cHCC-CCA: Consensus terminology for primary liver carcinomas with both hepatocytic and cholangiocytic differentation

Tumour evolution in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common form of primary liver cancer, typically develops on the background of chronic liver disease and is an aggressive disease with dismal prognosis. Studies using next-generation sequencing of multiple regions of the same tumour nodule suggest different patterns of HCC evolution and confirm the high molecular heterogeneity in a subset of patients. Different hypotheses have been proposed to explain tumour evolution, including clonal selection or neutral and punctuated acquisition of genetic alterations. In parallel, data indicate a fundamental contribution of nonmalignant cells of the tumour microenvironment to cancer clonal evolution. Delineating these dynamics is crucial to improve the treatment of patients with HCC, and particularly to help understand how HCC evolution drives resistance to systemic therapies. A number of new minimally invasive techniques, such as liquid biopsies, could help track cancer evolution in HCC. These tools might improve our understanding of how systemic therapies affect tumour clonal composition and could facilitate implementation of real-time molecular monitoring of patients with HCC.

Combined hepatocellular-cholangiocarcinoma after tetralogy of Fallot repair: a case report and review of literature

BACKGROUND

Liver fibrosis and cancer are serious hepatic complications for patients with congenital heart diseases. We present a rare case of combined hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) (cHCC-CCA) after the repair of tetralogy of Fallot (TOF).

CASE PRESENTATION

A 54-year-old Japanese woman had undergone biventricular repair for TOF at 7 years old. She presented with abdominal distension. Abdominal CT revealed ascites and a 90-mm tumor involving the liver's left lobe. Tumor marker values were: alpha-fetoprotein, 16,208 ng/mL and des-gamma-carboxy prothrombin, 33,920 mAU/mL. The preoperative diagnosis was malignant tumor of the liver (e.g., HCC or intrahepatic CCA). We performed a left lobectomy of the liver. Histopathologically, the tumor was composed of two components growing in trabecular and irregular tubular patterns accompanied by a transitional area; the tumor was diagnosed as cHCC-CCA. The non-cancerous area showed fibrous change mainly surrounding a central vein and sinusoid, expanding toward the portal area without inflammation.

CONCLUSIONS

We provide the details of our patient's cHCC-CCA that developed from fibrous congestive liver associated with right-sided heart failure after TOF repair, diagnosed based on histopathological features. We discuss liver fibrosis as a hepatic complication and a careful follow-up maneuver for improving the outcomes of patients with chronic hepatic congestion.

CD133 and epithelial cell adhesion molecule expressions in the cholangiocarcinoma component are prognostic factors for combined hepatocellular cholangiocarcinoma

AIM

A new classification of combined hepatocellular cholangiocarcinoma (CHC) was recently reported. Cancer stem cells have been associated with CHC carcinogenesis. This study examined the association of cancer stem cell marker expression and prognosis in CHC classified using the new classification.

METHODS

We enrolled 26 CHC patients and classified them according to the new classification. We evaluated the expression of cancer stem cell markers (CD56, CD133, and epithelial cell adhesion molecule [EpCAM]) by immunohistochemical staining in each component. We analyzed the association between expressions and prognosis.

RESULTS

Seven cases were hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) (cHCC-CCA), 12 were HCC and intermediate cell carcinoma (HCC-INT), and seven were intermediate cell carcinoma (INT). The CD133-positive rate tended to be higher in the CCA (42.9%) and INT component (50.0%) than the HCC component (14.3%) in cHCC-CCA. In HCC-INT, the CD133-positive rate in the INT component (83.3%) was significantly higher than the HCC component (8.3%; P = 0.001). For EpCAM, the positive rate in the CCA component (71.4%) and INT component (50.0%) tended to be higher than the HCC component (14.3%) in cHCC-CCA. Overall survival and disease-free survival were significantly worse in cases with CD133-positive (P = 0.048 and P = 0.048, respectively) or EpCAM-positive (P = 0.041 and P = 0.041, respectively) CCA component in cHCC-CCA.

CONCLUSIONS

INT and CCA components showed higher expression rates of cancer stem cell markers than the HCC component. CD133 or EpCAM expression in the CCA component was associated with poor prognosis in cHCC-CCA.

Intrahepatic cholangiocarcinoma: Limitations for resectability, current surgical concepts and future perspectives

Intrahepatic cholangiocarcinoma (iCCA) is the second most common hepatic malignancy and its incidence has been shown to increase significantly during the past decades. Complete surgical resection is currently acknowledged as the only curative treatment option able to provide adequate long-term outcomes. We herein review technical, functional and oncologic limitations for resectability, discuss current surgical aspects as well as highlight the fields in which future research and practice should focus on in order to ameliorate long-term outcomes in patients with iCCA.

Cholangiolocellular Carcinoma With "Ductal Plate Malformation" Pattern May Be Characterized by ARID1A Genetic Alterations

Cholangiolocellular carcinoma (CLC) is a unique subtype of primary liver carcinoma, which sometimes coexists with hepatocellular carcinoma (HCC), cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma (cHCC-CCA). "Ductal plate malformation" (DPM)-pattern of primary liver carcinoma, which resembles biliary lesions in Caroli disease and von Meyenburg complex, is sometimes associated with CLC. We examined genetic alterations of hTERT promoter (hTERT), IDH1 or 2 (IDH1/2), KRAS, ARID1A, PBRM1, ARID2, BAP1, p53 and their association with histologic features such as proportion of CLC and DPM-pattern in 77 patients with primary liver carcinoma diagnosed as cHCC-CCA or CLC. Primary liver carcinomas were histologically subdivided into 29 CLC-predominant (CLC component >80%), 31 with CLC (5% to 80%) and 17 without CLC (<5%). CLC-predominant group was characterized by older age, male-predominant and smaller tumor size. Genetic alterations were detected in hTERT (25%), ARID1A (21%), PBRM1 (20%), ARID2 (3%), BAP1 (1%), p53 (46%), KRAS (5%), and IDH1/2 (8%). ARID1A alteration was more frequent in CLC-predominant group, compared with other groups (P<0.05) and was correlated with the degree of DPM-pattern (P<0.01). Alterations of hTERT and p53 were less frequent in CLC-predominant group compared with "with CLC group" (P<0.05). hTERT mutation was less frequent in carcinomas with DPM-pattern (P<0.01). PBRM1 alteration was more frequent in CLC with focal HCC subgroup and without CLC group compared with other groups (P<0.05). CLC may be a distinct subgroup of primary liver carcinoma, which is different from cHCC-CCA, based on clinicopathologic and genetic alterations. ARID1A alterations may characterize CLC with DPM-pattern and could be a diagnostic immunohistochemical marker for small CLCs with DPM-pattern.

The distribution of immune cells within combined hepatocellular carcinoma and cholangiocarcinoma predicts clinical outcome

BACKGROUND

This study aimed to investigate the clinical relevance of the immune microenvironment in patients with combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-ICC).

PATIENTS AND METHODS

The density of tumor-infiltrating CD3+ , CD8+ , CD163+ , and Foxp3+ immune cells, as well as Programmed cell death 1, Programmed cell death-ligand 1, and Tumor necrosis factor receptor superfamily member 4, was measured in the peritumor liver, tumor invasive margin, and intratumor subregions of 56 cHCC-ICC by immunohistochemistry. The immune index was established to stratify patients. Prognostic significance of immune cell subsets and immune indices was evaluated.

RESULTS

The distribution of immune cells was highly heterogeneous among different subregions of cHCC-ICC. As compared with the hepatocellular carcinoma (HCC) component, the lower density of CD8+ T cells and higher intensity of Foxp3+ Tregs and immune checkpoints in the intrahepatic cholangiocarcinoma (ICC) component may indicate a stronger immune evasive ability of ICC. Based on clustering classification or a combination of random forest and lasso-cox, two models of immune indices were established and both were identified as independent prognostic factors for cHCC-ICC patients. The selected immune variables in the immune prognostic models derived from both HCC and ICC subregions, indicating that the prognosis of cHCC-ICC patients was a complex interaction of both components.

CONCLUSIONS

The immune contexture was heterogeneous among different subregions of cHCC-ICC patients and contributed differently to patient prognosis. Immune score based on the densities of immune cells might serve as a promising prognostic predictor for cHCC-ICC patients.

The distribution of immune cells within combined hepatocellular carcinoma and cholangiocarcinoma predicts clinical outcome

BACKGROUND

This study aimed to investigate the clinical relevance of the immune microenvironment in patients with combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-ICC).

PATIENTS AND METHODS

The density of tumor-infiltrating CD3+ , CD8+ , CD163+ , and Foxp3+ immune cells, as well as Programmed cell death 1, Programmed cell death-ligand 1, and Tumor necrosis factor receptor superfamily member 4, was measured in the peritumor liver, tumor invasive margin, and intratumor subregions of 56 cHCC-ICC by immunohistochemistry. The immune index was established to stratify patients. Prognostic significance of immune cell subsets and immune indices was evaluated.

RESULTS

The distribution of immune cells was highly heterogeneous among different subregions of cHCC-ICC. As compared with the hepatocellular carcinoma (HCC) component, the lower density of CD8+ T cells and higher intensity of Foxp3+ Tregs and immune checkpoints in the intrahepatic cholangiocarcinoma (ICC) component may indicate a stronger immune evasive ability of ICC. Based on clustering classification or a combination of random forest and lasso-cox, two models of immune indices were established and both were identified as independent prognostic factors for cHCC-ICC patients. The selected immune variables in the immune prognostic models derived from both HCC and ICC subregions, indicating that the prognosis of cHCC-ICC patients was a complex interaction of both components.

CONCLUSIONS

The immune contexture was heterogeneous among different subregions of cHCC-ICC patients and contributed differently to patient prognosis. Immune score based on the densities of immune cells might serve as a promising prognostic predictor for cHCC-ICC patients.

Distinctive clinicopathological features and KRAS and IDH1/2 mutation status of cholangiolocellular carcinoma

AIM

Cholangiolocellular carcinoma (CLC) is classified as a subtype of combined hepatocellular cholangiocarcinoma with stem-cell features (CHC-SC) in the latest World Health Organization classification. This subclassification of CHC-SCs is controversial and the relevance of such classification is unclear.

METHODS

We analyzed a series of CHC-SCs and intrahepatic cholangiocarcinoma (iCCA) to clarify the clinicopathological features and mutational status of each tumor.

RESULTS

Background liver disease, fibrosis stage, microvascular invasion, nodal metastasis, and IDH1/2 mutation status were associated with their histology. Compared with the intermediate cell subtype of CHC-SC (CHCs-SC-int), CLCs were less frequently associated with chronic viral hepatitis, and showed lower levels of serum alpha-fetoprotein. Compared with iCCAs, CLCs showed lower levels of serum carbohydrate antigen 19-9 (CA19-9) and a lower frequency of expression of S100P. Patients with iCCA showed worse overall survival than those with CLC or CHC-SC-int. In patients with iCCA, CLC, or CHC-SC-int, a histology of iCCA, microvascular invasion, and serum CA19-9 value of >100 U/mL were significant poor prognostic factors for overall survival in univariate analysis. Multivariate analysis showed that a high serum CA19-9 value was an independent poor prognostic factor for overall survival.

CONCLUSIONS

Patients with CLC are likely to have a different etiology and mutational background from those with CHC-SC-int. Their clinicopathological manifestations are also different from those with classic iCCA. Our results suggest that CLC might be a distinct entity among primary liver carcinomas.

Surgical Treatment of Hepatocholangiocarcinoma: A Systematic Review

BACKGROUND

Hepatocholangiocarcinoma (HCC-CC) is a rare liver malignancy that contains features of both hepatocellular carcinoma (HCC) and mass-forming cholangiocarcinoma (MFCCC). Three classification systems for HCC-CC are described in literature and the majority of these tumors appear to be of the transitional type. The aim of this study is to evaluate the characteristics of transitional HCC-CC and to compare long-term oncological outcomes with HCC and MFCCC in surgically treated patients.

SUMMARY

A systematic literature search was conducted to identify relevant studies analyzing demographic and clinical characteristics of patients with transitional HCC-CC and evaluating treatments and outcomes associated with this neoplasm. Only comparative, retrospective analyses were included. A total of 14 studies, involving 13,613 patients with primary liver malignancy, were analyzed. All patients underwent surgery, either liver resection or transplantation. Four hundred and thirty-seven patients were affected by transitional HCC-CC (3.2%). For further analysis, patients with transitional HCC-CC were divided into 2 groups, the resection group and the transplantation group. Disease-free survival (DFS) and overall survival (OS) of these patients were analyzed and compared to long-term oncological outcomes of patients with HCC and/or MFCCC, who underwent the same treatment. In the resection group, DFS rate at 5-year was 15, 31.6, and 20.3% for patients with transitional HCC-CC, HCC, and MFCCC, respectively; OS rate at 5-year was 32.7, 47.5, and 30.3% for patients with transitional HCC-CC, HCC, and MFCCC, respectively. In the transplantation group, DFS rate at 5-year was 40.9 and 87.4% for patients with transitional HCC-CC and HCC, respectively; OS rate at 5-year was 49.4 and 80.3% for patients with transitional HCC-CC and HCC, respectively.

KEY MESSAGES

Transitional HCC-CC patients have significantly worse DFS and OS rates compared to HCC patients in both the resection group and the transplantation group. However, in the resection group, both DFS and OS rates of transitional HCC-CC patients are not statistically different from those of MFCCC patients.

Immunomorphology and molecular biology of mixed primary liver cancers: is Nestin a marker of intermediate-cell carcinoma?

AIMS

Primary mixed liver cancers (PLCs), combined hepatocellular-cholangiocellular (cHCC-CC) and intermediate-cell carcinomas are rare tumours characterised by different molecular mechanisms. Nestin is a marker of progenitor cells with a promising application in human tumours. The aims of the present paper are (i) to determine the expression of Nestin in mixed PLCs; and (ii) to correlate the PLC immunoprofile with the gene expression in each tumour component.

METHODS AND RESULTS

We selected 28 mixed PLCs, 13 (46.4%) cHCC-CC and 15 (53.6%) intermediate-cell carcinomas. The immunohistochemistry panel consisted of keratin 7, keratin 19, CD56 and Nestin. Next-generation sequencing analysis was performed on 17 cases (27 specimens) using a multi-gene custom panel. The differentiated HCC and CC components of cHCC-CC were negative for Nestin in all cases. The intermediate areas of cHCC-CC were immunoreactive for Nestin in 92.3% of cases, for CD56 in 76.9% and for K7/K19 in all cases. The immunoprofile of the intermediate-cell carcinomas showed 73.3% of cases positive for Nestin and 66.7% for CD56. TP53 and TERT were the most frequently mutated genes (31.3% and 17.6% of samples, respectively). Mutations were also found in IDH1, IDH2, PIK3CA and NRAS genes. Intermediate and HCC areas of cHCC-CC seemed to share the same mutational profile, and both harboured different mutations than the CC component.

CONCLUSIONS

According to our preliminary data, Nestin was not expressed by hepatocellular or cholangiocellular-cell components, but was expressed by most of the intermediate cells in PLCs, and therefore could be considered in the differential diagnosis of PLCs, together with mutational profile.

Expanding the Liver Imaging Reporting and Data System (LI-RADS) v2018 diagnostic population: performance and reliability of LI-RADS for distinguishing hepatocellular carcinoma (HCC) from non-HCC primary liver carcinoma in patients who do not meet strict LI-RADS high-risk criteria

BACKGROUND

Hepatocellular carcinoma (HCC) can be diagnosed using imaging criteria in patients at high-risk for HCC, according to Liver Imaging Reporting and Data System (LI-RADS) guidelines. The aim of this study was to determine the diagnostic performance and inter-rater reliability (IRR) of LI-RADS v2018 for differentiating HCC from non-HCC primary liver carcinoma (PLC), in patients who are at increased risk for HCC but not included in the LI-RADS 'high-risk' population.

METHODS

This retrospective HIPAA-compliant study included a 10-year experience of pathologically-proven PLC at two liver transplant centers, and included patients with non-cirrhotic hepatitis C infection, non-cirrhotic non-alcoholic fatty liver disease, and fibrosis. Two readers evaluated each lesion and assigned an overall LI-RADS diagnostic category, additionally scoring all major, LR-M, and ancillary features.

RESULTS

The final study cohort consisted of 27 HCCs and 104 non-HCC PLC in 131 patients. The specificity of a 'definite HCC' designation was 97% for reader 1 and 100% for reader 2. The IRR was fair for overall LI-RADS category and substantial for most major features.

CONCLUSION

In a population at increased risk for HCC but not currently included in the LI-RADS 'high-risk' population, LI-RADS v2018 demonstrated very high specificity for distinguishing pathologically-proven HCC from non-HCC PLC.

Thermal Ablation for Intrahepatic Cholangiocarcinoma in Cirrhosis: Safety and Efficacy in Non-Surgical Patients

PURPOSE

To assess the effectiveness, safety, and overall survival (OS) of thermal ablation as upfront treatment of intrahepatic colangiocarcinoma (ICC) in patients with cirrhosis.

MATERIALS AND METHODS

This was a retrospective analysis of all biopsy-confirmed ICC in cirrhotic patients treated in the authors' unit from 2001 to 2017. Baseline characteristics, ablation procedures, and complications were recorded, and time to recurrence (TTR) and OS were calculated. Twenty-seven patients were identified. Seventy percent had Child-Pugh A disease, and most had clinically significant portal hypertension. Median tumor size was 21 mm. Twenty-one cases were uninodular, and 10 were single ≤ 2 cm.

RESULTS

Complete radiologic necrosis was achieved in 25 cases (92.6%). Median OS was 30.6 months (95% confidence interval [CI], 22.6-46.5), and recurrence was detected in 21 cases (77.8%) with a TTR of 10.1 months (95% CI, 7.7-20.9). In those patients with single ≤ 2-cm ICC, the OS was 94.5 months (95% CI, 11.7-not reached). Differences in OS were statistically significant between patients with single ICC ≤ 2 cm and patients with single ICC > 2 cm (P = .04) and between patients with single ICC > 2 cm and patients with multinodular ICC (P = .02). Only 1 patient had a treatment-related complication.

CONCLUSIONS

Thermal ablation is a safe and effective treatment for ICC in patients with cirrhosis who are not candidates for surgery. The OS is similar to that reported in surgical series, but the initial treatment success is hampered by a high rate of tumor recurrence. Encouraging long-term survival after thermal ablation is achieved in patients with single ≤ 2-cm ICC.

Immunohistochemical and molecular features of cholangiolocellular carcinoma are similar to well-differentiated intrahepatic cholangiocarcinoma

Cholangiolocellular carcinoma is characterized by low grade cytologic atypia, and anastomosing cords and glands resembling cholangioles or canals of Hering. Cholangiolocellular carcinoma has been variously regarded as a subtype of intrahepatic cholangiocarcinoma (World Health Organization 2000), combined hepatocellular-cholangiocarcinoma of stem cell subtype (World Health Organization 2010) and a distinct type of primary liver carcinoma. Capture-based next generation sequencing targeting the coding regions of 479 cancer genes and select introns was performed on 17 cases (5 cholangiolocellular carcinomas, 7 intrahepatic cholangiocarcinomas, 5 mixed cholangiolocellular-intrahepatic cholangiocarcinomas) along with immunohistochemistry for CK19, SALL4, CD56, CD117, and EMA. For 5 mixed cholangiolocellular-intrahepatic cholangiocarcinoma, the individual areas were micro-dissected prior to sequencing. CK19 and EMA were positive in all cases; both luminal and cytoplasmic EMA was seen in 3/5 cholangiolocellular carcinoma and 3/6 intrahepatic cholangiocarcinomas. CD117 and SALL4 were negative in all cases. CD56 was positive in 2/5 cholangiolocellular carcinoma, 4/6 intrahepatic cholangiocarcinoma and 2/5 mixed cases. Mutations typical of intrahepatic cholangiocarcinoma (IDH1/2, PBRM1, FGFR2) were present in 90% of cases with cholangiolocellular carcinoma component. The genomic profile (IDH1/2 mutations, FGFR2 fusions, chromatin-remodeling gene mutations such as ARID1A, PBRM1) and copy number alterations were similar in cholangiolocellular carcinoma, intrahepatic cholangiocarcinoma and mixed cholangiolocellular-intrahepatic cholangiocarcinoma. In all mixed cases, the immunohistochemistry results, mutational profile and copy number alterations in both components were similar. Cholangiolocellular carcinoma should be categorized as a histologic subtype of well-differentiated intrahepatic cholangiocarcinoma, and should not be considered a distinct entity, or combined hepatocellular-cholangiocarcinoma unless a distinct hepatocellular component is also present.

Pathology of liver disease: advances in the last 50 years

Liver disease has been recognized in various forms for centuries. Incredible advances, however, have been made especially in the last 50 years, driven by improvements in histology, the development of immunostains, the development of high resolution imaging methods, improved biopsy and resection methods, and the emergence of the molecular era. With these tools, pathologists and their clinical and basic science colleagues moved from classifying liver disease using an observational, pattern-based approach to a refined classification of disease, one based on etiology for medical disease and tumor classification for neoplastic disease. Examples of liver specific diseases are used to illustrate these exciting advances. These impressive advances of the past provide the foundation for hope in the future, as liver pathology continues to play an important role in improving patient care through disease identification and classification and emerging roles in guiding therapy for cures.

Malic enzyme 1 is a potential marker of combined hepatocellular cholangiocarcinoma, subtype with stem-cell features, intermediate-cell type

AIM

Combined hepatocellular cholangiocarcinoma, subtype with stem-cell features, intermediate-cell subtype (INT) shows various histological appearances and could be misdiagnosed as intrahepatic cholangiocarcinoma (iCCA). In the present study, we aimed to identify specific histological diagnostic markers of INT.

METHODS

We extracted RNA from FFPE sections of six INT, five iCCA, and five hepatocellular carcinoma (HCC) cases and compared gene expression between INT, iCCA, and HCC by microarray analysis. We then undertook immunohistochemical (IHC) staining of potential key molecules identified by microarray analysis, the conventional hepatocytic marker, hepatocyte paraffin (HepPar)-1, and the cholangiocytic markers, keratin (K) 7 and K19, on 35 INT, 25 iCCA, and 60 HCC cases.

RESULTS

Microarray analysis suggested that malic enzyme 1 (ME1) was significantly upregulated in INT. Immunohistochemical analysis revealed that the positive rates of ME1 in INT, iCCA, and HCC were 77.1% (27/35), 28.0% (7/25), and 61.7% (37/60), respectively. Analysis of classification and regression trees based on IHC scores indicated that HepPar-1 could be a good candidate for discriminating HCC from the others with high sensitivity (93.3%) and high specificity (96.7%). A multiple logistic regression model and receiver operating characteristic curve analysis based on the IHC scores of ME1, K7, and K19 generated a composite score that can discriminate between INT and iCCA. Using this composite score, INT could be discriminated from iCCA with high sensitivity (88.6%) and high specificity (88.0%).

CONCLUSIONS

We propose that ME1 is a useful diagnostic marker of INT when used in combination with other hepatocytic and cholangiocytic markers.

Development and validation of a prognostic score predicting recurrence in resected combined hepatocellular cholangiocarcinoma

Purpose: To develop and validate a decision aid to help make individualized estimates of tumor recurrence for patients with resected combined hepatocellular cholangiocarcinoma (CHC). Patients and methods: Risk factors of recurrence were identified in the derivation cohort of 208 patients who underwent liver resection between 1995 and 2014 at Zhongshan Hospital to develop a prediction score. The model was subsequently validated in an external cohort of 101 CHC patients using the C concordance statistic and net reclassification index (NRI). Results: On multivariate analysis, five independent predictors associated with tumor recurrence were identified, including sex, γ-glutamyl transferase, macrovascular invasion, hilar lymphoid metastasis and adjuvant transcatheter arterial chemoembolization. The prediction score was constructed using these 5 variables, with scores ranging from 0 to 5. A patient with a score of 0 had a predicted 1- and 5-year recurrence risk of 11.1% and 22.2%, respectively. In the validation cohort, the NRIs of prediction score vs American Joint Committee on Cancer 7^th TNM staging system at 1-year and 5-year were 0.185 (95% CI, 0.090-0.279, P<0.001) and 0.425 (95% CI, 0.044-0.806, P=0.03), respectively. Conclusion: Our developed and validated prediction score might be a simple and reliable method in postoperative CHC patients and help clinicians identify candidates who may benefit from future adjuvant therapies.

Hepatocellular carcinoma (HCC) versus non-HCC: accuracy and reliability of Liver Imaging Reporting and Data System v2018

PURPOSE

The Liver Imaging Reporting and Data System (LI-RADS) was created to standardize the diagnostic criteria for hepatocellular carcinoma (HCC) and has undergone multiple revisions including a recent update in 2018 (v2018). The primary aim of this study was to determine the diagnostic performance and interrater reliability (IRR) of LI-RADS v2018 for distinguishing HCC from non-HCC primary hepatic malignancy in patients 'at-risk' for HCC. A secondary aim was to assess the impact of changes introduced in the v2018 diagnostic algorithm.

METHODS

This retrospective study combined a 10-year experience of pathologically proven primary liver malignancies from two large liver transplant centers. Two blinded readers independently evaluated each lesion and assigned a LI-RADS diagnostic category, additionally scoring all relevant imaging features. Changes in category based on the reader-provided features and the new v2018 criteria were assessed by a study coordinator.

RESULTS

The final study cohort comprised 105 HCCs and 73 non-HCC primarily liver malignancies. LI-RADS had a high specificity for distinguishing HCC from non-HCC (89% and 90% for reader 1 and reader 2, respectively), and IRR was moderate to substantial for final LI-RADS category and most features. Revision of the LI-RADS v2018 diagnostic algorithm resulted in very few changes [5 (2.8%) and 3 (1.7%) for reader 1 and reader 2, respectively] in overall lesion classification.

CONCLUSION

LI-RADS diagnostic categories and features had moderate to substantial IRR and high specificity for distinguishing HCC from non-HCC primary liver malignancy. Revision of LI-RADS v2018 diagnostic algorithm resulted in reclassification of very few lesions.

Primary liver carcinoma with sarcomatous changes: Analysis of 10 cases

Primary liver carcinoma with sarcomatous change is a rare malignancy associated with high aggressiveness and poor prognosis. However, the characteristics of these types of tumors are still unknown. The aim of this study was to assess the imaging features, prognostic significance, and clinicopathological characteristics of patients with these tumors. Of 1070 patients who underwent surgical resection of primary liver carcinoma at Toranomon Hospital (Tokyo, Japan) from 2003 to 2017, 10 patients were diagnosed with primary liver carcinoma containing sarcomatous component. This study included all 10 patients. We evaluated the percentage of the sarcomatous component in each tumor. Patients were classified into two groups: the low percentage group (area of sarcomatous changes ≤30%) and high percentage group (area sarcomatous component ≥70%). We also divided patients into two groups based on the combination of the percentage of sarcomatous tissue and tumor size (≥40 mm or <40 mm). The overall survival rate of patients with ≥70% sarcomatous component and ≥40 mm tumor was significantly worse than that of patients with ≤30% sarcomatous tissue or <40 mm tumor size (P = 0.0059). The results confirmed the poor prognosis of patients with sarcomatous changes in primary liver carcinoma, especially those with large sarcomatous component and large tumor size. Radical resection in the early stage is recommended to improve prognosis.

Block of NF-kB signaling accelerates MYC-driven hepatocellular carcinogenesis and modifies the tumor phenotype towards combined hepatocellular cholangiocarcinoma

Primary liver cancer ranks among the leading causes of cancer death worldwide. Risk factors are closely linked to inflammation, such as viral hepatitis and alcoholic as well as non-alcoholic steatohepatitis. Among the pathways involved in the pathogenesis of malignant liver tumors, dysregulation of NF-κB signaling plays a prominent role. It provides a link between inflammation and cancer. To examine the role of NF-κB in a MYC-induced model of hepatocellular carcinoma we deleted NEMO (IKKγ) specifically from hepatocytes. NEMO deletion accelerated tumor development and shortened survival, suggesting a tumor-suppressive function of NF-κB signaling. We observed increased proliferation, inflammation and fibrosis, as well as activation of MAPK and STAT signaling. Importantly, deletion of NEMO modified the tumor phenotype from hepatocellular carcinoma to combined hepatocellular cholangiocarcinoma. The intrahepatic cholangiocarcinoma tumor component showed increased expression of progenitor markers such as Sox9 and reduced expression of mature hepatic markers such as CPS1. In both cases tumorigenesis was reversible by turning off MYC expression. To our knowledge this is the first mouse model of combined hepatocellular cholangiocarcinoma and may provide insights into the development of this rare malignant tumor.

Human Liver Regeneration: An Etiology Dependent Process

Regeneration of the liver has been an interesting and well-investigated topic for many decades. This etiology and time-dependent mechanism has proven to be extremely challenging to investigate, certainly in human diseases. A reason for this challenge is found in the numerous interactions of different cell components, of which some are even only temporarily present (e.g., inflammatory cells). To orchestrate regeneration of the epithelial cells, their interaction with the non-epithelial components is of utmost importance. Hepatocytes, cholangiocytes, liver progenitor cells, and peribiliary glands have proven to be compartments of regeneration. The ductular reaction is a common denominator in virtually all liver diseases; however, it is predominantly found in late-stage hepatic and biliary diseases. Ductular reaction is an intriguing example of interplay between epithelial and non-epithelial cells and encompasses bipotential liver progenitor cells which are able to compensate for the loss of the exhausted hepatocytes and cholangiocytes in biliary and hepatocytic liver diseases. In this manuscript, we focus on the etiology-specific damage that is observed in different human diseases and how the liver regulates the regenerative response in an acute and chronic setting. Furthermore, we describe the importance of morphological keynotes in different etiologies and how spatial information is of relevance for every basic and translational research of liver regeneration.

Emergence of the Dedifferentiated Phenotype in Hepatocyte-Derived Tumors in Mice: Roles of Oncogene-Induced Epigenetic Alterations

Hepatocellular carcinoma often reactivates the genes that are transiently expressed in fetal or neonatal livers. However, the mechanism of their activation has not been elucidated. To explore how oncogenic signaling pathways could be involved in the process, we examined the expression of fetal/neonatal genes in liver tumors induced by the introduction of myristoylated v-akt murine thymoma viral oncogene (AKT), HRas proto-oncogene, guanosine triphosphatase (HRASV12), and MYC proto-oncogene, bHLH transcription factor (Myc), in various combinations, into mouse hepatocytes in vivo. Distinct sets of fetal/neonatal genes were activated in HRAS- and HRAS/Myc-induced tumors: aldo-keto reductase family 1, member C18 (Akr1c18), glypican 3 (Gpc3), carboxypeptidase E (Cpe), adenosine triphosphate-binding cassette, subfamily D, member 2 (Abcd2), and trefoil factor 3 (Tff3) in the former; insulin-like growth factor 2 messenger RNA binding protein 3 (Igf2bp3), alpha fetoprotein (Afp), Igf2, and H19, imprinted maternally expressed transcript (H19) in the latter. Interestingly, HRAS/Myc-induced tumors comprised small cells with a high nuclear/cytoplasmic ratio and messenger RNA (mRNA) expression of delta-like noncanonical Notch ligand 1 (Dlk1), Nanog homeobox (Nanog), and sex determining region Y-box 2 (Sox2). Both HRAS- and HRAS/Myc-induced tumors showed decreased DNA methylation levels of Line1 and Igf2 differentially methylated region 1 and increased nuclear accumulation of 5-hydroxymethylcytosine, suggesting a state of global DNA hypomethylation. HRAS/Myc-induced tumors were characterized by an increase in the mRNA expression of enzymes involved in DNA methylation (DNA methyltransferase [Dnmt1, Dnmt3]) and demethylation (ten-eleven-translocation methylcytosine dioxygenase 1 [Tet1]), sharing similarities with the fetal liver. Although mouse hepatocytes could be transformed by the introduction of HRAS/Myc in vitro, they did not express fetal/neonatal genes and sustained global DNA methylation, suggesting that the epigenetic alterations were influenced by the in vivo microenvironment. Immunohistochemical analyses demonstrated that human hepatocellular carcinoma cases with nuclear MYC expression were more frequently positive for AFP, IGF2, and DLK1 compared with MYC-negative tumors. Conclusion: The HRAS signaling pathway and its interactions with the Myc pathway appear to reactivate fetal/neonatal gene expression in hepatocytic tumors partly through epigenetic alterations, which are dependent on the tumor microenvironment.

Anatomical, histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin-producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub-classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho-molecular groups can currently be discriminated. Large-duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2-fusions are typically seen in small-duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.

Gadoxetic Acid-enhanced MRI of Hepatocellular Carcinoma: Value of Washout in Transitional and Hepatobiliary Phases

Background Current Liver Imaging Reporting and Data System guidelines define the washout appearance of gadoxetic acid-enhanced MRI only during the portal venous phase. Defining washout only during the portal venous phase may lead to lower sensitivity for diagnosis of hepatocellular carcinoma (HCC). Purpose To compare the diagnostic performances of three gadoxetic acid-enhanced MRI criteria for HCC according to the phases during which washout appearance was determined. Materials and Methods In this retrospective study, patients with a hepatic nodule detected at US surveillance for HCC from January to December 2012 underwent gadoxetic acid-enhanced MRI. Three diagnostic MRI criteria for HCC were defined according to the phases during which washout appearance was observed, with the presence of arterial phase hyperenhancement and hypointensity noted (a) only during the portal venous phase, with washout confined to the portal venous phase; (b) during the portal venous phase or transitional phase, with washout extended to the transitional phase; or (c) during the portal venous, transitional, or hepatobiliary phase, with washout extended to the hepatobiliary phase. If a nodule showed marked T2 hyperintensity or a targetoid appearance, it was precluded from the diagnosis of HCC. The sensitivity and specificity were compared by using a generalized estimating equation. Results A total of 178 patients were included (mean age ± standard deviation, 55.3 years ± 9.1) with 203 surgically confirmed hepatic nodules (186 HCCs and 17 non-HCCs) measuring 3.0 cm or smaller. The sensitivity with washout extended to the hepatobiliary phase (95.2% [177 of 186]) was better than that with washout extended to the transitional phase (90.9% [169 of 186]; P = .01) and washout confined to the portal venous phase (75.3% [140 of 186]; P < .01). The specificity with extensions of washout to the transitional phase and hepatobiliary phase (82% [14 of 17] for both) was similar to that obtained with washout confined to the portal venous phase (94.1% [16 of 17]) (P = .47). Conclusion After exclusion of typical hemangiomas and nodules with a targetoid appearance, extending washout appearance to the transitional or hepatobiliary phase (instead of restricting it to the portal venous phase) allowed higher sensitivity without a reduction in specificity. © RSNA, 2019 See also the editorial by Fowler and Sirlin in this issue.

Update on hepatocellular carcinoma: Pathologists’ review

Histopathologic diversity and several distinct histologic subtypes of hepatocellular carcinoma (HCC) are well-recognized. Recent advances in molecular pathology and growing knowledge about the biology associated with distinct histologic features and immuno-profile in HCC allowed pathologists to update classifications. Improving sub-classification will allow for more clinically relevant diagnoses and may allow for stratification into biologically meaningful subgroups. Therefore, immuno-histochemical and molecular testing are not only diagnostically useful, but also are being incorporated as crucial components in predicting prognosis of the patients with HCC. Possibilities of targeted therapy are being explored in HCC, and it will be important for pathologists to provide any data that may be valuable from a theranostic perspective. Herein, we review and provide updates regarding the pathologic sub-classification of HCC. Pathologic diagnostic approach and the role of biomarkers as prognosticators are reviewed. Further, the histopathology of four particular subtypes of HCC: Steatohepatitic, clear cell, fibrolamellar and scirrhous - and their clinical relevance, and the recent consensus on combined HCC-cholangiocarcinoma is summarized. Finally, emerging novel biomarkers and new approaches to HCC stratification are reviewed.

Genomic profiling of combined hepatocellular-cholangiocarcinoma reveals similar genetics to hepatocellular carcinoma

Combined hepatocellular-cholangiocarcinomas (CHC) are mixed tumours with both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) components. CHC prognosis is similar to intrahepatic CC (ICC) and worse than HCC; staging and treatment generally follow ICC algorithms. However, the molecular biology of CHC remains poorly characterised. We performed capture-based next-generation sequencing of 20 CHC and, for comparison, 10 ICC arising in cirrhosis. Intratumour heterogeneity was assessed by separately sequencing the HCC and CC components of nine CHC. CHC demonstrated molecular profiles similar to HCC, even in the CC component. CHC harboured recurrent alterations in TERT (80%), TP53 (80%), cell cycle genes (40%; CCND1, CCNE1, CDKN2A), receptor tyrosine kinase/Ras/PI3-kinase pathway genes (55%; MET, ERBB2, KRAS, PTEN), chromatin regulators (20%; ARID1A, ARID2) and Wnt pathway genes (20%; CTNNB1, AXIN, APC). No CHC had alterations in IDH1, IDH2, FGFR2 or BAP1, genes typically mutated in ICC. TERT promoter mutations were consistently identified in both HCC and CC components, supporting TERT alteration as an early event in CHC evolution. TP53 mutations were present in both components in slightly over half the TP53-altered cases. By contrast, focal amplifications of CCND1, MET and ERRB2, as well as Wnt pathway alterations, were most often exclusive to one component, suggesting that these are late events in CHC evolution. ICC in cirrhosis demonstrated alterations similar to ICC in non-cirrhotic liver, including in IDH1 or IDH2 (30%), CDKN2A (40%), FGFR2 (20%), PBRM1 (20%), ARID1A (10%) and BAP1 (10%). TERT promoter and TP53 mutation were present in only one ICC each. Our data demonstrate that CHC genetics are distinct from ICC (even in cirrhosis) and similar to HCC, which has diagnostic utility and implications for treatment. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

YAP and TAZ Heterogeneity in Primary Liver Cancer: An Analysis of Its Prognostic and Diagnostic Role

Primary liver cancer comprises a diverse group of liver tumors. The heterogeneity of these tumors is seen as one of the obstacles to finding an effective therapy. The Hippo pathway, with its downstream transcriptional co-activator Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), has a decisive role in the carcinogenesis of primary liver cancer. Therefore, we examined the expression pattern of YAP and TAZ in 141 patients with hepatocellular carcinoma keratin 19 positive (HCC K19⁺), hepatocellular carcinoma keratin 19 negative (HCC K19⁻), combined hepatocellular–cholangiocarcinoma carcinoma (cHCC-CCA), or cholangiocarcinoma (CCA). All cHCC-CCA and CCA patients showed high expression levels for YAP and TAZ, while only some patients of the HCC group were positive. Notably, we found that a histoscore of both markers is useful in the challenging diagnosis of cHCC-CCA. In addition, positivity for YAP and TAZ was observed in the hepatocellular and cholangiocellular components of cHCC-CCA, which suggests a single cell origin in cHCC-CCA. Within the K19⁻ HCC group, our results demonstrate that the expression of YAP is a statistically significant predictor of poor prognosis when observed in the cytoplasm. Nuclear expression of TAZ is an even more specific and independent predictor of poor disease-free survival and overall survival of K19⁻ HCC patients. Our results thus identify different levels of YAP/TAZ expression in various liver cancers that can be used for diagnostics.

Gross and microscopic changes of liver neoplasms and background hepatic structures following neoadjuvant therapy

Liver transplantation is a surgical option with curative intent used in the management of some cases of hepatocellular carcinoma and cholangiocarcinoma (hilar, rarely intrahepatic). A number of different therapeutic modalities including ablative techniques, arterially directed therapies, radiation and chemotherapy are used in the neoadjuvant setting prior to liver transplantation with the goals of preventing tumour progression, decreasing post-transplant recurrence and possibly downstaging patients with tumour burden beyond what is acceptable by current transplant criteria. Pathologists evaluating hepatic explants must be aware of these neoadjuvant therapies and the alterations induced by them in both tumourous and non-tumourous tissue. In this review, we discuss common neoadjuvant therapies used in in this setting, as well as the gross and microscopic changes induced by these presurgical treatments within hepatic neoplasms as well as the background hepatic parenchyma and nearby structures. Select secondary tumours involving the liver which are pretreated will also be discussed. Finally, proper reporting of these changes will be mentioned.

Gadoxetic acid-enhanced magnetic resonance imaging: Hepatocellular carcinoma and mimickers

Gadoxetic acid, a hepatocyte-specific magnetic resonance imaging (MRI) contrast agent, has emerged as an important tool for hepatocellular carcinoma (HCC) diagnosis. Gadoxetic acid-enhanced MRI is useful for the evaluation of early-stage HCC, diagnosis of HCC precursor lesions, and highly sensitive diagnosis of HCC. Furthermore, functional information provided by gadoxetic acid-enhanced MRI can aid in the characterization of focal liver lesions. For example, whereas lesions lack functioning hepatocytes appear hypointense in the hepatobiliary phase, preserved or enhanced expression of organic anion transporting polypeptides in some HCCs as well as focal nodular hyperplasia lead to hyperintensity in the hepatobiliary phase; and a targetoid appearance on transitional phase or hepatobiliary phase imaging can be helpful for identifying the histopathological composition of tumors. While gadoxetic acid-enhanced MRI may improve the sensitivity of HCC diagnosis and provide new insights into the characterization of focal liver lesions, there are many challenges associated with its use. This article reviews the pros and cons of HCC diagnosis with gadoxetic acid-enhanced MRI and discuss some clues in the radiological differentiation of HCC from HCC mimickers.

Genomic Medicine and Implications for Hepatocellular Carcinoma Prevention and Therapy

The pathogenesis of hepatocellular carcinoma (HCC) is poorly understood, but recent advances in genomics have increased our understanding of the mechanisms by which hepatitis B virus, hepatitis C virus, alcohol, fatty liver disease, and other environmental factors, such as aflatoxin, cause liver cancer. Genetic analyses of liver tissues from patients have provided important information about tumor initiation and progression. Findings from these studies can potentially be used to individualize the management of HCC. In addition to sorafenib, other multi-kinase inhibitors have been approved recently for treatment of HCC, and the preliminary success of immunotherapy has raised hopes. Continued progress in genomic medicine could improve classification of HCCs based on their molecular features and lead to new treatments for patients with liver cancer.

Combined hepatocellular cholangiocarcinoma (cHCC-CC): an update of genetics, molecular biology, and therapeutic interventions

Combined hepatocellular cholangiocarcinoma (CC) is a rare and aggressive primary hepatic malignancy with significant histological and biological heterogeneity. It presents with more aggressive behavior and worse survival outcomes than either hepatocellular carcinoma or CC and remains a diagnostic challenge. An accurate diagnosis is crucial for its optimal management. Major hepatectomy with hilar node resection remains the mainstay of treatment in operable cases. Advances in the genetic and molecular characterization of this tumor will contribute to the better understanding of its pathogenesis and shape its future management.

How to utilize LR-M features of the LI-RADS to improve the diagnosis of combined hepatocellular-cholangiocarcinoma on gadoxetate-enhanced MRI?

OBJECTIVES

To investigate the diagnostic accuracy of each LR-M feature defined in version 2017 of the Liver Imaging Reporting and Data System (LI-RADS) and determine the optimal LR-M feature for differentiating combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and hepatocellular carcinoma (HCC) on gadoxetate-enhanced magnetic resonance imaging (MRI).

METHODS

Ninety-nine patients with pathologically proven cHCC-CCA (n = 33) or HCC (n = 66) after surgery were identified. Two radiologists retrospectively assessed preoperative gadoxetate-enhanced MRI for features favoring non-HCC malignancies (LR-M features) according to LI-RADS version 2017. Multivariate logistic regression analysis was performed to determine the independent differential features. The sensitivity and specificity for diagnosing cHCC-CCA were calculated for each LR-M feature.

RESULTS

Targetoid appearance showed the highest sensitivity (75.8%, 95% confidence interval [CI] 60.6%, 87.3%) to correctly identify cHCC-CCA as LR-M. At least one LR-M feature was observed in 31 (93.9%) patients with cHCC-CCA and 34 (51.5%) patients with HCC. The sensitivity and specificity for diagnosing cHCC-CCA using the presence of any one of the LR-M features were 93.9% (95% CI 80.7, 98.9) and 48.5% (95% CI 41.9, 51.0), respectively. The presence of three LR-M features yielded the highest diagnostic accuracy of 80.8% (95% CI 72.1, 86.1) with a reduced sensitivity of 54.5% (95% CI 41.4, 62.5).

CONCLUSION

The majority of cHCC-CCA cases can be properly categorized as LR-M when any one of the LR-M features defined in the LI-RADS version 2017 is used as a determiner. However, approximately half of HCC cases also show at least one LR-M feature.

KEY POINTS

• Targetoid appearance, including rim APHE, peripheral "washout" appearance, and delayed central enhancement, was the LR-M feature that identified cHCC-CCA as a non-HCC malignancy with the highest sensitivity. • Most cHCC-CCA cases can be properly categorized as LR-M when the presence of any one of the LR-M features was used as the determiner. • Approximately half of HCC cases also showed at least one LR-M feature.

Management of combined hepatocellular carcinoma-cholangiocarcinoma

PURPOSE OF REVIEW

To review the recent consensus on the nomenclature, clinical features, diagnosis, and treatment of combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA).

RECENT FINDING

cHCC-CCA is a primary liver carcinoma with varying degrees of hepatocytic and cholangiocytic cytology and architecture within the same tumor. The diagnosis of cHCC-CCA can only be established based on histologic examination. Surgical resection should be considered in patients with resectable tumors who do not have underlying liver disease or clinically significant portal hypertension. While treatment by liver transplantation (LT) is controversial due to the high risk of post LT recurrence, LT should remain as a potentially curative option in a highly selected group of patients. Little data exist for the outcome of other treatments.

SUMMARY

High quality multicenter prospective studies should be conducted to better understand this rare, but increasingly recognized tumor.

Epidermal growth factor-like domain multiple 7 (EGFL7): Expression and possible effect on biliary epithelium growth in cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive biliary tract malignancy with limited treatment options and low survival rates. The intrahepatic subtype comprises two forms: mucin-iCCA and mixed-iCCA. Epidermal growth factor-like domain multiple (EGFL7) is overexpressed in less differentiated liver tumors. The aim of this study was to assess the presence of EGFL7 due to its possible role in the growth of CCA. Hematoxylin & Eosin and periodic acid- Schiff staining were used to evaluate the morphological aspects and glycogen deposition. Immunohistochemistry and immunofluorescence were performed to identify the presence of EGFL7 both in tumor sections ex vivo and in appropriate cell lines in culture. We found that EGFL7 is expressed in malignant cholangiocytes of mixed-iCCA and absent in mucin-iCCA. In conclusion the expression of EGFL7 might be useful in the classification of CCA subtypes.

LI-RADS Classification and Prognosis of Primary Liver Cancers at Gadoxetic Acid-enhanced MRI

Purpose To (a) evaluate the postsurgical prognostic implication of the Liver Imaging Reporting and Data System (LI-RADS) categories of primary liver cancers and (b) determine the performance of LI-RADS version 2017 in differentiating hepatocellular carcinoma (HCC) from intrahepatic cholangiocarcinoma (IHCC) and combined hepatocellular-cholangiocarcinoma (cHCC-CC) at gadoxetic acid-enhanced MRI. Materials and Methods In this retrospective study, 194 patients with cirrhosis and surgically proven single primary liver cancer (53 with cHCC-CC, 44 with IHCC, and 97 with HCC) were evaluated with gadoxetic acid-enhanced MRI between 2009 and 2014. The mean patient age was 57 years (age range, 30-83 years). There were 155 men with a mean age of 56 years (range, 30-81 years) and 39 women with a mean age of 58 years (range, 38-83 years). Two independent readers assigned an LI-RADS category for each nodule. Overall survival (OS), recurrence-free survival (RFS), and their associated factors were evaluated by using the Kaplan-Meier method, log-rank test, and Cox proportional hazard model. Results In the multivariable analysis, the LI-RADS category was an independent factor for OS (hazard ratio, 4.2; P < .001) and RFS (hazard ratio, 2.6; P = .01). The LR-M category showed more correlation with poorer OS and RFS than did the LR-4 or LR-5 category for all primary liver cancers (P < .001 for both), HCCs (P = .01 and P < .001, respectively), and cHCC-CCs (P = .01 and P = .03, respectively). The LR-5 category had a sensitivity of 69% (67 of 97) and a specificity of 87% (84 of 97) in the diagnosis of HCC; most false-positive diagnoses (85%, 11 of 13) were the result of misclassification of cHCC-CCs. Conclusion The Liver Imaging Reporting and Data System (LI-RADS) category was associated with postsurgical prognosis of primary liver cancers, independent of pathologic diagnosis. The LI-RADS enabled the correct classification of most hepatocellular carcinomas (HCCs) and intrahepatic cholangiocarcinomas, whereas differentiation of combined hepatocellular-cholangiocarcinoma from HCC was unreliable. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Bashir and Chernyak in this issue.

Hepatocellular carcinoma: a review of diagnostic challenges for the pathologist

Histopathologists retain a critical role in the diagnosis and management of hepatocellular carcinoma (HCC). HCC arises usually but not exclusively in a background of advanced-stage chronic liver disease. The histological diagnosis of HCC poses many challenges particularly when dealing with liver biopsy specimens due to the heterogeneity of HCC and the difficulty to confirm hepatocellular differentiation in some instances. Primary liver tumors should be considered as a continuum with typical hepatocellular and cholangiocarcinoma at the two ends and a whole range of tumors showing both hepatocellular and cholangiocellular differentiation with or without an associated progenitor/stem cell component in the middle. Characterization of combined (or mixed) hepatocellular-cholangiocarcinoma can be very challenging. In advanced-stage chronic liver disease, the main challenge for the histopathologist is still to differentiate between HCC and its precursors, although this is rarely critical in the clinical setting at present. HCC originating in non-cirrhotic livers needs to be differentiated from other primary and extrahepatic tumors and from hepatocellular adenoma, bearing in mind that progression to malignancy is more through a continuum that watertight histological categories.

Update on the pathology of liver neoplasms

Many advances have developed in the pathology of liver tumors in the recent decade. Examples of these advances include the use of glutamine synthetase in the diagnosis of focal nodular hyperplasia, subtyping of hepatocellular adenomas using molecular and immunohistochemical methods, the unraveling of the fusion transcript between the DNAJB1 gene and the PRKACA gene in fibrolamellar carcinoma, and the more unified classification and terminology in intrahepatic bile duct tumors and their precursor lesions. Nevertheless, challenges still remain, e.g., the differential diagnosis between well-differentiated hepatocellular carcinoma and hepatocellular adenoma; distinction among poorly differentiated hepatocellular carcinoma, cholangiocarcinoma and metastatic neoplasm; terminology of the combined hepatocellular carcinoma-cholangiocarcinoma, etc. This review aims to address updates in the pathologic diagnosis and clinical relevance of tumors of the liver and intrahepatic bile ducts in adults and their differential diagnosis and diagnostic pitfalls.

[Indications for transplantation and bridging procedures for primary hepatobiliary malignancies]

Primary hepatobiliary malignancies are hepatocellular carcinoma, cholangiocarcinoma and the rare hepatocellular cholangiocarcinoma (mixed tumor). The indications for liver transplantation and the oncological prognosis differ considerably between these tumor entities. Treatment and decision making for these tumors are often complicated by an underlying chronic liver disease. The aim of this review is to delineate the indications for transplantation and bridging therapies for each cancer entity as well as to highlight some aspects pertinent to transplantation, such as the principles of organ allocation.

Changing role of histopathology in the diagnosis and management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and fatal cancer in the world. HCC frequently presents with advanced disease, has a high recurrence rate and limited treatment options, which leads to very poor prognosis. This warrants urgent improvement in the diagnosis and treatment. Liver biopsy plays very important role in the diagnosis and prognosis of HCC, but with technical advancements and progression in the field of imaging, clinical guidelines have restricted the role of biopsy to very limited situations. Biopsy also has its own problems of needle tract seeding of tumor, small risk of complications, technical and sampling errors along with interpretative errors. Despite this, tissue analysis is often required because imaging is not always specific, limited expertise and lack of advanced imaging in many centers and limitations of imaging in the diagnosis of small, mixed and other variant forms of HCC. In addition, biopsy confirmation is often required for clinical trials of new drugs and targeted therapies. Tissue biomarkers along with certain morphological features, phenotypes and immune-phenotypes that serve as important prognostic and outcome predictors and as decisive factors for therapy decisions, add to the continuing role of histopathology. Advancements in cancer biology and development of molecular classification of HCC with clinic pathological correlation, lead to discovery of HCC phenotypic surrogates of prognostic and therapeutically significant molecular signatures. Thus tissue characteristics and morphology based correlates of molecular subtypes provide invaluable information for management and prognosis. This review thus focuses on the importance of histopathology and resurgence of role of biopsy in the diagnosis, management and prognostication of HCC.

Cholangiocarcinoma

This article focuses on cholangiocarcinoma, both intrahepatic and extrahepatic. The various classification schemes based on anatomic location, macroscopic growth pattern, microscopic features, and cell of origin are outlined. The clinicopathologic, immunohistochemical and molecular differences between intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma, as well as differences in the 2 subtypes of intrahepatic cholangiocarcinoma, are discussed. Finally, precursor lesions, prognosis, treatment, and promising new potential targeted therapies are reviewed.