The formation of capsule and septum in human hepatocellular carcinoma

Research on multi-model imaging machine learning for distinguishing early hepatocellular carcinoma

OBJECTIVE

To investigate the value of differential diagnosis of hepatocellular carcinoma (HCC) and non-hepatocellular carcinoma (non-HCC) based on CT and MR multiphase radiomics combined with different machine learning models and compare the diagnostic efficacy between different radiomics models.

BACKGROUND

Primary liver cancer is one of the most common clinical malignancies, hepatocellular carcinoma (HCC) is the most common subtype of primary liver cancer, accounting for approximately 90% of cases. A clear diagnosis of HCC is important for the individualized treatment of patients with HCC. However, more sophisticated diagnostic modalities need to be explored.

METHODS

This retrospective study included 211 patients with liver lesions: 97 HCC and 124 non-hepatocellular carcinoma (non-HCC) who underwent CT and MRI. Imaging data were used to obtain imaging features of lesions and radiomics regions of interest (ROI). The extracted imaging features were combined to construct different radiomics models. The clinical data and imaging features were then combined with radiomics features to construct the combined models. Support Vector Machine (SVM), K-nearest Neighbor (KNN), RandomForest (RF), eXtreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), Multilayer Perceptron (MLP) six machine learning models were used for training. Five-fold cross-validation was used to train the models, and ROC curves were used to analyze the diagnostic efficacy of each model and calculate the accuracy rate. Model training and efficacy test were performed as before.

RESULTS

Statistical analysis showed that some clinical data (gender and concomitant cirrhosis) and imaging features (presence of envelope, marked enhancement in the arterial phase, rapid contouring in the portal phase, uniform density/signal and concomitant steatosis) were statistical differences (P < 0.001). The results of machine learning models showed that KNN had the best diagnostic efficacy. The results of the combined model showed that SVM had the best diagnostic efficacy, indicating that the combined model (accuracy 0.824) had better diagnostic efficacy than the radiomics-only model.

CONCLUSIONS

Our results demonstrate that the radiomic features of CT and MRI combined with machine learning models enable differential diagnosis of HCC and non-HCC (malignant, benign). The diagnostic model with dual radiomic had better diagnostic efficacy. The combined model was superior to the radiomic model alone.

Prognostic Value of Combined Neutrophil-to-Lymphocyte Ratio and Imaging Tumor Capsule in Solitary Hepatocellular Carcinoma Patients after Narrow-Margin Hepatectomy

BACKGROUND

The study aimed to investigate the clinical value and prognostic patterns of the neutrophil-to-lymphocyte ratio (NLR) and imaging tumor capsule (ITC) in solitary hepatocellular carcinoma (HCC) patients undergoing narrow-margin hepatectomy.

METHODS

Data for solitary HCC patients treated with narrow-margin surgery were extracted from Shanghai General Hospital. Clinical features of recurrence-free survival (RFS), overall survival (OS), and early recurrence were investigated by Cox/logistic regression. The significant variables were subsequently incorporated into the nomogram pattern. Survival analysis stratified by NLR and ITC was also performed.

RESULTS

The study included a cohort of 222 patients, with median RFS and OS of 24.083 and 32.283 months, respectively. Both an NLR ≥ 2.80 and incomplete ITC had a significant impact on prognosis. NLR and ITC independently affected RFS and OS, whereas alpha-fetoprotein (AFP) and ITC were identified as independent factors for early relapse. The RFS and OS nomogram, generated based on the Cox model, demonstrated good performance in validation. The combination of NLR and ITC showed greater predictive accuracy for 5-year RFS and OS. Subgroups with an NLR ≥ 2.80 and incomplete ITC had the worst prognosis.

CONCLUSIONS

Both NLR and ITC significantly affected RFS, OS, and early recurrence among solitary HCC patients who underwent narrow-margin hepatectomy. The combination of NLR and ITC has the potential to guide rational clinical treatment and determine the prognosis.

Associations Between Single Nucleotide Polymorphisms of Hypoxia-Related Genes and Capsule Formation in Hepatocellular Carcinoma

Purpose

Tumor capsule is an independent prognostic factor for patients with hepatocellular carcinoma (HCC) and used increasingly to guide clinical decision-making. Considering the genetic complexity for capsule formation and its potential association with hypoxia, the significance of the polymorphisms of hypoxia-related genes in capsule formation and HCC prognosis remains to be elucidated.

Patients and Methods

Peripheral blood samples from HCC patients were collected in this study. Single nucleotide polymorphism (SNP) genotyping was conducted by the iPLEX chemistry on a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (Sequenom, Inc.). The demographic and clinical data for the patients were obtained through medical chart review and/or consultation with the treating physicians. SPSS 25.0, R 4.1.1, and PLINK toolset were used to perform statistical analysis.

Results

A total of 183 patients were enrolled, including 88 patients assigned to the capsule group and 95 to the non-capsule group. SLC2A1 rs841858 T allele, SLC2A1 rs2297977 T allele, STAT1 rs1547550 C allele, and STAT1 rs34997637 G allele were associated with significantly increased risk of capsule formation. The genotypes of SLC2A1 rs841858, SLC2A1 rs2297977, STAT1 rs34997637, and STAT1 rs1914408 were significantly associated with the formation of HCC capsule. The polymorphisms of STAT1 rs2066802, STAT1 rs12693591, and HIF1A rs2057482 showed close relationship with the prognosis of HCC patients in the capsule group, while the genotype distributions of CTNNB1 rs4135385, IFNG rs1861494, and SERPINE1 rs2227631 were closely related to the survival of patients in the non-capsule group. Further haplotype analysis suggested that SLC2A1 block 1 and STAT1 block 2 were related to the susceptibility of HCC capsule.

Conclusion

The polymorphisms of the hypoxia-related genes (HIF1A, SERPINE1, IFNG, STAT1, CTNNB1, and SLC2A1) were correlated with the formation of HCC capsule. Several SNPs in these genes also showed association with HCC prognosis except SLC2A1. Further functional studies are warranted to explore the underlying mechanisms.

The extracellular matrix in hepatocellular carcinoma: Mechanisms and therapeutic vulnerability

The tumor microenvironment (TME) is influenced by a "disorganized" extracellular matrix (ECM) that sensitizes cancer cells toward mechanical stress, signaling, and structural alterations. In hepatocellular carcinoma (HCC), lack of knowledge about key ECM proteins driving the TME refractory to targeted therapies poses a barrier to the identification of new therapeutic targets. Herein, we discuss the contributions of various ECM components that impact hepatocytes and their surrounding support network during tumorigenesis. In addition, the underpinnings by which ECM proteins transduce mechanical signals to the liver TME are detailed. Finally, in view of the bidirectional feedback between the ECM, transformed hepatocytes, and immune cells, we highlight the potential role of the ECM disorganization process in shaping responses to immune checkpoint inhibitors and targeted therapies. Our comprehensive characterization of these ECM components may provide a roadmap for innovative therapeutic approaches to restrain HCC.

Comparison of clinicopathologic characteristics among patients with HBV-positive, HCV-positive and Non-B Non-C hepatocellular carcinoma after hepatectomy: a systematic review and meta-analysis

BACKGROUND

The incidence of HBV-negative and HCV-negative hepatocellular carcinoma (NBNC-HCC) is significantly increasing. However, their clinicopathologic features and prognosis remain elucidated. Our study aimed to compare the clinicopathologic characteristics and survival outcomes of NBNC-HCC with hepatitis virus-related HCC.

METHOD

A literature review was performed in several databases, including PubMed, Embase, Cochrane Library and Web of Science, to identify the studies comparing NBNC-HCC with HBV-positive HCV-negative HCC (B-HCC), HBV-negative HCV-positive (C-HCC) and/or HBV-positive HCV-positive HCC (BC-HCC). The clinicopathologic characteristics and survival outcomes were extracted and pooled to access the difference.

RESULTS

Thirty-two studies with 26,297 patients were included: 5390 patients in NBNC-HCC group, 9873 patients in B-HCC group, 10,848 patients in C-HCC group and 186 patients in BC-HCC group. Patients in NBNC-HCC group were more liable to be diagnosed at higher ages, but with better liver functions and lighter liver cirrhosis. Comparing to B-HCC and C-HCC groups, although NBNC-HCC group was prone to have larger tumor sizes, it did not have more advanced tumors. Meanwhile, there were no significant differences in both 5-year and 10-year disease-free survival and overall survival between NBNC-HCC group and B-HCC or C-HCC group.

CONCLUSIONS

Our meta-analysis revealed patients with NBNC-HCC had as worse prognosis as those with hepatitis virus-related HCC. More attention should be paid on patients with non-alcoholic steatohepatitis or metabolic syndromes to prevent the incidence of NBNC-HCC.

SONAR enables cell type deconvolution with spatially weighted Poisson-Gamma model for spatial transcriptomics

Recent advancements in spatial transcriptomic technologies have enabled the measurement of whole transcriptome profiles with preserved spatial context. However, limited by spatial resolution, the measured expressions at each spot are often from a mixture of multiple cells. Computational deconvolution methods designed for spatial transcriptomic data rarely make use of the valuable spatial information as well as the neighboring similarity information. Here, we propose SONAR, a Spatially weighted pOissoN-gAmma Regression model for cell-type deconvolution with spatial transcriptomic data. SONAR directly models the raw counts of spatial transcriptomic data and applies a geographically weighted regression framework that incorporates neighboring information to enhance local estimation of regional cell type composition. In addition, SONAR applies an additional elastic weighting step to adaptively filter dissimilar neighbors, which effectively prevents the introduction of local estimation bias in transition regions with sharp boundaries. We demonstrate the performance of SONAR over other state-of-the-art methods on synthetic data with various spatial patterns. We find that SONAR can accurately map region-specific cell types in real spatial transcriptomic data including mouse brain, human heart and human pancreatic ductal adenocarcinoma. We further show that SONAR can reveal the detailed distributions and fine-grained co-localization of immune cells within the microenvironment at the tumor-normal tissue margin in human liver cancer.

Macrophage-Derived MMP-9 and MMP-2 are Closely Related to the Rupture of the Fibrous Capsule of Hepatocellular Carcinoma Leading to Tumor Invasion

BACKGROUND

Hepatocellular carcinoma (HCC) is an aggressive tumor with a poor clinical prognosis. Rupture of the fibrous capsule (FC) is a very important clinical phenomenon in the invasion and metastasis of HCC. FC is mainly composed of type I collagen (COL1A1). However, it is not clear what caused the FC rupture. In this study, we aimed to determine whether the rupture of FC in HCC patients was related to macrophage-derived MMP-9 and MMP-2, and their clinical diagnostic value for FC rupture.

RESULTS

By performing immunohistochemical and immunofluorescence staining of ruptured FC and intact FC, the results showed that the ruptured area of FC aggregated a large number of macrophages with MMP-9 and MMP-2. Western blot analysis and Quantitative real-time PCR were used to assess the expression of MMP-9 and MMP-2 in the ruptured and relatively intact area of FC in ruptured FC patients, and the results revealed a significantly different expression of MMP-9 and MMP-2. ELISA experiments show that we could discriminate effectively between ruptured FC and intact FC by MMP-9 and MMP-2.

CONCLUSIONS

Taken together, macrophage-derived MMP-9 and MMP-2 were closely related to the rupture of the FC of HCC and subsequently led to the migration and invasion of the tumor cells through the ruptured area of FC to the para cancer. It is suggested that when performing surgical resection, it is necessary to expand the range of tumor resection for patients with ruptured FC and hence reduce the possibility of recurrence and metastasis in HCC patients.

Radiologic features of hepatocellular carcinoma related to prognosis

The cross-sectional imaging findings play a crucial role in the diagnosis of hepatocellular carcinoma (HCC). Recent studies have shown that imaging findings of HCC are not only relevant for the diagnosis of HCC, but also for identifying genetic and pathologic characteristics and determining prognosis. Imaging findings such as rim arterial phase hyperenhancement, arterial phase peritumoral hyperenhancement, hepatobiliary phase peritumoral hypointensity, non-smooth tumor margin, low apparent diffusion coefficient, and the LR-M category of the Liver Imaging-Reporting and Data System have been reported to be associated with poor prognosis. In contrast, imaging findings such as enhancing capsule appearance, hepatobiliary phase hyperintensity, and fat in mass have been reported to be associated with a favorable prognosis. Most of these imaging findings were examined in retrospective, single-center studies that were not adequately validated. However, the imaging findings can be applied for deciding the treatment strategy for HCC, if their significance can be confirmed by a large multicenter study. In this literature, we would like to review imaging findings related to the prognosis of HCC as well as their associated clinicopathological characteristics.

The Value of Contrast-Enhanced Magnetic Resonance Imaging Enhancement in the Differential Diagnosis of Hepatocellular Carcinoma and Combined Hepatocellular Cholangiocarinoma

Background

The distinction between combined hepatocellular-cholangiocarcinoma (cHCC-CC) and hepatocellular carcinoma (HCC) before the operation has an important clinical significance for optimizing the treatment plan and predicting the prognosis of patients. Magnetic resonance imaging (MRI) has been widely used in the preoperative diagnosis and evaluation of primary liver malignant tumors.

Purpose

The aim is to study the value of preoperative clinical data and enhanced MRI in the differential diagnosis of HCC and cHCC-CC and obtain independent risk factors for predicting cHCC-CC. Study type. Retrospective. Population. The clinical and imaging data of 157 HCC and 59 cHCC-CC patients confirmed by pathology were collected. Field Strength/Sequence. 1.5T; cross-sectional T1WI (gradient double echo sequence); cross-sectional T2WI (fast spin echo sequence, fat suppression); enhancement (3D LAVA technology). Assessment. The differences between the HCC and cHCC-CC patients were compared. Statistic Tests. Using the t-test, chi-square test, and logistic regression analysis, P < 0.05 was considered statistically significant.

Result

1. CHCC-CC was more likely to show multiple lesions than HCC (28.81% vs. 10.83%, P = 0.001) and more prone to microvascular invasion (MVI) (36.31% vs. 61.02%, P < 0.001). However, HCC had a higher incidence of liver cirrhosis than cHCC-CC (50.85% vs. 72.61%, P = 0.003). 2. The incidence of nonsmooth margin was higher in the cHCC-CC group (84.75% vs. 52.23%, P < 0.001). The incidence of peritumor enhancement in the arterial phase was higher in the cHCC-CC group (11.46% vs. 62.71%, P < 0.001) 3. According to the multivariate analysis, arterial peritumor enhancement (OR = 8.833,95%CI:4.033,19.346, P < 0.001) was an independent risk factor for cHCC-CC (P < 0.001)). It had high sensitivity (62.71%) and specificity (88.54%) in the diagnosis of cHCC-CC. Date Conclusions. Liver cirrhosis and the imaging findings of GD-DTPA-enhanced MRI are helpful for the differential diagnosis of HCC and cHCC-CC. In addition, the imaging sign of peritumoral enhancement in the arterial phase has high sensitivity and specificity for the diagnosis of cHCC-CC.

MRI features of histologic subtypes of hepatocellular carcinoma: correlation with histologic, genetic, and molecular biologic classification

HCC is a heterogeneous group of tumors in terms of histology, genetic aberration, and protein expression. Advancements in imaging techniques have allowed imaging diagnosis to become a critical part of managing HCC in the clinical setting, even without pathologic diagnosis. With the identification of many HCC subtypes, there is increasing correlative evidence between imaging phenotypes and histologic, molecular, and genetic characteristics of various HCC subtypes. In this review, current knowledge of histologic heterogeneity of HCC correlated to features on gadolinium-enhanced dynamic liver MRI will be discussed. In addition, HCC subtype classification according to transcriptomic profiles will be outlined with descriptions of histologic, genetic, and molecular characteristics of some relatively well-established morphologic subtypes, namely the low proliferation class (steatohepatitic HCC and CTNNB1-mutated HCC) and the high proliferation class (macrotrabecular-massive HCC (MTM-HCC), scirrhous HCC, and CK19-positive HCC). Characteristics of sarcomatoid HCC and fibrolamellar HCC will also be discussed. Further research on radiological characteristics of HCC subtypes may ultimately enable non-invasive diagnosis and serve as a biomarker in predicting prognosis, molecular characteristics, and therapeutic response. In the era of precision medicine, a multidisciplinary effort to develop an integrated radiologic and clinical diagnostic system of various HCC subtypes is necessary. KEY POINTS: • HCC is a heterogeneous group of tumors in terms of histology, genetic aberration, and protein expression, which can be divided into many subtypes according to transcriptome profiles. • There is increasing evidence of a correlation between imaging phenotypes and histologic, genetic, and molecular biologic characteristics of various HCC subtypes. • Imaging characteristics may ultimately enable non-invasive diagnosis and subtype characterization, serving as a biomarker for predicting prognosis, molecular characteristics, and therapeutic response.

T- and B-Cells in the Inner Invasive Margin of Hepatocellular Carcinoma after Resection Associate with Favorable Prognosis

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world, which frequently recurs after curative resection. Several options to predict recurrence of HCC have been proposed, however, their prognostic ability is limited. This study aimed to test the hypothesis that distribution and numbers of T- and B-lymphocytes in different regions of the resected tumor may have different prognostic significance. Different subregions of HCC demonstrated uneven lymphocyte infiltration. CD20+ B-lymphocytes and CD8+ T-lymphocytes, or their combination in the inner tumor invasive margin and inner/outer margin ratios, convey the best prediction for time to recurrence and disease-free survival. The results offer a novel approach to the stratification of the risk of early tumor recurrence after curative liver resection.

Abstract

In this retrospective study on 67 patients with hepatocellular carcinoma (HCC), after tumor resection, we evaluated the significance of CD3+ and CD8+ T-lymphocytes and CD20+ B-lymphocytes in tumor and non-tumor liver for time to recurrence (TTR), disease-free survival (DFS) and overall survival. After immunohistochemical staining, the density of nucleated lymphocyte profiles (Q_A) was estimated stereologically in the tumor center (TC), inner margin (inn M), outer margin (out M), peritumor and non-tumor liver. In TC, intermediate and high Q_A of CD8+ cells predicted longer TTR, whereas CD3+ and CD20+ were predictive only at high Q_A. DFS was predicted by high Q_A of CD3+, CD8+ and CD20+ cells in TC. The inn M harbored smaller Q_A of CD3+, CD8+ and CD20+ lymphocytes than out M. In contrast to out M, high T-cells’ Q_A and intermediate and high B-cell Q_A in inn M predicted longer TTR and DFS. High inn M/out M Q_A ratios of CD3+ and CD20+ cells were associated with longer TTR and DFS, whereas high inn M/out M Q_A ratio of CD8+ was predictive only for DFS. Patients with intermediate-high Q_A of combined CD8+ and CD20+ cells in inn M showed longer TTR and DFS, compared to CD8+-high or CD20+-high alone. Our findings highlight overall heterogeneity of the tumor invasive margin, the importance of inn M, and the predictive role of B-cells.

Gene Polymorphism of MUC15, MMP14, BRAF, and COL1A1 Is Associated with Capsule Formation in Hepatocellular Carcinoma

BACKGROUND

The presence of a capsule is an important prognostic factor in hepatocellular carcinoma (HCC). Capsule formation is affected by tumor-host interaction, which may include collagen deposition and extracellular matrix (ECM) degradation.

PURPOSE

This study aimed to examine whether single-nucleotide polymorphisms (SNPs) in the genes for COL1A1 MUC15, MMP14, CD97, SMYD3, BRAF, and transforming growth factor beta 1 (TGF-β) are related to capsule formation.

METHODS

We prospectively recruited and analyzed 185 patients with HCC with or without a capsule between 2019 and 2020. The SNPs involved were analyzed by polymerase chain reaction. Differences in the allele and genotype frequency between the cases and controls were evaluated using the chi-square test. Odds ratios and 95% confidence intervals were calculated by logistic regression analysis with adjustment for age and sex. Stratification analyses were also performed with preselected variables.

RESULTS

The single-locus analysis showed that the presence of a capsule was significantly associated with five SNPs : MUC15 rs17309195 (P=0.01), rs12271124 (P= 0.02), rs10430847 (P=0.04), MMP14 rs17884816 (P=0.01), and BRAF rs74512895 (P=0.03). Adjusted logistic regression revealed that the decreased capsule formation was statistically significantly associated with BRAF rs76603725, COL1A1 rs2269336, and MUC15 rs17309195, while MMP14 rs17884816 and MUC15 rs10430847, rs2063278, and rs967490 were associated with increased capsule formation. The MUC15 block 2 haplotype was associated with increased capsule formation.

CONCLUSIONS

MUC15, MMP14, BRAF, and COL1A1 gene polymorphisms are associated with capsule formation in HCC. Studies involving larger samples are needed to confirm our results.

CT Image-Based Texture Analysis to Predict Microvascular Invasion in Primary Hepatocellular Carcinoma

The objective of this study was to determine the clinical value of computed tomography (CT) image-based texture analysis in predicting microvascular invasion of primary hepatocellular carcinoma (HCC). CT images of patients with HCC from May 2017 to May 2019 confirmed by surgery and histopathology were retrospectively analyzed. Image features including tumor margin, tumor capsule, peritumoral enhancement, hypoattenuating halo, intratumoral arteries, and tumor-liver differences were assessed. All patients were divided into microvascular invasion (MVI)-negative group (n = 34) and MVI-positive group (n = 68). Preoperative CT images were further imported into MaZda software, where the regions of interest of the lesions were manually delineated. Texture features of lesions based on pre-contrast, arterial, portal, and equilibrium phase CT images were extracted. Thirty optimal texture parameters were selected from each phase by Fisher's coefficient (Fisher), classification error probability combined with average correlation coefficient (POE+ACC), and mutual information (MI). Finally, receiver operating characteristic curve analysis was performed. The results showed that the Edmonson-Steiner grades, tumor size, tumor margin, and intratumoral artery characteristics were significantly different between the two groups (P = 0.012, < 0.001, < 0.001, = 0.003, respectively). There were 58 parameters with significant differences between the MVI-negative and MVI-positive groups (P < 0.001 for all). Among them, 12, 14, 17, and 15 parameters were derived from the pre-contrast phase, arterial phase, portal phase, and equilibrium phase respectively. According to the ROC analysis, optimal texture parameters based on the pre-contrast, arterial, portal, and equilibrium phases were 135dr_GLevNonU (AUC, 0.766; the cutoff value, 1055.00), Vertl_RLNonUni (AUC, 0.764; the cutoff value, 5974.38), 45dgr_GLevNonU (AUC, 0.762; the cutoff value, 924.34), and Vertl_RLNonUni (AUC, 0.754; the cutoff value, 4868.80), respectively. Texture analysis of preoperative CT images may be used as a non-invasive method to predict microvascular invasion in patients with primary hepatocellular carcinomas, and further to guide the treatment and evaluate prognosis. The most valuable parameters were derived from the gray-level run-length matrix.

A Complex and Evolutive Character: Two Face Aspects of ECM in Tumor Progression

Tumor microenvironment, including extracellular matrix (ECM) and stromal cells, is a key player during tumor development, from initiation, growth and progression to metastasis. During all of these steps, remodeling of matrix components occurs, changing its biochemical and physical properties. The global and basic cancer ECM model is that tumors are surrounded by activated stromal cells, that remodel physiological ECM to evolve into a stiffer and more crosslinked ECM than in normal conditions, thereby increasing invasive capacities of cancer cells. In this review, we show that this too simple model does not consider the complexity, specificity and heterogeneity of each organ and tumor. First, we describe the general ECM in context of cancer. Then, we go through five invasive and most frequent cancers from different origins (breast, liver, pancreas, colon, and skin), and show that each cancer has its own specific matrix, with different stromal cells, ECM components, biochemical properties and activated signaling pathways. Furthermore, in these five cancers, we describe the dual role of tumor ECM: as a protective barrier against tumor cell proliferation and invasion, and as a major player in tumor progression. Indeed, crosstalk between tumor and stromal cells induce changes in matrix organization by remodeling ECM through invadosome formation in order to degrade it, promoting tumor progression and cell invasion. To sum up, in this review, we highlight the specificities of matrix composition in five cancers and the necessity not to consider the ECM as one general and simple entity, but one complex, dynamic and specific entity for each cancer type and subtype.

Hepatic Stellate Cells and Hepatocarcinogenesis

Hepatic stellate cells (HSCs) are a significant component of the hepatocellular carcinoma (HCC) tumor microenvironment (TME). Activated HSCs transform into myofibroblast-like cells to promote fibrosis in response to liver injury or chronic inflammation, leading to cirrhosis and HCC. The hepatic TME is comprised of cellular components, including activated HSCs, tumor-associated macrophages, endothelial cells, immune cells, and non-cellular components, such as growth factors, proteolytic enzymes and their inhibitors, and other extracellular matrix (ECM) proteins. Interactions between HCC cells and their microenvironment have become topics under active investigation. These interactions within the hepatic TME have the potential to drive carcinogenesis and create challenges in generating effective therapies. Current studies reveal potential mechanisms through which activated HSCs drive hepatocarcinogenesis utilizing matricellular proteins and paracrine crosstalk within the TME. Since activated HSCs are primary secretors of ECM proteins during liver injury and inflammation, they help promote fibrogenesis, infiltrate the HCC stroma, and contribute to HCC development. In this review, we examine several recent studies revealing the roles of HSCs and their clinical implications in the development of fibrosis and cirrhosis within the hepatic TME.

Hepatocellular carcinoma in non-cirrhotic versus cirrhotic liver: a clinico-radiological comparative analysis

AIM

To compare clinico-radiological pattern of non-cirrhotic versus cirrhotic HCC and correlate them with histopathological tumor grade.

MATERIALS AND METHODS

This prospective study was carried out on 94 patients enrolled following ultrasound diagnosis of a liver mass measuring > 3 cm. Multiphasic MDCT was performed on all treatment-naïve cases and 56 cases with imaging pattern consistent with unifocal HCC were selected. Background liver parenchyma was assessed on ultrasound for cirrhosis and NAFLD. Cases were categorized into cirrhotic liver (CL) and non-cirrhotic liver (NCL) groups with 26 and 30 cases, respectively, and guided biopsy of each liver mass was performed. AFP levels were compared in both groups. Serum markers for hepatitis B and C were assessed. Masses in both groups were compared for morphology, attenuation on each phase and washout time. Presence of capsule, corona enhancement, satellite nodules and portal vein invasion was noted.

RESULTS

AFP level was higher in CL group. HBV serum marker was raised in both groups. Most HCCs in NCL were moderately differentiated (histopathology), larger, had well-defined margins, showed mosaic pattern of enhancement, complete capsule and delayed phase washout. Majority in CL group were poorly differentiated, smaller, had ill-defined margins, showed heterogeneous enhancement, absent capsule and portal venous phase washout. Time of washout correlated with histopathological differentiation of masses, with earlier washout indicating poorer differentiation.

CONCLUSION

HCCs in NCL have different clinico-radiological characteristics than HCCs in CL. Time of contrast washout correlates with histopathological grade of HCC. Non-cirrhotic NAFLD may require formulation of new screening guidelines for HCC.

Evaluation of Multiple Prognostic Factors of Hepatocellular Carcinoma with Intra-Voxel Incoherent Motions Imaging by Extracting the Histogram Metrics

Purpose

To predict multiple prognostic factors of HCC including histopathologic grade, the expression of Ki67 as well as capsule formation with intravoxel incoherent motions imaging by extracting the histogram metrics.

Patients and Methods

A total of 52 patients with HCC were recruited with the MR examinations undertaken at a 3T scanner. Histogram metrics were extracted from IVIM-derived parametric maps. Independent student t-test was performed to explore the differences in metrics across different subtypes of prognostic factors. Spearman correlation test was utilized to evaluate the correlations between the IVIM metrics and prognostic factors. ROC analysis was applied to evaluate the diagnostic performance.

Results

According to the independent student t-test, there were 18, 4, and 8 IVIM-derived histogram metrics showing the capability for differentiating the subtypes of histopathologic grade, Ki67, and capsule formation, respectively, with P-values of less than 0.05. Besides, there existed a lot of significant correlations between IVIM metrics and prognostic factors. Finally, by integrating different histogram metrics showing significant differences between various subgroups together via establishing logistic regression based diagnostic models, greatest diagnostic power was obtained for grading HCC (AUC=0.917), diagnosing patients with highly expressed Ki67 (AUC=0.861) and diagnosing patients with capsule formation (AUC=0.839).

Conclusion

Multiple prognostic factors including histopathologic grade, Ki67 expression status, and capsule formation can be accurately predicted with assistance of histogram metrics sourced from a single IVIM scan.

Hepatocellular carcinoma with ring calcification mimicking hydatid disease: a case report

Background

Ring calcification in hepatocellular carcinoma is extremely rare. Untreated hepatocellular carcinoma occasionally includes calcified lesions. Here, we report a case of ring-calcified hepatocellular carcinoma.

Case presentation

A 60-year-old man with a hepatic tumor was referred to Tokyo Women’s Medical University Hospital. He had a history of chronic hepatitis C. Computed tomography showed a liver tumor 20 mm in diameter in segment 6 of the Couinaud classification, with ring calcification. Based on this uncommon imaging presentation and the patient’s past exposure to the definitive hosts of Echinococcus multilocularis, he was preoperatively diagnosed with echinococcosis. Partial hepatectomy was performed as a radical treatment for echinococcosis. A final diagnosis of hepatocellular carcinoma was confirmed based on pathological findings. The patient was discharged uneventfully.

Conclusion

The presentation of an extremely rare hepatocellular carcinoma with ring calcification may be disguised as hydatid disease.

Quantification of intratumoral collagen and elastin fibers within hepatocellular carcinoma tissues finds correlations with clinico-patho-radiological features

AIM

Emerging evidence suggests a promising role for tumor stromal factors in characterizing patients with various types of malignancies, including hepatocellular carcinoma (HCC). We quantified the amount of collagen and elastin fibers in HCC samples with the aim of clarifying the clinico-patho-radiological significance of fiber deposition in HCC.

METHODS

We computed the amount of collagen and elastin fibers using digital image analysis of whole-slide images of Elastica van Gieson-stained tissues from 156 surgically resected HCCs. Furthermore, we assessed the correlations between the fiber content of HCC samples and clinical, pathological, and radiological features, including immunohistochemistry-based molecular subtypes and immunosubtypes.

RESULTS

The intratumoral area ratio of collagen in HCC tissues (median 3.4%, range 0.1-22.2%) was more than threefold that of elastin (median 0.9%, range 0.1-9.0%); there was a strong positive correlation between the amounts of collagen and elastin. Higher levels of combined collagen and elastin were significantly associated with the confluent multinodular macroscopic tumor type, the absence of a fibrous capsule, intratumoral steatosis, scirrhous tumor stroma, dense inflammatory-cell infiltrates, and the biliary/stem cell markers-positive HCC subtype. The associations of higher collagen levels with radiological findings, including heterogeneous enhancement and persistent enhancement on dynamic computed tomography, were significant. In contrast, the associations of radiological findings with elastin fibers were not significant. Intratumoral fibrous stroma in HCC comprised septum-like and perisinusoidal fibrosis; these two forms represented distinct distribution patterns of fibers and fibroblasts.

CONCLUSION

Quantitative analysis suggested that stromal fiber-rich HCCs likely represent a distinct clinico-patho-radiological entity.

Imaging response predictors following drug eluting beads chemoembolization in the neoadjuvant liver transplant treatment of hepatocellular carcinoma

BACKGROUND

Drug-eluting bead transarterial chemoembolization (DEB-TACE) is an endovascular treatment to release chemotherapeutic agents within a target lesion, minimizing systemic exposure and adverse effects to chemotherapeutics. Therefore, identifying which patient characteristics may predict imaging response to DEB-TACE can improve treatment results while selecting the best candidates. Predictors of the response after DEB-TACE still have not been fully elucidated. This is the first prospective study performed with standardized DEB-TACE technique that aim to identify predictors of radiological response, assessing patients clinical and laboratory characteristics, diagnostic imaging and intraprocedure data of the hepatocellular carcinoma treated in the neoadjuvant context for liver transplantation.

AIM

To identify pre- and intraoperative clinical and imaging predictors of the radiological response of drug-eluting bead transarterial chemoembolization (DEB-TACE) for the neoadjuvant treatment of hepatocellular carcinoma (HCC).

METHODS

This is prospective, cohort study, performed in a single transplant center, from 2011 to 2014. Consecutive patients with HCC considered for liver transplant who underwent DEB-TACE in the first session for downstaging or bridging purposes were recruited. Pre and post-chemoembolization imaging studies were performed by computed tomography or magnetic resonance. The radiological response of each individual HCC was evaluated by objective response using mRECIST and the percentage of necrosis.

RESULTS

Two hundred patients with 380 HCCs were examined. Analysis of the objective response (nodule-based analysis) demonstrated that HCC with pseudocapsules had a 2.01 times greater chance of being responders than those without pseudocapsules (P = 0.01), and the addition of every 1mg of chemoembolic agent increased the chance of therapeutic response in 4% (P < 0.001). Analysis of the percentage of necrosis through multiple linear regression revealed that the addition of each 1mg of the chemoembolic agent caused an average increase of 0.65% (P < 0.001) in necrosis in the treated lesion, whereas the hepatocellular carcinoma with pseudocapsules presented 18.27% (P < 0.001) increased necrosis compared to those without pseudocapsules.

CONCLUSION

The presence of a pseudocapsule and the addition of the amount of chemoembolic agent increases the chance of an objective response in hepatocellular carcinoma and increases the percentage of tumor necrosis following drug-eluting bead chemoembolization in the neoadjuvant treatment, prior to liver transplantation.

Redefinition of tumor capsule: Rho-dependent clustering of cancer-associated fibroblasts in favor of tensional homeostasis

Fibroblasts are the most frequent cells of the connective tissues. Having the ability to sense and respond to mechanical stimuli in addition to the biochemical ones makes them crucial for such a composite-like and tension-preserving tissue. Over the last decade, the investigation of the role of these cells in tumor progression was a hot topic of research in tumor biology. Literatures almost unanimously describe the re-education of stromal fibroblasts by tumor cells in favor of tumor progression, which resulted in the birth of a new nomenclature, the cancer-associated fibroblasts. On the other hand, some studies reported anti-tumor roles for these cells. Herein, author suggests that the previously described pro-migratory and pro-contractile contexts, which respectively results in divergent and convergent distribution of fibroblasts by changing Rho-Rac1 balance, could be applied for cancer-associated fibroblasts as well. Based on this proposed concept, stromal fibroblasts could represent different roles, either pro-tumor or anti-tumor, during the course of tumor progression. In the earlier phases, they tend to assemble along tumor-stroma interface in the form of tumor capsules in order to resist tumor growth and to maintain tensional homeostasis in stroma. But in later phases, after being chronically subjected to tumor-induced chemical and mechanical stimuli, they will gradually lose their substantial abilities to oppose tumor expansion and, in contrary, will promote tumorigenesis. In summary, this paper redefines tumor capsule from chemical and mechanical standpoints as Rho-dependent clustering of cancer-associated fibroblasts in favor of tensional homeostasis. Furthermore, it proposes that stromal fibroblasts will undergo some irreversible epigenetic changes in Rac1- and Rho-related proteins through tumor-stroma crosstalk, which irreversibly diminish their ability of capsule formation. Finally, the author discusses the possible researches helping us to assess the proposed concept and its clinical implications.

Adding ancillary features to enhancement patterns of hepatocellular carcinoma on gadoxetic acid-enhanced magnetic resonance imaging improves diagnostic performance

PURPOSE

To assess the added value of intratumoral ancillary features to conventional enhancement pattern-based diagnosis of hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A total of 773 consecutive patients with surgically resected 773 primary hepatic tumors (699 HCCs, 63 intrahepatic cholangiocarcinomas, and 11 benign nodules) who underwent gadoxetic acid-enhanced MRI were retrospectively identified. Enhancement patterns and three ancillary features of capsule, septum, and T2 spotty hyperintensity were assessed by two radiologists. Performance of enhancement pattern-based diagnosis of HCC was compared to diagnosis of HCC based on enhancement pattern plus ancillary features.

RESULTS

Enhancement patterns were positive (arterial diffuse hyperenhancement with washout) for 562 (72.7%) tumors, negative (no arterial hyperenhancement and no washout) for 75 (9.7%), and inconclusive (either no arterial hyperenhancement or no washout) for 136 (17.6%). Capsule was observed in 498 (64.4%) tumors, septum in 521 (67.3%), and T2 spotty hyperintensity in 107 (13.8%). The accuracy and sensitivity of HCC diagnosis was improved significantly after adding at least one ancillary feature compared with enhancement pattern-based diagnosis of HCCs (79.9% vs. 91.1% for accuracy, p < 0.0001 and 79.1% vs. 92.0% for sensitivity, p < 0.0001) with a minor tradeoff in specificity (87.8% vs. 82.4%, p = 0.125). Adding at least two ancillary features improved accuracy (88.1%, p < 0.0001) and sensitivity (88.1%, p < 0.0001) without changing specificity (87.8%, p = 1.0).

CONCLUSION

Adding intratumoral ancillary features of capsule, septum and T2 spotty hyperintensity to conventional enhancement patterns on gadoxetic acid-enhanced MRI improved accuracy and sensitivity, while maintaining specificity for HCC diagnosis.

Evidence Supporting LI-RADS Major Features for CT- and MR Imaging-based Diagnosis of Hepatocellular Carcinoma: A Systematic Review

The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation, reporting, and data collection for imaging examinations in patients at risk for hepatocellular carcinoma (HCC). It assigns category codes reflecting relative probability of HCC to imaging-detected liver observations based on major and ancillary imaging features. LI-RADS also includes imaging features suggesting malignancy other than HCC. Supported and endorsed by the American College of Radiology (ACR), the system has been developed by a committee of radiologists, hepatologists, pathologists, surgeons, lexicon experts, and ACR staff, with input from the American Association for the Study of Liver Diseases and the Organ Procurement Transplantation Network/United Network for Organ Sharing. Development of LI-RADS has been based on literature review, expert opinion, rounds of testing and iteration, and feedback from users. This article summarizes and assesses the quality of evidence supporting each LI-RADS major feature for diagnosis of HCC, as well as of the LI-RADS imaging features suggesting malignancy other than HCC. Based on the evidence, recommendations are provided for or against their continued inclusion in LI-RADS. ^© RSNA, 2017 Online supplemental material is available for this article.

Emergence of spatial patterns in a mathematical model for the co-culture dynamics of epithelial-like and mesenchymal-like cells

Accumulating evidence indicates that the interaction between epithelial and mesenchymal cells plays a pivotal role in cancer development and metastasis formation. Here we propose an integro-differential model for the co-culture dynamics of epithelial-like and mesenchymal-like cells. Our model takes into account the effects of chemotaxis, adhesive interactions between epithelial-like cells, proliferation and competition for nutrients. We present a sample of numerical results which display the emergence of spots, stripes and honeycomb patterns, depending on parameters and initial data. These simulations also suggest that epithelial-like and mesenchymal-like cells can segregate when there is little competition for nutrients. Furthermore, our computational results provide a possible explanation for how the concerted action between epithelial-cell adhesion and mesenchymal-cell spreading can precipitate the formation of ring-like structures, which resemble the fibrous capsules frequently observed in hepatic tumours.

Evaluating the current surgical strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Despite careful surveillance programs and the development of antiviral therapy for hepatitis virus infection, the occurrence rate of HCC remains high. Liver resection and liver transplantation are mainstay curative treatments. Most patients with HCC have impaired liver function, and surgical treatment is always accompanied by the risk of decompensation of the remnant liver, especially when the volume of the remnant liver is too small and the liver function too low to meet metabolic demands. The mortality of liver resection has dramatically decreased over the last three decades from 20% to less than 5% due to the accumulation of knowledge of liver anatomy, perioperative management and preoperative assessment of liver function. Here we provide an overview of the multidisciplinary treatments and current standard treatment strategies for HCC, to explore the possibility of expanding surgical treatments beyond the current standards.

Hepatocellular Carcinoma with Metastasis to the Spleen in a Holstein Cow

Hepatocellular carcinoma (HCC) with metastasis to the spleen in a Holstein cow was studied by histopathologic and immunohistochemical methods. The tumor was characterized by a pseudoglandular (acinar) pattern with an associated fibrous stroma. Individual cells often had a “hepatoid” appearance but were interspersed with scattered cells exhibiting a clear, periodic acid-Schiff (PAS)-positive cytoplasm and small eccentric nuclei. This pattern was present in nodules found in both liver and spleen. Moreover, hepatoid tumor cells were positive for alpha-fetoprotein. Immunohistochemical studies suggest that myofibroblasts were responsible for the production of fibrous septa surrounding the pseudoglandular structures of bovine HCC. In summary, our histologic and immunohistochemical findings support a diagnosis of primary HCC with splenic metastasis. Furthermore, the associated stromal response appears to be of a myofibroblast origin. The primary etiology of bovine HCC and the significance of the intralesional, PAS-positive clear cells remain undetermined.

CT and MR imaging diagnosis and staging of hepatocellular carcinoma: part I. Development, growth, and spread: key pathologic and imaging aspects

Computed tomography (CT) and magnetic resonance (MR) imaging play critical roles in the diagnosis and staging of hepatocellular carcinoma (HCC). The first article of this two-part review discusses key concepts of HCC development, growth, and spread, emphasizing those features with imaging correlates and hence most relevant to radiologists; state-of-the-art CT and MR imaging technique with extracellular and hepatobiliary contrast agents; and the imaging appearance of precursor nodules that eventually may transform into overt HCC.

Usefulness of thin-section single-shot turbo spin echo with half-Fourier acquisition in evaluation of local invasion of lung cancer

PURPOSE

To evaluate the usefulness of thin-section single-shot turbo spin echo with half-Fourier acquisition (SS-TSE-HF) alone for evaluation of local invasion of lung cancer.

MATERIALS AND METHODS

Our Institutional Review Board approved this retrospective study. Thirty-six patients with lung cancer who underwent magnetic resonance imaging (MRI) for evaluation of local invasion followed by curative surgery from July 2008 to June 2012 were enrolled in this study. Two reviewers independently and blindly reviewed computed tomography (CT) and MRI (thin-section SS-TSE-HF and conventional MRI, which consisted of conventional axial SS-TSE-HF, dynamic MRI with respiratory and/or cardiac cine, and T1 -weighted high-resolution isotropic volume examination [THRIVE]) for the presence of local invasion. Diagnostic performances were evaluated using gross surgical findings and pathological results as a standard reference.

RESULTS

The overall diagnostic performance for detecting local invasion of lung cancer between the two reviewers were as follows: specificity and accuracy of thin-section SS-TSE-HF (89.0% and 87.5%) were significantly higher than those of CT (25.6% and 46.9%, P < 0.001 for both) or conventional MRI (61.0% and 69.5%, P < 0.001 and P = 0.008, respectively). Sensitivity was 84.8% for thin-section SS-TSE-HF with the same value for CT (P = 0.246) and conventional MRI (P = 0.209).

CONCLUSION

Thin-section SS-TSE-HF sequence alone without any contrast agent demonstrated a relatively high diagnostic performance in evaluation of local invasion of lung cancer.

Infiltrative hepatocellular carcinoma on gadoxetic acid-enhanced and diffusion-weighted MRI at 3.0T

PURPOSE

To determine imaging features of infiltrative hepatocellular carcinoma (HCC) on 3T magnetic resonance imaging (MRI) including gadoxetic acid-enhanced and diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Eighteen patients with infiltrative HCC underwent liver MRI that consisted of T1- and T2-weighted image (T2WI), gadoxetic acid-enhanced arterial, portal, 3-min late and 20-min hepatobiliary phase (HBP), and DWI. Two reviewers evaluated in consensus tumor characteristics and lesion conspicuity using a 4-point scale. The tumor-to-liver contrast ratio was also measured.

RESULTS

Most of the tumors (n = 16, 88.9%) were seen as irregular permeative masses (4.0-23.0 cm, mean 10.5 cm in diameter) and the remaining two as poorly defined amorphous infiltration among thrombosed portal veins. Internal reticulation within the tumor was characteristic and was most frequently observed on 3-min late phase (n = 18), followed by HBP (n = 15). Tumor conspicuity and tumor-to-liver contrast ratio was highest with b-800 DWI, which was significantly higher than those of other images (P < 0.05).

CONCLUSION

DWI provides the highest conspicuity for infiltrative HCC compared to unenhanced T1- and T2WI and gadoxetic acid-enhanced MRI. The gadoxetic acid-enhanced 3-min late image is useful in characterizing infiltrative HCC, as it clearly depicts internal reticulation in all tumors.

Complete tumor encapsulation on magnetic resonance imaging: a potentially useful imaging biomarker for better survival in solitary large hepatocellular carcinoma

The aim of this study was to determine the prognostic value of complete tumor encapsulation as visualized on magnetic resonance imaging (MRI) in patients with a solitary large hepatocellular carcinoma (HCC) beyond the Milan criteria for liver transplantation (LT). Between December 2000 and March 2011, 57 patients who had a solitary HCC exceeding 5 cm in diameter at the time of initial MRI before any treatment were identified. MRI images of the patients were independently reviewed by 2 experienced readers for the presence of complete tumoral encapsulation. The medical records of the patients were reviewed for an outcome analysis. Thirty of the 57 patients had completely encapsulated HCC according to MRI. There was excellent interobserver agreement between the 2 readers for the assessment of complete encapsulation (κ=0.86). Overall survival was significantly longer for patients with completely encapsulated HCC versus patients with incompletely or nonencapsulated tumors (P<0.001), and this included a subanalysis of 33 patients who received locoregional treatment (LRT; P=0.04). The presence of complete encapsulation was a strong predictor for survival in these patients according to both univariate [hazard ratio (HR)=0.24, 95% confidence interval (CI)=0.12-0.52, P<0.001] and multivariate analyses (HR=0.25, 95% CI=0.07-0.85, P=0.03). The rates of down-staging (P<0.001) and eventual LT (P=0.02) after LRT were also significantly higher in the patients with completely encapsulated tumors. In conclusion, complete tumor encapsulation on MRI is a potentially useful predictor for favorable biology in patients with a solitary large HCC. This new imaging biomarker may have a role in treatment selection for patients whose tumors exceed the Milan criteria size limits.

Small hepatocellular carcinoma with ring calcification: A case report and literature review

Ring calcification in untreated hepatocellular carcinoma (HCC) is extremely rare, with only 3 previously reported cases in the English-language literature. A case of HCC with ring calcification was reported in this paper. Additionally, 3 previously reported cases of HCC with ring calcification were reviewed. In 3 of these 4 cases (including our case), surgery was performed. Although the size of the ring-calcified lesion ranged from 3.0-3.7 cm in previously reported cases, the size was only 1 cm in ours. The differentiation of the tumor was moderate in the 2 previously reported cases in the histological findings and poor in ours. In spite of their poor differentiation for their sizes, these tumors showed no early enhancement in dynamic computed tomography. All calcified tumors showed a thick fibrous capsule and extensive necrosis histologically. Ring calcification was considered to result from a circulatory disturbance caused by the imbalance between the less abundant arterial blood flow and high inner pressure induced by either the thick fibrous capsule or vigorous proliferation due to the poor differentiation. Ring calcification in untreated HCC may suggest a lower differentiation of the tumor. Even if its size is small, hepatic resection should be performed for any tumor with ring calcification because poor differentiation is considered to be one of the risk factors for recurrence after local ablation therapy, including radio frequency ablation.

Characterizing hepatocellular carcinoma using multi-breath-hold two-dimensional susceptibility-weighted imaging: comparison to conventional liver MRI

AIM

To characterize the imaging manifestations of hepatocellular carcinoma (HCC) using multi-breath-hold two-dimensional susceptibility-weighted imaging (SWI) and compare to conventional liver magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Forty-three patients with histopathologically confirmed HCC underwent conventional liver MRI, multi-breath-hold two-dimensional SWI, and contrast-enhanced CT preoperatively. The T1-weighted imaging (WI), T2WI, and SWI images were evaluated in consensus by two experienced radiologists. The tumour boundaries, blood products in the tumour, venous vessels, and non-tumour liver parenchyma were compared.

RESULTS

SWI demonstrated significantly better tumour boundary detection than T1WI and T2WI imaging (67.4 and 25.6%, respectively). The detection rate for intra-tumoural blood products using SWI was higher than that of T1WI and T2WI (76.7 and 16.3%, respectively). The detection rate for tumour venous vessels using SWI was 72.1%, while none was detected with conventional T1WI and T2WI. The detection rate for siderotic nodules in non-tumour liver parenchyma using SWI was higher than that of conventional T1WI and T2WI (65.1 and 20.9%, respectively).

CONCLUSIONS

SWI can provide more detailed information than conventional liver MRI in evaluation of tumour boundaries, blood products, venous vasculature, and non-tumour liver parenchyma. SWI is a valuable complement to conventional liver MRI.

Histologic characteristics of hepatocellular carcinomas showing atypical enhancement patterns on 4-phase MDCT examination

Objective

To retrospectively define which histologic characteristics of small-sized hepatocellular carcinomas (HCCs) are related to atypical dynamic enhancement on multi-detector computed tomography (MDCT) imaging.

Materials and Methods

Seventy-three patients with 83 HCCs (3 cm or less in diameter) were included in this study. All patients underwent 4-phase MDCT imaging and subsequent surgery within eight weeks. Two independent radiologists blinded to the histologic findings retrospectively classified the HCCs as either typical (showing increased enhancement on arterial phase images followed by washout in late phase images) or atypical lesions demonstrating any other enhancement pattern. From the original pathologic reports, various histologic characteristics including gross morphology, nuclear histologic grades, presence of capsule formation, and capsule infiltration when a capsule was present, were compared among the two groups.

Results

An atypical enhancement pattern was seen in 30 (36.2%) of the 83 HCCs. The mean size of atypical HCCs (1.71 ± 0.764) was significantly smaller than that of typical HCCs (2.31 ± 0.598, p < 0.001). Atypical HCCs were frequently found to be vaguely nodular in gross morphology (n = 13, 43.3%) and to have grade I nuclear grades (n = 17, 56.7%). Capsule formation was significantly more common in typical HCCs (p < 0.001). Capsular infiltration was also more common in typical HCCs (p = 0.001).

Conclusion

HCCs showing atypical dynamic enhancement on MDCT imaging are usually smaller than typical HCCs, vaguely nodular type in gross morphology in most cases, and well-differentiated in nuclear grades, and they lack of capsule formation or capsular infiltration.

Independent factors and predictive score for extrahepatic metastasis of hepatocellular carcinoma following curative hepatectomy

BACKGROUND

Postoperative extrahepatic metastasis (EHM) contributes to a poor prognosis in patients with hepatocellular carcinoma (HCC) after hepatectomy. This study was aimed to develop a practical method that can be used to predict postoperative EHM.

METHODS

In total, 578 patients were enrolled. We analyzed the clinicopathological features of the tumors and did a long-term follow-up to observe HCC recurrence. Postoperative EHM was detected in 136 patients, and multivariate analysis was used to confirm independent risk factors for postoperative EHM. After the factors were identified, a predictive scoring system was constructed as a weighted sum of these factors. The cutoff value that determines a high risk for EHM was defined by maximizing the Youden's index of the receiver operating characteristic curve.

RESULTS

Microvascular invasion, incomplete capsule, and larger tumor diameter were the three independent factors predictive for a high risk for EHM. The scoring system was derived with an area under the curve (AUC) of 0.81 for postoperative 10-year EHM prediction. A cutoff value of 43 was derived and validated with a sensitivity >90% and specificity >60% to predict the development of EHM. This system was further verified in a subgroup of Barcelona Clinic Liver Cancer stage 0-A patients with an AUC of 0.82. When the cutoff value was set at 43, the sensitivity and specificity were 90.38% and 64.88%, respectively.

CONCLUSIONS

Our predictive scoring system may be used to identify HCC patients who have a high risk for EHM following curative hepatectomy.

Encapsulation is a significant prognostic factor for better outcome in large hepatocellular carcinoma

BACKGROUND

The aim of this study was to determine the effect of tumor encapsulation of hepatocellular carcinoma (HCC) on long-term survival.

METHODS

A retrospective review of 1,240 patients who underwent hepatectomy from January 1993 to June 2005 was conducted. There were 891 patients with tumor encapsulation (EC type) and 349 patients without tumor encapsulation (NC type). Clinicopathological factors, surgical outcome, and long-term survival were analyzed.

RESULTS

Disease-free survival (DFS) was affected by surgical margin involvement, the presence of surgical complications, vascular invasion, liver cirrhosis, tumor encapsulation, tumor size >5 cm, tumor rupture, and the presence of satellite lesions (all, P < 0.05). Overall survival (OS) was also affected by the same parameters, except for satellite lesions. When the patients were grouped by tumor size >5 or ≤5 cm, the protective effect of encapsulation was only observed when the tumor size was >5 cm [odds ratio (OR) for DFS = 0.75, P = 0.02; OR for OS = 0.68, P < 0.01].

CONCLUSIONS

Tumor encapsulation is a significant prognostic factor for HCC >5 cm.

Prediction of microvascular invasion of hepatocellular carcinoma by pre-operative CT imaging

OBJECTIVE

The aim of this study was to diagnose microvascular invasion in patients with solitary hepatocellular carcinoma (HCC) from pre-operative CT imaging.

METHODS

102 patients with solitary HCC who underwent curative hepatectomy were retrospectively included in our study. The pre-operative 3-phase CT imaging and laboratory data for the 102 patients were reviewed. Tumour size, tumour margin, peritumoral enhancement and α-fetoprotein level were assessed. Surgical pathology was reviewed; tumour differentiation, liver fibrosis score and microvascular invasion were recorded.

RESULTS

The histopathological results revealed that 50 HCCs were positive and the other 52 were negative for microvascular invasion. Univariate analysis revealed that tumour size (p = 0.036), higher Edmondson-Steiner grade (p = 0.047) and non-smooth tumour margin (p < 0.001) showed statistically significant associations with microvascular invasion. Multivariate logistic regression analysis showed that non-smooth tumour margin had a statistically significant association with microvascular invasion only (p < 0.001). The sensitivity, specificity, positive predictive value and negative predictive value of the non-smooth tumour margin in the prediction of microvascular invasion were 66%, 86.5%, 82.5% and 72.6%, respectively.

CONCLUSION

Non-smooth tumour margin in pre-operative CT had a statistically significant association with microvascular invasion. More aggressive treatment should be considered in HCC patients with suspected positive microvascular invasion.

Magnetic resonance imaging of the liver: New imaging strategies for evaluating focal liver lesions

The early detection of focal liver lesions, particularly those which are malignant, is of utmost importance. The resection of liver metastases of some malignancies (including colorectal cancer) has been shown to improve the survival of patients. Exact knowledge of the number, size, and regional distribution of liver metastases is essential to determine their resectability. Almost all focal liver lesions larger than 10 mm are demonstrated with current imaging techniques but the detection of smaller focal liver lesions is still relatively poor. One of the advantages of magnetic resonance imaging (MRI) of the liver is better soft tissue contrast (compared to other radiologic modalities), which allows better detection and characterization of the focal liver lesions in question. Developments in MRI hardware and software and the availability of novel MRI contrast agents have further improved the diagnostic yield of MRI in lesion detection and characterization. Although the primary modalities for liver imaging are ultrasound and computed tomography, recent studies have suggested that MRI is the most sensitive method for detecting small liver metastatic lesions, and MRI is now considered the pre-operative standard method for diagnosis. Two recent developments in MRI sequences for the upper abdomen comprise unenhanced diffusion-weighted imaging (DWI), and keyhole-based dynamic contrast-enhanced (DCE) MRI (4D THRIVE). DWI allows improved detection (b = 10 s/mm²) of small (< 10 mm) focal liver lesions in particular, and is useful as a road map sequence. Also, using higher b-values, the calculation of the apparent diffusion coefficient value, true diffusion coefficient, D, and the perfusion fraction, f, has been used for the characterization of focal liver lesions. DCE 4D THRIVE enables MRI of the liver with high temporal and spatial resolution and full liver coverage. 4D THRIVE improves evaluation of focal liver lesions, providing multiple arterial and venous phases, and allows the calculation of perfusion parameters using pharmacokinetic models. 4D THRIVE has potential benefits in terms of detection, characterization and staging of focal liver lesions and in monitoring therapy.

Both fibrous capsule formation and extracapsular penetration are powerful predictors of poor survival in human hepatocellular carcinoma: a histological assessment of 365 patients in Japan

BACKGROUND

A new definition of infiltration to the capsule (fc-inf) has been proposed as a novel marker for predicting the prognosis of 88 patients with hepatocellular carcinoma (HCC). The current aim was to present evidence to develop the fibrous capsule and fc-inf, from the Japanese histological findings for HCC, and to validate their biological significances and predictive power of survival in a large series.

METHODS

A total of 365 HCCs were divided into HCCs without the fibrous capsule (NC type; n = 135) and HCCs with the fibrous capsule (FC type; n = 230). Then, FC type was subclassified into two types: extracapsular infiltrating (EC) type (n = 125), in which cancer cells penetrated outside the fibrous capsule, and intracapsular (IC) type (n = 105), in which the infiltrating cancer cells stayed inside the fibrous capsule.

RESULTS

The proportion of less histological differentiation and portal venous invasion was higher in FC type than in NC type. The fibrous capsule came to be observed according to the increase of tumor size (P < 0.0001). FC type had significantly poorer outcome for overall survival than NC type (P = 0.0022). EC type showed more intrahepatic metastasis than IC type. The macroscopic subclassifications were significantly affected the presence of fc-inf. EC type had significantly poorer outcome for disease-free survival than IC type (P = 0.0132) and was an independent prognostic factor for disease-free survival (P = 0.0482).

CONCLUSIONS

Fc-inf defined as extracapsular penetration was verified to be a novel marker for predicting prognosis, and presence of fc-inf might be predicted by tumor gross features.

Impact factors for microinvasion in patients with hepatocellular carcinoma: possible application to the definition of clinical tumor volume

PURPOSE

To evaluate the degree of invasion of hepatocellular carcinoma (HCC) microscopically that will provide a potential application for gross tumor volume to clinical tumor volume (GTV-to-CTV) expansion.

METHODS AND MATERIALS

From January 2002 to January 2006, 149 HCC patients were selected from those who had undergone surgical resection. Pathology slides and clinical data of all patients were reviewed, including platelet counts, serum alpha-fetoprotein (AFP) levels, degree of liver cirrhosis, tumor size, capsular status, portal vein invasion, TNM stage, and histologic tumor grade. The distance between the tumor margin (or fibrous capsule) and the invasive lesions was measured by senior pathologists.

RESULTS

Of these 149 patients, 79 (53.0%) patients presented with tumor microinvasion between 0.5 and 4 mm. This degree of microinvasion was inversely correlated with lower platelet counts and positively correlated with higher AFP levels, larger tumor sizes, portal vein invasion, and advanced TNM stage. Microinvasion distances less than or equal to 2 mm were found in 96.1% of patients (74/77) with tumor dimensions less than or equal to 5 cm and in 94.5% of patients (85/90) with AFP levels less than 400 microg/l.

CONCLUSIONS

Based on our study findings, GTV-to-CTV expansions of 4 mm for HCC are required to conceal the gross tumor and any microscopic disease with 100% accuracy. Tumor size and AFP levels are the simplest indicators for determining the GTV-to-CTV distance for HCC.

Hepatocellular carcinoma with a pseudocapsule on gadolinium-enhanced MR images: correlation with histopathologic findings

PURPOSE

To evaluate the characteristics of hepatocellular carcinoma (HCC) with a pseudocapsule on dynamic magnetic resonance (MR) images.

MATERIALS AND METHODS

The institutional review board approval was obtained, and the requirements for informed consent were waived for this retrospective study. Dynamic MR studies of surgically resected 106 HCCs in 93 patients were retrospectively reviewed. A false-positive fibrous capsule (FC) on dynamic MR images was considered to be a pseudocapsule. Pathologic specimens of HCCs with a pseudocapsule were reviewed. The differences in size, tumor grade, the degree of liver fibrosis and background liver diseases, and the incidence of vascular invasion were compared between HCCs with a pseudocapsule on MR images and those with FC at histologic examination by using Student t, Kruskal-Wallis, and chi(2) tests.

RESULTS

The sensitivity, specificity, and accuracy of dynamic MR in the diagnosis of histologic FC were 94.0% (47 of 50), 73.2% (41 of 56), and 83.0% (88 of 106), respectively. There were 15 (14.2%) HCCs with a pseudocapsule. The pathologic specimens suggested possible causes of the pseudocapsule that included prominent sinusoids (n = 6), peritumoral fibrosis mimicking bridging fibrosis (n = 3), and both (n = 5). In one case, the capsulated HCC was surrounded by a well-differentiated HCC component. The mean size of a HCC with a pseudocapsule tended to be smaller than that with histologic FC, although it was not significant (mean +/- standard deviation: 2.8 cm +/- 1.0 vs 3.5 cm +/- 2.0, P = .09). Liver cirrhosis was less frequent in HCCs with a pseudocapsule than in those with a histologic FC (one of 14 [7.1%] vs 20 of 49 [40.8%], P < .05). The tumor grades were not significantly different, and the incidence of vascular invasion after standardizing the tumor size (<or=4 cm) was similar (five of 14 [35.7%] vs 12 of 37 [32.4%]).

CONCLUSION

Dynamic MR imaging is accurate in depicting FC in HCCs. HCC with a pseudocapsule at MR possibly consists of peritumoral sinusoids and/or fibrosis. The pseudocapsule may be similar to histologic FC in terms of tumor invasiveness.

Does nonalcoholic fatty liver disease predispose patients to hepatocellular carcinoma in the absence of cirrhosis?

CONTEXT

Hepatocellular carcinoma (HCC) is recognized as a complication of cirrhosis related to nonalcoholic fatty liver disease (NAFLD). Diabetes and the metabolic syndrome are also associated with HCC. However, it is not clear whether NAFLD predisposes patients to HCC in the absence of cirrhosis.

OBJECTIVE

To seek evidence that HCC can develop in NAFLD unaccompanied by cirrhosis.

DESIGN

Retrospective case study was performed on cases from 2004 to 2007 at the University of Illinois at Chicago Medical Center, using the key words hepatocellular carcinoma, liver explant, and liver resection. The diagnosis of HCC was identified and confirmed by hematoxylin-eosin-stained slides in 50 cases. Cause of liver disease was determined by review of liver histology, clinical history, and laboratory data.

RESULTS

Three patients presented with advanced HCC with features of metabolic syndrome, including an elevated body mass index. Each patient had bland steatosis on liver biopsy, without fibrosis or cirrhosis. None of the 3 patients had evidence of any cause for liver disease other than NAFLD.

CONCLUSIONS

The cases presented here suggest that NAFLD may predispose patients to HCC in the absence of cirrhosis. Further studies are needed to confirm this potentially important observation.

Extracapsular penetration is a new prognostic factor in human hepatocellular carcinoma

The fibrous capsule is a unique characteristic of hepatocellular carcinoma (HCC) and acts as a barricade preventing the spread of cancer cells. Infiltration to the capsule (fc-inf) is the invasive feature in HCC; however, there are no reports of a detailed investigation regarding fc-inf. We selected 88 HCCs of <or=5 cm in diameter, when considered together with both the single nodular and the single nodular with extranodular growth types. We classified the infiltrating pattern into 2 types: extracapsular (EC) infiltrating type (n=38), in which cancer cells infiltrated outside the capsule and touched the existing liver parenchyma, and intracapsular (IC) infiltrating type (n=50), in which the infiltrating cancer cells stayed inside the capsule. The distance of infiltration and the capsular thickness were measured and the ratio of capsular infiltration (CI index) was calculated. There were no clinicopathologic differences between the 2 types, but the capsular thickness of IC type was greater than that of EC type (P<0.0001). EC type showed a poorer outcome for the overall survival and the disease-free survival (P=0.0210 and P=0.0115, respectively) and EC type was an independent prognostic factor for a disease-free survival (P=0.0158). However, CI index did not correlate with any clinicopathologic factors or the patient prognosis in IC type. We propose a new definition of fc-inf as a histologic feature of cancer cells penetrating to the liver parenchyma through the fibrous capsule. It may be closely related to the patient prognosis and may therefore, become a new and useful pathologic factor.

High tumor-infiltrating macrophage density predicts poor prognosis in patients with primary hepatocellular carcinoma after resection

Macrophages constitute a major component of the leukocyte infiltrate of tumors and perform distinct roles in different tumor microenvironments. This study attempted to investigate the prognostic values of tumor-infiltrating macrophages in patients with hepatocellular carcinoma after resection, paying particular attention to their tissue microlocalization. The CD68(+) macrophages were assessed by immunohistochemistry in tissues from 137 patients with hepatocellular carcinoma. Prognostic value of intratumoral, marginal, and peritumoral macrophage densities was evaluated by Kaplan-Meier analysis and Cox regression. Both intratumoral and marginal macrophage densities were associated inversely with overall survival (P = .034 and .004, respectively) and disease-free survival (P = .006 and .008, respectively). In contrast, peritumoral macrophage density was associated with neither overall survival nor disease-free survival. Intratumoral macrophage density emerged as an independent prognosticator of overall survival (hazard ratio = 1.721, P = .049) and disease-free survival (hazard ratio = 2.165, P = .007). Marginal macrophage density, but not intratumoral macrophage density, was associated with vascular invasion, tumor multiplicity, and fibrous capsule formation. Our results demonstrate that high macrophage infiltration predicts poor prognosis in patients with hepatocellular carcinoma. These results, together with our previous report showing the distinct activation patterns of macrophages in different areas of tumor tissue, implies that macrophages in those areas may use different strategies to promote the tumor progression.

Clinicopathological and prognostic features of primary clear cell carcinoma of the liver

AIM

Primary clear cell carcinoma of the liver (PCCCL) is a subgroup of primary hepatocellular carcinoma (HCC), pathologically characterized by diffuse clear cells of the tumor, showing a clear cytoplasm that does not stain with hematoxylin-eosin. At present, its clinicopathological and prognostic features are not fully clarified. This study aims to clarify the clinicopathological and prognostic features of PCCCL.

METHODS

The clinicopathological data of 43 patients with PCCCL treated with hepatectomy in our hospital from January 1999 to December 2003 were retrospectively analyzed.

RESULTS

The chi(2)-test showed a positive rate of hepatitis C virus (HCV) infection and capsule formation in the PCCCL group, which was markedly higher than in the common type HCC (CHCC) group (P = 0.000 and P = 0.005). Meanwhile, the vascular invasion rate was notably lower in the PCCCL group, but there were no significant differences between the twogroups (P = 0.129). The Kaplan-Meier method showed that the 1-, 3-, and 5-year survival rates were significantly higher in the PCCCL group than in the CHCC group (P = 0.021). The prognosis of patients in the PCCCL group was related to capsule formation, vascular invasion, liver cirrhosis, and clear cell ratio. The 1-, 3-, and 5-year survival rates were markedly higher in the group with a higher clear cell ratio than in the group with a lower clear cell ratio (P = 0.011).

CONCLUSION

The notable clinicopathological features of the patients in the PCCCL group included a higher rate of HCV infection, capsule formation, and a lower rate of vascular invasion. The prognosis was better than that of the patients in the CHCC group and related to the ratio of clear cells.

Histogenesis of intralesional fibrous septum in chordoma

Intralesional fibrous septum (IFS), a histologic architecture that is typical of chordoma, consists of proliferating spindle-shaped, fibroblast-like cells with an abundance of collagen fibers. However, the histogenesis of IFS is still controversial. In a series of 122 chordomas, special emphasis was placed on the morphology of host tissues involved in IFS and on a transition between IFS and neighboring tissues. In 23 lesions, IFS was also characterized both histochemically and immunohistochemically. IFS was observed in 79 (64.8%) lesions. Occasionally, IFS contained bone fragments and hyalinized matrix with no lining of osteoblastic cells, suggesting degenerated rather than metaplastic bone tissue. Moreover, IFS occasionally showed a direct transition to host bone trabeculae. Histochemically and immunohistochemically, IFS included calcium deposits positive for Alizarin red S staining and expressed both type I and type III collagen. In extraosseous lesions extending to the adjacent soft tissues, IFS frequently involved muscle fibers or peripheral nerve fibers and displayed a smooth transition to neighboring soft tissues. We believe that IFS is induced by a tumor-host interaction that is based on the host bone trabeculae in intraosseous lesions or on soft tissues in extraosseous lesions.