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

Evaluation of combined hepatocellular-cholangiocarcinoma using CEUS LI-RADS: correlation with pathological characteristics

OBJECTIVE

To explore the factors that influence the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) classification of combined hepatocellular-cholangiocarcinoma (cHCC-ICC).

METHODS

Between September 2014 to July 2020, the CEUS features of 58 patients with pathologically confirmed cHCC-ICC were retrospectively evaluated and assigned according to the CEUS LI-RADS (version 2017). The pathological characteristics of nodules categorizing as different CEUS LI-RADS categories were compared. Multivariate logistic regression analysis was conducted to explore potential factors that may influence the CEUS LI-RADS classification of cHCC-ICC.

RESULTS

According to CEUS LI-RADS, 32.8% (19/58), 63.8% (37/58), and 3.4% (2/58) were categorized as LR-5, LR-M, and LR-TIV, respectively. There was significant difference between the LR-M and LR-5 groups with regard to the pathological grade, nodule size, and HCC/ICC-component ratio of cHCC-ICC. Multivariate logistic regression analysis identified tumor size and the relative proportions of hepatocellular carcinomas (HCC) and intrahepatic cholangiocarcinomas (ICC) components as the independent influencing factors.

CONCLUSION

Tumor size and the relative proportion of HCC and ICC components within the nodule had a significant impact on the CEUS LI-RADS classification of cHCC-ICC.

Prognostic Impact of CCA Components in Combined Hepatocellular Carcinoma-Cholangiocarcinoma

Purpose

To investigate the differences of combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) patients with a cholangiocarcinoma (CCA) component ≥ 30% or < 30% versus intrahepatic cholangiocarcinoma (iCCA) patients in recurrence-free survival (RFS) and overall survival (OS) prognoses.

Methods

Patients with cHCC-CCA and iCCA after surgery were recruited. All cHCC-CCA patients were divided into two subgroups (CCA components ≥ 30% and < 30%). Then, Kaplan-Meier survival analysis and Cox regression analysis were used to investigate and compare the differences of cHCC-CCAs with a CCA component ≥ 30% or < 30% versus iCCAs in RFS and OS prognoses, respectively. The differences of MRI features between cHCC-CCAs with a CCA component ≥ 30% and < 30% were also compared.

Results

One hundred sixty-four cHCC-CCAs and 146 iCCAs were enrolled. Compared with iCCAs, cHCC-CCAs with a CCA component < 30% had better OS prognosis (HR: 2.888, p = 0.045). However, Cox regression analysis revealed that cHCC-CCAs with a CCA component ≥ 30% had poorer RFS (HR: 0.503, p < 0.001) and OS (HR: 0.58, p = 0.033) prognoses than iCCAs. In addition, rim APHE (OR = 0.286, p < 0.001), targetoid diffusion restriction (OR = 0.316, p = 0.019), corona enhancement (OR = 0.481, p = 0.033), delayed enhancement (OR = 0.251, p = 0.001), and LR-M (OR = 1.586, p < 0.001) were significant factors associated with cHCC-CCAs with a CCA component ≥ 30%. Multivariable regression analyses showed that only LR-M (OR = 1.522, p = 0.042) was a significantly independent predictor for cHCC-CCAs with a CCA component ≥ 30%.

Conclusion

cHCC-CCAs with a CCA component ≥ 30% had worse prognoses than iCCAs. Therefore, we suggest that the postoperative treatment of cHCC-CCAs with a CCA component ≥ 30% can be based on the treatment strategy for iCCAs.

Is it necessary to distinguish between combined hepatocellular carcinoma-cholangiocarcinoma with less than 10% of cholangiocarcinoma components versus hepatocellular carcinoma?

PURPOSE

Whether there are differences in recurrence-free survival (RFS) prognosis between combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) cases with a small proportion of CCA components and HCC cases remains unknown. We aim to investigate the differences in RFS prognosis between cHCC-CCAs with a small proportion of CCA components and HCCs.

METHODS

Patients with malignant liver neoplasms who underwent MRI and surgery were prospectively recruited. All cHCC-CCA patients were divided into different groups according to the ratio of CCA components. The primary end point was recurrence-free-survival. Cox regression analysis and Kaplan-Meier survival analysis was used to investigate and compare RFS prognosis.

RESULTS

One hundred sixty-four cHCC-CCA cases and 271 HCC cases were enrolled. There was no significant difference in RFS prognosis between cHCC-CCA cases with a CCA component of < 10% and HCC cases (log rank p = 0.169). There were no significant differences in some major HCC-favoring MR features, such as nonrim APHE (85.7% vs. 81.5%, p = 0.546), nonperipheral washout (80.0% vs. 84.1%, p = 0.534), and enhancing capsule (62.9% vs. 45.4%, p = 0.051) between them. In addition, some clinicopathological findings had no significant differences between cHCC-CCAs with a CCA component of < 10% and HCCs (all p > 0.05).

CONCLUSIONS

There were no significant differences in RFS prognosis, major HCC-favoring MRI features, and clinicopathological findings between cHCC-CCAs with a CCA component of < 10% and HCCs. Therefore, we suggest that cHCC-CCAs with pathological diagnosis of less than 10% of CCA components may be treated as HCCs in clinical setting.

Re-assessing the diagnostic value of the enhancing capsule in hepatocellular carcinoma imaging

BACKGROUNDS/AIMS

The enhancing capsule (EC) in hepatocellular carcinoma (HCC) diagnosis has received varying degrees of recognition across major guidelines. This study aimed to assess the diagnostic utility of EC in HCC detection.

METHODS

We retrospectively analyzed patients who underwent pre-surgical computed tomography (CT) and hepatobiliary agent-enhanced magnetic resonance imaging (HBA-MRI) between January 2016 and December 2019. A single hepatic tumor was confirmed based on the pathology of each patient. Three radiologists independently reviewed the images according to the Liver Imaging Reporting and Data System (LI-RADS) v2018 criteria and reached a consensus. Interobserver agreement for EC before reaching a consensus was quantified using Fleiss κ statistics. The impact of EC on the LI-RADS classification was assessed by comparing the positive predictive values for HCC detection in the presence and absence of EC.

RESULTS

In total, 237 patients (median age, 60 years; 184 men) with 237 observations were included. The interobserver agreement for EC detection was notably low for CT (κ=0.169) and HBA-MRI (κ=0.138). The presence of EC did not significantly alter the positive predictive value for HCC detection in LI-RADS category 5 observations on CT (94.1% [80/85] vs. 94.6% [88/93], P=0.886) or HBAMRI (95.7% [88/92] vs. 90.6% [77/85], P=0.178).

CONCLUSIONS

The diagnostic value of EC in HCC diagnosis remains questionable, given its poor interobserver agreement and negligible impact on positive predictive values for HCC detection. This study challenges the emphasis on EC in certain diagnostic guidelines and suggests the need to re-evaluate its role in HCC imaging.

Quantitative Assessment of Hypovascular Component in Arterial Phase to Help the Discrimination of Combined Hepatocellular-Cholangiocarcinoma and Hepatocellular Carcinoma

Purpose

To explore the imaging performance for discrimination of combined hepatocellular- cholangiocarcinoma (cHCC-CCA) and hepatocellular carcinoma (HCC).

Methods

In total, 35 patients with cHCC-CCA and a matched control group of HCC patients (n = 35) were included retrospectively. We quantitatively evaluated the hypovascular component in tumor and qualitatively assessed LI-RADS features and other aggressive features to develop model for cHCC-CCA diagnose. Subgroup analyses were performed by tumor size and LI-RADS category.

Results

cHCC-CCA frequently showed a larger proportion (≥50%) of hypovascular areas followed by HCC (P = 0.000). Among those patients with ≥50% hypovascular areas, 8 patients did not present rim enhancement in atrial phase. The LI-RADS major features were more commonly observed in HCC (82.9-45.7%,), than cHCC-CCA (P = 0.003-0.022). The targetoid appearances and non-smooth margin frequently appeared in cHCC-CCA (34.3-63.9%), compared with HCC (P = 0.000-0.023). We developed a radiologic model based on ≥50% hypovascular component and delayed enhancement, which presented AUC of 0.821, accuracy of 80%. We also obtained good performance by radiologic model in LR-M group and tumor size <50mm group (AUC: 0.841 and 0.866, respectively). Combined group which included CA 19-9 and ≥50% hypovascular component and delayed enhancement did not improve the distinction performance between cHCC-CCA and HCC, which presented good performance of identifying cHCC-CCA in the LR-4/5 subgroup and tumor size ≥50 mm subgroup (AUC: 0.717, 0.730, respectively). cHCC-CCA group presented heterogeneous dominant pathology involving 15 of HCC, 7 of intrahepatic cholangiocarcinoma (iCCA) or cholangiolocellular carcinoma (CLC), 13 of intermediate cells component. Macrotrabecular appearances were higher in cHCC-CCA than that in HCC. The proportion of Hepa-1 was significantly higher in true negative (TN) patients (29 [93.5%]) and false negative (FN) patients (10 [100%]) than in true positive (TP) patients (16 [64%]; P = 0.036).

Conclusion

Quantitative assessment of hypovascular component could help the discrimination of cHCC-CCA. Macrotrabecular appearances were more exhibited in cHCC-CCA than that in HCC.

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.

Histopathological components correlated with MRI features and prognosis in combined hepatocellular carcinoma-cholangiocarcinoma

OBJECTIVES

To distinguish MR features according to different proportions of the histopathological hepatocellular carcinoma (HCC) component and to investigate whether the proportion of the HCC component can predict the prognosis of patients with cHCC-CCA.

METHODS

The study enrolled 106 cHCC-CCA patients confirmed by histopathology. The MR imaging features and clinicopathological findings were retrospectively evaluated and compared between two subgroups with different proportions of the HCC component. The recurrence-free survival (RFS) and overall survival (OS) were evaluated using Kaplan-Meier survival curves and compared using the log-rank test. Moreover, whether the proportion of the HCC component was a predictor of RFS and OS was investigated using Cox regression analyses.

RESULTS

The Liver Imaging Reporting and Data System (LI-RADS) category 4/5 was more prevalent in cHCC-CCAs with an HCC component > 50% (odds ratio (OR) = 5.559, p = 0.018), 70% (OR = 4.031, p = 0.008), and 90% (OR = 6.282, p = 0.012) than in those with an HCC component ≤ 50%, 70%, and 90%, respectively. In addition, cHCC-CCAs with an HCC component > 70% (HR: 0.241, p = 0.023) had a better OS prognosis than those with an HCC component ≤ 70%.

CONCLUSIONS

cHCC-CCAs categorized as LR-4/5 are mainly composed of HCC component, and cHCC-CCAs with an HCC component > 70% are associated with better OS than those with an HCC component ≤ 70%. These findings suggest that the proportion of HCC or CCA component can predict the prognosis of cHCC-CCA patients.

KEY POINTS

• cHCC-CCAs categorized as LR-4/5 are mainly composed of HCC component. • cHCC-CCAs with an HCC component > 70% are associated with better OS than those with an HCC component ≤ 70%.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic Performance of LI-RADS Version 2018 for Primary Liver Cancer in Patients With Liver Cirrhosis on Enhanced MRI

Purpose

The study evaluated the diagnostic performance of the Liver Imaging Reporting and Data System (LI-RADS) version 2018 for differentiating hepatocellular carcinoma (HCC) from primary liver cancer in patients with liver cirrhosis based on the updated 2019 WHO classification.

Materials and Methods

From 2016 to 2021, 300 patients with surgically confirmed primary liver cancer (PLC) and liver cirrhosis based on the updated 2019 WHO classification were eligible for this retrospective study (100 cases in each of three groups including HCC, ICC, and cHCC-CCA). Two radiologists were blinded to the final diagnosis and independently assigned an LI-RADS category to each liver nodule. The diagnostic performances of the LR-5 category (definitely HCC), and the LR-M category (probably or definitely malignant, but not specific for HCC) were calculated in overall and small observations (<20 mm). Comparisons between groups of categorical variables were performed by one-way analysis of variance and the Chi-squared or Fisher’s exact test.

Results

The mean age of 300 patients (226 men and 74 women) was 57.40 ± 11.05 years. The sensitivity and specificity of the LR-5 category for differentiating HCCs from other primary liver cancers were 81% (81 of 100) and 82% (164 of 200), respectively. The LR-M category had a sensitivity of 63% (126 of 200) for diagnosing non-HCCs (ICCs and cHCC-CCAs), with a specificity of 90% (90 of 100). The LR-5 category had a sensitivity of 82.5% (33 of 40) for diagnosing HCCs in small observations (<20 mm) with a specificity of 76.6% (59 of 77). On the contrary, LR-M demonstrated slightly higher specificity (93.8%) and sensitivity (73.8%) for diagnosing non-HCCs with tumor size <20 mm.

Conclusion

The LR-5 category as well as the LR-M category of Liver Imaging Reporting and Data System (LI-RADS) version 2018 can effectively distinguish hepatocellular carcinoma from other primary hepatic malignancies in patients with liver cirrhosis, especially for small observations (<20 mm).

Contrast-enhanced ultrasound manifestations of synchronous combined hepatocellular-cholangiocarcinoma and hepatocellular carcinoma: A case report

BACKGROUND

Synchronous combined hepatocellular-cholangiocarcinoma (CHC) and hepatocellular carcinoma (HCC) is very rare, with few literature reports and poor clinical outcomes associated with the disorder. Surgical resection is the main treatment, which makes the preoperative diagnosis very important. However, due to imaging manifestations overlapping with HCC, diagnosis of this type of synchronous cancer is challenging and it tends to be misdiagnosed as multiple HCC. Herein, we report the contrast-enhanced ultrasound (CEUS) manifestations of a case of synchronous CHC and HCC, aiming at adding to the understanding of this disease. CEUS displayed exquisite vascularity and tissue perfusion in real time with good spatial and temporal resolution and more accurately reflect tumor washin and washout times than contrast-enhanced computed tomography (CT) in this case.

CASE SUMMARY

The patient was a 69-year-old female with a 20-year history of chronic hepatitis B. Due to months of epigastric pain and anorexia, she reffered to our hospital for treatment. Five days before hospitalization, abdominal magnetic resonance imaging performed at another hospital detected a space-occupying lesion in the liver. After her hospitalization, laboratory tests showed elevated alpha-fetoprotein and carbohydrate antigen 19-9 level. Two suspicious liver lesions located in S4 and S6, respectively, were identified in a cirrhotic background by abdominal contrast-enhanced CT (CECT). Furthermore, the lesion in S4 and S6 were detected by CEUS and assigned to CEUS LI-RADS 5 and M categories, respectively. The patient underwent tumor radical resections. Post-operative pathology confirmed the S4 and S6 lesions to be HCC and CHC, respectively. A newly-found suspicious liver nodule with potential malignancy was detected in liver S1 by both CEUS and CECT 7 mo after operation.

CONCLUSION

The CEUS characteristics of CHC and HCC are different. CEUS features in combination with clinical information could help in effective diagnosis, clinical decision-making and better prognosis.

Risk stratification of LI-RADS M and LI-RADS 4/5 combined hepatocellular cholangiocarcinoma: prognostic values of MR imaging features and clinicopathological factors

OBJECTIVES

To investigate the role of clinicopathological factors and MR imaging factors in risk stratification of combined hepatocellular cholangiocarcinoma (cHCC-CCA) patients who were classified as LR-M and LR-4/5.

METHODS

We retrospectively identified consecutive patients who were confirmed as cHCC-CCA after surgical surgery in our institution from June 2015 to November 2020. Two radiologists evaluated the preoperative MR imaging features independently, and each lesion was assigned with a LI-RADS category. Preoperative clinical data were also collected. Multivariate Cox proportional hazards model was applied to separately identify the independent factors correlated with the recurrence of cHCC-CCAs in LR-M and LR-4/5. Risk stratifications were conducted separately in LR-M and LR-4/5. Recurrence-free survival (RFS) rates and overall survival (OS) rates were analyzed by using the Kaplan-Meier survival curves and log-rank test.

RESULTS

A total of 131 patients with single primary lesion which met the 2019 WHO classification criteria were finally included. Corona enhancement, delayed central enhancement, and microvascular invasion (MVI) were identified as predictors of RFS in LR-M. Mosaic architecture, CA19-9, and MVI were independently associated with RFS in LR-4/5. Based on the number of these independent predictors, patients were stratified into favorable-outcome groups (LR-ML subgroup and LR-4/5L subgroup) and dismal-outcome groups (LR-MH subgroup and LR-4/5H subgroup). The corresponding median RFS for LR-ML, LR-MH, LR-5L, and LR-5H were 25.6 months, 8.2 months, 51.7 months, and 18.1 months.

CONCLUSION

Our study explored the prognostic values of imaging and clinicopathological factors for LR-M and LR-4/5 cHCC-CCA patients, and different survival outcomes were observed among four subgroups after conducting risk stratifications.

KEY POINTS

• Corona enhancement, delayed central enhancement, and MVI were identified as predictors of RFS in cHCC-CCAs which were classified into LR-M. Mosaic architecture, CA19-9, and MVI were independently associated with RFS in cHCC-CCAs which were classified into LR-4/5. • Based on the identified risk factors, LR-M and LR-4/5 cHCC-CCA patients could be stratified into two subgroups respectively, with significantly different RFS and OS. • cHCC-CCA patients from LR-M did not always have worse RFS and OS than those from LR-4/5 in some cases.

Intrahepatic cholangiocarcinoma: tumour heterogeneity and its clinical relevance

Treatment of intrahepatic cholangiocarcinoma (iCCA) is currently at a significant turning point due to the identification of isocitrate dehydrogenase (IDH) mutations and fibroblast growth factor receptor (FGFR) fusions that can be targeted with currently available therapies. Clinical trials of these targeted therapies have been promising, and the iCCA patients who may benefit from these targeted treatments can be identified by pathological examination prior to molecular investigations. This is because IDH mutations and FGFR fusions are mainly seen in the small duct type iCCA, a subtype of iCCA defined by the 5th World Health Organization classification, which can be recognized by the pathological diagnostic process. Therefore, pathology plays an important role in precision medicine for iCCA, not only in confirming the diagnosis, but also in identifying the iCCA patients who may benefit from targeted treatments. However, caution is advised with the pathological diagnosis, as iCCA shows tumour heterogeneity, making it difficult to distinguish small duct type iCCA from hepatocellular carcinoma (HCC), and combined HCC-CCA. This review focuses on the pathological/molecular features of both subtypes of iCCA (large and small duct types), as well as their diagnostic pitfalls, clinical relevance, and future perspectives.