis, ischemic cholangitis, acquired immunodeficiency syndrome-related cholangitis, and eosinophilic cholangitis. In this review, we suggest a systemic approach to the differential diagnosis of sclerosing cholangitis based on the clinical and laboratory findings, as well as the typical imaging features on computed tomography and magnetic resonance (MR) imaging with MR cholangiography. Familiarity with various etiologies of sclerosing cholangitis and awareness of their typical clinical and imaging findings are essential for an accurate diagnosis and appropriate management.

Progressive HIV-associated Cholangiopathy in an HIV Patient Treated with Combination Antiretroviral Therapy

We herein describe a case of progressive human immunodeficiency virus (HIV)-associated cholangiopathy despite normalization of laboratory parameters, which had indicated liver dysfunction, after the initiation of combined anti-retroviral therapy (cART). HIV-associated cholangiopathy remains important as a differential diagnosis of bile duct disorders, although it is considered to be a rare disease in the era of cART. Magnetic resonance cholangiopancreatography could thus be a powerful tool for the diagnosis and follow-up of this disease.

MRI of common and uncommon pathologies involving the periportal space: a pictorial essay

Imaging detection and differential diagnoses of pathology involving the periportal space can be challenging. MRI is a useful technique for assessment of the periportal space since it readily distinguishes normal and abnormal vascular and biliary anatomy, and the excellent soft tissue discrimination allows for detection of subtle lesions. This pictorial essay describes the anatomy of the periportal space and illustrates the MRI appearance of a variety of pathologies that can affect this region.

Hepatolithiasis and intrahepatic cholangiocarcinoma: A review

Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis is an established risk factor for cholangiocarcinoma (CCA), and chronic proliferative inflammation may be involved in biliary carcinogenesis and in inducing the upregulation of cell-proliferating factors. With the use of advanced imaging modalities, there has been much improvement in the management of hepatolithiasis and the diagnosis of hepatolithiasis-associated CCA (HL-CCA). However, there are many problems in managing the strictures in hepatolithiasis and differentiating them from infiltrating types of CCA. Surgical resection is recommended in cases of single lobe hepatolithiasis with atrophy, uncontrolled stricture, symptom duration of more than 10 years, and long history of biliary-enteric anastomosis. Even after resection, patients should be followed with caution for development of HL-CCA, because HL-CCA is an independent prognostic factor for survival. It is not yet clear whether hepatic resection can reduce the occurrence of subsequent HL-CCA. Furthermore, there are no consistent findings regarding prediction of subsequent HL-CCA in patients with hepatolithiasis. In the management of hepatolithiasis, important factors are the reduction of recurrence of cholangitis and suspicion of unrecognized HL-CCA.

Imaging findings of mimickers of hepatocellular carcinoma

Radiological imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC) as the noninvasive diagnosis of HCC in high-risk patients by typical imaging findings alone is widely adopted in major practice guidelines for HCC. While imaging techniques have markedly improved in detecting small liver lesions, they often detect incidental benign liver lesions and non-hepatocellular malignancy that can be misdiagnosed as HCC. The most common mimicker of HCC in cirrhotic liver is nontumorous arterioportal shunts that are seen as focal hypervascular liver lesions on dynamic contrast-enhanced cross-sectional imaging. Rapidly enhancing hemangiomas can be easily misdiagnosed as HCC especially on MR imaging with liver-specific contrast agent. Focal inflammatory liver lesions mimic HCC by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging. It is important to recognize the suggestive imaging findings for intrahepatic cholangiocarcinoma (CC) as the management of CC is largely different from that of HCC. There are other benign mimickers of HCC such as angiomyolipomas and focal nodular hyperplasia-like nodules. Recognition of their typical imaging findings can reduce false-positive HCC diagnosis.

Emergency abdominal MRI: current uses and trends

When evaluating the abdomen in the emergency setting, CT and ultrasound are the imaging modalities of choice, mainly because of accessibility, speed and lower relative cost. CT has the added benefit of assessing the whole abdomen for a wide spectrum of gastrointestinal disease, whereas ultrasound has the benefit of avoiding ionizing radiation. MRI is another tool that has demonstrated increasing utility in the emergency setting and also avoids the use of ionizing radiation. MRI also has the additional advantage of excellent soft-tissue contrast. However, widespread use of MRI in the emergency setting is limited by availability and relative cost. Despite such limitations, advances in MRI technology, including improved pulse sequences and coil technology and increasing clinician awareness of MRI, have led to an increased demand in abdominal MRI in the emergency setting. This is particularly true in the evaluation of acute pancreatitis; choledocholithiasis with or without cholecystitis; acute appendicitis, particularly in pregnant patients; and, in some cases, Crohn's disease. In cases of pancreatitis and Crohn's disease, MRI also plays a role in subsequent follow-up examinations.

Intrahepatic and hilar mass-forming cholangiocarcinoma: Qualitative and quantitative evaluation with diffusion-weighted MR imaging

OBJECTIVE

To qualitatively and quantitatively analyze the presentation of intrahepatic and hilar mass-forming cholangiocarcinoma with diffusion-weighted magnetic resonance imaging (DW-MRI).

MATERIALS AND METHODS

Twenty-eight patients with histopathologically proven mass-forming cholangiocarcinoma (hilar, n=17; intrahepatic, n=11) underwent hepatic DW-MRI at 1.5-T using free-breathing acquisition and three b-values (0,400,800s/mm(2)). Cholangiocarcinomas were evaluated qualitatively using visual analysis of DW-MR images and quantitatively with conventional ADC and normalized ADC measurements using liver and spleen as reference organs.

RESULTS

All cholangiocarcinomas (28/28; 100%) were visible on DW-MR images. DW-MRI yielded best conspicuity of cholangiocarcinomas than the other MRI sequences (P<0.001). Seven cholangiocarcinomas (7/11; 64%) showed hypointense central area on DW-MR images. Conventional ADC value of cholangiocarcinomas (1.042×10(-3)mm(2)/s±0.221×10(-3)mm(2)/s; range: 0.616×10(-3)mm(2)/s to 2.050×10(-3)mm(2)/s) was significantly lower than that of apparently normal hepatic parenchyma (1.362×10(-3)mm(2)/s±0.187×10(-3)mm(2)/s) (P<0.0001), although substantial overlap was found. No significant differences in ADC and normalized ADC values were found between intrahepatic and hilar cholangiocarcinomas. The use of normalized ADC using the liver as reference organ resulted in the most restricted distribution of ADC values of cholangiocarcinomas (variation coefficient=16.6%).

CONCLUSION

There is a trend towards a common appearance of intrahepatic and hilar mass-forming cholangiocarcinomas on DW-MRI but variations may be observed. Familiarity with these variations may improve the diagnosis of mass-forming cholangiocarcinoma.

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.

Hilar Inflammatory Pseudotumour with Hepatic Artery Atheroma- mimicker of Klatskin Tumour

Inflammatory pseudotumour of hilar biliary structures is an extremely rare benign lesion that can mimic hilar cholangiocarcinoma. Clinical presentation and imaging findings often pose diagnostic difficulties. Main histopathological findings are the presence of myofibroblastic spindle cells, plasma cells, macrophages, and lymphocytes without cellular atypia or atypical mitotic figures. We describe a case of 62 year old male who presented with surgical obstructive jaundice. Imaging revealed a mass lesion involving the biliary confluence with upstream dilatation of biliary tree. Diagnosis of hilar cholangiocarcinoma with type III hilar block was made. Intraoperately hilar mass lesion was found which was encasing right hepatic artery with no evidence of metastasis. The patient underwent Right hepatectomy with caudate lobectomy with complete common bile duct (CBD) excision with Roux en Y hepaticojejunostomy. Unexpectedly histopathological examination showed no evidence of malignancy and revealed hilar inflammatory pseudotumour with hepatic artery atherosclerosis. Preoperative imaging, operative management, pathologic diagnosis and literature review are being presented in view of rarity of the case.

Fascioliasis simulating an intrahepatic cholangiocarcinoma-Case report with imaging and pathology correlation

Human fascioliasis is a rare zoonosis in Chile. Clinically it presents with a highly polymorphous group of symptoms that evolve in two periods. The first, acute or a result of hepatic invasion, lasts 2 weeks to 4 months and is characterized essentially by pain in the right hypochondrium and/or epigastrium, continuous fever and painful hepatomegaly. This clinical picture, associated with eosinophilia and a history of raw watercress consumption, corresponds to the classic presentation of the disease in its initial stage. We report the case of a 57-year-old female patient with no risk factors for and no clinical signs of fascioliasis, with a lesion in the right hepatic lobe compatible with intrahepatic cholangiocarcinoma, studied with computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET-CT). With the clinical suspicion of intrahepatic cholangiocarcinoma, a regulated right hepatectomy was performed, the pathological study of which revealed cholangitis and granulomatous pericholangitis resulting from trematode eggs, compatible with Fasciola hepatica.