Clinicopathological significance of 'subtypes with stem-cell feature' in combined hepatocellular-cholangiocarcinoma

Genetic re-classification of combined hepatocellular-cholangiocarcinoma and small duct type intrahepatic cholangiocarcinoma

BACKGROUND

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) shares various features with small duct type intrahepatic cholangiocarcinoma (SmD-iCCA) and sometimes histological diagnosis may be difficult.

METHODS

We examined genetic alterations such as hTERT promoter (hTERT), p53, and fibroblast growth factor receptor 2 (FGFR2) in 103 PLCs diagnosed as cHCC-CCA or SmD-iCCA. A cluster analysis was performed on the R software for re-classification of PLCs including cHCC-CCA and SmD-iCCA.

RESULTS

The primary liver carcinomas (PLCs) were divided into 5 clusters; 19 tumors (18 %) in Cluster-1 (with alterations in hTERT and/or p53), 24 (23 %) in Cluster-2 (FGFR2 and/or p53), 13 (13 %) in Cluster-3 (IDH2 or null), 19 (18 %) in Cluster-4 (MTAP and/or FGFR2), 28 (27 %) in Cluster-5 (ARID1A and/or PBRM1), being based on genetic alterations. Cluster-1 and Clusters-2 to- 5 formed distinct 2 groups. Cluster-1 was characterized by significantly bigger size, rich and higher histological grade of HCC component, significantly less cholangiolocellular carcinoma (CLC)-component, ductal plate malformation pattern and bile duct adenoma in the background livers. No SmD-iCCA was included in Cluster-1, whereas SmD-iCCA distributed evenly in Clusters 2-5. Cluster-4 was characterized by higher prevalence of hepatitis B and higher histological diversity scores.

CONCLUSION

PLCs diagnosed as cHCC-CCA or SmD-iCCAs could be divided into 5 clusters based on genetic alterations. Cluster-1 was HCC-like cluster characterized by hTERT alteration, rich and higher grade of HCC and bigger size. Clusters-2-5 may be iCCA-like clusters characterized by different genetic alterations. cHCC-CCA in Cluster-1 and Clusters-2-5 may be handled separately for further analysis and treatment.

Liver transplantation for combined hepatocellular cholangiocarcinoma: Current evidence, selection criteria, and therapeutic controversies

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a rare and aggressive primary liver malignancy characterized by features of both HCC and CCA. Preoperative diagnosis remains challenging because of overlapping imaging and histopathological features, which often lead to misclassification. Although liver resection is the primary curative therapy, the efficacy of liver transplantation (LT) remains controversial. Historically, LT has been considered contraindicated owing to the poor prognosis, high recurrence rate of cHCC-CCA, and the potential for organ wastage. Recent studies have suggested that LT may benefit carefully selected patients, particularly those with early-stage tumors or cirrhosis. However, there is no consensus on the criteria for LT in patients with cHCC-CCA. Lymphadenectomy and vascular resection strategies were discussed along with locoregional and systemic therapies. This review synthesized the current evidence on surgical strategies for cHCC-CCA, focusing on evolving LT criteria and outcomes.

Other Primary Epithelial Neoplasms of the Liver

Primary liver carcinoma (PLC) is the sixth most common malignancy worldwide and the third leading cause of cancer-related mortalities. Hepatocellular carcinoma (HCC) is the most prevalent form of PLC, followed by intrahepatic cholangiocarcinoma (iCCA). In addition, there is a group of rarer PLCs that do not fit neatly into the HCC or iCCA categories. This review explores this heterogeneous group, including combined hepatocellular-cholangiocarcinoma (cHCC-CCA), intermediate cell carcinoma (ICC), mixed hepatocellular-neuroendocrine carcinoma, and undifferentiated primary liver carcinoma. cHCC-CCA is a rare subtype of PLC, characterized by both hepatocytic and cholangiocytic differentiation within the same tumor. The latest WHO classification (2019, fifth edition) redefined cHCC-CCA by eliminating the "stem cell subtypes" and emphasized that diagnosis should primarily rely on morphologic features, supported by immunohistochemical staining to better define subtypes. Intermediate cell carcinoma is a subtype of cHCC-CCA and is comprised of monomorphic tumor cells that exhibit characteristics intermediate between hepatocytes and cholangiocytes, with immunohistochemical expression of hepatocytic and cholangiocytic markers within the same cell. Another rare entity, combined HCC and neuroendocrine carcinoma (NEC), contains an admixture of HCC and NEC components within the same tumor. Undifferentiated primary liver carcinoma, on the other hand, lacks definitive lineage differentiation beyond an epithelial phenotype. These heterogeneous PLCs pose diagnostic challenges owing to their mixed/unusual histologic features and overlapping immunohistochemical markers. They tend to have poor prognoses, highlighting the critical importance of accurate and timely diagnosis.

Prognostic Impact of the Cholangiolar Component in Combined Hepatocellular-Cholangiocarcinoma: Insights From a Western Single-Center Study

INTRODUCTION

Primary liver malignancies, such as hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), and combined hepatocellular-cholangiocarcinoma (cHCC-CCA), represent significant contributors to global cancer-related mortality. The diagnostic challenges associated with distinguishing cHCC-CCA from HCC and ICC stem from their rarity and overlapping histological features.

OBJECTIVES

This study aimed to reclassify primary liver tumors resected at a Western center and to compare clinicopathological features and prognosis among patients with HCC, ICC, and cHCC-CCA.

METHODS

A retrospective analysis was conducted on patients undergoing resection for HCC, ICC, or cHCC-CCA between 2007 and 2017. Clinical and perioperative data were collected, and pathological specimens were reclassified by a specialized pathologist. Statistical analysis was employed to compare clinical features and survival outcomes among the different tumor types.

RESULTS

Out of the initially identified 192 patients, 140 were included in the analysis. Following reclassification, 71.42% were diagnosed with HCC, 12.14% with ICC, and 16.42% with cHCC-CCA. Patients with HCC were predominantly male and exhibited a higher incidence of isolated liver recurrence. ICC patients more frequently underwent open procedures. Additionally, patients with HCC and cHCC-CCA showed higher rates of cirrhosis, elevated alpha-fetoprotein levels, and extrahepatic recurrence, while those with ICC and cHCC-CCA demonstrated elevated CA 19-9 levels. Overall survival and disease-free survival were longer for HCC compared to cases with a cholangiolar component (ICC and cHCC-CCA).

CONCLUSIONS

Histological evaluation should actively incorporate the search for a cholangiolar component in primary liver tumors to prevent misdiagnosis, as its presence indicates a poorer prognosis.

Combined hepatocellular cholangiocarcinoma: A clinicopathological update

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer associated with an appalling prognosis. The diagnosis and management of this entity have been challenging to physicians, radiologists, surgeons, pathologists, and oncologists alike. The diagnostic and prognostic value of biomarkers such as the immunohistochemical expression of nestin, a progenitor cell marker, have been explored recently. With a better understanding of biology and the clinical course of cHCC-CCA, newer treatment modalities like immune checkpoint inhibitors are being tried to improve the survival of patients with this rare disease. In this review, we give an account of the recent developments in the pathology, diagnostic approach, and management of cHCC-CCA.

Combined Hepatocellular-Cholangiocarcinoma: Biology, Diagnosis, and Management

BACKGROUND

Combined hepatocellular-cholangiocarcinoma (cHCC-iCCA) is a rare type of primary liver cancer displaying characteristics of both hepatocytic and cholangiocytic differentiation.

SUMMARY

Because of its aggressive nature, patients with cHCC-iCCA exhibit a poorer prognosis than those with HCC. Surgical resection and liver transplantation may be considered curative treatment approaches; however, only a minority of patients are eligible at the time of diagnosis, and postoperative recurrence rates are high. For cases that are not eligible for surgery, locoregional and systemic therapy are often administered based on treatment protocols applied for HCC or iCCA. Owing to the rarity of this cancer, there are still no established standard treatment protocols; therefore, the choice of therapy is often personalized and guided by the suspected predominant component. Further, the genomic and molecular heterogeneity of cHCC-iCCA can severely compromise the efficacy of the available therapies.

KEY MESSAGES

In the present review, we summarize the latest advances in cHCC-iCCA and attempt to clarify its terminology and molecular biology. We provide an overview of the etiology of cHCC-iCCA and present new insights into the molecular pathology of this disease that could contribute to further studies aiming to improve the patient outcomes through new systemic therapies.

Nestin may be a candidate marker for differential diagnosis between small duct type and large duct type intrahepatic cholangiocarcinomas

BACKGROUNDS/AIMS

Intrahepatic cholangiocarcinoma (iCCA) is subclassified into small and large duct types. These two subtypes show distinct differences in various clinicopathological features and possible cell origin and pathways of carcinogenesis, however, a differential diagnosis may be sometimes difficult. Given the type IV intermediate filament, Nestin, may be a candidate diagnostic marker for combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and small duct type iCCAs, the significance of nestin as a differential diagnostic marker between small and large duct types of iCCAs was addressed in the present study.

METHODS

Nestin expression was immunohistochemically assessed in the sections from 36 patients with small duct-type iCCA, 30 with large duct-type iCCA, and 27 with extrahepatic cholangiocarcinoma (CCA). Nestin expression and its relationship with clinicopathological features and genetic alterations were investigated in small duct type iCCAs.

RESULTS

Nestin expression was detected in 17 small duct type iCCAs (47.2%), one large duct type iCCA (3.8%) and zero extrahepatic CCA. Nestin expression was significantly more frequent in the patients with small duct type iCCAs than in those with large duct type iCCA and extrahepatic CCA (p < 0.01). In 10 liver biopsies, all samples with nestin expression were small duct type iCCAs. Nestin-positive small duct type iCCAs were characterized by a higher histological grade, compared to Nestin-negative small duct type iCCAs (p < 0.01). Nestin-positive small duct type iCCAs tended to have 2 or more genetic alterations, but there was no statistic difference (p > 0.05).

CONCLUSION

Different nestin expression may reflect differences between small duct type iCCA and large duct type/extrahepatic CCA and may be a useful diagnostic marker for small duct type iCCAs.

Coexistence of primary clear cell subtype of hepatocellular carcinoma, cholangiocarcinoma, and ordinary type hepatocellular carcinoma: A case report

INTRODUCTION AND IMPORTANCE

Primary Clear Cell subtype of Hepatocellular Carcinoma (PCHCC) is a rare kind of Hepatocellular Carcinoma (HCC). The coexistence of PCHCC, Intrahepatic Cholangiocarcinoma (ICC), and ordinary-type HCC(OHCC) in different parts of the liver is seldom reported in the literature.

CASE PRESENTATION

A 66 years old man with three masses in his liver was admitted. Positron emission tomography-computed tomography suggested that 2 of the lesions were low-density and likely malignant, while the 3rd lesion was considered benign. Magnetic Resonance Imaging indicated all were malignant tumors. Minor hepatectomies were underwent respectively, and the pathology indicated the 3 tumors were PCHCC, ICC, and OHCC. Twelve months post operation, the patient was readmitted because of the recurrence of a 10.2 × 9.2 × 8.9 cm hepatic tumor. Transarterial chemoembolization and three courses of systemic chemotherapy were carried out, but the effectiveness was limited. The patient passed away 20 months after surgery.

CLINICAL DISCUSSION

Surgical resection is the primary treatment of CHCC and minor hepatectomy should be considered especially when complicated with cirrhosis. Considering the poor prognosis and the high recurrence rate, sequential treatments like hepatectomy, targeted therapy, and TACE are recommended.

CONCLUSION

PCHCC, ICC, and OHCC coexisted in a different part of one liver is particularly rare, comprehensive treatment with minor hepatectomy should be recommended, but the prognosis is poor.

Biphenotypic Immunohistochemical Features and NTRK1 Amplification in Intermediate Cell Carcinoma of the Liver

Intermediate cell carcinoma is one of the rarest forms of primary liver cancer comprising relatively monomorphic populations of neoplastic epithelial cells demonstrating simultaneous positivity of both hepatocyte and cholangiocyte immunohistochemical markers. Here in, we describe an adult male patient who underwent left hepatectomy for a large liver tumor. The pathological and immunohistochemical analysis revealed the malignant primary liver cancer with intermediate cell morphology and mixed immunophenotypic features consistent with intermediate cell carcinoma. Furthermore, the genomic profiling using the Next-generation sequencing (NGS) platform demonstrated that there is a novel amplification with copy number gain 12 (12 gene copies) in the Neurotrophic Receptor Tyrosine Kinase 1 (NTRK1) gene, being an oncogenic driver of intermediate cell carcinoma. This is the first case report with the amplification in NTRK1 and emphasizes the importance of molecular oncology.

Non-invasive imaging in the diagnosis of combined hepatocellular carcinoma and cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare type of primary liver cancer. It is a complex "biphenotypic" tumor type consisting of bipotential hepatic progenitor cells that can differentiate into cholangiocytes subtype and hepatocytes subtype. The prognosis of patients with cHCC-CC is quite poor with its specific and more aggressive nature. Furthermore, there are no definite demographic or clinical features of cHCC-CC, thus a clear preoperative identification and accurate non-invasive imaging diagnostic analysis of cHCC-CC are of great value. In this review, we first summarized the epidemiological features, pathological findings, molecular biological information and serological indicators of cHCC-CC disease. Then we reviewed the important applications of non-invasive imaging modalities-particularly ultrasound (US)-in cHCC-CC, covering both diagnostic and prognostic assessment of patients with cHCC-CC. Finally, we presented the shortcomings and potential outlooks for imaging studies in cHCC-CC.

Bile duct adenoma and small-sized small duct type intrahepatic cholangiocarcinoma show distinct differences in genetic alterations, expression of IMP3 and EZH2 and stromal and inflammatory components

AIMS

Given that bile duct adenoma was significantly more prevalent in the liver with small duct type intrahepatic cholangiocarcinoma (small duct iCCA), compared to other primary liver carcinomas, we examined the possibility of bile duct adenoma as a precursor of small duct iCCA by analysing genetic alterations and other features in bile duct adenomas.

METHODS AND RESULTS

Subjects included 33 bile duct adenomas and 17 small-sized (up to 2 cm in diameter) small duct iCCAs. Genetic alterations were examined by direct sequencing for hot-spot regions and immunohistochemical staining. The expression of p16^INK4a , EZH2 and IMP3 and stromal and inflammatory components were also examined. Genetic alterations examined including BRAF were not detected in bile duct adenomas, whereas genetic alterations of p53 (47%), ARID1A (41%), PBRM1 (12%), MTAP (12%), IDH1 (6%), KRAS (6%) and TERT promoter (6%) were detected in 16 small-sized small duct iCCA (94%) (P < 0.01). The expression of IMP3 and EZH2 was not detected in bile duct adenomas, whereas it was detected in most small duct iCCA (94%) (P < 0.01). Immature stroma and neutrophilic infiltration were significantly more prevalent in small duct iCCA, compared to bile duct adenoma (P < 0.01).

CONCLUSION

Bile duct adenomas and small-sized small duct iCCAs show distinct differences in genetic alterations, expression of IMP3 and EZH2 and stromal and inflammatory components. There was no evidence suggesting that bile duct adenoma is a precursor of small duct iCCA. Immunohistochemical staining for IMP3, EZH2, p53, ARID1A and MTAP may be useful for differential diagnosis between bile duct adenomas and small duct iCCAs.

Pathology of Combined Hepatocellular Carcinoma-Cholangiocarcinoma: An Update

Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer that is composed of both hepatocellular and cholangiocellular differentiated cells. It is slightly more common in men and among Asian and Pacific islanders. Overall, risk factors are similar to classic risk factors of hepatocellular carcinoma (HCC). The classification has significantly evolved over time. The last WHO classification (2019) mainly emphasized diagnosis on morphological basis with routine stainings, discarded previously recognized classifications with carcinomas with stem cell features, introduced intermediate cell carcinoma as a specific subtype and considered cholangiolocarcinoma as a subtype of cholangiocellular carcinoma. Immunohistochemical markers may be applied for further specification but have limited value for diagnosis. Recent discoveries in molecular pathway regulation may pioneer new therapeutic approaches for this poor prognostic and challenging diagnosis.

The Diagnostic Approach towards Combined Hepatocellular-Cholangiocarcinoma-State of the Art and Future Perspectives

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer which displays clinicopathologic features of both hepatocellular (HCC) and cholangiocellular carcinoma (CCA). The similarity to HCC and CCA makes the diagnostic workup particularly challenging. Alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA 19-9) are blood tumour markers related with HCC and CCA, respectively. They can be used as diagnostic markers in cHCC-CCA as well, albeit with low sensitivity. The imaging features of cHCC-CCA overlap with those of HCC and CCA, dependent on the predominant histopathological component. Using the Liver Imaging and Reporting Data System (LI-RADS), as many as half of cHCC-CCAs may be falsely categorised as HCC. This is especially relevant since the diagnosis of HCC may be made without histopathological confirmation in certain cases. Thus, in instances of diagnostic uncertainty (e.g., simultaneous radiological HCC and CCA features, elevation of CA 19-9 and AFP, HCC imaging features and elevated CA 19-9, and vice versa) multiple image-guided core needle biopsies should be performed and analysed by an experienced pathologist. Recent advances in the molecular characterisation of cHCC-CCA, innovative diagnostic approaches (e.g., liquid biopsies) and methods to analyse multiple data points (e.g., clinical, radiological, laboratory, molecular, histopathological features) in an all-encompassing way (e.g., by using artificial intelligence) might help to address some of the existing diagnostic challenges.

Combined Hepatocellular-Cholangiocarcinoma: An Update on Pathology and Diagnostic Approach

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver carcinoma displaying both hepatocytic and cholangiocytic differentiation within the same tumor. Relative to classic hepatocellular carcinoma (HCC), cHCC-CCA has more aggressive behavior and a poorer prognosis. Though recent advances have improved our understanding of the biology underlying cHCC-CCAs, they remain diagnostically challenging for pathologists because of their morphologic and phenotypic diversity. Accurate diagnosis of cHCC-CCA is important for patient management and prognostication. Herein, we review recent updates on cHCC-CCA, focusing on tumor classification, pathology, and diagnostic approach.

Survival outcomes of combined hepatocellular-cholangiocarcinoma compared with intrahepatic cholangiocarcinoma: A SEER population-based cohort study

Background

Combined hepatocellular‐cholangiocarcinoma (CHC) is a heterogeneous group of primary liver cancers characterized by the coexistence of both hepatic and biliary cellular contents. The aim of this study was to compare CHC and intrahepatic cholangiocarcinoma (ICC) and investigate the treatment and survival of patients with CHC.

Methods

Data on CHC and ICC, including clinicopathological characteristics, treatments, and survival outcomes were extracted from the SEER database between 2004 and 2016. Univariate and multivariate analyses of all data were performed to identify the risk factors associated with survival outcomes. The overall survival (OS) rates of CHC patients who underwent hepatic resection (HR) or liver transplantation (LT) were also assessed before and after propensity score matching.

Results

A total of 1066 consecutive patients who had been diagnosed with CHC (n = 286) or ICC (n = 780) were identified. The mean age of the CHC cohort was 60.8±10.7 years old. Among the CHC group, a large proportion of the patients were men and of White ethnicity (73.1% and 71.3%, respectively). The majority of tumors were poorly differentiated (37.8%), while the most common AJCC stage at presentation was stage I (31.4%). Multivariable analysis of all CHC patients revealed that only tumor size, M₁ stage, AJCC stage IIIC, AJCC stage IV, surgery, and chemotherapy were significantly associated with OS. The OS was comparable with the ICC in the initial 36 months and better in the subsequent follow‐up after treatment. Surgery was associated with better survival outcomes, whether in the early or advanced stages. Regarding the specific types of surgery, the OS rates were similar in selected patients following HR or LT.

Conclusion

In patients with CHC, surgical intervention resulted in better long‐term survival outcomes than nonsurgical treatments. The OS rate of CHC patients compared with that of ICC patients was discriminated before and after a 3‐year follow‐up.

Magnetic Resonance Imaging of Nonhepatocellular Malignancies in Chronic Liver Disease

Hepatocellular carcinoma (HCC) is the most common liver malignancy associated with chronic liver disease. Nonhepatocellular malignancies may also arise in the setting of chronic liver disease. The imaging diagnosis of non-HCC malignancies may be challenging. Non-HCC malignancies in patients with chronic liver disease most commonly include intrahepatic cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma, and less commonly hepatic lymphomas and metastases. On MR imaging, non-HCC malignancies often demonstrate a targetoid appearance, manifesting as rim arterial phase hyperenhancement, peripheral washout, central delayed enhancement, and peripheral restricted diffusion. When applying the Liver Imaging Reporting and Data System algorithm, observations with targetoid appearance are categorized as LR-M.

Locoregional Treatments in Cholangiocarcinoma and Combined Hepatocellular Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary and aggressive cancer of the biliary tree. Combined hepatocellular cholangiocarcinoma (CHC) is a distinctive primary liver malignancy which has properties of both hepatocytic and cholangiocytic differentiation. CHC appears to have a worse prognosis compared to hepatocellular carcinoma, and similar to that of intrahepatic CCA. While significant advances have been made in understanding the pathophysiology and treatment of these two tumor types, their prognosis remains poor. Currently, liver resection is the primary treatment modality; however, only a minority of patients are eligible for surgery. However, the use of locoregional therapies proves an alternative approach to treating locally advanced disease with the aim of converting to resectability or even transplantation. Locoregional therapies such as transarterial chemoembolization (TACE), selective internal radiation therapy (SIRT), radiofrequency ablation (RFA), and photodynamic therapy (PDT) can provide patients with tumor control and increase the chances of survival. In this review, we appraise the evidence surrounding the use of locoregional therapies in treating patients with CCA and CHC.

Radio-pathologic correlation of biphenotypic primary liver cancer (combined hepatocellular cholangiocarcinoma): changes in the 2019 WHO classification and impact on LI-RADS classification at liver MRI

OBJECTIVES

To explain the new changes in pathologic diagnoses of biphenotypic primary liver cancer (PLC) according to the updated 2019 World Health Organization (WHO) classification and how it impacts Liver Imaging Reporting and Data System (LI-RADS) classification using gadoxetic acid-enhanced MRI (Gd-EOB-MRI).

METHODS

We retrospectively included 209 patients with pathologically proven biphenotypic PLCs according to the 2010 WHO classification who had undergone preoperative Gd-EOB-MRI between January 2009 and December 2018. Imaging analysis including LI-RADS classification and pathologic review including the proportion of tumor components were performed. Frequencies of each diagnosis and subtype according to the 2010 and 2019 WHO classifications were compared, and changes in LI-RADS classification were evaluated. Univariable and multivariable analysis were performed to determine significant tumor component for LI-RADS classification.

RESULTS

Of the 209 biphenotypic PLCs of the 2010 WHO classification, 177 (84.7%) were diagnosed as bipheonotypic PLCs, 25 (12.0%) as hepatocellular carcinomas (HCCs), and 7 (3.3%) as cholangiocarcinomas (CCAs) using the 2019 WHO classification. Of the 177 biphenotypic PLCs, LR-M, LR-4, and LR-5 were assigned in 77 (43.5%), 21 (11.9%), and 63 (35.5%), respectively. There were no significant differences in the proportion of LR-5 and LR-M categories between the WHO 2010 and 2019 classifications (p = 0.941). Proportion of HCC component was the only independent factor for LI-RADS classification (adjusted odds ratio, 1.02; p < 0.001).

CONCLUSION

According to the 2019 WHO classification, 15% of biphenotypic PLCs from the 2010 WHO classification were re-diagnosed as HCCs or CCAs, and a substantial proportion of biphenotypic PLCs of the 2019 WHO classification could be categorized as LR-4 or LR-5 on Gd-EOB-MRI.

KEY POINTS

• Among 209 diagnosed biphenotypic PLCs according to the 2010 WHO classification, 177 (84.7%) lesions were reclassified as bipheonotypic PLCs, 25 (12.0%) as HCCs, and 7 (3.3%) as CCAs using the 2019 WHO classification. • Of the 177 biphenotypic PLCs at the 2019 WHO classification, LR-M, LR-4, and LR-5 were assigned in 77 (43.5%), 21 (11.9%), and 63 (35.5%), respectively. • LI-RADS classification relied on the proportion of HCC component (adjusted odds ratio,1.02; p < 0.001).

Postresection prognosis of combined hepatocellular carcinoma-cholangiocarcinoma according to the 2010 World Health Organization classification: single-center experience of 168 patients

Purpose

Combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) has wide histologic diversity. This study investigated the effects of cHCC-CC histology, according to the 2010 World Health Organization (WHO) classification, on patient prognosis.

Methods

The medical records of patients who underwent surgical resection for cHCC-CC at our institution between July 2012 and June 2019 were retrospectively evaluated.

Results

During the study period, 168 patients, 122 males (72.6%) and 46 females (27.4%), underwent surgical resection for cHCC-CC, including 159 patients (94.6%) who underwent R0 resection. Mean tumor diameter was 4.4 ± 2.8 cm, and 161 patients (95.8%) had solitary tumors. Histologically, 86 patients (51.2%) had classical type, and 82 (48.8%) had tumors with stem cell (SC) features, including 33 (19.6%) with intermediate-cell and 23 (13.7%) each with typical SC and cholangiolocellular features; 3 tumors (1.8%) were unclassifiable. At 1, 3, and 5 years, tumor recurrence rates were 31.9%, 49.6%, and 58.1%, respectively, and patient survival rates were 91.0%, 70.2%, and 60.3%, respectively. Univariate analysis showed that tumor size of >5 cm, microscopic and macroscopic vascular invasion, lymph node metastasis, 8th edition of the American Joint Committee on Cancer (AJCC) tumor stage, and 2010 WHO classification were significantly prognostic. Multivariate analysis showed that the 8th AJCC tumor stage and 2010 WHO histologic classification were independently prognostic for tumor recurrence and patient survival. There were no significant prognostic differences among the 3 SC subtypes.

Conclusion

Postresection outcomes are better in patients with SC-type than with classical-type cHCC-CC.

Post-resection prognosis of combined hepatocellular carcinoma-cholangiocarcinoma cannot be predicted by the 2019 World Health Organization classification

BACKGROUND

Combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CCA) has wide histologic diversity. This study investigated the prognostic impacts of cHCC-CCA histology according to the 2019 World Health Organization (WHO) classification.

METHODS

This retrospective observational study included 153 patients who underwent surgical resection for cHCC-CCA at Asan Medical Center between August 2012 and July 2019.

RESULTS

During the study period, 153 patients, 112 (73.2%) men and 41 (26.8%) women with a mean age of 56.4 ± 10.8 years, underwent R0 resection for cHCC-CCA. Mean tumor diameter was 4.2 ± 2.6 cm, and 147 (96.1%) patients had solitary tumors. According to 2019 WHO classification, 111 (72.5%) patients had cHCC-CCA alone, and 29 of them (26.1%) showed stem cell features. cHCC-CCA-intermediate cell carcinoma and cHCC-CCA-cholangiolocellular carcinoma were identified in 27 (17.6%) and 15 (9.8%), respectively. The 1-, 3-, and 5-year tumor recurrence and patient survival rates were 31.8% and 92.1%, 49.8% and 70.9%, and 59.0% and 61.7%, respectively. Univariate analyses revealed that significant prognostic factors were tumor size >5 cm, microscopic and macroscopic vascular invasion, lymph node metastasis, 8th American Joint Committee on Cancer (AJCC) tumor stage, and status of stem cell features. Multivariate analysis revealed 8th AJCC tumor stage and status of stem cell features as independent prognostic factors. 2019 WHO classification was not associated with post-resection prognosis.

CONCLUSIONS

2019 WHO classification was not associated with post-resection prognosis, thus was considered as simplified histologic classification requiring prognostic validation. We suggest that stem cell features should be included as an essential component of the pathology report for cHCC-CCA.

Update on Pathologic and Radiologic Diagnosis of Combined Hepatocellular-Cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a malignant primary liver carcinoma characterized by the unequivocal presence of both hepatocytic and cholangiocytic differentiation within the same tumor. Recent research has highlighted that cHCC-CCAs are more heterogeneous than previously expected. In the updated consensus terminology and WHO 2019 classification, "classical type" and "subtypes with stem-cell features" of the WHO 2010 classification are no longer recommended. Instead, it is recommended that the presence and percentages of various histopathologic components and stem-cell features be mentioned in the pathologic report. The new terminology and classification enable the exchange of clearer and more objective information about cHCC-CCAs, facilitating multi-center and multi-national research. However, there are limitations to the diagnosis of cHCC-CCA by imaging and biopsy. cHCC-CCAs showing typical imaging findings of HCC could be misdiagnosed as HCC and subjected to inappropriate treatment, if other clinical findings are not sufficiently considered. cHCC-CCAs showing at least one of the CCA-like imaging features or unusual clinical features should be subjected to biopsy. There may be a sampling error for the biopsy diagnosis of cHCC-CCA. An optimized diagnostic algorithm integrating clinical, radiological, and histopathologic information of biopsy is required to resolve these diagnostic pitfalls.

New insights into the pathophysiology and clinical care of rare primary liver cancers

Hepatocholangiocarcinoma, fibrolamellar carcinoma, hepatic haemangioendothelioma and hepatic angiosarcoma represent less than 5% of primary liver cancers. Fibrolamellar carcinoma and hepatic haemangioendothelioma are driven by unique somatic genetic alterations (DNAJB1-PRKCA and CAMTA1-WWTR1 fusions, respectively), while the pathogenesis of hepatocholangiocarcinoma remains more complex, as suggested by its histological diversity. Histology is the gold standard for diagnosis, which remains challenging even in an expert centre because of the low incidences of these liver cancers. Resection, when feasible, is the cornerstone of treatment, together with liver transplantation for hepatic haemangioendothelioma. The role of locoregional therapies and systemic treatments remains poorly studied. In this review, we aim to describe the recent advances in terms of diagnosis and clinical management of these rare primary liver cancers.

Cell of origin in biliary tract cancers and clinical implications

Biliary tract cancers (BTCs) are aggressive epithelial malignancies that can arise at any point of the biliary tree. Albeit rare, their incidence and mortality rates have been rising steadily over the past 40 years, highlighting the need to improve current diagnostic and therapeutic strategies. BTCs show high inter- and intra-tumour heterogeneity both at the morphological and molecular level. Such complex heterogeneity poses a substantial obstacle to effective interventions. It is widely accepted that the observed heterogeneity may be the result of a complex interplay of different elements, including risk factors, distinct molecular alterations and multiple potential cells of origin. The use of genetic lineage tracing systems in experimental models has identified cholangiocytes, hepatocytes and/or progenitor-like cells as the cells of origin of BTCs. Genomic evidence in support of the distinct cell of origin hypotheses is growing. In this review, we focus on recent advances in the histopathological subtyping of BTCs, discuss current genomic evidence and outline lineage tracing studies that have contributed to the current knowledge surrounding the cell of origin of these tumours.

Combined hepatocellular-cholangiocarcinoma: An update on epidemiology, classification, diagnosis and management

BACKGROUND

Combined hepatocellular-cholangiocarcinoma (CHC) is a rare subtype of primary hepatic malignancies, with variably reported incidence between 0.4%-14.2% of primary liver cancer cases. This study aimed to systematically review the epidemiological, clinicopathological, diagnostic and therapeutic data for this rare entity.

DATA SOURCES

We reviewed the literature of diagnostic approach of CHC with special reference to its clinical, molecular and histopathological characteristics. Additional analysis of the recent literature in order to evaluate the results of surgical and systemic treatment of this entity has been accomplished.

RESULTS

The median age at CHC's diagnosis appears to be between 50 and 75 years. Evaluation of tumor markers [alpha fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA)] along with imaging patterns provides better opportunities for CHC's preoperative diagnosis. Reported clinicopathologic prognostic parameters possibly correlated with increased tumor recurrence and grimmer survival odds include advanced age, tumor size, nodal and distal metastases, vascular and regional organ invasion, multifocality, decreased capsule formation, stem-cell features verification and increased GGT as well as CA19-9 and CEA levels. In case of inoperable or recurrent disease, combinations of cholangiocarcinoma-directed systemic agents display superior results over sorafenib. Liver-directed methods, such as transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), hepatic arterial infusion chemotherapy (HAIC), radioembolization and ablative therapies, demonstrate inferior efficacy than in cases of hepatocellular carcinoma (HCC) due to CHC's common hypovascularity.

CONCLUSIONS

CHC demonstrates an overlapping clinical and biological pattern between its malignant ingredients. Natural history of the disease seems to be determined by the predominant tumor element. Gold standard for diagnosis is histology of surgical specimens. Regarding therapeutic interventions, major hepatectomy is acknowledged as the cornerstone of treatment whereas minor hepatectomy and liver transplantation may be applied in patients with advanced cirrhosis. Despite all therapeutic attempts, prognosis of CHC remains dismal.

Usefulness of 18F-FDG PET/CT and Multiphase CT in the Differential Diagnosis of Hepatocellular Carcinoma and Combined Hepatocellular Carcinoma-Cholangiocarcinoma

PURPOSE

The purpose of this study was to evaluate the usefulness of multiphasic CT and ¹⁸F-fluorodeoxyglucose (FDG) PET/CT for the differentiation of combined hepatocellular carcinomacholangiocarcinoma (cHCC-CCA) from hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From January 2007 to April 2016, 93 patients with pathologically confirmed HCC (n = 84) or cHCC-CCA (n = 9) underwent CT and PET/CT imaging. Contrast enhancement patterns were divided into three types based on the attenuation of the surrounding liver parenchyma: type I (early arterial enhancement with delayed washout), type II (early arterial enhancement without delayed washout), and type III (early hypovascular, infiltrative appearance, or peripheral rim enhancement).

RESULTS

cHCC-CCAs (89%) had a higher PET/CT positive rate than did HCCs (61%), but the PET/CT positive rate did not differ significantly (p = 0.095). Among the 19 cases of the type II enhancement pattern, 3 (21%) of 14 HCCs and 4 (80%) of 5 cHCC-CCAs were PET/CT positive. cHCC-CCAs had a significantly higher PET/CT positive rate (p = 0.020) in the type II enhancement pattern.

CONCLUSION

The PET/CT positive rate of cHCC-CCA was significantly higher than that of HCC in lesions with a type II enhancement pattern. The ¹⁸F-FDG PET/CT can be useful for the differentiation of cHCC-CCA from HCC in lesions with a type II enhancement pattern on multiphasic CT.

A Contemporary Approach to Diagnosis and Treatment of Combined Hepatocellular-Cholangiocarcinoma

Purpose of review

To provide updates on terminology, epidemiology, diagnosis, and treatment of combined hepatocellular-cholangiocarcinoma (cHCC-CCA).

Recent findings

cHCC-CCAs are tumors that in the same nodule contain a variable degree of HCC and CCA components with a transition zone. cHCC-CCAs develop in cirrhotic and non-cirrhotic livers like and is associated with poor outcomes. Mutations in TP53, TERT promoter, and ARID1A are the most common genetic aberrations in cHCC-CCA. Fusion gene PTMS-AP1G1 is unique for cHCC-CCA. A biopsy is required for diagnosis. Surgical resection remains treatment of choice, while liver transplantation for early cHCC-CCA is associated with favorable outcomes. Gemcitabine-based therapy shows benefits for advanced cHCC-CCA.

Summary

cHCC-CCAs are a heterogeneous group of primary liver cancers with unique biological behavior. Multicenter studies are required for a molecular analysis to inform novel therapeutic approaches, and understand epidemiology and benefits of liver transplantation, liver-directed and targeted therapies for this rare aggressive cancer.

Clinical features and diagnostic imaging of cholangiolocellular carcinoma compared with other primary liver cancers: a surgical perspective

Background and Objectives:

Although cholangiolocellular carcinoma is considered a combined hepatocellular and cholangiocarcinoma, we feel that this classification is not appropriate. Therefore, we compared the diagnostic imaging findings, surgical prognosis, and pathological features of cholangiolocellular carcinoma with those of other combined hepatocellular and cholangiocarcinoma subtypes, hepatocellular carcinoma, and cholangiocarcinoma.

Methods:

The study patients included 7 with classical type combined hepatocellular and cholangiocarcinoma; 8 with stem cell feature, intermediate type combined hepatocellular and cholangiocarcinoma; 13 with cholangiolocellular carcinoma; 58 with cholangiocarcinoma; and 359 with hepatocellular carcinoma. All patients underwent hepatectomy or living-related donor liver transplantation from 2001 to 2014.

Results:

cholangiolocellular carcinoma could be distinguished from hepatocellular carcinom, other combined hepatocellular and cholangiocarcinoma subtypes, and cholangiocarcinoma by the presence of intratumoral Glisson’s pedicle, hepatic vein penetration, and tumor-staining pattern on angiography-assisted CT. Cholangiolocellular carcinoma was associated with a significantly lower SUV-max than that of cholangiocarcinoma on FDG-PET. Hepatocellular carcinoma, classical type, and cholangiolocellular carcinoma had significantly better prognoses than stem cell feature, intermediate type and cholangiocarcinoma. A cholangiocarcinoma component was detected in cholangiolocellular carcinoma that progressed to the hepatic hilum, and the cholangiocarcinoma component was found in perineural invasion and lymph node metastases.

Conclusions:

From the viewpoint of surgeon, cholangiolocellular carcinoma should be classified as a good-prognosis subtype of biliary tract carcinoma because of its tendency to differentiate into cholangiocarcinoma during its progression, and its distinctive imaging and few recurrence rates different from other combined hepatocellular and cholangiocarcinoma subtypes.

Update on the Genetics of and Systemic Therapy Options for Combined Hepatocellular Cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (cHCC-ICC) is an uncommon and aggressive form of primary liver cancer. Currently, there are no international guidelines for optimal management. For localized tumors, radical resection represents the preferred treatment option, whereas for advanced tumors, systemic therapies recommended for intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) are often selected. Emerging information from comparative cohort studies, genomic and transcriptomic data sets are starting to build a case for rationalized approaches to systemic treatment in the advanced setting specific to cHCC-ICC.

Combined Hepatocellular-Cholangiocarcinoma: Changes in the 2019 World Health Organization Histological Classification System and Potential Impact on Imaging-Based Diagnosis

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver cancer (PLC) with both hepatocytic and cholangiocytic phenotypes. Recently, the World Health Organization (WHO) updated its histological classification system for cHCC-CCA. Compared to the previous WHO histological classification system, the new version no longer recognizes subtypes of cHCC-CCA with stem cell features. Furthermore, some of these cHCC-CCA subtypes with stem cell features have been recategorized as either hepatocellular carcinomas (HCCs) or intrahepatic cholangiocarcinomas (ICCs). Additionally, distinctive diagnostic terms for intermediate cell carcinomas and cholangiolocarcinomas (previous cholangiolocellular carcinoma subtype) are now recommended. It is important for radiologists to understand these changes because of its potential impact on the imaging-based diagnosis of HCC, particularly because cHCC-CCAs frequently manifest as HCC mimickers, ICC mimickers, or as indeterminate on imaging studies. Therefore, in this review, we introduce the 2019 WHO classification system for cHCC-CCA, illustrate important imaging features characteristic of its subtypes, discuss the impact on imaging-based diagnosis of HCC, and address other important considerations.

Pearls and pitfalls in magnetic resonance imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy, which usually arises in cirrhotic liver. When the typical enhancement pattern, consisting of late arterial hyperenhancement followed by washout, is present in nodules larger than 1 cm, HCC can be confidently diagnosed without the need for tissue biopsy. Nevertheless, HCC can display an atypical enhancement pattern, either as iso or hypovascular lesion, or hypervascular lesion without washout. Not only the enhancement pattern of HCC could be atypical, but also a variety of histological types of HCC, such as steatotic, scirrhous, fibrolamellar, or combined hepatocellular-cholangiocellular carcinoma could raise diagnostic dilemmas. In addition, distinct morphological types of HCC or different growth pattern can occur. Awareness of these atypical and rare HCC presentations on magnetic resonance imaging is important for accurate differentiation from other focal liver lesions and timely diagnosis, which allows optimal treatment of patients.

Recent Topics Concerning Combined Hepatocellular Cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (CHC) is a relatively rare tumor with an incidence range of 1.0-4.7%. CHC is defined as a tumor containing unequivocal, intimately mixed components of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The recent development of biochemical methodologies and cancer stem cell theory have paved the way for a clearer understanding of the histogenesis of CHC. The latest edited WHO classification published in 2010 adopted the concept of stem cell/hepatic progenitor cells in the pathological classification of CHC. Although this classification includes novel and unique concepts of histogenesis and facilitates the recognition of CHC, there are several problems with it in practice. To reduce confusion, an international group of hepatic pathologists, radiologists, surgeons, and clinicians formulated a nomenclature for CHC and issued a consensus article in 2018. In this review article, we discuss the problems with the latest WHO classification and introduce recent topics concerning CHC from pathologic and genetic points of view.

Murine hepatoblast-derived liver tumors resembling human combined hepatocellular-cholangiocarcinoma with stem cell features

BACKGROUND

Combined hepatocellular-cholangiocarcinoma (CHC) is a primary hepatic malignancy with heterogeneously combined histological features of putative hepatic progenitor cells (HPC) origin. We describe a mouse model that exhibits the heterogenous histological and phenotypic finding similar to human CHC.

METHODS

We injected hepatoblasts isolated from p53-/- C57BL/6 mice into syngeneic wild-type pre-conditioned C57BL/6 mice. We confirmed that p53-/- murine hepatoblasts act as tumor-initiating cells (TICs) that generate CHC both in situ and within metastases. For comparative pathological study, 8 human cases of CHC with stem cell features were recruited by immunohistochemistry and multicolor fluorescence immunostaining.

RESULTS

We identified corresponding areas in murine tumors matching each WHO criteria-described subtype of human CHC. In both murine and human tumors, HPC-like cells in tumor nests and associated stem cell features/traits are suggested histologically to be the progenitor origin of the cancer.

CONCLUSIONS

The pathological characteristics of murine tumors recapitulate human CHC with stem cell features. These data provide additional comparative pathological evidence that CHC with stem cell features originate from HPCs and validate a model to study this cancer type in vivo.

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.

Combining imaging and tumour biopsy improves the diagnosis of combined hepatocellular-cholangiocarcinoma

BACKGROUND & AIMS

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is by definition a highly heterogeneous tumour, which significantly impacts its diagnosis. The aim of the study was to evaluate the diagnostic performance of imaging using computed tomography and/or magnetic resonance (MR) and biopsy for the diagnosis of cHCC-CCA.

METHODS

cHCC-CCA resected between December 2006 and April 2017 with available pre-operative imaging and tumour biopsy were retrospectively included. cHCC-CCA diagnosis was based on morphological and immunophenotypical features. A total of 21 cHCC-CCA were compared to 21 intrahepatic cholangiocarcinoma (iCCA) as controls. All biopsies were reviewed. Two radiologists reviewed the cases and classified tumours into four patterns (type 1 [progressive enhancement of the entire lesion, iCCA type], type 2 [arterial enhancement with washout, HCC type], type 3 [mixed pattern with combinations of 1, 2 and 4] and type 4 [atypical pattern, areas of arterial enhancement without washout and/or hypovascular]).

RESULTS

The presence of a type 3 pattern at imaging had a 48% sensitivity and 81% specificity for cHCC-CCA diagnosis. The initial diagnosis performed on biopsy was cHCC-CCA in 8/21 patients (38%). After reviewing and including immunophenotypical markers, two more cases were diagnosed as cHCC-CCA (48% sensibility, 100% specificity). When either imaging or biopsy suggested the diagnosis of cHCC-CCA, the sensitivity and specificity were 60% and 82% respectively.

CONCLUSIONS

We showed that a two-step strategy combining imaging as the first step and biopsy as the second step improved the diagnostic performance of cHCC-CCA.

Combined Hepatocellular Cholangiocarcinoma: A Population-Based Retrospective Study

OBJECTIVES

Combined hepatocellular cholangiocarcinoma (CHC) is a rare form of primary liver cancer with features of hepatocellular carcinoma and cholangiocarcinoma. The objective of this study was to investigate the incidence, demographics, tumor characteristics, treatment, and survival of patients with CHC.

METHODS

Data on CHC between 2004 and 2014 were extracted from the Surveillance, Epidemiology, and End Results Registry and analyzed.

RESULTS

Five hundred twenty-nine patients with CHC were identified; 367 were male. Median age at diagnosis was 62.5 ± 12 years. The overall incidence of CHC between 2004 and 2014 was 0.05 per 100,000 per year. Incidence increased with age, with the highest incidence in men occurring between 60 and 64 years and 75-79 years for women. Women had a higher incidence of CHC compared to men (0.08 vs 0.03 per 100,000 per year). Most tumors were poorly differentiated (30.8%) while the most common stage at presentation was stage 4 (26.8%). 39.5% of these tumors were resected while 6.8% received radiation and 34% received chemotherapy. One- and 5-year cause-specific survival for CHC was 41.9% and 17.7%, respectively, with a median survival of 8 months. Worse outcomes were noted among patients with tumor stage 3 (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.44-2.87, P = 0.000), stage 4 (HR 1.71, 95% CI 1.06-2.75, P = 0.027), those not treated with surgery (HR 4.94, 95% CI 3.64-6.68, P = 0.000), those who did not receive radiation (HR 1.71, 95% CI 1.08-2.70, P = 0.021), those who did not receive chemotherapy (HR 1.54, 95% CI 1.20-1.99, P = 0.001), and those with increasing tumor size on chemotherapy (HR 1.00, 95% CI 1.00-1.00, P = 0.013).

DISCUSSION

CHC is the combined presentation of 2 malignancies. Incidence appears to be increasing and is associated with age and male gender. While surgery, radiation, and chemotherapy are associated with improved outcomes, patients who did not undergo surgery are at highest risk for death.

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.

Combined hepatocellular-cholangiocarcinoma successfully treated with sorafenib: case report and review of the literature

Sorafenib, a multiple kinase inhibitor, has been established as first-line standard systemic chemotherapy for patients with advanced hepatocellular carcinoma (HCC). We encountered a patient with combined hepatocellular and cholangiocarcinoma (CHC) who achieved complete remission in response to sorafenib treatment. A 58-year old man with hepatitis C virus (HCV)-induced liver cirrhosis was diagnosed with CHC in segments 6th and 7th of the liver and underwent partial surgical resection. Three months later, CHC recurred as metastases at multiple intrahepatic sites, lymph nodes, and bones, making surgery impossible. Treatment with sorafenib was initiated at 400 mg b.i.d., later reduced to 400 mg/day. After 6 months of sorafenib administration, he no longer showed abnormal uptake on fluorodeoxyglucose positron emission tomography. He was continued on sorafenib for 2.5 years, but later discontinued due to adverse events. He has shown no evidence of tumor recurrence more than 1 year after sorafenib discontinuation. His HCV was eradicated by direct-acting antivirals, and he remains in good health.

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.

Response to Loco-Regional Therapy Predicts Outcomes After Liver Transplantation for Combined Hepatocellular-Cholangiocarcinoma

INTRODUCTION AND AIM

Combined hepatocellular-cholangiocarcinoma (HCC-CCA) is a rare liver malignancy distinct from either hepatocellular carcinoma (HCC) or cholangiocarcinoma. Liver transplantation (LT) is not recommended for HCC-CCA because of suboptimal outcomes. Non-invasive diagnosis of HCC-CCA is extremely challenging; thus, some HCC-CCAs are presumed as HCC on imaging and listed for LT with the correct diagnosis ultimately made on explant pathology. We compared HCC-CCA with HCC to determine the utility of response to pre-transplant loco-regional therapy (LRT) in predicting outcomes for HCC-CCA after LT as a potential means of identifying appropriate HCC-CCA patients for LT.

MATERIAL AND METHODS

Retrospective review of 19 patients with pathologically confirmed HCC-CCA were individually matched to 38 HCC patients (1:2) based on age, sex, and Milan criteria at listing was performed. The modified response evaluation criteria in solid tumors was used to categorize patients as responders or non-responders to pre-transplant LRT based on imaging performed before and after LRT. Overall survival (OS) and recurrence-free survival (RFS) were examined.

RESULTS

OS at 3 years post-transplant was 74% for HCC-CCA and 87% for HCC. RFS at 3 years was 74% for HCC-CCA, and 87% for HCC. Among responders to LRT, the 3-year OS was 92% for HCC-CCA and 88% for HCC; among non-responders, 3-year OS was 43% for HCC-CCA and 83% for HCC. Higher 3-year OS was observed among HCC-CCA responders (77%) compared with HCC-CCA non-responders (23%).

CONCLUSIONS

OS was similarly high among.

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.

Mucin-producing hepatocellular carcinoma without morphological features of biliary differentiation: A case report

RATIONALE

Hepatocellular carcinoma has been believed not to produce mucin unless it has biliary differentiation. However, some cases of hepatocellular carcinoma with extracellular myxoid change have been reported recently, raising the possibility that, in rare cases, hepatocellular carcinoma cells produce mucin.

PATIENT CONCERNS

Here we report a case of hepatocellular carcinoma that contained intracellular and extracellular myxoid matrix without morphological evidence of biliary differentiation, although cells in a portion of the tumor were positive for the epithelial markers cytokeratin 7 and 19. She was brought to our hospital due to abnormal liver tests and a large liver tumor found by ultrasound examination.

DIAGNOSES

The liver tumor showed typical imaging findings of hepatocellular carcinoma.

INTERVENTIONS

The tumor was resected with negative margins, and pathologically diagnosed as hepatocellular carcinoma with mucin production.

OUTCOMES

The patient has been free from recurrence of cancer during two-years' follow-up.

LESSONS

Our case suggests that hepatocellular carcinoma cells can produce mucin without or before morphological differentiation to biliary phenotypes, an observation that may help elucidate the mechanism for the development of combined hepatocellular and cholangiocarcinoma.

Two Surgical Cases of Combined Hepatocellular-Cholangiocarcinoma, Intermediate-Cell Subtype: Potentially Characteristic Gross Features

We herein reported two rare surgical cases of primary combined hepatocellular-cholangiocellular carcinoma, intermediate-cell subtype (CHC-INT), showing potentially characteristic and specific gross findings on their cut surface: both CHC-INTs demonstrated poorly demarcated and expansive and/or infiltrative hepatic nodules in lobulated margins, appearing clearly whitish in color. We were finally able to accurately diagnose the current lesions after thorough analyses including an appropriate and wide panel of immunohistochemical antibodies. Despite that, all pathologists should be aware that the potentially characteristic gross features of primary CHC-INT might also be one of the powerful supplementary tools for reaching its correct, conclusive diagnosis.

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

Primary liver carcinomas with both hepatocytic and cholangiocytic differentiation have been referred to as "combined (or mixed) hepatocellular-cholangiocarcinoma." These tumors, although described over 100 years ago, have attracted greater attention recently because of interest in possible stem cell origin and perhaps because of greater frequency and clinical recognition. Currently, because of a lack of common terminology in the literature, effective treatment and predictable outcome data have been challenging to accrue. This article represents a consensus document from an international community of pathologists, radiologists, and clinicians who have studied and reported on these tumors and recommends a working terminology for diagnostic and research approaches for further study and evaluation.

CONCLUSION

It is recommended that diagnosis is based on routine histopathology with hematoxylin and eosin (H&E); immunostains are supportive, but not essential for diagnosis. (Hepatology 2018;68:113-126).

Combined hepatocellular cholangiocarcinoma: LI-RADS v2017 categorisation for differential diagnosis and prognostication on gadoxetic acid-enhanced MR imaging

OBJECTIVES

To investigate the performance of the Liver Imaging Reporting and Data System (LI-RADS) v2017 for combined hepatocellular cholangiocarcinoma (cHCC-CCA) in the differential diagnosis from hepatocellular carcinoma (HCC) and prediction of prognosis on gadoxetic acid-enhanced MRI (Gd-EOB-MRI).

METHODS

Patients at high risk of HCC with pathologically confirmed cHCC-CCAs (n = 70) and a matched control of HCCs (n = 70) who had undergone Gd-EOB-MRI were included. LI-RADS category was assigned for each lesion by two radiologists. Imaging features and surgical outcomes were compared between cHCC-CCAs of LR-M and LR-5/4 using the χ² test or Fisher's exact test. Recurrence-free survival (RFS) was estimated using Kaplan-Meier survival curves and compared using the log-rank test.

RESULTS

cHCC-CCAs and HCCs were categorised as LR-M, LR-5/4 and LR-TIV in 61.4% (43/70), 37.1% (26/70) and 1.4% (1/70) and 10.0% (7/70), 88.6% (62/70) and 1.4% (1/70), respectively. cHCC-CCAs of LR-5/4, in comparison to LR-M, showed significantly higher frequencies of major HCC features: arterial hyperenhancement (96.2% (25/26) vs. 58.1% (25/43), p = 0.001), washout appearance (80.8% (21/26) vs. 48.8% (21/43), p = 0.011) and enhancing capsule (34.6% (9/26) vs. 11.6% (5/43), p = 0.031). After curative surgery, patients with cHCC-CCAs of LR-M showed a higher early recurrence rate (≤ 6 months) than did those with LR-5/4 (27.8% (10/36) vs. 4.8% (1/21), p = 0.041), whereas no significant difference was observed in RFS (log-rank p = 0.084).

CONCLUSIONS

By using LI-RADS on Gd-EOB-MRI, a substantial proportion of cHCC-CCAs can be categorised as non-LR-M. In addition, cHCC-CCAs mimicking HCCs on imaging (LR-5/4) may indicate better surgical outcomes with regard to early recurrence than those of LR-M.

KEY POINTS

• cHCC-CCAs can be categorised as either LR-M or non-LR-M on Gd-EOB-MRI. • cHCC-CCAs of LR-5/4 frequently demonstrate major HCC imaging features. • LI-RADS categorisation may provide prognostic information after surgery in cHCC-CCAs.

The effectiveness of transarterial chemoembolization in recurrent hepatocellular-cholangiocarcinoma after resection

Background

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) can present as a hypervascular or peripherally enhancing tumor in dynamic imaging. We evaluated the effect of transarterial chemoembolization (TACE) on prognosis according to post-operative recurrence imaging patterns.

Methods

We retrospectively analyzed 42 cHCC-CC and 59 hepatocellular carcinoma (HCC-control) patients at the Asan Medical Center. We classified recurrent cHCC-CC according to enhancement pattern (globally enhancing: GE cHCC-CC, peripherally enhancing: PE cHCC-CC) and evaluated tumor response, time-to-local progression (TTP_local), and overall survival (OS).

Results

The GE cHCC-CC group had a significantly higher best objective response rate (complete remission + partial response) than the PE cHCC-CC group (36% vs 0%, P = 0.005), and it was comparable to that of the HCC-control group (35.6%, P = 0.97). TTP_local in the GE cHCC-CC group was significantly shorter than in the HCC-control group (6.6 vs 27.1 months, P < 0.001), and was not significantly different from that in the PE cHCC-CC group (5.3 months, P = 0.12). OS was 12.4 months, 52.8 months, and 67.5 months in the PE cHCC-CC, GE cHCC-CC, and HCC-control groups, respectively (Ps < 0.05). The adjusted hazard ratios (HRs) for TTP_local and OS revealed an independent association with enhancement pattern of recurrent cHCC-CC (TTP_local: HR 2.46; 95% CI 1.10–5.46; P = 0.03; OS: HR 5.97; 95% CI 2.38–14.96; P < 0.001).

Conclusions

The GE cHCC-CC group showed better response and prognosis after TACE than the PE cHCC-CC group, but poorer response and prognosis than the HCC-control group. Enhancement patterns at recurrence were crucially associated with tumor response and overall survival.

Proliferating EpCAM-Positive Ductal Cells in the Inflamed Liver Give Rise to Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) originates from regenerating liver cells with genetic alterations in chronically inflamed liver. Ductal cells and hepatocytes proliferate for liver regeneration, and proliferating ductal cells (PDC) derived from bile ductules have long been considered putative liver stem/progenitor cells and candidate cellular origins of HCC. The potential of PDC as tumor-originating cells, however, remains controversial in contrast to accumulating evidence that HCC originates from hepatocytes. Here, we demonstrate that PDCs expressing the established surface and cancer stem cell marker EpCAM give rise to HCC in inflamed liver. EpCAM-expressing PDCs were specifically labeled in newly developed Epcam^CreERT2 mice and traced in a chemically induced liver injury model. Stepwise accumulation of genetic alterations in EpCAM-positive cells was induced by the mutagenesis activity of activation-induced cytidine deaminase using conditional transgenic mice. Lineage-tracing experiments revealed that labeled PDC differentiated into cholangiocytes, but not into hepatocytes, in the chemically damaged liver. Nevertheless, EpCAM-positive PDC with genetic alterations gave rise to HCC after 8 months of chemical administration. PDC-derived HCC showed histologic characteristics of concomitant ductule-like structures resembling human cholangiolocellular carcinoma (CLC) and exhibited serial transitions from PDC-like CLC cells to hepatocyte-like HCC cells. The Wnt signaling pathway was specifically upregulated in the CLC components of PDC-derived HCC. Our findings provide direct experimental evidence that EpCAM-expressing PDC could be a cellular origin of HCC, suggesting the existence of stem/progenitor-derived hepatocarcinogenesis. Cancer Res; 77(22); 6131-43. ©2017 AACR.