Cross-Sectional Imaging of Intrahepatic Cholangiocarcinoma: Development, Growth, Spread, and Prognosis. AJR Am J Roentgenol. 2017;209:W64-W75. [PMID: 28570102 DOI: 10.2214/ajr.16.16923]

Primary hepatic diffuse large B- cell lymphoma mimicking cholangiocarcinoma

Primary lymphoma of liver is a rare malignancy with non-specific clinical features and tumor markers. The presentation and imaging features may be indistinguishable from other hepatic malignant lesions. Pathological diagnosis is the gold standard, and early detection is essential to choose the treatment modality. Here, we share an interesting case of Primary Diffuse Large B cell lymphoma of liver and its imaging findings on Computed tomography (CT), Magnetic Resonance Imaging (MRI) and F-18 FDG PET/CT.

Cholangiocarcinoma imaging: from diagnosis to response assessment

Cholangiocarcinoma (CCA), a highly aggressive primary liver cancer arising from the bile duct epithelium, represents a substantial proportion of hepatobiliary malignancies, posing formidable challenges in diagnosis and treatment. Notably, the global incidence of intrahepatic CCA has seen a rise, necessitating a critical examination of diagnostic and management strategies, especially due to presence of close imaging mimics such as hepatocellular carcinoma (HCC) and combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA). Hence, it is imperative to understand the role of various imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), elucidating their strengths, and limitations in diagnostic precision and staging accuracy. Beyond conventional approaches, there is emerging significance of functional imaging tools including positron emission tomography (PET)-CT and diffusion-weighted (DW)-MRI, providing pivotal insights into diagnosis, therapeutic assessment, and prognostic evaluation. This comprehensive review explores the risk factors, classification, clinical features, and role of imaging in the holistic spectrum of diagnosis, staging, management, and restaging for CCA, hence serving as a valuable resource for radiologists evaluating CCA.

A hepatic sparganosis misdiagnosed as intrahepatic mass-forming cholangiocarcinoma: a case report and literature review

Hepatic sparganosis (HS) is extremely rare and has not been previously reported in Eastern China. We report the diagnosis and treatment of a patient with HS from Xuzhou City, Jiangsu Province, China. The patient was admitted due to an acute biliary tract infection, and the symptoms improved after treatment at the Gastroenterology Department. During an ultrasound examination on admission, an abnormal echo was incidentally discovered at the junction of the left and right lobes of the liver. Thereafter, upper abdominal computed tomography (CT) and magnetic resonance imaging (MRI) non-contrast and contrast-enhanced examinations, and serum tumor biomarker examination were completed. After a multidisciplinary treatment (MDT) discussion at the Department of Hepatobiliary Surgery, the patient was diagnosed with intrahepatic mass-type cholangiocarcinoma (IMCC) and surgery was recommended. The patient underwent surgical treatment, and postoperative pathology revealed HS. No signs of intrahepatic recurrence were observed during the 1-year follow-up period.

Molecular targeted and systemic therapy for intrahepatic cholangiocarcinoma: a multi-disciplinary approach

Most patients with intrahepatic cholangiocarcinoma (ICC) are diagnosed with advanced disease. For individuals with resectable tumors, R0 resection with lymphadenectomy is the best potentially curative-intent treatment. After resection, adjuvant therapy with capecitabine is the current standard of care. For patients with unresectable or distant metastatic disease, doublet chemotherapy with gemcitabine and cisplatin is the most utilized first-line regimen, but recent studies using triplet regimens and even the addition of immunotherapy have begun to shift the paradigm of systemic therapy. Molecular therapies have recently received US FDA approval for second-line treatment for patients harboring actionable genomic alterations. This review focuses on the multidisciplinary approach to the treatment of ICC with an emphasis on molecular targeted and systemic therapy.

Annals of Surgical Oncology Practice Guidelines Series: Management of Primary Liver and Biliary Tract Cancers

Primary cancers of the liver and biliary tract are rare and aggressive tumors that often present with locally advanced or metastatic disease. For patients with localized disease amenable to resection, surgery typically offers the best chance at curative-intent therapy. Unfortunately, the incidence of recurrence even after curative-intent surgery remains high. In turn, patients with hepatobiliary cancers commonly require multimodality therapy including a combination of resection, systemic therapy (i.e., targeted therapy, cytotoxic chemotherapy, immunotherapy), and/or loco-regional therapies. With advancements in the field, it is crucial for surgical oncologists to remain updated on the latest guidelines and recommendations for surgical management and optimal patient selection. Given the complex and evolving nature of treatment, this report highlights the latest practice guidelines for the surgical management of hepatobiliary cancers.

Percutaneous transhepatic cholangioscopy for benign and malignant biliary disease using a novel short single-operator cholangioscope

BACKGROUND

The length of conventional single-use cholangioscopes poses a challenge for percutaneous or laparoscopic approaches for direct visualization of the biliary tract. The aim of this retrospective observational clinical study was to assess the use of a dedicated percutaneous short single-operator cholangioscope (PSSOC) for diagnosis and treatment of benign or malignant biliary diseases.

METHODS

Retrospective analysis of a prospectively maintained database including all consecutive patients undergoing percutaneous transhepatic cholangioscopy with the PSSOC between 06/2021 and 01/2023.

RESULTS

Forty patients were included (22F/18 M, age 58.7 ± 16.7 years). The diagnostic and therapeutic management plan was based on procedural findings. Indications were bile duct obstruction associated with complex anatomy (n = 13), choledocholithiasis (n = 11), suspected malignant stenosis of the biliary tract (n = 11), biliary stent placement (n = 2) and removal (n = 1), and failed endoscopic retrograde cholangiopancreatography (n = 2). The cholangioscopies were diagnostic (n = 5), therapeutic (n = 20) or both simultaneously (n = 15). The most frequent procedures were electrohydraulic lithotripsy (n = 25) and biopsy sampling (n = 12). Complications occurred in 7 cases (17.5%), including cholangitis (n = 4, B2), pleural perforation (n = 1, B2), portal bleeding (n = 1, B3), and Tako-Tsubo syndrome (n = 1, B3), classified according to the Society of Interventional Radiology classification. Intraprocedural visual diagnosis was confirmed by the histopathologic result in 11/12 patients in which biopsies were performed (91.7%). PSSOC was relevant to avoid surgery in 2 patients (5%) with indeterminate strictures, allowing to rule out malignancy and treat the lithiasis.

CONCLUSIONS

Direct visualization of the biliary tract enabled targeted biopsies for histopathological diagnosis. The visual and histopathological diagnoses were concordant in all but one case. Percutaneous cholangioscopy with a dedicated PSSOC allows to optimize identification and treatment of complex biliary disease including biliary lithiasis while assessing bile duct patency. The clinical use of the novel PSSOC system was safe and effective and could prevent surgical exploration in select patients.

MRI-Based Radiomics Nomogram for Preoperatively Differentiating Intrahepatic Mass-Forming Cholangiocarcinoma From Resectable Colorectal Liver Metastases

RATIONALE AND OBJECTIVES

To establish a radiomics nomogram based on multiparameter magnetic resonance (MR) images for preoperatively differentiating intrahepatic mass-forming cholangiocarcinoma (IMCC) from colorectal cancer liver metastasis (CRLM).

MATERIALS AND METHODS

A total of 133 patients in training cohort (64 IMCC and 69 CRLM), 57 patients in internal validation cohort (29 IMCC and 28 CRLM), and 51 patients (23 IMCC and 28 CRLM) in external validation cohort were included. Radiomics features were extracted from the multiparameter MR images and selected by the least absolute shrinkage and selection operator algorithm to establish the radiomics model. Clinical variables and magnetic resonance imaging (MRI) findings were selected by univariate and multivariate analyses to construct a clinical model. The radiomics nomogram was combined with radiomics model and clinical model.

RESULTS

Six features were selected to construct the radiomics model. The radiomics signature showed better discrimination than the clinical model in the training cohort (Area Under the Curve (AUC), 0.92; 95% confidence interval (CI), 0.87-0.96 vs. AUC, 0.74; 95% CI, 0.66-0.83) and the external validation cohort (AUC, 0.90; 95% CI, 0.82-0.98 vs. AUC, 0.81; 95% CI, 0.69-0.93). The radiomics nomogram showed the best discrimination performance with favorable calibration in the training cohort (AUC, 0.94; 95% CI, 0.90-0.97) and the external validation cohort (AUC, 0.92; 95% CI, 0.84-1.00).

CONCLUSION

The radiomics nomogram combining radiomics signatures based on multiparameter MRI with clinical factors (serum carcinoembryonic antigen level and tumor diameter) may provide a reliable and noninvasive tool to discriminate IMCC from CRLM, which could help guide treatment strategies and prognosis preoperatively prediction.

Delayed Metastatic Cholangiocarcinoma to the Stomach With Imaging Characteristics Resembling Gastrointestinal Stromal Tumor: A Case Report and Review of the Literature

Intrahepatic cholangiocarcinoma (ICC) is a relatively rare subtype of cholangiocarcinoma, and there has been an increasing incidence of ICC in Western countries in recent years. Surgical resection is the most effective treatment for ICC. However, overall outcomes are extremely poor given that most patients are diagnosed at an advanced stage, and postoperative ICC recurrence is still very high despite hepatic resection. We report a case of metastatic ICC to the stomach presenting after resection of the original tumor, with imaging characteristics highly resembling gastrointestinal stromal tumor (GIST) on imaging. Reported cases of metastatic ICC to the liver are sparse. Given that there is a significant difference in the survival rate between metastatic cholangiocarcinoma and other tumors arising from the gastrointestinal tract, including GISTs, it is important to delineate the differences via imaging features. We further discuss the imaging characteristics of intrahepatic ICC, comparing and contrasting it to other gastric tumors.

Imaging features based on CT and MRI for predicting prognosis of patients with intrahepatic cholangiocarcinoma: a single-center study and meta-analysis

BACKGROUND

To evaluate the prognostic role of imaging features based on CT and MRI in intrahepatic cholangiocarcinoma (ICC).

METHODS

Two hundred and four patients from a single-center database who underwent radical ICC surgery from 2010 to 2019 were enrolled in the study. Cox proportional hazard model was used for survival analysis of imaging features. A meta-analysis was performed to determine imaging features that predict overall survival (OS) and event-free survival (EFS) in ICC.

RESULTS

In the CT group of the retrospective cohort, tumor multiplicity, infiltrative tumor margin, lymph node metastasis, enhancement pattern in hepatic arterial phase and tumor necrosis correlated with poorer EFS and OS; moreover, enhancing capsules, high carcinoembryonic antigen levels contributed to poor OS. In the MRI group, tumor multiplicity and enhancement pattern were prognostic factors for OS; tumor multiplicity and enhancement pattern resulted in poor EFS. A total of 13 articles containing 1822 patients with ICC were enrolled in the adjusted hazard ratios meta-analysis. The results showed that enhancement pattern and infiltrative tumor margin were predictors of OS and EFS, whereas bile duct invasion was a predictor of OS.

CONCLUSIONS

Arterial enhancement patterns and tumor margin status were associated with both OS and EFS of ICC patients following resection.

Preoperative subcategorization based on magnetic resonance imaging in intrahepatic cholangiocarcinoma

BACKGROUND

Appropriate preoperative identification of iCCA subtype is essential for personalized management, so the aim of this study is to investigate the role of MR imaging features in preoperatively differentiating the iCCA subtype.

METHODS

Ninety-three patients with mass-forming intrahepatic cholangiocarcinoma (iCCA, 63 small duct type and 30 large duct type) were retrospectively enrolled according to the latest 5th WHO classification (mean age, males vs. females: 60.66 ± 10.53 vs. 61.88 ± 12.82, 50 men). Significant imaging features for differentiating large duct iCCA and small duct iCCA were identified using univariate and multivariate logistic regression analyses, and a regression-based predictive model was then generated. Furthermore, diagnostic performance parameters of single significant imaging features and the predictive model were obtained, and corresponding receiver operating characteristic (ROC) curves were subsequently presented.

RESULTS

The univariate analysis showed that tumor in vein, arterial phase hypoenhancement, intrahepatic duct dilatation, lack of targetoid restriction and lack of targetoid appearance in T2 were predictors of large duct type iCCA. Arterial phase hypoenhancement, intrahepatic duct dilatation and lack of targetoid restriction were independent predictors for large duct type iCCA in multivariate analysis. The regression-based predictive model has achieved the best preoperative prediction performance in iCCA subcategorization so far. The area under the ROC curve of the regression-based predictive model was up to 0.91 (95% CI: 0.85, 0.98), and it was significantly higher than every single significant imaging feature.

CONCLUSIONS

Arterial phase hypoenhancement, intrahepatic duct dilatation and lack of targetoid restriction could be considered reliable MR imaging indicators of large duct type iCCA. MR imaging features can facilitate noninvasive prediction of iCCA subtype with satisfactory predictive performance.

New Imaging Techniques

The chapter discusses the advancement of new imaging techniques, the role of imaging in CCA diagnosis, anatomical and morphological classification, ultrasound screening of CCA, ultrasound findings of MF-CCA, PI-CCA, ID-CCA, the use of CT in CCA diagnosis, staging and treatment planning, CT volumetry and estimation of future liver remnant, post-treatment follow-up and surveillance, MRI imaging, Positron Emission Tomography (PET)/CT, limitations to contrast studies and resolution, internal receivers for CCA imaging, and in vitro imaging of CCA.

Intrahepatic cholangiocarcinoma with gastric metastasis misdiagnosed as primary gastric cancer: A case report and literature review

We describe a case of intrahepatic cholangiocarcinoma with gastric metastasis misdiagnosed as primary gastric cancer. In addition, combined with the literature, we summarized the clinical and imaging features of gastric metastasis of intrahepatic cholangiocarcinoma in order to improve the understanding of the preoperative diagnosis. Positron emission tomography/computed tomography (PET/CT) is accurate in evaluating the primary tumor, lymph node metastasis, and distant metastasis of patients. In addition, immunohistochemical staining can determine the primary site of metastatic adenocarcinoma. For patients who can not determine the location of the primary tumor, the rigorous preoperative examination is necessary, it can improve the accuracy of diagnosis and avoid excessive treatment of patients.

Diffusion-weighted imaging as an imaging biomarker for assessing survival of patients with intrahepatic mass-forming cholangiocarcinoma

BACKGROUND

Mass-forming cholangiocarcinoma is the most common form of intrahepatic cholangiocarcinoma and is associated with a worse prognosis. This study aimed to assess the role of diffusion-weighted imaging and other imaging features as prognostic markers to predict the survival of patients with intrahepatic mass-forming cholangiocarcinoma (IMCC).

MATERIALS AND METHODS

The study included patients with pathologically proven IMCC from January 2011 to January 2018. Two radiologists retrospectively reviewed various imaging findings and manually estimated the area of diffusion restriction. Patients were grouped according to their restriction area into (group 1) restriction ≥ 1/3 of the tumor and (group 2) restriction < 1/3 of the tumor. Statistical analysis was performed to assess the relationship between various imaging features and patients' survival.

RESULTS

Seventy-three patients were included in the study. IMCC patients with tumor size ≥ 5 cm had increased intrahepatic- and peritoneal metastases (p = 039 and p = 0.001 for reader 1 and p = 0.048 and p = 0.057 for reader 2). There was no significant relationship between the diffusion restriction area and tumor size, enhancement pattern, vascular involvement, lymph node metastasis, peritoneal- and distant metastasis. The number of deaths was significantly higher in patients with group 2 restriction (63.6% for group 1 vs. 96.6% for group 2; p = 0.001 for reader 1)(68.2% for group 1 vs. 89.7%% for group 2; p = 0.030 for reader 2). Patients with group 2 restriction had shorter 1- and 3-year survival rates and lower median survival time. Multivariable survival analysis showed two independent prognostic factors relating to poor survival outcomes: peritoneal metastasis (p = 0.04 for reader 1 and p = 0.041 for reader 2) and diffusion restriction < 1/3 (p = 0.011 for reader 1 and p = 0.042 for reader 2). Lymph node metastasis and intrahepatic metastasis were associated with shorter survival in the univariate analysis. However, these factors were non-significant in the multivariate analysis.

CONCLUSION

Restriction diffusion of less than 1/3 and peritoneal metastasis were associated with shorter overall survival of IMCC patients. Other features that might correlate with the outcome are suspicious lymph nodes and multifocal lesions.

Efficacy of percutaneous image-guided biopsy for diagnosis of intrahepatic cholangiocarcinoma

PURPOSE

To evaluate the efficacy of percutaneous biopsy for diagnosing intrahepatic cholangiocarcinoma (IHCCA).

METHODS

Retrospective review of biopsy and pathology databases from 2006 to 2019 yielded 112 patients (54F/58 M; mean age, 62.9 years; 27 cirrhotic) with IHCCA who underwent percutaneous biopsy. Data regarding the lesion, biopsy procedure technique, and diagnostic yield were collected. If biopsy was non-diagnostic or discordant with imaging, details of repeat biopsy or resection/explant were gathered. A control group of 100 consecutive patients (56F/44 M; mean age, 63 years, 5 cirrhotic) with focal liver lesions > 1 cm was similarly assessed.

RESULTS

Mean IHCCA lesion size was 6.1 ± 3.6 cm, with dominant lesion sampled in 78% (vs. satellite in 22%). 95% (n = 106) were US guided and 96% were core biopsies (n = 108), typically 18G (n = 102, 91%), median 2 passes. 18 patients (16%) had discordant/ambiguous pathology results requiring repeat biopsy, with two patients requiring 3-4 total attempts. A 4.4% minor complication rate was seen. Mean time from initial biopsy to final diagnosis was 60 ± 120 days. Control group had mean lesion size of 2.9 ± 2.5 cm and showed a non-diagnostic rate of 3.3%, both significantly lower than that seen with CCA, with average time to diagnosis of 21 ± 28.8 days (p = 0.002, p = 0.001).

CONCLUSION

IHCCA is associated with lower diagnostic yield at initial percutaneous biopsy, despite larger target lesion size. If a suspicious lesion yields a biopsy result discordant with imaging, the radiologist should recommend prompt repeat biopsy to prevent delay in diagnosis.

Morphomolecular Classification Update on Hepatocellular Adenoma, Hepatocellular Carcinoma, and Intrahepatic Cholangiocarcinoma

Hepatocellular adenomas (HCAs), hepatocellular carcinomas (HCCs), and intrahepatic cholangiocarcinomas (iCCAs) are a highly heterogeneous group of liver tumors with diverse pathomolecular features and prognoses. High-throughput gene sequencing techniques have allowed discovery of distinct genetic and molecular underpinnings of these tumors and identified distinct subtypes that demonstrate varied clinicobiologic behaviors, imaging findings, and complications. The combination of histopathologic findings and molecular profiling form the basis for the morphomolecular classification of liver tumors. Distinct HCA subtypes with characteristic imaging findings and complications include HNF1A-inactivated, inflammatory, β-catenin-activated, β-catenin-activated inflammatory, and sonic hedgehog HCAs. HCCs can be grouped into proliferative and nonproliferative subtypes. Proliferative HCCs include macrotrabecular-massive, TP53-mutated, scirrhous, clear cell, fibrolamellar, and sarcomatoid HCCs and combined HCC-cholangiocarcinoma. Steatohepatitic and β-catenin-mutated HCCs constitute the nonproliferative subtypes. iCCAs are classified as small-duct and large-duct types on the basis of the level of bile duct involvement, with significant differences in pathogenesis, molecular signatures, imaging findings, and biologic behaviors. Cross-sectional imaging modalities, including multiphase CT and multiparametric MRI, play an essential role in diagnosis, staging, treatment response assessment, and surveillance. Select imaging phenotypes can be correlated with genetic abnormalities, and identification of surrogate imaging markers may help avoid genetic testing. Improved understanding of morphomolecular features of liver tumors has opened new areas of research in the targeted therapeutics and management guidelines. The purpose of this article is to review imaging findings of select morphomolecular subtypes of HCAs, HCCs, and iCCAs and discuss therapeutic and prognostic implications. Online supplemental material is available for this article. ^©RSNA, 2022.

Integrative Analysis of Intrahepatic Cholangiocarcinoma Subtypes for Improved Patient Stratification: Clinical, Pathological, and Radiological Considerations

Simple Summary

Liver cancer subtypes differ in prognosis and genetic alterations. An accurate diagnosis made on time is the key aspect of clinical decision-making. Hence, a correct diagnosis is of pivotal importance for individual patients. In this study, we identified the most relevant clinical, radiological, and histological parameters for an improved subtype diagnosis of intrahepatic cholangiocarcinoma. As a result of our study, the radiologist should consider factors such as growth pattern, location, and contrast agent behavior. For the pathologist, precursor lesions, mucin secretion, and a periductal-infiltrating growth are of utmost importance, while immunohistochemical analyses are essential for exclusion of extrahepatic malignancies, but have so far only value for iCCA subtype analysis in the context with other parameters.

Abstract

Intrahepatic cholangiocarcinomas (iCCAs) may be subdivided into large and small duct types that differ in etiology, molecular alterations, therapy, and prognosis. Therefore, the optimal iCCA subtyping is crucial for the best possible patient outcome. In our study, we analyzed 148 small and 84 large duct iCCAs regarding their clinical, radiological, histological, and immunohistochemical features. Only 8% of small duct iCCAs, but 27% of large duct iCCAs, presented with initial jaundice. Ductal tumor growth pattern and biliary obstruction were significant radiological findings in 33% and 48% of large duct iCCAs, respectively. Biliary epithelial neoplasia and intraductal papillary neoplasms of the bile duct were detected exclusively in large duct type iCCAs. Other distinctive histological features were mucin formation and periductal-infiltrating growth pattern. Immunohistochemical staining against CK20, CA19-9, EMA, CD56, N-cadherin, and CRP could help distinguish between the subtypes. To summarize, correct subtyping of iCCA requires an interplay of several factors. While the diagnosis of a precursor lesion, evidence of mucin, or a periductal-infiltrating growth pattern indicates the diagnosis of a large duct type, in their absence, several other criteria of diagnosis need to be combined.

Subtype Classification of Intrahepatic Cholangiocarcinoma Using Liver MR Imaging Features and Its Prognostic Value

Introduction

Small-duct (SD) and large-duct (LD) subtypes of cholangiocarcinoma have been investigated for their prognostic factors. This study aimed to evaluate the diagnostic value of liver magnetic resonance imaging (MRI) in differentiating SD and LD types of intrahepatic cholangiocarcinoma (iCCA) and its prognostic value in predicting survival outcomes.

Methods

One hundred forty patients with surgically confirmed iCCAs (93 SD type and 47 LD type) who had available preoperative gadoxetic acid-enhanced liver MR images were retrospectively included. MRI features suggestive of the LD type over the SD type were analyzed using multivariate logistic analyses. Postoperative recurrence-free survival (RFS) and overall survival (OS) for 107 patients with available survival data were compared according to MRI features.

Results

MRI features suggestive of the LD type included infiltrative contour (odds ratio [OR] 14.2, 95% confidence interval [CI]: 2.5-81.7, p = 0.003), diffuse biliary dilatation (OR 9.7, 95% CI: 1.2-76.9, p = 0.032), no arterial phase hyperenhancement (OR 17.8, 95% CI: 2.7-118.6, p = 0.003), and vascular invasion (OR 4.5, 95% CI: 1.3-15.4, p = 0.018). When two or more features were combined, sensitivity was 59.6% (28/47), and specificity was 95.7% (89/93) in discriminating the LD type. RFS/OS was significantly shorter in patients with two or more MRI features, compared to those with none or one (310 days vs. 529 days, p = 0.011/964 days vs. 2,023 days, p = 0.010).

Conclusions

Preoperative liver MRI may help predict the pathological subtype of iCCAs as either the SD type or LD type, allowing preoperative identification of patients with poorer survival outcomes.

A Case of Cystic Intrahepatic Cholangiocarcinoma Mimicking a Cyst

ABSTRACT

Intrahepatic cholangiocarcinoma (ICC) classically presents as irregular soft tissue lesions. Very rarely, ICC may manifest as a predominantly cystic mass. Here, we describe a 59-year-old man who was referred to the hospital due to abdominal pain. The presentation was highly suggestive of a hepatic cyst based on MRI. 18F-FDG PET/CT could not exclude a malignant hepatic tumor due to the high metabolism in the margin. Subsequently, the patient underwent a left hemihepatectomy. Histopathology revealed malignant ICC.

Combined arterial and delayed enhancement patterns of MRI assist in prognostic prediction for intrahepatic mass-forming cholangiocarcinoma (IMCC)

OBJECTIVES

This study valued MR delayed enhancement pattern in predicting postoperative prognosis of intrahepatic mass-forming cholangiocarcinoma (IMCC).

METHODS

From 2011 to 2015, 231 patients of IMCC underwent DCE-MRI preoperatively. Enhancement patterns and MRI characteristics were evaluated. Recurrence and mortality data were compared among IMCCs with different enhancement patterns. Prognostic factor analysis was performed using preoperative and postoperative clinical-pathologic factors, as well as imaging findings.

RESULTS

Fifty-six (24.2%), 142 (61.5%) and 33 (14.3%) tumors showed hypo, peripheral rim and diffuse hyper enhancement in AP. Fifty-six (24.2%), 81 (35.1%) and 94 (40.7%) tumors showed hypo, heterogeneous and uniform enhancement in DP. Patients with arterial diffuse hyper enhancement or delayed uniform enhancement IMCCs had lower preoperative CA19-9 levels, smaller tumor sizes and minor operations than the rest patients (p < 0.05) and they were less associated with lymph nodes metastasis, vascular invasion, necrosis or poor tumor differentiation (p < 0.05), therefore with higher overall and disease-free survival rates (p < 0.05). The combination of AP and DP increased the detection rate of patients with good prognosis in the arterial rim enhancement group. Multivariate analysis revealed the delayed enhancement pattern (hypo HR = 6.304/10.028 for DFS/OS; heterogenous HR = 4.579/4.972 for DFS/OS), multitude of lesions (HR = 1.6/1.5 for DFS/OS) and tumor sizes (HR = 1.6 for DFS) were independent prognostic factors.

CONCLUSIONS

The uniform enhancement pattern in delayed MRI was an independent optimal prognostic factor for IMCCs and increased the detection rate of patients with good prognosis compared to the arterial diffuse hyper enhancement pattern.

Liver Transplantation for Unresectable Intrahepatic Cholangiocarcinoma: The Role of Sequencing Genetic Profiling

Intrahepatic cholangiocarcinoma (iCCA) is a rare and aggressive primary liver tumor, characterized by a range of different clinical manifestations and by increasing incidence and mortality rates even after curative treatment with radical resection. In recent years, growing attention has been devoted to this disease and some evidence supports liver transplantation (LT) as an appropriate treatment for intrahepatic cholangiocarcinoma; evolving work has also provided a framework for better understanding the genetic basis of this cancer. The aim of this study was to provide a clinical description of our series of patients complemented with Next-Generation Sequencing genomic profiling. From 1999 to 2021, 12 patients who underwent LT with either iCCA or a combined hepatocellular and cholangiocellular carcinoma (HCC-iCCA) were included in this study. Mutations were observed in gene activating signaling pathways known to be involved with iCCA tumorigenesis (KRAS/MAPK, P53, PI3K-Akt/mTOR, cAMP, WNT, epigenetic regulation and chromatin remodeling). Among several others, a strong association was observed between the Notch pathway and tumor size (point-biserial rhopb = 0.93). Our results are suggestive of the benefit potentially derived from molecular analysis to improve our diagnostic capabilities and to devise new treatment protocols, and eventually ameliorate long-term survival of patients affected by iCCA or HCC-iCCA.

Minimally Invasive Surgery for Intrahepatic Cholangiocarcinoma: Patient Selection and Special Considerations

Intrahepatic cholangiocarcinoma (ICC) is an aggressive primary hepatic malignancy. Unfortunately, despite advancements in diagnosis, staging and management, mortality is high. Surgery remains the only curative treatment, but many patients present with advanced, unresectable disease. For patients able to undergo surgical resection, overall survival is improved, but remains low, with high rates of disease recurrence. Minimally invasive surgery (MIS), including laparoscopic and robotic approaches, are increasingly used in surgical resection for ICC. These approaches variably demonstrate faster recovery times, less blood loss, decreased postoperative pain and fewer postoperative complications, with adequate oncologic resections. This review examines patient selection and special considerations for MIS for ICC. Patient selection is critical and includes evaluation of a patient’s anatomic and oncologic resectability, as well as comorbidities.

Intrahepatic cholangiocarcinoma and its differential diagnosis at MRI: how radiologist should assess MR features

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is the second most common type of primary hepatic malignancy. Aim of this work is to analyse the features of ICC and its differential diagnosis at MRI, assessing two categories intraparenchymal and peribiliary lesions.

METHODS

The study population included 88 patients with histological diagnosis of ICCs: 61 with mass-forming type, 23 with periductal-infiltrating tumours and 4 with intraductal-growing type. As a control study groups, we identified: 86 consecutive patients with liver colorectal intrahepatic metastases (mCRC) (groups A); 35 consecutive patients with peribiliary metastases (groups B); 62 consecutive patients (groups C) with hepatocellular carcinoma (HCC); 18 consecutive patients (groups D) with combined hepatocellular cholangiocarcinoma (cHCC-CCA); and 26 consecutive patients (groups E) with hepatic hemangioma. For all lesions, magnetic resonance (MR) features were assessed according to Liver Imaging Reporting and Data System (LI-RADS) version 2018. The liver-specific gadolinium ethoxybenzyl dimeglumine-EOB (Primovist, Bayer Schering Pharma, Germany), was employed. Chi-square test was employed to analyse differences in percentage values of categorical variable, while the nonparametric Kruskal-Wallis test was used to test for statistically significant differences between the median values of the continuous variables. However, false discovery rate adjustment according to Benjamin and Hochberg for multiple testing was considered.

RESULTS

T1- and T2-weighted signal intensity (SI), restricted diffusion, transitional phase (TP) and hepatobiliary phase (HP) aspects allowed the differentiation between study group (mass-forming ICCs) and each other control group (A, C, D, E) with statistical significance, while arterial phase (AP) appearance allowed the differentiation between study group and the control groups C and D with statistical significance and PP appearance allowed the differentiation between study group and the control groups A, C and D with statistical significance. Instead, no MR feature allowed the differentiation between study group (periductal-infiltrating type) and control group B.

CONCLUSION

T1 and T2 W SI, restricted diffusion, TP and HP appearance allowed the differentiation between mass-forming ICCs and mimickers with statistical significance, while AP appearance allowed the differentiation between study group and the control groups C and D with statistical significance and PP appearance allowed the differentiation between study group and the control groups A, C and D.

Surgical management of intrahepatic cholangiocarcinoma

INTRODUCTION

Intrahepatic cholangiocarcinoma (ICC) incidence continues to rise worldwide, and overall survival remains poor. Complete surgical resection remains the only opportunity for cure in patients with ICC yet only one-third of patients present with resectable disease.

AREAS COVERED

While the low incidence rate of ICC hinders accrual of patients to large, randomized control trials, larger database and long-term institutional studies provide evidence to guide surgical management of ICC. These studies demonstrate feasibility, safety, and efficacy of aggressive surgical management in appropriately selected patients with ICC. Recent advances in the management of ICC, with a focus on surgical considerations, are reviewed.

EXPERT OPINION

Historically, little progress has been made in the management of ICC with stagnant mortality rates and poor long-term outcomes. However, regionalization of care to centers with experienced multidisciplinary teams, advances in minimally invasive surgical techniques, discovery and development of targeted and immunotherapy agents, and combination locoregional and systemic therapies offer signs of progress in the management of ICC.

Challenges and Opportunities for Treating Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is one of the rarest and most aggressive types of cancer. The symptoms of ICC patients can be vague, leading to late diagnosis and dismal prognosis. In this review, we investigated the treatment options for ICC, as well as ways to overcome challenges in identifying and treating this disease. Imaging remains the gold standard to diagnose ICC. Patients are staged based on the tumor, nodes and metastases (TNM) staging system. Patients eligible for surgical resection should undergo surgery with curative intent with the goal of microscopically disease-free margins (R0 resection) along with lymphadenectomy. Minimal invasive surgery (MIS) and liver transplantation have recently been offered as possible ways to improve disease outcomes. ICC recurrence is relatively common and, thus, most patients will need to be treated with systemic therapy. Several clinical trials have recently investigated the use of neoadjuvant (NT) and adjuvant therapies for ICC. NT may offer an opportunity to downsize larger tumors and provide patients, initially ineligible for surgery, with an opportunity for resection. NT may also treat occult micro-metastatic disease, as well as define tumor biology prior to surgical resection, thereby decreasing the risk for early postoperative recurrence. Adjuvant systemic therapy may improve outcomes of patients with ICC following surgery. Ongoing clinical trials are investigating new targeted therapies that hold the hope of improving long-term outcomes of patients with ICC.

Role of noninvasive imaging in the evaluation of intrahepatic cholangiocarcinoma: from diagnosis and prognosis to treatment response

INTRODUCTION

Intrahepatic cholangiocarcinoma is the second most common liver cancer. Desmoplastic stroma may be revealed as distinctive histopathologic findings favoring intrahepatic cholangiocarcinoma. Meanwhile, a range of imaging manifestations is often accompanied with rich desmoplastic stroma in intrahepatic cholangiocarcinoma, which can indicate large bile duct ICC, and a higher level of cancer-associated fibroblasts with poor prognosis and weak treatment response.

AREAS COVERED

We provide a comprehensive review of current state-of-the-art and recent advances in the imaging evaluation for diagnosis, staging, prognosis and treatment response of intrahepatic cholangiocarcinoma. In addition, we discuss precursor lesions, cells of origin, molecular mutation, which would cause the different histological classification. Moreover, histological classification and tumor microenvironment, which are related to the proportion of desmoplastic stroma with many imaging manifestations, would be also discussed.

EXPERT OPINION

The diagnosis, prognosis, treatment response of intrahepatic cholangiocarcinoma may be revealed as the presence and the proportion of desmoplastic stroma with a range of imaging manifestations. With the utility of radiomics and artificial intelligence, imaging is helpful for ICC evaluation. Multicentre, large-scale, prospective studies with external validation are in need to develop comprehensive prediction models based on clinical data, imaging findings, genetic parameters, molecular, metabolic, and immune biomarkers.

Hepatic tuberculosis masquerading as malignancy

BACKGROUND AND AIMS

Hepatic tuberculosis (HTB) is rare and mimics neoplastic liver lesions clinico-radiologically leading to misdiagnosis and even unnecessary surgery.

METHODS AND MATERIAL

We analysed 43 cases of HTB diagnosed at a referral cancer centre over 10 years. Clinical details, investigations and treatment received were noted.

RESULTS

The median age was 46 years with a female preponderance (58%). HTB was diagnosed incidentally in 28% cases during surveillance imaging for a previous cancer. Constitutional symptoms (31, 72%), abdominal pain (25, 58%), fever (12, 28%), hepatomegaly (22, 51%), elevated alkaline phosphatase (34, 79%), elevated aminotransferases (18, 42%) and hypoalbuminemia (19, 45%) were common features. All cases had negative HIV serology and normal tumor markers. Twenty-two (52.5%) had solitary liver lesion and lesions > 2 cm in 28 (65%). Ultrasound showed hypoechoic lesions in 31 of 33 cases. Computed tomography showed hypodense lesions (43,100%) with mild peripheral enhancement (32, 74%). Calcifications (5, 12%) and capsular retraction (8, 19%) was uncommon. MRI was performed in seven cases commonly showed T1 hypointense, T2 hyperintense lesions with restricted diffusion. Histopathology showed granulomatous inflammation (42, 97.5%), Langhan's giant cells (41, 95%) and caseation necrosis (35, 85%). Acid-fast stain and PCR positivity was uncommon. Extrahepatic organs were involved in 20 (46.5%). HTB mimicked cholangiocarcinoma (25, 58%), liver metastasis (11, 26%) and lymphoma (3, 7%). Six patients underwent liver resection with a presumptive diagnosis of cancer without a preoperative biopsy. All patients received antitubercular therapy, 37 had clinico-radiological response, there were 3 deaths and 3 patients were lost to follow-up.

CONCLUSION

HTB is rare and can mimic a malignancy clinico-radiologically. Calcifications and pseudocapsule appearance on multiphase CT scan may help in differentiating HTB from hepatic malignancy. Tumor markers are normal while histopathology is generally diagnostic. A high index of suspicion is required to avoid unnecessary surgery as the patients respond well to ATT.

TRIAL REGISTRATION

This is a retrospective and observational study hence clinical trial registration is not applicable.

Clinical Importance of Incidentally Detected Hyperenhancing Liver Observations on Portal Venous Phase Computed Tomography in Patients Without Known Malignancy or Liver Disease

OBJECTIVE

The aim of the study was to determine the prevalence of clinically important masses among incidental hyperenhancing liver observations on portal venous phase computed tomography (CT) in patients without known malignancy or liver disease.

METHODS

Retrospective search of portal venous phase CTs was performed to identify hyperenhancing liver observations in patients without cancer or liver disease. Observations were assigned a morphology of homogeneous, hemangioma, or heterogeneous. The reference standard was pathology (n = 2), liver protocol CT/magnetic resonance imaging (n = 40), follow-up portal venous phase CT for 2 years or more (n = 81), or clinical follow-up for 5 years or more (n = 107).

RESULTS

There were no clinically important masses among 83 observations with homogeneous morphology or 110 with hemangioma morphology. There were 2 clinically important masses (1 hepatocellular carcinoma and 1 hepatic adenoma) among 37 (5.4%) heterogeneous morphology observations.

CONCLUSIONS

Incidental hyperenhancing liver observations on portal venous phase CT with homogeneous or typical hemangioma morphology in patients without known cancer or liver disease are highly likely benign.

Differentiation of Intrahepatic Cholangiocarcinoma and Hepatic Lymphoma Based on Radiomics and Machine Learning in Contrast-Enhanced Computer Tomography

Purpose: This study aimed to explore the ability of texture parameters combining with machine learning methods in distinguishing intrahepatic cholangiocarcinoma (ICCA) and hepatic lymphoma (HL). Method: A total of 28 patients with HL and 101 patients with ICCA were included. A total of 45 texture features were extracted by the software LifeX from contrast-enhanced computer tomography (CECT) images and 38 of them were eligible. A total of 5 feature selection methods and 9 feature classification methods were used to build the best diagnostic models, combining with the 10-fold cross-validation to assess the accuracy of these models. The discriminative ability of each model was evaluated by receiver operating characteristic analysis. Result: A total of 45 predictive models were built by the cross combination of each selection and classification method to differentiate ICCA from HL. According to the results of test group, most of the models performed well with a large area under the curve (AUC) (>0.85) and high accuracy (>0.85). Random Forest (RF)_Linear Discriminant Analysis (LDA) (AUC  =  0.997, accuracy  =  0.969) was the best model among all the 45 models. Conclusion: Combining texture parameters from CECT with multiple machine learning models can differentiate ICCA and HL effectively, and RF_LDA performed the best in this process.

Imaging of Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma is the second most common primary hepatic malignancy and is a heterogeneous tumor of biliary epithelium. We discuss the risk factors, anatomic classification of cholangiocarcinoma (CC) as well as the different morphologic subtypes of CC. Imaging findings of CC on different modalities are described, focusing on intrahepatic CC. Recently recognized imaging features that carry prognostic significance, such as a worse prognosis in tumors that have more desmoplastic stroma, are detailed. Other benign and malignant entities that should be considered in the differential diagnosis of CC will also be discussed.

Intrahepatic cholangiocarcinoma: Introducing the preoperative prediction score based on preoperative imaging

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) still has a poor long-term outcome, even after complete resection. We investigated different parameters gathered in preoperative imaging and analyzed their influence on resectability, recurrence, and survival.

METHODS

All patients who underwent exploration due to ICC between January 2008 and June 2018 were analyzed retrospectively. Kaplan-Meier model, log-rank test and Cox regression were used.

RESULTS

Out of 184 patients, 135 (73.4%) underwent curative intended resection. Median overall survival (OS) was 22.2 months with a consecutive 1-, 3- and 5-year OS of 73%, 29%, and 17%. Median recurrence-free survival (RFS) was 9.3 months with a consecutive 1-, 3- and 5-year RFS of 36%, 15%, and 11%. Site of tumor, parenchymal localization, tumor configuration/dissemination, and estimated tumor volume had significant influence on resectability. Univariate analyses showed that site of tumor, tumor configuration/dissemination, number of nodules, and estimated tumor volume had predictive values for OS and RFS. Together with tumor size the preoperative prediction (POP) score was created showing significance for OS and RFS (all P < 0.001). In multivariate analysis, POP score (HR = 1.779; 95% CI: 1.268-2.495; P = 0.001), T stage (HR = 1.255; 95% CI: 1.040-1.514; P = 0.018) and N stage (HR = 1.334; 95% CI: 1.081-1.645; P = 0.007) were the independent predictors for OS. For RFS, POP score (HR = 1.733; 95% CI: 1.300-2.311; P < 0.001) and M stage (HR = 3.036; 95% CI: 1.376-6.697; P = 0.006) were the independent predictors.

CONCLUSIONS

The POP score showed to have a highly significant influence on OS and RFS. The score is easy to assess through preoperative imaging. For patients in the high risk group at least staging laparoscopy or preoperative chemotherapy should be evaluated, because they showed equal outcome compared to the irresectable group.

Intrahepatic Cholangiocarcinoma with Lymph Node Metastasis: Treatment-Related Outcomes and the Role of Tumor Genomics in Patient Selection

PURPOSE

Lymph node metastasis (LNM) drastically reduces survival after resection of intrahepatic cholangiocarcinoma (IHC). Optimal treatment is ill defined, and it is unclear whether tumor mutational profiling can support treatment decisions.

EXPERIMENTAL DESIGN

Patients with liver-limited IHC with or without LNM treated with resection (N = 237), hepatic arterial infusion chemotherapy (HAIC; N = 196), or systemic chemotherapy alone (SYS; N = 140) at our institution between 2000 and 2018 were included. Genomic sequencing was analyzed to determine whether genetic alterations could stratify outcomes for patients with LNM.

RESULTS

For node-negative patients, resection was associated with the longest median overall survival [OS, 59.9 months; 95% confidence interval (CI), 47.2-74.31], followed by HAIC (24.9 months; 95% CI, 20.3-29.6), and SYS (13.7 months; 95% CI, 8.9-15.9; P < 0.001). There was no difference in survival for node-positive patients treated with resection (median OS, 19.7 months; 95% CI, 12.1-27.2) or HAIC (18.1 months; 95% CI, 14.1-26.6; P = 0.560); however, survival in both groups was greater than SYS (11.2 months; 95% CI, 14.1-26.6; P = 0.024). Node-positive patients with at least one high-risk genetic alteration (TP53 mutation, KRAS mutation, CDKN2A/B deletion) had worse survival compared to wild-type patients (median OS, 12.1 months; 95% CI, 5.7-21.5; P = 0.002), regardless of treatment. Conversely, there was no difference in survival for node-positive patients with IDH1/2 mutations compared to wild-type patients.

CONCLUSIONS

There was no difference in OS for patients with node-positive IHC treated by resection versus HAIC, and both treatments had better survival than SYS alone. The presence of high-risk genetic alterations provides valuable prognostic information that may help guide treatment.

Cholangiocarcinoma: Part 1, Pathological and Morphological Subtypes, Spectrum of Imaging Appearances, Prognostic Factors and Staging

Cholangiocarcinoma (CC) is the most frequent malignant tumor of the biliary tract. The vast majority of cholangiocarcinomas are adenocarcinomas with a high proportion of fibrous stroma. Based on the macroscopic growth pattern, CC is classified as mass-forming, periductal infiltrating, or intraductal, with each type having its own characteristic imaging findings and prognostic outcome. The recently proposed pathological classification of cholangiocarcinoma into two types: perihilar large duct type and peripheral small duct and/or ductular type helps in better understanding of the morphology and the imaging appearances. Computed tomography (CT) and magnetic resonance imaging (MRI) remain the main tools of imaging. We aim to provide a comprehensive outline of the different subtypes and the rationale behind various imaging features of these subtypes. Cholangiocarcinoma is one of the more difficult tumors to treat and till date, surgery remains the only definitive curative treatment.

Convolutional neural network for classifying primary liver cancer based on triple-phase CT and tumor marker information: a pilot study

PURPOSE

To develop convolutional neural network (CNN) models for differentiating intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC) and predicting histopathological grade of HCC.

MATERIALS AND METHODS

Preoperative computed tomography and tumor marker information of 617 primary liver cancer patients were retrospectively collected to develop CNN models categorizing tumors into three categories: moderately differentiated HCC (mHCC), poorly differentiated HCC (pHCC), and ICC, where the histopathological diagnoses were considered as ground truths. The models processed manually cropped tumor with and without tumor marker information (two-input and one-input models, respectively). Overall accuracy was assessed using a held-out dataset (10%). Area under the curve, sensitivity, and specificity for differentiating ICC from HCCs (mHCC + pHCC), and pHCC from mHCC were also evaluated. We assessed two radiologists' performance without tumor marker information as references (overall accuracy, sensitivity, and specificity). The two-input model was compared with the one-input model and radiologists using permutation tests.

RESULTS

The overall accuracy was 0.61, 0.60, 0.55, 0.53 for the two-input model, one-input model, radiologist 1, and radiologist 2, respectively. For differentiating pHCC from mHCC, the two-input model showed significantly higher specificity than radiologist 1 (0.68 [95% confidence interval: 0.50-0.83] vs 0.45 [95% confidence interval: 0.27-0.63]; p = 0.04).

CONCLUSION

Our CNN model with tumor marker information showed feasibility and potential for three-class classification within primary liver cancer.

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.

The Role of 18F-FDG PET/MRI in the Assessment of Primary Intrahepatic Neoplasms

RATIONALE AND OBJECTIVES

To evaluate the results of 18F-FDG PET/MRI in relation to the histopathologic subtypes and histologic grades of mass-forming primary intrahepatic neoplasms.

MATERIALS AND METHODS

We retrospectively evaluated 18F-FDG positron emission tomography/magnetic resonance imaging (PET/MRI) results for 39 patients with histopathologically confirmed primary hepatic neoplasms, 15 with mass-forming intrahepatic cholangiocarcinoma (ICC) and 24 with hepatocellular carcinoma (HCC). The apparent diffusion coefficient (ADC) and standardized uptake value (SUV) were analyzed in relation to the histopathologic diagnosis and histologic grade, including calculating the sensitivity and specificity of the imaging findings.

RESULTS

The median SUV of ICC (6.0 [interquartile range, 5-10]) was significantly higher than that of HCC (4.0 [2.62-6.50]) (p = 0.002). An area under the curve (AUC) of 0.79 (95% confidence interval 0.649-0.932) had a sensitivity of 86.7% and a specificity of 67% at the best cut-off SUV of 4.41 to differentiate between ICC and HCC. ADC values did not differ significantly between HCCs and ICCs (p = 0.283). Both SUV and ADC values differed significantly between low-grade (well- and moderately differentiated) and high-grade (poorly differentiated) HCCs. Combining ADC and SUV further improved differentiation of low- from high-grade HCCs to a significant level (0.929). The SUV did not differ significantly between ICC histologic grades (p = 0.280), while the ADC differed significantly only between well and poorly differentiated ICCs (p = 0.004).

CONCLUSION

Assessing primary hepatic neoplasms with 18F-Fluorodeoxyglucose PET/MRI may help to predict tumor grade and differentiate between types of intrahepatic neoplasms.

Surgical Treatment of Intrahepatic Cholangiocarcinoma: Current and Emerging Principles

Intrahepatic cholangiocarcinoma (ICC) is a rare, aggressive cancer of the biliary tract. It often presents with locally advanced or metastatic disease, but for patients with early-stage disease, surgical resection with negative margins and portahepatis lymphadenectomy is the standard of care. Recent advancements in ICC include refinement of staging, improvement in liver-directed therapies, clarification of the role of adjuvant therapy based on new randomized controlled trials, and advances in minimally invasive liver surgery. In addition, improvements in neoadjuvant strategies and surgical techniques have enabled expanded surgical indications and reduced surgical morbidity and mortality. However, recurrence rates remain high and more effective systemic therapies are still necessary to improve recurrence-free and overall survival. In this review, we focus on current and emerging surgical principals for the management of ICC including preoperative evaluation, current indications for surgery, strategies for future liver remnant augmentation, technical principles, and the role of neoadjuvant and adjuvant therapies.

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.

Multimodality Imaging of Abdominopelvic Tumors with Venous Invasion

A broad range of abdominal and pelvic tumors can manifest with or develop intraluminal venous invasion. Imaging features at cross-sectional modalities and contrast-enhanced US that allow differentiation of tumor extension within veins from bland thrombus include the expansile nature of tumor thrombus and attenuation and enhancement similar to those of the primary tumor. Venous invasion is a distinctive feature of hepatocellular carcinoma and renal cell carcinoma with known prognostic and treatment implications; however, this finding remains an underrecognized characteristic of multiple other malignancies-including cholangiocarcinoma, adrenocortical carcinoma, pancreatic neuroendocrine tumor, and primary venous leiomyosarcoma-and can be a feature of benign tumors such as renal angiomyolipoma and uterine leiomyomatosis. Recognition of tumor venous invasion at imaging has clinical significance and management implications for a range of abdominal and pelvic tumors. For example, portal vein invasion is a strong negative prognostic indicator in patients with hepatocellular carcinoma. In patients with rectal cancer, diagnosis of extramural venous invasion helps predict local and distant recurrence and is associated with worse survival. The authors present venous invasion by vascular distribution and organ of primary tumor origin with review of typical imaging features. Common pitfalls and mimics of neoplastic thrombus, including artifacts and anatomic variants, are described to help differentiate these findings from tumor in vein. By accurately diagnosing tumor venous invasion, especially in tumors where its presence may not be a typical feature, radiologists can help referring clinicians develop the best treatment strategies for their patients. ^©RSNA, 2020.

Usefulness of intraductal RFA in patients with malignant biliary obstruction

BACKGROUND/AIMS

Intraductal radiofrequency ablation (ID-RFA) is a novel therapy for unresectable malignant biliary obstructions. ID-RFA for perihilar lesions is associated with a high risk of adverse events. We aimed to evaluate the feasibility and efficacy of temperature-controlled ID-RFA for perihilar malignant biliary obstruction.

METHODS

Sixteen patients with pathologically proven perihilar cholangiocarcinoma were prospectively enrolled to evaluate the feasibility of hilar ID-RFA. Clinical efficacy and outcomes were subsequently evaluated in a multicenter retrospective cohort.

RESULTS

Nine of the 16 patients in the prospective cohort had Bismuth type IV and 7 had type IIIA perihilar cholangiocarcinoma. The median length of stricture was 34.5 mm. The median number of ID-RFA sessions was three, and all sessions were technically and functionally successful without severe adverse events. Clinical outcomes were assessed using a multicenter hilar ID-RFA cohort of 21 patients; the median stent patency and overall survival were 90 days (range: 35-483 days) and 147 days (range: 92-487 days), respectively. An approximate 16-month patency of the bile duct was maintained in one patient who had an intraductal growth pattern. In a comparison of the self-expandable metallic stent (SEMS) and plastic stent (PS) after hilar ID-RFA, no differences in stent patency (89 vs 90.5 days, respectively; P = .912) and adverse events (20.0% vs 10%, respectively; P = .739) were observed.

CONCLUSIONS

ID-RFA at 7 W for 120 seconds is safe and feasible in patients with advanced perihilar cholangiocarcinoma. After ID-RFA, SEMS and PS placement showed comparable patency and survival rates.

TRIAL REGISTRATION NUMBER

KCT0003223.

Gadoxetic acid magnetic-enhanced resonance imaging in the diagnosis of cholangiocarcinoma

The use of liver magnetic resonance imaging is increasing thanks to its multiparametric sequences that allow a better tissue characterization, and the use of hepatobiliary contrast agents. This review aims to evaluate gadoxetic acid enhanced magnetic resonance imaging in the diagnosis and staging of cholangiocarcinoma and its different clinical and radiological classifications proposed in the literature. We also analyze the epidemiology, risk factors in correlation with clinical findings and laboratory data.

Outcomes assessment in intrahepatic cholangiocarcinoma using qualitative and quantitative imaging features

BACKGROUND

To assess the performance of imaging features, including radiomics texture features, in predicting histopathologic tumor grade, AJCC stage, and outcomes [time to recurrence (TTR) and overall survival (OS)] in patients with intrahepatic cholangiocarcinoma (ICC).

METHODS

Seventy-three patients (26 M/47F, mean age 63y) with pre-operative imaging (CT, n = 37; MRI, n = 21; CT and MRI, n = 15] within 6 months of resection were included in this retrospective study. Qualitative imaging traits were assessed by 2 observers. A 3rd observer measured tumor apparent diffusion coefficient (ADC), enhancement ratios (ERs), and Haralick texture features. Blood biomarkers and imaging features were compared with histopathology (tumor grade and AJCC stage) and outcomes (TTR and OS) using log-rank, generalized Wilcoxon, Cox proportional hazards regression, and Fisher exact tests.

RESULTS

Median TTR and OS were 53.9 and 79.7 months. ICC recurred in 64.4% (47/73) of patients and 46.6% (34/73) of patients died. There was fair accuracy for some qualitative imaging features in the prediction of worse tumor grade (maximal AUC of 0.68 for biliary obstruction on MRI, p = 0.032, observer 1) and higher AJCC stage (maximal AUC of 0.73 for biliary obstruction on CT, p = 0.002, observer 2; and AUC of 0.73 for vascular involvement on MRI, p = 0.01, observer 2). Cox proportional hazards regression analysis showed that CA 19-9 [hazard ratio (HR) 2.44/95% confidence interval (CI) 1.31-4.57/p = 0.005)] and tumor size on imaging (HR 1.13/95% CI 1.04-1.22/p = 0.003) were significant predictors of TTR, while CA 19-9 (HR 4.08/95% CI 1.75-9.56, p = 0.001) and presence of metastatic lymph nodes at histopathology (HR 2.86/95% CI 1.35-6.07/p = 0.006) were significant predictors of OS. On multivariable analysis, satellite lesions on CT (HR 2.79/95%CI 1.01-7.15/p = 0.032, observer 2), vascular involvement on MRI (HR 0.10/95% CI 0.01-0.85/p = 0.032, observer 1), and texture feature MRI variance (HR 0.55/95% CI 0.31-0.97, p = 0.040) predicted TTR once adjusted for the independent predictors CA 19-9 and tumor size on imaging. Several qualitative and quantitative features demonstrated associations with TTR, OS, and AJCC stage at univariable analysis (range: HR 0.35-19; p < 0.001-0.045), however none were predictive of OS at multivariable analysis when adjusted for CA 19-9 and metastatic lymph nodes (p > 0.088).

CONCLUSIONS

There was reasonable accuracy in predicting tumor grade and higher AJCC stage in ICC utilizing certain qualitative and quantitative imaging traits. Serum CA 19-9, tumor size, presence of metastatic lymph nodes, and qualitative imaging traits of satellite lesions and vascular involvement are predictors of patient outcomes, along with a promising predictive ability of certain quantitative texture features.

Clinical and pathological characteristics of cholangiolocellular carcinoma

Cholangiolocellular carcinoma (CLC), due to its special cell origin, has dual clinical and radiological features of hepatocellular carcinoma and cholangiocellular carcinoma, and has a relatively good prognosis due to the characteristics of inert growth. Its growth characteristics and clinical characteristics are obviously different from those of traditional intrahepatic cholangiocarcinoma (ICC). Therefore, CLC is a special type of primary liver malignancy. With regard to cell origin, clinical pathology, growth characteristics, and prognosis, CLC is a distinct disease from traditional hepatic cholangiocarcinoma; however, it is often confused with ICC in the relevant research worldwide. In this paper, we review the clinical and pathological characteristics of CLC to raise the attention to this problem and strengthen the relevant research.

Hepatic sarcomatoid carcinoma: magnetic resonance imaging evaluation by using the liver imaging reporting and data system

OBJECTIVES

To evaluate how sarcomatoid carcinomas (SCs) would be classified on magnetic resonance imaging (MRI) by using the Liver Imaging Reporting and Data System (LI-RADS) and to assess imaging features of SC compared with other hepatic malignancies.

METHODS

We retrieved 184 patients with pathologically confirmed SC (n = 46), hepatocellular carcinoma (HCC, n = 92), and intrahepatic cholangiocarcinoma (iCCA, n = 46) diagnosed between January 2006 and December 2017. Two readers independently reviewed MRI according to LI-RADS v2017. Classification rate of SC, as probably or definitely malignant but not specific for HCC (LR-M), was calculated. LR-TIV (tumor in vein) was subclassified as either 5V or MV. MRI features were compared between SC, HCC, and iCCA and between SC of LR-M and non-LR-M categories.

RESULTS

Chronic liver disease was present in 71.7% (33/46) of patients with SC, and LI-RADS was applied for these patients. SC was classified as LR-M in 24 (72.7%) of 33 patients at risk. SCs that had been classified as LR-4/5/5V were significantly smaller (median, 1.9 cm; range, 1.0-4.2 cm) than SCs classified as LR-M/MV (median, 4.3 cm; range, 1.3-20.6 cm) on independent t test (p = 0.012). SCs commonly showed MRI features similar to iCCAs than to HCCs. Targetoid appearance and capsular retraction were more frequent in iCCA than in SC (p ≤ 0.009) on Pearson's chi-squared test or Fisher's exact test.

CONCLUSION

Most SCs can be classified as LR-M on MRI, but small lesions may be indistinguishable from HCCs.

KEY POINTS

• Most sarcomatoid carcinomas (SCs) are classified as LR-M on MRI by using LI-RADS v2017. • SC showed various LR-M features similar to those of intrahepatic cholangiocarcinoma. • Size of LR-4/5/5V SC was significantly smaller than that of LR-M/MV SC.

[Radiologic diagnosis of the gallbladder and bile ducts - part 2 : Acute and chronic cholecystitis, primary sclerosing cholangitis (PSC), benign and malignant masses of the biliary system]

Upper abdominal pain, icterus and cholestasis are the symptoms leading to evaluation of the biliary tract. Together with its complications biliary stone disease is the main reason for inflammation of the biliary system. A distinction is made between acute and chronic variants. In chronic bile duct inflammation primary sclerosing cholangitis (PSC), primary biliary cirrhosis (PBC) and more recently IgG4-associated sclerosing cholangitis are of particular importance. Besides benign and tumor-like-lesions, malignant entities as gallbladder carcinoma and cholangiocarcinoma (CCC) in its three locations have to be mentioned. Despite all recent improvements, specificity of bile-tract imaging still remains limited, especially regarding malignant masses. Therefore the final diagnosis is made in many cases by histological analysis.

Intrahepatic cholangiocarcinoma in the setting of HBV-related cirrhosis: Differentiation with hepatocellular carcinoma by using Intravoxel incoherent motion diffusion-weighted MR imaging

Accurate preoperative differentiation of intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) in the setting of cirrhotic liver is of great clinical significance because the treatment and prognosis of these entities differ markedly. Through a retrospectively research, we sought to determine the diagnostic performances of intravoxel incoherent motion (IVIM) and diffusion weighted imaging (DWI) parameters in the differentiating of ICC and HCC. According to the results, we found that apparent diffusion coefficient (ADC) derived from mono-exponential model and true ADC (ADC^slow) derived from bi-exponential model can be used to distinguish the ICC and HCC, and ADC^slowentailed the higher diagnostic performance than ADC. However, pseudo-ADC (ADC^fast) and perfusion fraction (f) can not be used to differentiate ICC and HCC. These results suggested that IVIM and DWI parameters can be useful in differentiating ICC and HCC and might be helpful in selecting the treatment plan and predicting prognosis.