Hypervascular benign and malignant liver tumors that require differentiation from hepatocellular carcinoma: key points of imaging diagnosis

Liver Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms

ABSTRACT

The incidence of neuroendocrine neoplasms (NENs) has gradually increased over the past few decades with the majority of patients presenting with metastases on initial presentation. The liver is the most common site of initial metastatic disease, and the presence of liver metastasis is an independent prognostic factor associated with a negative outcome. Because NENs are heterogenous neoplasms with variable differentiation, grading, and risk of grade transformation over time, accurate diagnosis and management of neuroendocrine liver lesions are both important and challenging. This is particularly so with the multiple liver-directed treatment options available. In this review article, we discuss the diagnosis, treatment, and response evaluation of NEN liver metastases.

Perfluorobutane-Enhanced Ultrasound for Characterization of Hepatocellular Carcinoma From Non-hepatocellular Malignancies or Benignancy: Comparison of Imaging Acquisition Methods

OBJECTIVE

The aim of the work described here was to evaluate the diagnostic performance of perfluorobutane (PFB)-enhanced ultrasound in differentiating hepatocellular carcinoma (HCC) from non-HCC malignancies and other benign lesions using different acquisition methods.

METHODS

This prospective study included 69 patients with solid liver lesions larger than 1 cm who were scheduled for biopsy or radiofrequency ablation between September 2020 and March 2021. Lesion diagnosis was designated by three blinded radiologists after reviewing three different sets of acquired images selected according to the following presumed acquisition methods: (i) method A, acquisition up to 5 min after contrast injection; (ii) method B, acquisition up to 1 min after contrast injection with additional Kupffer phase; and (iii) method C, acquisition up to 5 min after contrast injection with additional Kupffer phase.

RESULTS

After excluding 7 technical failures, 62 patients with liver lesions (mean size: 24.2 ± 14.8 mm), which consisted of 7 benign lesions, 37 non-HCC malignancies and 18 HCCs. For the HCC diagnosis, method C had the highest sensitivity (75.9%), followed by method B (72.2%) and method A (68.5%), but failed to exhibit statistical significance (p = 0.12). There was no significant difference with respect to the pooled specificity between the three methods (p = 0.28). Diagnostic accuracy was the highest with method C (87.1%) but failed to exhibit statistical significance (p = 0.24).

CONCLUSION

Image acquisition up to 5 min after contrast injection with additional Kupffer phase could potentially result in high accuracy and sensitivity without loss of specificity in diagnosing HCC with PFB-enhanced ultrasound.

Focal Lesions of the Liver and Radiomics: What Do We Know?

Despite differences in pathological analysis, focal liver lesions are not always distinguishable in contrast-enhanced magnetic resonance imaging (MRI), contrast-enhanced computed tomography (CT), and positron emission tomography (PET). This issue can cause problems of differential diagnosis, treatment, and follow-up, especially in patients affected by HBV/HCV chronic liver disease or fatty liver disease. Radiomics is an innovative imaging approach that extracts and analyzes non-visible quantitative imaging features, supporting the radiologist in the most challenging differential diagnosis when the best-known methods are not conclusive. The purpose of this review is to evaluate the most significant CT and MRI texture features, which can discriminate between the main benign and malignant focal liver lesions and can be helpful to predict the response to pharmacological or surgical therapy and the patient's prognosis.

Evaluation and Application of Drug Resistance by Biomarkers in the Clinical Treatment of Liver Cancer

Liver cancer is one of the most lethal cancers in the world, mainly owing to the lack of effective means for early monitoring and treatment. Accordingly, there is considerable research interest in various clinically applicable methods for addressing these unmet needs. At present, the most commonly used biomarker for the early diagnosis of liver cancer is alpha-fetoprotein (AFP), but AFP is sensitive to interference from other factors and cannot really be used as the basis for determining liver cancer. Treatment options in addition to liver surgery (resection, transplantation) include radiation therapy, chemotherapy, and targeted therapy. However, even more expensive targeted drug therapies have a limited impact on the clinical outcome of liver cancer. One of the big reasons is the rapid emergence of drug resistance. Therefore, in addition to finding effective biomarkers for early diagnosis, an important focus of current discussions is on how to effectively adjust and select drug strategies and guidelines for the treatment of liver cancer patients. In this review, we bring this thought process to the drug resistance problem faced by different treatment strategies, approaching it from the perspective of gene expression and molecular biology and the possibility of finding effective solutions.

Prognostic value of des-γ-carboxyprothrombin in patients with AFP-negative HCC treated with TACE

In patients with AFP-negative hepatocellular carcinoma (HCC), des-γ-carboxyprothrombin (DCP) is an important prognostic indicator for the preoperative assessment of transarterial chemoembolization (TACE). However, the association between the serum DCP levels and the degree of progression and prognosis of patients with AFP-negative HCC treated with TACE has not been thoroughly investigated to date, and the molecular mechanism is also unclear. The present study retrospectively analyzed the clinical data of 107 patients with AFP-negative HCC treated with TACE and divided them into two groups based on the median serum DCP levels. The association between DCP and the clinical characteristics of the patients was analyzed, and the survival data were analyzed using Kaplan-Meier curves and Cox regression models. The results demonstrated that the median follow-up time was 755 days (range, 64-1,556 days), and patients in the low-DCP group (n=11; 20.8%) had a lower mortality rate than those in the high-DCP group (n=20; 37.0%). Cox multivariate regression analysis suggested that preoperative lymph node metastasis [hazard ratio (HR), 3.903; 95% CI, 1.778-8.519; P=0.001] and DCP group (HR, 2.465; 95% CI, 1.038-5.854; P=0.041) were independent risk factors. Furthermore, the Gene Expression Omnibus database was utilized to screen differentially expressed mRNAs. Enrichment analyses were then performed, and a protein-protein interaction (PPI) network was constructed to identify hub genes. A total of 169 differentially expressed genes were screened. Enrichment analyses revealed that cancer-related and ribosomal pathways were significantly enriched. Furthermore, 10 hub genes were identified in the PPI network by counting the number of gene interactions, the majority of which belonged to the ribosomal protein (RPS) family, and the top three significant genes were RPS23, RPS11 and RPS3A. In patients with AFP-negative HCC, higher serum DCP levels were associated with poor prognosis after TACE. This may be associated with genes such as those belonging to the RPS family, which may contribute to future personalized therapy for this disease.

A clinical trial of super-stable homogeneous lipiodol-nanoICG formulation-guided precise fluorescent laparoscopic hepatocellular carcinoma resection

BACKGROUND

Applying traditional fluorescence navigation technologies in hepatocellular carcinoma is severely restricted by high false-positive rates, variable tumor differentiation, and unstable fluorescence performance.

RESULTS

In this study, a green, economical and safe nanomedicine formulation technology was developed to construct carrier-free indocyanine green nanoparticles (nanoICG) with a small uniform size and better fluorescent properties without any molecular structure changes compared to the ICG molecule. Subsequently, nanoICG dispersed into lipiodol via a super-stable homogeneous intermixed formulation technology (SHIFT&nanoICG) for transhepatic arterial embolization combined with fluorescent laparoscopic hepatectomy to eliminate the existing shortcomings. A 52-year-old liver cancer patient was recruited for the clinical trial of SHIFT&nanoICG. We demonstrate that SHIFT&nanoICG could accurately identify and mark the lesion with excellent stability, embolism, optical imaging performance, and higher tumor-to-normal tissue ratio, especially in the detection of the microsatellite lesions (0.4 × 0.3 cm), which could not be detected by preoperative imaging, to realize a complete resection of hepatocellular carcinoma under fluorescence laparoscopy in a shorter period (within 2 h) and with less intraoperative blood loss (50 mL).

CONCLUSIONS

This simple and effective strategy integrates the diagnosis and treatment of hepatocellular carcinoma, and thus, it has great potential in various clinical applications.

Imaging of Tumor-Associated Vascular Prostate-Specific Membrane Antigen in Woodchuck Model of Hepatocellular Carcinoma

BACKGROUND AND AIMS

Radiolabeled short peptide ligands targeting prostate-specific membrane antigen (PSMA) were developed initially for imaging and treatment of prostate cancers. While many nonprostate solid tumors including hepatocellular carcinoma (HCC) express little PSMA, their neovasculature expresses a high level of PSMA, which is avid for Gallium-68-labeled PSMA-targeting radio-ligand (⁶⁸Ga-PSMA-11) for positron emission tomography (PET). However, the lack of a spontaneous animal model of tumor-associated vascular PSMA overexpression has hindered the development and assessment of PSMA-targeting radioligands for imaging and therapy of the nonprostatic cancers. We identified detectable indigenous PSMA expression on tumor neovascular endothelia in a naturally occurring woodchuck model of HCC.

METHODS

Molecular docking was performed with 3 bait PSMA ligands and compared between human and woodchuck PSMA. Initially, PET images were acquired dynamically after intravenously injecting 37 MBq (1.0 mCi) of ⁶⁸Ga-PSMA-11 into woodchuck models of HCC. Subsequently, 10-minute static PET scans were conducted for other animals 1-hour after injection due to HCC and liver background uptake stabilization at 30-45 minutes after injection. Liver tissue samples were harvested after imaging, fresh-frozen for quantitative reverse transcription polymerase chain reaction and western blot for validation, or fixed for histology for correlation.

RESULTS

Our preclinical studies confirmed the initial clinical findings of ⁶⁸Ga-PSMA-11 uptake in HCC. The agents (ligands and antibodies) developed against human PSMA were found to be reactive against the woodchuck PSMA.

CONCLUSION

This animal model offers a unique opportunity for investigating the biogenesis of tumor-associated vascular PSMA, its functional role(s), and potentials for future treatment strategies targeting tumor vascular PSMA using already developed PSMA-targeting agents.

Liver imaging: it is time to adopt standardized terminology

Liver imaging plays a vital role in the management of patients at risk for hepatocellular carcinoma (HCC); however, progress in the field is challenged by nonuniform and inconsistent terminology in the published literature. The Steering Committee of the American College of Radiology (ACR)'s Liver Imaging Reporting And Data System (LI-RADS), in conjunction with the LI-RADS Lexicon Writing Group and the LI-RADS International Working Group, present this consensus document to establish a single universal liver imaging lexicon. The lexicon is intended for use in research, education, and clinical care of patients at risk for HCC (i.e., the LI-RADS population) and in the general population (i.e., even when LI-RADS algorithms are not applicable). We anticipate that the universal adoption of this lexicon will provide research, educational, and clinical benefits. KEY POINTS: •To standardize terminology, we encourage authors of research and educational materials on liver imaging to use the standardized LI-RADS Lexicon. •We encourage reviewers to promote the use of the standardized LI-RADS Lexicon for publications on liver imaging. •We encourage radiologists to use the standardized LI-RADS Lexicon for liver imaging in clinical care.

Liver disease severity predicts carcinogenesis of dysplastic liver nodules in cirrhosis

While dysplastic liver nodules in cirrhosis are pre-malignant, little is known about the predictors of hepatocarcinogenesis of these lesions. This was a retrospective observational study of subjects with cirrhosis who had at least one hypervascular, non-malignant intrahepatic nodule on imaging while undergoing outpatient management by a tertiary hepatology referral centre between Jan 2009 and Jan 2019. Clinical and biochemical parameters were collected. The primary endpoint was transformation to hepatocellular carcinoma (HCC) as determined by Liver Imaging Reporting and Data System. During the study period, 163 non-malignant hypervascular nodules were identified in 77 patients; 147 had at least 6 months of follow up imaging and 16 received upfront radiofrequency ablation upon detection. During a median follow up of 38.5 months (IQR 16.5-74.5), 25 (17%) of the 147 hypervascular nodules being monitored transformed to HCC. On multivariate analysis, Child-Pugh grade was found to be the only independent predictor of nodule transformation into HCC (p = 0.02). Those with Child-Pugh B and C liver disease had a 10.1 (95% CI 1.22-83.8; p = 0.03) and 32.6-fold (95% CI 2.3-467; p = 0.01) increased risk respectively for HCC transformation compared to Child-Pugh A subjects. This large, single centre study demonstrates that around 20% of dysplastic nodules in cirrhotic patients undergo hepatocarcinogenesis during follow up, and that Child Pugh grade is the only independent predictor of transformation to HCC. Additional prospective studies are warranted to better understand the risk profile of these nodules, and how best they should be managed.

Focal hepatic lesions in acid sphingomyelinase deficiency: Differential diagnosis between foamy macrophages aggregates and malignancy

Acid sphingomyelinase deficiency (ASMD) is a rare metabolic disorder due to biallelic mutation in the SMPD1 gene. The defect leads to the accumulation of sphingomyelin within the cells of the reticulo-endothelial system, particularly in the spleen, liver, lungs, and bone marrow causing hepato-splenomegaly, lung disease and hematological abnormalities. At present, data on abdominal imaging in ASMD are limited. Here we describe the characteristics of focal liver lesions observed in a 30 years old female. During the Magnetic Resonance follow up an increase in number and size of the lesions, showing T1 hypointensity and T2 hyperintensity with contrast enhancement, was observed. Contrast enhanced ultrasound evidenced rapid wash-in and steady isoecogenicity without appreciable wash-out at 80 seconds. The main lesion was biopsied to rule out the presence of a hepatocellular carcinoma, and showed to be a benign foamy macrophages aggregate. In this report, we discuss the possible pathogenesis of focal hepatic lesions in ASMD and their differential diagnosis.

IgG4-related hepatic inflammatory pseudotumor mimicking cholangiolocellular carcinoma

Inflammatory pseudotumor (IPT) is a benign tumor mass composed of chronic infiltration of inflammatory cells and fibrous tissue. IgG4-RD (related disease) in the hepatobiliary system has been widely recognized and includes IgG4-related hepatic IPT. This report describes a patient with IgG4-related hepatic IPT with sclerosing cholangitis. A 75-year-old woman was admitted to our hospital for the treatment of rectal cancer. Abdominal contrast-enhanced computed tomography revealed a low-density mass, 2.5 cm in diameter, in the left lateral lobe. Magnetic resonance imaging showed that the mass was slightly hypointense on T1-weighted images and slightly hyperintense on T2-weighted images. Based on these results, we made a diagnosis of cholangiolocellular carcinoma, and we performed a left hepatectomy. Histopathological examination showed that the mass was composed of fibrous stroma with dense lymphoplasmacytic infiltration. Immunohistochemically, IgG4-positive plasma cells were observed. The final diagnosis was IgG4-related hepatic IPT with sclerosing cholangitis. IgG4-related IPT is a relatively rare disease that can occur in any organ of the body. Although the accurate diagnosis of IgG4-related hepatic IPT remains difficult, IgG4-RD should be included in the differential diagnosis of liver tumors and histological analysis performed.

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.

An MR-based radiomics model for differentiation between hepatocellular carcinoma and focal nodular hyperplasia in non-cirrhotic liver

Purpose

We aimed to develop and validate a radiomics model for differentiating hepatocellular carcinoma (HCC) from focal nodular hyperplasia (FNH) in non-cirrhotic livers using Gd-DTPA contrast-enhanced magnetic resonance imaging (MRI).

Methods

We retrospectively enrolled 149 HCC and 75 FNH patients treated between May 2015 and May 2019 at our center. Patients were randomly allocated to a training (n=156) and validation set (n=68). In total, 2260 radiomics features were extracted from the arterial phase and portal venous phase of Gd-DTPA contrast-enhanced MRI. Using Max-Relevance and Min-Redundancy, random forest, least absolute shrinkage, and selection operator algorithm for dimensionality reduction, multivariable logistic regression was used to build the radiomics model. A clinical model and combined model were also established. The diagnostic performance of the models was compared.

Results

Eight radiomics features were chosen for the radiomics model, and four clinical factors (age, sex, HbsAg, and enhancement pattern) were chosen for the clinical model. A combined model was built using the factors from the previous models. The classification accuracy of the combined model differentiated HCC from FNH in both the training and validation sets (0.956 and 0.941, respectively). The area under the receiver operating characteristic curve of the combined model was significantly better than that of the clinical model for both the training (0.984 vs. 0.937, p=0.002) and validation (0.972 vs. 0.903, p=0.032) sets.

Conclusions

The combined model provided a non-invasive quantitative method for differentiating HCC from FNH in non-cirrhotic liver with high accuracy. Our model may assist clinicians in the clinical decision-making process.

Outpatient Yttrium-90 microsphere radioembolization: assessment of radiation safety and quantification of post-treatment adverse events causing hospitalization

PURPOSE

Quantification of post-interventional adverse events of outpatient SIRT leading to hospitalization and quantification of radiation exposure.

MATERIALS AND METHODS

In this single-center, retrospective cohort study, we reviewed 212 patients treated with SIRT (⁹⁰Y-microspheres) for primary and secondary liver malignancies. We searched for adverse events (AEs) and serious adverse events (SAEs), defined as AE's causing hospitalization. Additionally, radiation exposure was measured in 36 patients.

RESULTS

Seven patients had an SAE (3.3%), four patients had AE without readmission/hospitalization (1.9%) and 201 patients had no complications (94.8%). The mean ambient dose rate at 1 m distance from the source after administration of ⁹⁰Y-microspheres was 1.88 µSv/h ± 0.74 (± SD) with a range from 4.3 to 0.2 µSv/h.

CONCLUSION

Outpatient radioembolization with ⁹⁰Y-microspheres is safe and requires hospitalization only in a very small number of patients. The mean dose rate was low and met the national conditions for outpatient treatment (< 5 µSv/h).

Hepatic tumors: pitfall in diagnostic imaging

On computed tomography (CT) and magnetic resonance imaging (MRI), hepatocellular tumors are characterized based on typical imaging findings. However, hepatocellular adenoma, focal nodular hyperplasia, and hepatocellular carcinoma can show uncommon appearances at CT and MRI, which may lead to diagnostic challenges. When assessing focal hepatic lesions, radiologists need to be aware of these atypical imaging findings to avoid misdiagnoses that can alter the management plan. The purpose of this review is to illustrate a variety of pitfalls and atypical features of hepatocellular tumors that can lead to misinterpretations providing specific clues to the correct diagnoses. (www.actabiomedica.it)

Intraindividual Comparison between Gadoxetate-Enhanced Magnetic Resonance Imaging and Dynamic Computed Tomography for Characterizing Focal Hepatic Lesions: A Multicenter, Multireader Study

OBJECTIVE

To compare the diagnostic accuracy of dynamic computed tomography (CT) and gadoxetate-enhanced magnetic resonance imaging (MRI) for characterization of hepatic lesions by using the Liver Imaging Reporting and Data System (LI-RADS) in a multicenter, off-site evaluation.

MATERIALS AND METHODS

In this retrospective multicenter study, we evaluated 231 hepatic lesions (114 hepatocellular carcinomas [HCCs], 58 non-HCC malignancies, and 59 benign lesions) confirmed histologically in 217 patients with chronic liver disease who underwent both gadoxetate-enhanced MRI and dynamic CT at one of five tertiary hospitals. Four radiologists at different institutes independently reviewed all MR images first and the CT images 4 weeks later. They evaluated the major and ancillary imaging features and categorized each hepatic lesion according to the LI-RADS v2014. Diagnostic performance was calculated and compared using generalized estimating equations.

RESULTS

MRI showed higher sensitivity and accuracy than CT for diagnosing hepatic malignancies; the pooled sensitivities, specificities, and accuracies for categorizing LR-5/5V/M were 59.0% vs. 72.4% (CT vs. MRI; p < 0.001), 83.5% vs. 83.9% (p = 0.906), and 65.3% vs. 75.3% (p < 0.001), respectively. CT and MRI showed comparable capabilities for differentiating between HCC and other malignancies, with pooled accuracies of 79.9% and 82.4% for categorizing LR-M, respectively (p = 0.139).

CONCLUSION

Gadoxetate-enhanced MRI showed superior accuracy for categorizing LR-5/5V/M in hepatic malignancies in comparison with dynamic CT. Both modalities had comparable accuracies for distinguishing other malignancies from HCC.

Distinguishing intrahepatic mass-forming biliary carcinomas from hepatocellular carcinoma by computed tomography and magnetic resonance imaging using the Bayesian method: a bi-center study

OBJECTIVES

To determine imaging hallmarks for distinguishing intrahepatic mass-forming biliary carcinomas (IMBCs) from hepatocellular carcinoma (HCC) and to validate their diagnostic ability using Bayesian statistics.

METHODS

Study 1 retrospectively identified clinical and imaging hallmarks that distinguish IMBCs (n = 41) from HCC (n = 247) using computed tomography (CT) and magnetic resonance imaging (MRI). Study 2 retrospectively assessed the diagnostic ability of these hallmarks to distinguish IMBCs (n = 37) from HCC (n = 111) using Bayesian statistics with images obtained from a different institution. We also assessed the diagnostic ability of the hallmarks in the patient subgroup with high diagnostic confidence (≥ 80% of post-test probability). Two radiologists independently evaluated the imaging findings in studies 1 and 2.

RESULTS

In study 1, arterial phase peritumoral parenchymal enhancement on CT/MRI, delayed enhancement on CT/MRI, diffusion-weighted imaging peripheral hyperintensity, and bile duct dilatation were hallmarks indicating IMBCs, whereas chronic liver disease, non-rim arterial phase hyperenhancement on CT/MRI, enhancing capsule on CT/MRI, and opposed-phase signal drop were hallmarks indicating HCC (p = 0.001-0.04). In study 2, Bayesian statistics-based post-test probability combining all hallmark features had a diagnostic accuracy of 89.2% (132/148) in distinguishing IMBCs from HCC for both readers. In the high diagnostic confidence subgroup (n = 120 and n = 124 for readers 1 and 2, respectively), the accuracy improved (95.0% (114/120) and 93.5% (116/124) for readers 1 and 2, respectively).

CONCLUSIONS

Combined interpretation of CT and MRI to identify hallmark features is useful in discriminating IMBCs from HCCs. High post-test probability by Bayesian statistics allows for a more reliable non-invasive diagnosis.

KEY POINTS

• Combined interpretation of CT and MRI to identify hallmark features was useful in discriminating intrahepatic mass-forming biliary carcinomas from hepatocellular carcinoma. • Bayesian method-based post-test probability combining all hallmark features determined in study 1 showed high (> 90%) sensitivity and specificity for distinguishing intrahepatic mass-forming biliary carcinomas from hepatocellular carcinoma. • If the post-test probability or the confidence was ≥ 80% when combining the imaging features of CT and MRI, the high specificity of > 95% was achieved without any loss of sensitivity to distinguish hepatocellular carcinoma from intrahepatic mass-forming biliary carcinomas.

Unclassified hepatocellular adenoma with histological brown pigment deposition and serum PIVKA-II level elevation: a case report

Background

Hepatocellular adenoma (HCA) is conventionally considered a rare benign liver tumor, but advanced studies have revealed that HCA is heterogeneous, and may include a type that is prone to malignant transformations. Differentiation between well-differentiated hepatocellular carcinoma and focal nodular hyperplasia is necessary to diagnose hepatocellular adenoma through imaging; however, the tumor marker of hepatocellular carcinoma, protein induced by vitamin K absence, or antagonist II (PIVKA-II), is rarely positive in hepatocellular adenoma.

Case presentation

A 44-year-old woman presented to our hospital with complaints of loss of appetite and weight loss. Multidetector row computed tomography revealed a liver tumor (diameter, 80 mm) that was enhanced in the arterial phase. Her serum PIVKA-II level was very high (3327 mAU/mL). Based on the enlargement of the mass and the results of the diagnostic imaging, hepatocellular adenoma or hepatocellular carcinoma was suspected, and we considered the possibility of a malignant transformation due to the high level of serum PIVKA-II; thus, we performed hepatectomy. Histological examination showed brown pigment deposition in the hepatocytes, which was determined to be lipofuscin granules. Based on immunohistochemical findings, the diagnosis was unclassified hepatocellular adenoma. Immunohistochemical examinations revealed that the adenoma cells in the tumor were positive for PIVKA-II. Her serum PIVKA-II level returned to normal after the resection.

Conclusions

We present a case of unclassified hepatocellular adenoma with brown pigment deposition and elevation of serum PIVKA-II level. For the differentiation of liver tumors with high levels of PIVKA-II and hypervascular mass, hepatocellular adenoma should be considered.

Application of new ultrasound techniques for focal liver lesions

Ultrasonography (US) has the overwhelming advantages of not entailing radiation exposure and being a noninvasive, real-time, convenient, easy-to-perform, and relatively inexpensive imaging modality. It is used as the first-line imaging modality for screening, detection, and diagnosis of focal liver lesions (FLLs) [small hepatocellular carcinomas (HCCs), in particular]. However, with the increasing demand for accurate and early diagnosis of small HCCs, newer radiologic methods need to be explored to overcome certain limitations of US. For example, the imaging is easily negatively affected by the presence of gas, rib cage, and subcutaneous fat, and is insensitive for capturing the subtle but vital information on the blood flow. It was in response to this need that new promising technologies such as contrast-enhanced ultrasound and fusion imaging were introduced for the detection of liver lesions. This paper presents an overview of the epidemiology and mechanisms of the development of HCCs, with an emphasis on the application of US in the diagnosis and treatment of FLLs. The aim of this article is to provide the state-of-the-art developments in the imaging diagnosis of FLLs and evaluation of ablation treatment of early HCCs. By keeping abreast of these recent advances, we hope that doctors and researchers working in the field of diagnosis/treatment of liver diseases will be able to discriminate benign FLLs such as regenerative nodules and focal nodular hyperplasia from HCCs, so as to avoid unnecessary repeated tumor biopsies and overtreatment. In particular, we expect that small HCCs or precancerous nodules (such as dysplastic nodules) can be accurately diagnosed and appropriately treated even at an early stage.

Current Imaging Standards for Nonmetastatic Benign and Malignant Liver Tumors

The accurate diagnosis of a liver mass can usually be established with a thorough history, examination, laboratory inquiry, and imaging. The necessity of a liver biopsy to determine the nature of a liver mass is rarely necessary. Contrast-enhanced computed tomography and magnetic resonance are the standard of care for diagnosing liver lesions and high-quality imaging should be performed before performing a biopsy. This article discusses current consensus guidelines for imaging of liver masses, as well as masses found on surveillance imaging. The ability to accurately characterize lesions requires proper use and understanding of the technology and expert interpretation.

Evaluation of unenhanced axial T1W and T2W liver MR images acquired from institutions within the Republic of Ireland and the Kingdom of Saudi Arabia

INTRODUCTION

This multi-site study evaluated two breath-hold sequences commonly utilised for liver MRI; non-enhanced T1W-3D-FS-GRE-TRA and T2W-2D-FSE-TRA sequences, using physical measurements of SNR and CNR, and observer perceptions' (Visual Grading Analysis: VGA).

METHODS

Liver MR image datasets (n = 168) from nine hospitals in the Kingdom of Saudi Arabia (KSA) and 11 hospitals in the Republic of Ireland were evaluated. Images were categorised into two groups per sequence, defined by slice thickness (T2W-2D-FSE, ≤5 mm vs ≥ 6 mm and T1W-3D-GRE-FS, ≤3 mm vs 4 mm). Images were evaluated using visual grading analysis VGA and physical measurements: SNR/CNR. Account was taken of varying patient sizes based on AP/transverse diameter measurements.

RESULTS

Physical image quality measurements (SNR/CNR) returned no significant findings across Irish and KSA hospitals, for both sequences, despite variations in acquisition parameters. Statistically significant differences were found for some scoring criteria based on the observers' perceptions including spleen parenchyma, and spatial resolution for the non-enhanced T1W-3D-FS-GRE-TRA images, with a preference for images acquired using thin slices (≤3 mm). In addition, statistically significant difference was found for the scoring criteria motion artefact for the axial T2W-2D-FSE-TRA images, with a preference for images acquired using thick slices (≥5 mm). Negligible correlation was noted between SNR/CNR and measured abdominal AP/transverse diameters.

CONCLUSION

Whilst variations in sequences rendered no statistical differences in SNR/CNR findings, significant differences in observer image criteria scores was noted. The importance of both physical measurements and observers' perceptions evaluation methods for quality assessment of MR images was demonstrated and optimisation of liver sequence parameters is warranted.

Common pitfalls when using the Liver Imaging Reporting and Data System (LI-RADS): lessons learned from a multi-year experience

The goal of the Liver Imaging Reporting and Data System (LI-RADS) is to standardize the interpretation and reporting of liver observations on contrast-enhanced CT and MR imaging of patients at risk for hepatocellular carcinoma. Although LI-RADS represents a significant achievement in standardization of the diagnosis and management of cirrhotic patients, complexity and caveats to the algorithm may challenge correct application in clinical practice. The purpose of this paper is to discuss common pitfalls and potential solutions when applying LI-RADS in practice. Knowledge of the most common pitfalls may improve the diagnostic confidence and performance when using the LI-RADS system for the interpretation of CT and MR imaging of the liver.

Iodine quantification to distinguish hepatic neuroendocrine tumor metastasis from hepatocellular carcinoma at dual-source dual-energy liver CT

PURPOSE

To investigate the value of third-generation dual-source dual-energy computed tomography (DECT) iodine quantification to distinguish hepatic neuroendocrine tumor (NET) metastasis from hepatocellular carcinoma (HCC) in non-cirrhotic liver parenchyma.

MATERIAL AND METHODS

Forty-six patients (mean age, 64.9 ± 10.1 years; 28 male and 18 female) with either hepatic NET metastasis or HCC, who had undergone liver DECT, were included in this retrospective study. For each lesion, arterial-phase attenuation values and DECT quantitative parameters, including iodine uptake, fat fraction, normalized iodine uptake (NIU), and lesion-to-liver-parenchyma ratio (LPR) were evaluated. Available cumulative data from histopathology, MRI, PET/CT, or interval imaging follow-up served as the reference standard for all liver lesions. In addition, the diagnostic accuracy of contrast-enhanced and material decomposition analysis for the differentiation of hepatic NET metastasis and HCC was assessed using receiver operating characteristics (ROC) curve analysis.

RESULTS

Hepatic NET metastasis and HCC showed significant differences in arterial attenuation (P = 0.003), iodine uptake (P < 0.001), NIU (P < 0.001), and LPR (P = 0.003). No significant differences were found for unenhanced attenuation and fat fraction values (P = 0.686 and P = 0.892, respectively). NIU showed superior sensitivity (100%; iodine uptake, 71%), while both iodine uptake and NIU revealed superior specificity (100% and 90%, respectively) compared to LPR (sensitivity, 96%; specificity, 80%) and arterial attenuation analysis (sensitivity, 79%; specificity, 80%) (P ≤ 0.016).

CONCLUSION

Third-generation DECT with assessment of iodine uptake improves the differentiation of hepatic NET metastasis and HCC in non-cirrhotic liver, with NIU showing the strongest diagnostic performance.

The Histopathological Features and CT/MRI Imaging Performances in Hepatic Angiomyolipoma Patients

AIM

To evaluate the diagnostic value of dynamic contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the differential diagnosis of hepatic angiomyolipoma (HAML) and hepatocellular carcinoma (HCC) and to clarify the relationship between histopathological features and CT or MRI imaging performances in HAML.

MATERIAL AND METHODS

Six HAML and 33 non-cirrhotic HCC patients confirmed by histopathology were retrospectively analyzed. The serum biomarkers, CT and MRI examinations were conventionally performed before the confirmatory histological diagnosis. The clinical data from their medical records was also analyzed.

RESULTS

Six HAML patients were annotated as two types according to CT and MRI imaging characteristics, including hypovascular type (n = 1) and hypervascular type (n = 5). The imaging performances of the 33 HCC patients were hypervascular type. Moreover, all the 5 hypervascular type HAML patients were misdiagnosed as HCC by CT or MRI. We also found that the hypervascular type of HAML patients contained more vessels and less fatty tissues in histopathology than hypovascular type of HAML patients. However, the clinical features included HCC high risk factors (hepatitis B or C), non-specific symptoms, male and increased serum alpha fetoprotein (AFP) were more common in HCC patients than HAML patients (P < 0.05, respectively).

CONCLUSIONS

The CT or MRI imaging performances of HAML patients containing more vessels and less fatty tissues in histopathology resemble the imaging performance of HCC patients. These clinical features may be of great help in the differential diagnosis in the current clinical practices.

Primary Hepatic Neoplasms of Vascular Origin: Key Imaging Features and Differential Diagnoses With Radiology-Pathology Correlation

OBJECTIVE

This article describes, illustrates, and correlates imaging and pathologic features of primary vascular mesenchymal neoplasms of the liver, which arise from the vascular endothelium and perivascular epithelioid cells.

CONCLUSION

Familiarity with the spectrum of benign, malignant-potential and malignant vascular neoplasms, and nonneoplastic mimickers allows consideration in the differential diagnosis of enhancing hepatic masses. Understanding relevant pathologic features facilitates recognition of key imaging features, specifically dynamic contrast enhancement patterns on CT and MRI, which provide a useful classification system.

The potential of cell sheet technique on the development of hepatocellular carcinoma in rat models

BACKGROUND

Hepatocellular carcinoma (HCC) is considered the 3rd leading cause of death by cancer worldwide with the majority of patients were diagnosed in the late stages. Currently, there is no effective therapy. The selection of an animal model that mimics human cancer is essential for the identification of prognostic/predictive markers, candidate genes underlying cancer induction and the examination of factors that may influence the response of cancers to therapeutic agents and regimens. In this study, we developed a HCC nude rat models using cell sheet and examined the effect of human stromal cells (SCs) on the development of the HCC model and on different liver parameters such as albumin and urea.

METHODS

Transplanted cell sheet for HCC rat models was fabricated using thermo-responsive culture dishes. The effect of human umbilical cord mesenchymal stromal cells (UC-MSCs) and human bone marrow mesenchymal stromal cells (BM-MSCs) on the developed tumour was tested. Furthermore, development of tumour and detection of the liver parameter was studied. Additionally, angiogenesis assay was performed using Matrigel.

RESULTS

HepG2 cells requires five days to form a complete cell sheet while HepG2 co-cultured with UC-MSCs or BM-MSCs took only three days. The tumour developed within 4 weeks after transplantation of the HCC sheet on the liver of nude rats. Both UC-MSCs and BM-MSCs improved the secretion of liver parameters by increasing the secretion of albumin and urea. Comparatively, the UC-MSCs were more effective than BM-MSCs, but unlike BM-MSCs, UC-MSCs prevented liver tumour formation and the tube formation of HCC.

CONCLUSIONS

Since this is a novel study to induce liver tumour in rats using hepatocellular carcinoma sheet and stromal cells, the data obtained suggest that cell sheet is a fast and easy technique to develop HCC models as well as UC-MSCs have therapeutic potential for liver diseases. Additionally, the data procured indicates that stromal cells enhanced the fabrication of HepG2 cell sheets. This provides the foundation for future research using stromal cells in preclinical and clinical investigations.

Role of selective intra-arterial embolization in benign liver tumors

OBJECTIVE

To present cases of symptomatic benign liver tumors diagnosed and treated with intra-arterial embolization before surgery.

MATERIAL AND METHODS

We present the cases of 7 patients diagnosed with symptomatic benign liver tumors that required treatment: 1 focal nodular hyperplasia, 2 giant cavernous hemangiomas, 1 hepatic adenomatosis, and 3 hepatic adenomas. Once the feeding arteries were identified, tumors were embolized with polyvinyl alcohol particles (500μm-700μm) and then the feeding artery was plugged with coils if there was an arterial pedicle to ensure the total vascular exclusion of the tumor. The surgical intervention took place 4 to 7 days after embolization.

RESULTS

All 7 patients were women (age range, 23-74 years); presurgical intra-arterial embolization was done in 6. In 1 patient with adenomatosis, embolization was done to control intraparenchymal hepatic hemorrhage. In the 6 patients who underwent surgery, the tumor was completely excised and no intraoperative bleeding events or postoperative complications occurred.

CONCLUSIONS

Provided there is a consensus among the multidisciplinary team, embolization is a useful option in the perioperative management of giant and/or symptomatic benign liver tumors.

A case of cholangiolocellular carcinoma featuring intratumoral hepatic artery penetration: A case report

INTRODUCTION

Cholangiolocellular carcinoma (CoCC) is thought to originate from hepatic stem cells. Its clinical characteristics, including radiological and prognostic factors, remain unclear.

PRESENTATION OF CASE

A 79-year-old woman with hypertension was admitted to our hospital after abnormal tumor marker levels were detected during an annual physical examination. Her laboratory data results were within normal range, and she was classified as Child-Pugh A. Enhanced computed tomography revealed a tumor located on the left side of the liver, with a maximum size of 60mm. The tumor showed heterogeneously enhancing edges in the arterial phase, while prolonged tumor enhancement was detected in the delayed phase. Tumor penetration by the left hepatic artery was evident, whereas the left portal vein was invaded by the tumor. The preoperative diagnosis was cholangiocellular carcinoma. Left hepatectomy and cholecystectomy were performed with no postoperative complications; the final diagnosis was CoCC. Multiple liver metastases appeared 6 months after surgery; the patient is now receiving systematic chemotherapy.

DISCUSSION

While portal vein penetration into CoCCs has been reported, the same is not true of the hepatic artery; therefore, this case illustrates a unique tumor growth pattern.

CONCLUSION

A unique growth pattern as well as a large primary tumor may contribute to earlier recurrence.

Recent Trends in the Management of Hepatocellular Carcinoma with Special Emphasis on Treatment with Regorafenib and Immune Checkpoint Inhibitors

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer deaths worldwide. Sonazoid-enhanced ultrasound and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI are the most important imaging modalities in diagnosing HCC. There are 2 non-contradictory HCC treatment algorithms in Japan. Hepatic arterial infusion chemotherapy plays an important role in the treatment of advanced HCC with main or branch portal vein invasion. Regorafenib, as a second-line systemic treatment, prolongs survival in patients with intermediate and advanced HCC who progressed on sorafenib. In recent clinical trials, immune check point inhibitors show promising results for the treatment of HCC. This review describes recent trends in the management of HCC.

Current trends and recent advances in diagnosis, therapy, and prevention of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has been one of the most fatal malignant tumors worldwide and its associated morbidity and mortality remain of significant concern. Based on in-depth reviews of serological diagnosis of HCC, in addition to AFP, there are other biomarkers: Lens culinaris agglutinin-reactive AFP (AFP-L3), des- carboxyprothrombin (DCP), tyrosine kinase with Ig and eprdermal growth factor (EGF) homology domains 2 (TIE2)-espressing monocytes (TEMs), glypican-3 (GPC3), Golgi protein 73 (GP73), interleukin-6 (IL-6), and squamous cell carcinoma antigen (SCCA) have been proposed as biomarkers for the early detection of HCC. The diagnosis of HCC is primarily based on noninvasive standard imaging methods, such as ultrasound (US), dynamic multiphasic multidetector-row CT (MDCT) and magnetic resonance imaging (MRI). Some experts advocate gadolinium diethyl-enetriamine pentaacetic acid (Gd-EOB-DTPA) MRI and contrast-enhanced US as the promising imaging madalities of choice. With regard to recent advancements in tissue markers, many cuting-edge technologies using genome-wide DNA microarrays, qRT-PCR, and proteomic and inmunostaining studies have been implemented in an attempt to identify markers for early diagnosis of HCC. Only less than half of HCC patients at initial diagnosis are at an early stage treatable with curative options: local ablation, surgical resection, or liver transplant. Transarterial chemoembolization (TACE) is considered the standard of care with palliation for intermediate stage HCC. Recent innovative procedures using drug-eluting-beads and radioembolization using Yttrium-90 may exhibit beneficial effects in HCC treatment. During the past few years, several molecular targeted agents have been evaluated in clinical trials in advanced HCC. Sorafenib is currently the only approved systemic treatment for HCC. It has been approved for the therapy of asymptomatic HCC patients with well-preserved liver function who are not candidates for potentially curative treatments, such as surgical resection or liver transplantation. In the USA, Europe and particularly Japan, hepatitis C virus (HCV) related HCC accounts for most liver cancer, as compared with Asia-Pacific regions, where hepatitis B virus (HBV) may play a more important role in HCC development. HBV vaccination, while a vaccine is not yet available against HCV, has been recognized as a best primary prevention method for HBV-related HCC, although in patients already infected with HBV or HCV, secondary prevention with antiviral therapy is still a reasonable strategy. In addition to HBV and HCV, attention should be paid to other relevant HCC risk factors, including nonalcoholic fatty liver disease due to obesity and diabetes, heavy alcohol consumption, and prolonged aflatoxin exposure. Interestingly, coffee and vitamin K2 have been proven to provide protective effects against HCC. Regarding tertiary prevention of HCC recurrence after surgical resection, addition of antiviral treatment has proven to be a rational strategy.

Percutaneous real-time sonoelastography as a non-invasive tool for the characterization of solid focal liver lesions: A prospective study

BACKGROUND

Real-time sonoelastography is currently used for the characterization of superficial solid lesions such as thyroid and breast masses. This study evaluates the usefulness of percutaneous sonoelastography for the characterization of solid focal liver lesions.

METHODS

30 out of 43 patients with 38 known liver lesions were included in a prospective, diagnostic study. Qualitative analysis (pattern of deformation, elasticity type of liver tumour) and semi-quantitative measurements (strain ratio, hardness percentage, histogram) were evaluated. Sensitivity, specificity, positive and negative predictive values were calculated and the area under the receiver operating characteristics curve was constructed.

RESULTS

Patterns A and C-D are specific of benign lesions and metastases respectively. The patterns for haemangiomas, focal nodular hyperplasia and metastases were significantly different to each other in terms of strain ratio, hardness percentage and histogram (p<0.05). A statistically significant difference (p<0.001) was observed between the median values of the 3 measured parameters for benign (1.02; 12%; 47) and malignant lesions (1.66; 65%; 20.5) respectively. The area under the receiver operating characteristics curve values for strain ratio, hardness percentage and histogram were 0.88, 0.89, and 0.86 respectively for cut-off values of 1.2, 45, and 30.

CONCLUSIONS

By percutaneous sonoelastography it is possible to differentiate benign versus malignant focal liver lesions, metastases in particular, with good diagnostic performance.

Imaging of HCC-Current State of the Art

Early diagnosis of hepatocellular carcinoma (HCC) is crucial for optimizing treatment outcome. Ongoing advances are being made in imaging of HCC regarding detection, grading, staging, and also treatment monitoring. This review gives an overview of the current international guidelines for diagnosing HCC and their discrepancies as well as critically summarizes the role of magnetic resonance imaging (MRI) and computed tomography (CT) techniques for imaging in HCC. The diagnostic performance of MRI with nonspecific and hepatobililiary contrast agents and the role of functional imaging with diffusion-weighted imaging will be discussed. On the other hand, CT as a fast, cheap and easily accessible imaging modality plays a major role in the clinical routine work-up of HCC. Technical advances in CT, such as dual energy CT and volume perfusion CT, are currently being explored for improving detection, characterization and staging of HCC with promising results. Cone beam CT can provide a three-dimensional analysis of the liver with tumor and vessel characterization comparable to cross-sectional imaging so that this technique is gaining an increasing role in the peri-procedural imaging of HCC treated with interventional techniques.

Initial Experience Performing Percutaneous Ultrasound Examination with Real-Time Virtual Sonography with Color Display

PURPOSE

We report the efficacy of percutaneous ultrasound (US) examination using a novel real-time virtual sonography (RVS) method that collates multiple Digital Imaging and Communications in Medicine (DICOM) data sources and displays reference images in color.

MATERIALS AND METHODS

A total of 7 patients with 9 hepatocellular carcinomas were evaluated. Using the SYNAPSE VINCENT volume analyzer, DICOM data of the portal vein, hepatic vein, tumor, and hepatic segment were isolated from contrast-enhanced computed tomography DICOM data. Each portion of DICOM data was uploaded into an US scanner (HI VISION Ascendus, Hitachi Aloka Medical Ltd., Tokyo, Japan) and unified on a US platform to create a single reference image. Each uploaded portion of DICOM data was assigned a different color. Further, conventional RVS was performed using this information.

RESULTS

The maximal tumoral diameter ranged from 6.4 to 15 mm (mean ± SD, 11.0 ± 2.8). DICOM data could be isolated, enabling the display of color RVS in all patients. Color RVS facilitated superior visibility compared with conventional grayscale RVS and facilitated the comprehension of spatial positioning.

CONCLUSION

RVS with color display demonstrates utility in increasing operator comprehension of spatial and positional relationships during percutaneous US examination.

Recent Advances in the Management of Chronic Hepatitis B Including Suppression of Hepatocellular Carcinoma by Entecavir and Interferon

At present, for adults with chronic hepatitis B virus (HBV) infection, two new analogues, entecavir (ETV) and tenofovir, are recommended as the first-line therapy by the EASL (European Association for the Study of the Liver), AASLD (American Association for the Study of Liver Diseases), and APASL (Asian Pacific Association for the Study of the Liver) guidelines. The use of pegylated interferon-α (PEG IFN-α) is recommended as the first-line therapy instead of standard IFN-α according to the above 3 guidelines. In this paper, the aim was to assess: (1) the long-term efficacy and safety as well as the resistance to ETV and tenofovir disoproxil fumarate (TDF); (2) the efficacy of PEG IFN-α; (3) the role of combination therapy with IFN plus two analogues, such as lamivudine and ETV; (4) the efficacy and safety of two analogues with cirrhosis, and (5) suppression of hepatocellular carcinoma (HCC) by ETV and IFN treatment. The results are as follows: (1) both ETV and TDF showed long-term efficacy and safety; (2) PEG IFN-α resulted in a greater decline in HBV DNA levels and a higher rate of HBeAg seroconversion; (3) combination therapy with IFN plus two analogues did not elevate the rate of sustained responses; (4) both ETV and TDF showed efficacy and safety with cirrhosis (ETV especially displayed efficacy and safety with decompensated cirrhosis), and (5) suppression of HCC was observed by ETV and IFN.

Validation of a Modified Substaging System (Kinki Criteria) for Patients with Intermediate-Stage Hepatocellular Carcinoma

INTRODUCTION

Barcelona Clinic Liver Cancer (BCLC) stage B, an intermediate stage, includes various conditions of hepatocellular carcinoma (HCC). This heterogeneity of the patients with intermediate-stage HCC makes it difficult to predict their survival rates. In the present study, we examined the validity of the modified Bolondi classification (Kinki criteria) as a subclassification of patients with BCLC stage B HCC.

METHODS

Of 906 patients who underwent conventional transarterial chemoembolization at Kinki University Hospital, 753, who met the inclusion criteria, were examined. Of these 753 patients, 425 (56.4%) with BCLC stage B were subclassified using the Kinki criteria to examine the survival rate.

RESULTS

According to the Kinki criteria, 158 (37.2%) were subclassified into subclass B1, 236 (55.5%) into B2, and 31 (7.3%) into B3. The comparison of the survival rates showed that the median overall survival was 3.9 years (95% CI, 3.2-4.6) in the BCLC subclass B1 group, 2.5 years (95% CI, 2.2-3.1) in the B2 group, and 1.1 years (95% CI, 0.6-1.5) in the B3 group (p < 0.001).

CONCLUSION

When the BCLC stage B patients were subclassified according to the Kinki criteria, survival curves were stratified with significant differences, suggesting that the Kinki criteria were suitable for the subclassification of the intermediate-stage HCC patients.

Characteristics of Hypovascular versus Hypervascular Well-Differentiated Hepatocellular Carcinoma Smaller Than 2 cm - Focus on Tumor Size, Markers and Imaging Detectability

OBJECTIVES

The characteristics of hypovascular and hypervascular well-differentiated hepatocellular carcinomas (HCCs) were compared in terms of tumor size, tumor markers and detectability by imaging modalities.

METHODS

Well-differentiated HCC nodules that are smaller than 2 cm (n = 27) were evaluated in 27 patients using histopathology and divided into 2 groups: hypovascular (n = 10) and hypervascular (n = 17). The diagnostic sensitivity of imaging modalities was then evaluated for efficiency in disclosing tumor size and tumor markers in the 2 types.

RESULTS

No difference was observed in tumor size and tumor markers between the 2 types; however, the sensitivity of contrast-enhanced CT, contrast-enhanced ultrasonography and arterioportal angiography was significantly different between the 2 types, whereas that by Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging (Gd-EOB-DTPA MRI) demonstrated no difference.

CONCLUSION

Hypovascular HCC could be diagnosed by Gd-EOB-DTPA MRI in the hepatobiliary phase.

Challenges of Clinical Research on Hepatocellular Carcinoma

Challenges of clinical practice and research on hepatocellular carcinoma (HCC) were reviewed. There are several differences in clinical practice between Japan and the Western countries such as tumor markers, understanding of pathological early HCC, imaging diagnosis, treatment strategy, staging system and subclassification of HCC. Further studies are warranted for the clinical practices of Japan to be adopted in the rest of the world.

[Focal nodular hyperplasia and hepatocellular adenoma]

CLINICAL ISSUE

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are liver lesions of hepatocellular origin. The FNH is a commonly occurring hepatic lesion whereas HCA is very rare. Non-invasive differentiation between HCA subtypes and atypical FNH may pose a diagnostic challenge as both entities predominantly occur in middle-aged female patients.

STANDARD RADIOLOGICAL METHODS

The conventional imaging modalities include ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI). Distinguishing FNH from HCA is of great importance clinically as FNH is considered to be a benign lesion and needs no further management. In contrast HCA is considered to be a borderline tumor due to the risk of hemorrhage, growth and even malignant transformation and requires individualized management.

METHODOLOGICAL INNOVATIONS

The above mentioned radiological procedures usually enable an accurate and certain diagnosis of a typical FNH to be achieved. In cases of atypical FNH, particularly in patients with a clinical history of malignancy, these imaging modalities are insufficient to establish a clear diagnosis. In this scenario, the use of modern hepatobiliary contrast-enhanced MRI will enable a differentiation between FNH and metastasis with a high sensitivity and specificity. Furthermore, it allows a differentiation of FNH from 90 % of adenoma subtypes.

ACHIEVEMENTS

This article describes the histopathological and radiological features of these lesions and explains the advantages and limitations of various imaging modalities used for the diagnosis and differentiation of these entities.

PRACTICAL RECOMMENDATIONS

The new classification of HCAs according to phenotype and genotype and their imaging features, as well as different enhancement patterns, are described. The correlation between HCA subtypes and their individual management are also discussed.

Insufficient ablative margin determined by early computed tomography may predict the recurrence of hepatocellular carcinoma after radiofrequency ablation

Tumor recurrence in hepatocellular carcinoma (HCC) patients after radiofrequency ablation (RFA) remains common; some studies have reported that insufficient ablative margin after RFA might contribute to HCC recurrence. The aim of this study was to investigate whether insufficient ablative safety margins determined by early computed tomography (CT) predicts HCC recurrence after RFA. This retrospective study recruited patients with a single HCC lesion after RFA in our department between May 2013 and March 2014. Early follow-up CT was performed within 7 days after RFA. An adequate ablative margin assessed by follow-up CT was defined as (maximum post-RFA CT radius)(3)/(maximum pre-RFA CT radius + 5 mm)(3)> 1. All patients in whom complete ablation was achieved underwent a CT scan every 3 months for early detection of HCC recurrence. In total, 72 patients (48 male, mean age 69.4 years) were analyzed. Of these, eight patients had local tumor progression, four had intra-hepatic distant recurrence, and two had extra-hepatic metastasis. Insufficient ablative margin, defined as an ablative volume with a safety margin of less than 5 mm, was an important predictor of local tumor progression (LTP) (p = 0.015) and overall recurrence (p = 0.012). The sensitivity, specificity, and positive and negative predictive values of an insufficient ablative margin for predicting LTP and overall recurrence were 36.4%, 97.2%, 50.0%, and 87.9%, and 46.2%, 89.7%, 42.9%, and 87.9%, respectively. An ablative volume with an ablative margin of less than 5 mm is associated with higher rates of both LTP and overall recurrence in HCC after RFA.

Imaging Modalities for Assessment of Treatment Response to Nonsurgical Hepatocellular Carcinoma Therapy: Contrast-Enhanced US, CT, and MRI

Tumor response and time to progression have been considered pivotal for surrogate assessment of treatment efficacy for patients with hepatocellular carcinoma (HCC). Recent advancements in imaging modalities such as contrast-enhanced ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) are playing an important role in assessing the therapeutic effects of HCC treatments. According to some HCC clinical guidelines, post-therapeutic evaluation of HCC patients is based exclusively on contrast-enhanced dynamic imaging criteria. The recommended techniques are contrast-enhanced CT or contrast-enhanced MRI. Contrast-enhanced US is employed more in the positive diagnosis of HCC than in post-therapeutic monitoring. Although contrast enhancement is an important finding on imaging, enhancement does not necessarily depict the same phenomenon across modalities. We need to become well acquainted with the characteristics of each modality, including not only contrast-enhanced CT and MRI but also contrast-enhanced US. Many nonsurgical treatment options are now available for unresectable HCC, and accurate assessment of tumor response is essential to achieve favorable outcomes. For the assessment of successful radiofrequency ablation (RFA), the achievement of a sufficient ablation margin as well the absence of tumor vascular enhancement is essential. To evaluate the response to transcatheter arterial chemoembolization (TACE), enhanced tumor shrinkage is relied on as a measure of antitumor activity. Here, we give an overview of the current status of imaging assessment of HCC response to nonsurgical treatments including RFA and TACE.

Integrin beta-8 (ITGB8) silencing reverses gefitinib resistance of human hepatic cancer HepG2/G cell line

Hepatic cancer is a class of cancer that is relatively insensitive to chemotherapy, and cancers that harbor EGFR active mutations are more sensitive to EGFR-TK inhibitor such as gefitinib, which becomes the first-line treatment of this subtype of cancer. However, almost all patients treated with gefitinib will develop drug resistance. Here we show that a protein called integrin beta-8 (ITGB8) when over-expressed, is correlated with the gefitinib resistance of hepatic cancer cell line HepG2/G. After ITGB8 silencing, the drug resistance is reversed as the cell proliferation decreases and apoptosis rate increases significantly by gefitinib treatment when compared to HepG2/G. We demonstrated that multi-drug resistant proteins ABCB1, ABCC2 and ABCG2, anti-apoptosis proteins like survivin and Bcl-2, and cycle promoting protein CDK1 are involved in drug resistance of HepG2/G. Other drug-resistance relative proteins like SOD, GST, TS and HIF-1 are also modulated by ITGB8 silencing, but their role in this gefitinib resistance might be indirect. TGF beta pathway could be a critical pathway by which ITGB8 modulates the sensitivity of HepG2/G to gefitinib.

Hypervascular Lesion in a Cirrhotic Liver: A Case Report

Hepatocellular carcinoma (HCC) is the leading cause of death among patients with cirrhosis. Therefore, a focal hepatic lesion in a patient with cirrhosis must always be investigated for its high risk of cancer. However, when hepatic lesions in an imaging exam do not present the typical characteristics of a malignant or a benignant tumor, diagnosis may be a challenge. The biopsy can be used in these circumstances, but, as shown by this case, even that can be misleading. A 54-year-old male patient with cirrhosis presented with abdominal pain, jaundice, nausea and vomits. He performed a biopsy at another service, with the result being focal nodular hyperplasia (FNH). He presented adequate hepatic function, and alpha-fetoprotein level was 6.4. Upon first consultation, we required the slides to be brought to our service and reviewed. Our revision also showed no signs of malignancy. Magnetic resonance imaging showed a large hepatic tumor in segments V and VI, predominantly exofitic, with a central scar. The tumor was surgically removed, and its dimensions were 14 × 10 × 9 cm. Microscopic examination revealed an HCC. Even though histological diagnosis was not necessary to indicate surgery, due to its exofitic nature and adequate hepatic function, we discuss the diagnostic characteristics of both HCC and FNH that could help other medical groups in cases where the position of a liver tumor could make the decision to operate more difficult.