Dysplastic nodules frequently develop into hepatocellular carcinoma in patients with chronic viral hepatitis and cirrhosis

Comparison of diffusion-weighted imaging and gadoxetic acid-enhanced MR images in the evaluation of hepatocellular carcinoma and hypovascular hepatocellular nodules

PURPOSE

To compare diffusion-weighted imaging (DWI) and gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) magnetic resonance imaging (MRI) in the evaluation of hepatocellular carcinoma (HCC) and nodules at high risk of HCC transformation.

MATERIALS AND METHODS

We evaluated nodules' size, vascular pattern, and signal intensity on hepatobiliary phase images and on DWI of 105 nodules (41 cirrhotic patients).

RESULTS

A total of 35/66 HCCs identified on Gd-EOB-DTPA MRI showed hyperintensity on DWI. A total of 25/39 nodules (hypovascular and hypointense nodule on hepatobiliary phase images) progressed to HCC (higher risk for nodules ≥10mm in size and hyperintense on DWI, P<.05).

CONCLUSION

Gd-EOB-DTPA MRI demonstrated a significant role in the identification of nodule at higher risk of HCC transformation, and hyperintensity on DWI was associated with progression to HCC.

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

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

Clinical significance of the ubiquitin ligase UBE3C in hepatocellular carcinoma revealed by exome sequencing

Virus-induced hepatocarcinogenesis involves a series of histological developmental processes with the stepwise acquisition of several genetic changes that are necessary for the malignant transformation of hepatocytes. Although genetic alterations are known to be involved in the pathogenesis of hepatocellular carcinoma (HCC), little is known about the contributions of specific genes to this process. To gain insight into the genetic alterations involved in the neoplastic evolution from chronic hepatitis B virus infection to dysplastic nodules (DN) to HCC, we captured and sequenced the exomes of four DNA samples: one DN sample, two HCC samples, and one control peripheral blood sample from a single HCC patient. Mutations in the UBE3C gene (encoding ubiquitin ligase E3C) were observed in both tumor tissues. Then we resequenced the UBE3C gene in a cohort of 105 HCC patients and identified mutations in 17 out of a total of 106 (16.0%) HCC patients. The subsequent experiments showed that UBE3C promoted HCC progression by regulating HCC cells epithelial-mesenchymal transition. Clinically, a tissue microarray study of a cohort containing 323 HCC patients revealed that the overexpression of UBE3C in primary HCC tissues correlated with decreased survival (hazard ratio [HR] =1.657, 95% confidence interval [CI] =1.220-2.251, P=0.001) and early tumor recurrence (HR=1.653, 95% CI=1.227-2.228, P=0.001) in postoperative HCC patients.

CONCLUSION

Our findings indicate that UBE3C is a candidate oncogene involved in tumor development and progression and therefore a potential therapeutic target in applicable HCC patients.

Increased expression of stathmin and elongation factor 1α in precancerous nodules with telomere dysfunction in hepatitis B viral cirrhotic patients

Background

Telomere dysfunction is important in carcinogenesis, and recently, stathmin and elongation factor 1α (EF1α) were reported to be up-regulated in telomere dysfunctional mice.

Methods

In the present study, the expression levels of stathmin and EF1α in relation to telomere length, telomere dysfunction-induced foci (TIF), γ-H2AX, and p21^WAF1/CIP1 expression were assessed in specimens of hepatitis B virus (HBV)-related multistep hepatocarcinogenesis, including 13 liver cirrhosis specimens, 14 low-grade dysplastic nodules (DN), 17 high-grade DNs, and 14 hepatocellular carcinomas (HCC). Five normal liver specimens were used as controls. TIF were analyzed by telomere fluorescent in situ hybridization (FISH) combined with immunostaining, while the protein expressions of stathmin, EF1α, γ-H2AX, and p21^WAF1/CIP1 were detected by immunohistochemistry.

Result

The expressions of stathmin and EF1α gradually increased as multistep hepatocarcinogenesis progressed, showing the highest levels in HCC. Stathmin mRNA levels were higher in high-grade DNs than normal liver and liver cirrhosis, whereas EF1α mRNA expression did not show such a difference. The protein expressions of stathmin and EF1α were found in DNs of precancerous lesions, whereas they were absent or present at very low levels in normal liver and liver cirrhosis. Stathmin histoscores were higher in high-grade DNs and low-grade DNs than in normal liver (all, P < 0.05). EF1α histoscores were higher in high-grade DNs than in normal liver and liver cirrhosis (all, P < 0.05). Stathmin mRNA levels and histoscores, as well as EF1α histoscores (but not mRNA levels), were positively correlated with telomere shortening and γ-H2AX labeling index (all, P < 0.05). EF1α histoscores were also positively correlated with TIF (P < 0.001). Significantly greater inactivation of p21^WAF1/CIP1 was observed in low-grade DNs, high-grade DNs, and HCC, compared to liver cirrhosis (all, P < 0.05). p21^WAF1/CIP1 labeling index was inversely correlated with TIF, stathmin mRNA level, and EF1α histoscore (all, P < 0.05).

Conclusion

Stathmin and EF1α are suggested to be closely related to telomere dysfunction, DNA damage, and inactivation of p21^WAF1/CIP1 in HBV-related multistep hepatocarcinogenesis. Accordingly, assessment of stathmin and EF1α levels as a reflection of telomere dysfunction may be helpful in evaluating the biological characteristics of precancerous hepatic nodules in hepatitis B viral cirrhotic patients.

Magnetic resonance imaging in cirrhosis: what's new?

Cirrhosis is the main risk factor for the development of hepatocellular carcinoma (HCC). The major causative factors of cirrhosis in the United States and Europe are chronic hepatitis C infection and excessive alcohol consumption with nonalcoholic steatohepatitis emerging as another important risk factor. Magnetic resonance imaging is the most sensitive imaging technique for the diagnosis of HCC, and the sensitivity can be further improved with the use of diffusion-weighted imaging and hepatocyte-specific contrast agents. The combination of arterial phase hyperenhancement, venous or delayed phase hypointensity "washout feature," and capsular enhancement are features highly specific for HCC with reported specificities of 96% and higher. When these features are present in a mass in the cirrhotic liver, confirmatory biopsy to establish the diagnosis of HCC is not necessary. Other tumors, such as cholangiocarcinoma, sometimes occur in the cirrhotic at a much lower rate than HCC and can mimic HCC, as do other benign lesions such as perfusion abnormalities. In this article, we discuss the imaging features of cirrhosis and HCC, the role of magnetic resonance imaging in the diagnosis of HCC and other benign and malignant lesions that occur in the cirrhotic liver, and the issue of nonspecific arterially hyperenhancing nodules often seen in cirrhosis.

Tumor Hemodynamics and Hepatocarcinogenesis: Radio-Pathological Correlations and Outcomes of Carcinogenic Hepatocyte Nodules

Tumor hemodynamics of carcinogenic hepatocytes nodules, that is, low grade dysplastic nodules, high grade dysplastic nodules, early hepatocellular carcinomas (HCCs), and progressed HCCs, change during multistep dedifferentiation of the nodules. Morphometric analyses of inflow vessels of these nodules indicate that the portal veins of carcinogenic hepatocyte nodules monotonically decrease whereas the arteries bitonically change, first decrease and then increase. Findings on imaging techniques depicting these changes in tumor blood inflows, especially intra-arterial contrast-enhanced computed tomography, closely related not only to the histological differentiation of the nodules but also to the outcomes of the nodules. Histological analyses of connections between the vessels within the tumors and those in the surrounding livers and findings on imaging techniques indicate that drainage vessels of HCC change from hepatic veins to hepatic sinusoids and then to portal veins during multistep hepatocarcinogenesis. Understanding of tumor hemodynamics through radio-pathological correlations will be helpful in drawing up therapeutic strategies for carcinogenic hepatocyte nodules arising in cirrhosis.

Differentiating hepatocellular carcinoma from dysplastic nodules at gadobenate dimeglumine-enhanced hepatobiliary-phase magnetic resonance imaging

PURPOSE

We evaluated whether the addition of delayed phase imaging (DPI) gadobenate dimeglumine-enhanced MRI to dynamic postcontrast imaging improves the characterization of small hepatocellular carcinoma (HCC) and the differentiation between HCC, high grade dysplastic nodules (HGDN), and low grade dysplastic nodules (LGDN).

METHODS

Twenty-five cirrhotic patients with 30 nodules (16 HCC, 8 HGDNs, and 6 LGDNs; maximum size of 3 cm) were included in this retrospective study. The diagnostic reference standard was histology. All the patients underwent MRI both prior to and following intravenous administration of gadobenate dimeglumine. The lesions were classified as hypointense, isointense, hyperintense on DPI for qualitative assessment. In the quantitative analysis the relative tumor-liver contrast to noise ratio (CNR) of the lesions on DPI was calculated.

RESULTS

All HCCs were hypointense on DPI while only 8 (57.1%) of 14 DNs were hypointense and only 1 of 6 (16.6%) LGDNs was hypointense. There was a statistically significant difference in the hypointensity on DPI between HCCs and DNs (p = 0.003) in the qualitative analysis but not in the CNR values while there was a strong statistically significant difference in the hypointensity on DPI in the qualitative (p = 0.00001) and quantitative analysis (p < 0.05) between LGDNs and the group obtained by unifying HGDNs and HCCs.

CONCLUSION

DPI is helpful in differentiating HCCs and HGDNs from LGDNs. Demonstration of hypointensity on DPI should raise the suspicion of HGDN or hypovascular HCC in the case of nodules with atypical dynamic pattern.

Gadoxetic acid-enhanced MRI for hepatocellular carcinoma and hypointense nodule observed in the hepatobiliary phase

PURPOSE

The aim of our study was to evaluate the diagnostic accuracy of gadoxetic acid-enhanced magnetic resonance (MR) imaging both in the detection of hepatocellular carcinoma (HCC) and precancerous lesions and in the assessment of their evolution.

MATERIALS AND METHODS

A retrospective study was undertaken on 56 patients with chronic liver disease and suspected liver lesions. We evaluated the number, size and signal intensity of the nodules on dynamic and hepatobiliary MR images. Follow-up studies were carried out every 3 months. Statistical analysis was performed using the Fisher's exact test.

RESULTS

A total of 120 nodules were identified in 41 patients. Of these, 92/120 nodules (76.6%; mean diameter 18.4 mm) showed the typical HCC vascular pattern: 90/92 nodules appeared hypointense and 2/92 were hyperintense on hepatobiliary phase images. An additional 28/120 hypointense, nonhypervascular nodules (23.3%; mean diameter 11 mm) were detected on hepatobiliary phase images, 15 of which showed hypointensity also on the equilibrium phase images. During the 3- to 12-month follow-up, 14/28 nodules (mean diameter 13.3 mm) developed the typical vascular pattern of HCC.

CONCLUSIONS

Gadoxetic acid-enhanced MR imaging is useful for detecting HCC as well as hypovascular nodules with potential progression to HCC. Lesions measuring more than 10 mm in diameter are at higher risk of developing into HCC (p = 0.0128).

Gastrointestinal imaging: tips and traps in the diagnosis of small HCC

Improvement in survival of patients with HCC depends on detecting small lesions. This is possible by screening all patients with cirrhosis for HCC. However, these small lesions are difficult to characterise as only 50 to 80% of lesions less than 3cm have a typical HCC appearance, depending on the imaging technique used. MRI, with its various possibilities (dynamic sequences, diffusion-weighting, liver-specific contrast agents), is currently the most effective imaging technique for characterising these small HCCs, but at present we do not know the best combination of imaging examinations for diagnosing the condition.

Imaging of hepatocellular carcinoma: current concepts

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy, and usually develops in the setting of liver cirrhosis. The early diagnosis of HCC is essential as curative treatment (including surgical resection and liver transplantation) improves survival. While screening and surveillance are traditionally performed with ultrasound, reported accuracies of ultrasound vary greatly, and poor sensitivity for small nodules is a uniformly recognized concern. Advances in computed tomography (CT) and magnetic resonance imaging (MRI), including multidetector technology and fast breath hold sequences now allow dynamic multiphasic enhanced imaging of the liver with excellent spatial and temporal resolution, holding much promise for improved HCC detection.

Contrast-enhanced computed tomography and ultrasound-guided liver biopsy to diagnose dysplastic liver nodules in cirrhosis

BACKGROUND

Dysplastic nodules in cirrhosis herald a very high risk of transition to hepatocellular carcinoma. A better understanding of the relationships between dysplastic nodules and hepatocellular carcinoma development may help refining strategies of enhanced follow-up.

METHODS

All consecutive cirrhotics with a histologically proven de novo dysplastic nodule, were retrospectively identified and underwent alternating abdominal ultrasound and contrast-computed tomography every 3 months. An ultrasound-guided liver biopsy was the diagnostic gold standard, whereas surveillance and recall policies were according to current guidelines.

RESULTS

Among 36 patients with dysplastic nodule (21 low-grade, 15 high-grade, 17.4 ± 2.6mm), 17 (47%) showed arterial wash-in, 15 (42%) portal/venous hypodensity whereas 4 (11%) had neither pattern. During 6-128 (median 36) months, 21 patients developed a hepatocellular carcinoma at a rate of 13.8% per year, intranodular=8.7% vs extranodular=7.1% per year. Hepatocellular carcinoma occurred more frequently in high-grade than low-grade dysplastic nodules (32.2% vs 9.3% per year, p=0.0039); the maximum time to hepatocellular carcinoma transformation was 27 months for intranodular vs 67 months for extranodular tumours (p=0.025). No contrast-computed tomography pattern predicted neoplastic transformation of dysplastic nodules.

CONCLUSION

The histological examination of liver nodules in cirrhosis lacking the imaging hallmark of hepatocellular carcinoma improves both prognostication and outcome of surveillance, since it dictates the intensity of the radiological follow-up.

Comparative histomorphological review of rat and human hepatocellular proliferative lesions

In this comparative review, histomorphological features of common nonneoplastic and neoplastic hepatocyte lesions of rats and humans are examined using H&E-stained slides. The morphological similarities and differences of both neoplastic (hepatocellular carcinoma and hepatocellular adenoma) and presumptive preneoplastic lesions (large and small cell change in humans and foci of cellular alteration in rats) are presented and discussed. There are major similarities in the diagnostic features, growth patterns and behavior of both rat and human hepatocellular proliferative lesions and in the process of hepatocarcinogenesis. Further study of presumptive preneoplastic lesions in humans and rats should help to further define their role in progression to hepatocellular neoplasia in both species.

Fate of hypointense lesions on Gd-EOB-DTPA-enhanced magnetic resonance imaging

PURPOSE

To investigate the natural outcome and clinical implication of hypointense lesions in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI.

MATERIALS AND METHODS

Forty patients underwent Gd-EOB-DTPA-enhanced MRI for preoperative evaluation of HCC. Hypointense lesions in the hepatobiliary phase that were hypovascular 5mm of more were extracted for follow-up. We performed a longitudinal study retrospectively for these lesions regardless of whether classical HCC developed or emerged in a different area from that of the lesions being followed.

RESULTS

Thirty one patients displayed 130 hypointense lesions on MRI and only nine showed no hypointense lesions. In total, 17 (13.1%) of 130 hypointense lesions on MRI developed into classical HCC. The cumulative rates for these lesions to develop into classical HCC were 3.2% at 1 year, 11.1% at 2 years and 15.9% at 3 years. The total occurrence rates of classical HCC (25.8% at 1 year, 52.6% at 2 years and 76.4% at 3 years) were higher compared to those regarding only occurrence of classical HCC from hypointense lesions on MRI (10.0% at 1 year, 35.6% at 2 years and 44.6% at 3 years), although no significant difference was observed (p=0.073).

CONCLUSIONS

Hypointense lesions that are detected in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI have some malignant potential, although treating these lesions aggressively in patients who already have HCC may be too severe.

Radiofrequency ablation of high-grade dysplastic nodules

High-grade dysplastic nodules (HGDNs) are known to be premalignant lesions of hepatocellular carcinoma (HCC). We devised a model to estimate the long-term survival benefit of treating HGDNs by radiofrequency ablation (RFA) (Group I), as compared with regular follow-up and timely treatment by resection (Group II). A hypothetical 60-year-old compensated patient with cirrhosis was assumed. The system being modeled was assumed to be a simple Markov process, and state transition probabilities were given as parameters. Data used for simulation were obtained by a systematic review of the literature. The reported overall malignant transformation rates of HGDNs ranged from 12.5% to 80.8%, and were assumed to be 20%, 50%, and 80% using the best, moderate, and worst scenarios for Group II, respectively. The 5-year overall survival benefit of Group I compared with Group II was calculated by summing the detrimental effect of overtreatment and the beneficial effects of avoiding operative mortality. When the overall malignant transformation rate was set at 20%, 50%, or 80% the expected additional 5-year overall survival benefits of Group I compared with Group II were -0.05%, 0.20%, and 0.47%, respectively, and the corresponding additional 10-year overall survival benefits were 0.03%, 0.33%, and 0.55%, respectively. One-way sensitivity analysis showed that Group I was preferable to Group II in terms of 5-year overall survival when the 5-year overall malignant transformation rate was greater than 25.9%.

CONCLUSION

No definite evidence indicates that the treatment of HGDNs by RFA provides additional long-term overall survival benefit as compared with regular follow-up and timely treatment. The findings of the present study concur with the present American Association for the Study of Liver Diseases guidelines.

Hepatocarcinogenesis: imaging-pathologic correlation

Rapid advances in liver surgery, including liver transplantation, radiology, and pathology, have created a need for clinically relevant nomenclature for premalignant and early lesions of hepatocellular carcinoma (HCC). Precancerous lesions include dysplastic foci and dysplastic nodules (DNs) characterized by cytologic or structural atypia. Although imaging diagnosis is playing a crucial role in the evaluation of hepatocarcinogenesis and early diagnosis of HCC, it is still challenging to accurately characterize borderline nodules such as small arterially enhancing lesions or hypovascular nodules. This article discusses pathological and radiological features of these small nodular lesions and offers insights into the multistep process of hepatocarcinogenesis by describing the progression of pathologic change linking DNs to HCC.

Detection of small hepatocellular carcinoma: intraindividual comparison of gadoxetic acid-enhanced MRI at 3.0 and 1.5 T

PURPOSE

To investigate the diagnostic efficacy of gadoxetic acid-enhanced magnetic resonance imaging (MRI) at 3.0 T for the detection of hepatocellular carcinomas (HCC) and compare with that at 1.5 T.

MATERIALS

Forty patients with 54 HCCs (size range: 0.6-2.0 cm) underwent gadoxetic acid-enhanced MRIs at both 1.5 and 3.0 T with 3 to 8 days interval. The MRIs were compared quantitatively by measuring tumor-liver contrast-to-noise ratio, and qualitatively by evaluating tumor-liver contrast using matched pairs analysis. Diagnostic accuracy and sensitivity were also evaluated by the consensus readings of 2 reviewers using the alternative-free response receiver operator characteristic (ROC) method.

RESULTS

Although the tumor-liver contrast-to-noise ratio for the arterial phase was significantly higher at 3.0 T than at 1.5 T (30.2 ± 21.4 vs. 35.2 ± 22.9; P = 0.04), we found similar values for the hepatocyte phase (38.2 ± 24.6 vs. 38.4 ± 25.3; P = 0.762). Matched pairs analysis indicated that the relative tumor-liver contrast was better in 7 and 9 lesions in the arterial phase and hepatocyte phase at 3.0 T, respectively, than those at 1.5 T. The diagnostic accuracy and sensitivity of 3.0-T imaging [Az, 0.988; 92.6% (n = 50)] were slightly higher than those of 1.5-T imaging [Az, 0.981; 88.9% (n = 48)], but the difference was not statistically significant (P = 0.487).

CONCLUSIONS

Gadoxetic acid-enhanced MRIs at 1.5 and 3.0 T showed similar diagnostic performances for detecting small HCCs. However, there was a tendency toward increased reader confidence for the arterial phase and hepatocyte phase with 3.0 T compared with 1.5 T.

iTRAQ-2DLC-ESI-MS/MS based identification of a new set of immunohistochemical biomarkers for classification of dysplastic nodules and small hepatocellular carcinoma

The study aims to develop novel clinical immunohistochemical biomarkers for distinguishing small hepatocellular carcinoma (sHCC) from dysplastic nodules (DN). iTRAQ-2DLC-ESI-MS/MS technique was used to screen immunohistochemical biomarkers between precancerous lesions (liver cirrhosis and DN) and sHCC. A total of 1951 proteins were quantified, including 52 proteins upregulated in sHCC and 95 proteins downregulated in sHCC by at least 1.25- or 0.8-fold at p < 0.05. The selected biomarker candidates were further verified using Western blotting and immunohistochemistry. Furthermore, receiver operation characteristics (ROC) curves and logistic regression model were carried out to evaluate the diagnostic values of the biomarkers. Finally, aminoacylase-1 (ACY1) and sequestosome-1 (SQSTM1) were chosen as novel candidate biomarkers for distinction of sHCC from DN. A constructed logistic regression model included ACY1, SQSTM1, and CD34. The sensitivity and specificity of this model for distinguishing sHCC from DN was 96.1% and 96.7%. In conclusion, ACY1 and SQSTM1 were identified as novel immunohistochemical biomarkers distinguishing sHCC from DN. In conclusion, expression levels of CD34, ACY1, and SQSTM1 can be used to establish an accurate diagnostic model for distinction of sHCC from DN.

Update on precursor and early lesions of hepatocellular carcinomas

CONTEXT

There is increasing evidence to support a multistep model of the process of human hepatocarcinogenesis. Precursor lesions are characterized by the appearance of dysplastic lesions in the form of microscopic dysplastic foci and macroscopic dysplastic nodules. There are 2 types of small hepatocellular carcinoma (HCC) (≤2 cm in diameter): (1) early HCC with an indistinct margin and (2) progressed HCC with a distinct margin. Pathologic diagnostic criteria for early HCC have recently been set up based on a consensus between Eastern and Western pathologists.

OBJECTIVE

To review the nomenclature, pathology, and biomarkers of precursor and early lesions of HCC.

DATA SOURCES

Literature review and illustrations from case materials were used.

CONCLUSIONS

Dysplastic foci are composed of large and small cell changes. Small cell change is considered to be a more advanced precursor lesion than large cell change, and large cell change is a rather heterogeneous lesion that may represent both reactive change and true dysplasia. Dysplastic nodules can be categorized as low or high grade according to the degree of atypia. High-grade dysplastic nodules have been reported to show molecular changes similar to HCC and have a high risk of malignant transformation. Early HCC, which may correspond to microinvasive carcinomas of other organs, is a well-differentiated HCC, and differential diagnosis between early HCC and high-grade dysplastic nodule is difficult. Identification of stromal invasion and application of a panel of markers (glypican-3, heat shock protein 70, and glutamine synthetase) is helpful for diagnosis of early HCC. Detection of precursor lesions of HCC is important in recognizing patients with higher risk of developing HCC, and diagnosis of early HCC can improve patient survival by allowing for early and adequate treatment.

MR imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy typically associated with chronic liver disease and is a leading cause of mortality among these patients. Prognosis is improved when detected early. MRI is the best imaging examination for accurate diagnosis. Although arterial enhancement with delayed washout, increased T2-weighted signal intensity, delayed capsular enhancement, restricted diffusion, and tumor thrombus are typical features, not all lesions demonstrate these findings. The radiologist must be familiar with these typical imaging characteristics, and less common appearances and associated findings of HCC, and must be able to differentiate them from those of lesions that mimic HCC. Knowledge of therapeutic options and how those are related to imaging findings is imperative to assist clinicians in managing these patients.

Liver precancerous lesions and hepatocellular carcinoma: the histology report

The current ability to increase the survival of patients with hepatocellular carcinoma (HCC) relies upon the surveillance of cirrhotic patients. Surveillance allows HCC precursors (dysplastic nodules) and malignant tumors to be recognized at an earlier stage making cure possible. Radiology plays a major role in HCC diagnosis because HCC is characterized by neoarterial vascularisation with a typical imaging pattern. Current international guidelines have restricted the use of the liver biopsy to the characterization of hepatocellular nodules which remain diagnostically equivocal after imaging. Thus pathologists are today facing very challenging and often well differentiated lesions, leading to difficulties in distinguishing high grade dysplasia and well differentiated HCC. In this scenario novel concepts obtained through international consensus have been proposed with emphasis on HCC of small size (up to 2 cm) which includes 2 distinct types, the early and progressed HCC. In this paper we will report the main histopathological criteria of a biopsy which allow the differentiation of HCC precursors (dysplastic nodules) from well differentiated HCC with attention to the role and weight of both classical histopathological criteria and novel immunocytochemical markers. The second part of the paper is devoted to the histopathology report of HCC on surgical specimens including explanted livers and on the differential diagnosis between HCC and liver metastasis.

Imaging of the liver for hepatocellular cancer

BACKGROUND

Imaging of the liver is a key component in the detection, diagnosis, management, and follow-up of patients with hepatocellular carcinoma.

METHODS

The author uses his own experience as well as a review of pertinent literature to describe the capabilities and the limitations of the principal currently available imaging techniques for the liver.

RESULTS

Ultrasound is widely available, but sensitivity and specificity for small nodules are limited. Computed tomography effectively demonstrates extrahepatic lesions and can differentiate between cysts or hemangiomas and hepatocellular carcinomas. Magnetic resonance imaging better characterizes hepatic lesions, but positron emission tomography is of limited value.

CONCLUSIONS

Cross-sectional imaging with ultrasound, CT, or MRI is critical for nodule characterization in the cirrhotic liver, surgical planning of HCC, and treatment response evaluation.

Hepatocellular carcinoma--what's new?

The increasing incidence of hepatocellular carcinoma (HCC) has led several countries to standardize and update its management. This review aims at summarizing these evolutions through six questions focusing on diagnosis and treatment. The radiological diagnosis of this tumor has been refined. Besides being hypervascular at the arterial phase, the "washout" in particular at the late phase of injection has become a prominent feature. Although routine ultrasound remains the corner stone of screening, contrast ultrasound has become a very reliable characterization tool as it allows continuous monitoring of the vascular kinetics. Biopsy of the tumor allows identification of conventional or molecular prognosis features, some of which could be used in current practice. The metabolic syndrome is an increasing etiology of HCC and carcinogenesis in this context may not always require the development of formal underlying cirrhosis. Associated (in particular cardiovascular) conditions account for an increased morbidity-mortality following surgery. Liver transplantation is the most effective treatment of early-stage tumors. The limited availability of grafts has led some countries including France to implement new allocation rules that are still evaluated and might need to be refined. Sorafenib is the first medical treatment shown to be effective in the treatment of HCC. This efficacy is however still limited and its indication is therefore restricted to Child-Pugh A, OMS 0-2 patients in whom a potentially curative treatment is contraindicated.

Hepatocellular carcinoma in a 10-month-old biliary atresia child

We present a case of a 10-month-old boy with BA who developed HCC and was treated with liver transplantation. A four-month-old boy was referred to our institution because of persistent jaundice, hepatomegaly, and coagulopathy. He had been treated for the diagnosis of neonatal hepatitis at an outside hospital. He was evaluated and was accepted as a liver transplant candidate, and was subsequently transplanted with a deceased donor liver allograft at the age of 10 months. His native liver showed established cirrhosis because of BA with one focus of moderately differentiated HCC, measuring 0.7 cm in a diameter with microscopic vascular invasion in pathological study. The postoperative course was uneventful, and he is well without recurrence four months after liver transplantation. The occurrence of HCC in a child under one yr old is extremely rare, and only three cases are reported so far including our case.

Hepatocarcinogenesis: multistep changes of drainage vessels at CT during arterial portography and hepatic arteriography--radiologic-pathologic correlation

PURPOSE

To clarify the changes that occur in drainage vessels of dysplastic nodules and hepatocellular carcinoma (HCC) during hepatocarcinogenesis by using computed tomography (CT) during arterial portography (CTAP) and CT during hepatic arteriography (CTHA), with histologic findings as the reference standard.

MATERIALS AND METHODS

Institutional ethics committee approval and informed consent were obtained. According to the findings at CTAP and CTHA, 46 surgically resected hepatocellular nodules were classified into three types: type A (n = 18) (equivalent or decreased portal perfusion compared with background liver at CTAP, decreased arterial perfusion, and no corona enhancement [perinodular contrast material drainage] at CTHA), type B (n = 13) (no portal perfusion, increased arterial perfusion, and thin (< or = 2-mm) corona enhancement), or type C (n = 15) (no portal perfusion, increased arterial perfusion, and thick (> 2-mm) corona enhancement). We compared the histopathologic features and microangioarchitecture between the types.

RESULTS

Type A nodules histologically consisted of dysplastic nodules and well-differentiated HCC; type B and C nodules were moderately differentiated HCC. Replacing growth was commonly observed in type A nodules, whereas compressing growth was more frequently seen in types B and C. Sixty percent of type C nodules had a fibrous capsule. There were significantly fewer intranodular hepatic veins in types B and C. Serial pathologic slices demonstrated continuity from intranodular capillarized sinusoids to hepatic veins in type A nodules and to surrounding hepatic sinusoids in type B nodules. In type C nodules, intranodular capillarized sinusoids were connected to extranodular portal veins either directly or through portal venules within the fibrous capsule.

CONCLUSION

Drainage vessels of HCC change from hepatic veins to hepatic sinusoids and then to portal veins during multistep hepatocarcinogenesis.

Chromosomal instability, telomere shortening, and inactivation of p21(WAF1/CIP1) in dysplastic nodules of hepatitis B virus-associated multistep hepatocarcinogenesis

Systemic analysis for chromosomal instability and inactivation of cell cycle checkpoints are scarce during hepatocarcinogenesis. We studied 24 patients with chronic B viral cirrhosis including 30 cirrhotic regenerative nodules, 35 low-grade dysplastic nodules, 15 high-grade dysplastic nodules, 7 dysplastic nodules with hepatocellular carcinoma foci, and 18 hepatocellular carcinomas. Eight normal livers were studied as the control group. Telomere length and micronuclei were detected by Southern blot and Feulgen-fast green dyeing technique, respectively, and p21(WAF1/CIP1) expression was studied by immunohistochemistry. Micronuclei >1 per 3000 hepatocytes were found in 17% of low-grade dysplastic nodules, 87% of high-grade dysplastic nodules, and 100% of high-grade dysplastic nodules with hepatocellular carcinoma foci and hepatocellular carcinomas in contrast to those of all normal livers, and 90% of cirrhosis showed no micronuclei. The micronuclei index showed a gradual increase during hepatocarcinogenesis and there was a significant increase between cirrhosis and low-grade dysplastic nodules, low-grade dysplastic nodules and high-grade dysplastic nodules, and high-grade dysplastic nodules and hepatocellular carcinomas. Telomere length showed a gradual shortening during hepatocarcinogenesis and a significant reduction was found in high-grade dysplastic nodules (P=0.024) and hepatocellular carcinomas (P=0.031) compared with normal and cirrhotic livers. The micronuclei index was correlated with telomere shortening (P=0.016). The p21(WAF1/CIP1) labeling index was significantly higher in cirrhosis than in normal livers (P=0.024) and markedly decreased in low-grade dysplastic nodules, high-grade dysplastic nodules, and hepatocellular carcinomas compared with cirrhosis (P<0.05). The p21(WAF1/CIP1) labeling index was associated with telomere length (P<0.001) but not micronuclei index. This study shows that telomere shortening, chromosomal instability, and inactivation of p21(WAF1/CIP1) checkpoint function occur in low-grade dysplastic nodules as well as in high-grade dysplastic nodules, and their cooperation is considered to be critical for malignant transformation during hepatitis B virus associated-multistep hepatocarcinogenesis.

Hepatitis B virus-associated multistep hepatocarcinogenesis: a stepwise increase in allelic alterations

Hepatocarcinogenesis is a multistep process, but systematic analysis using a genetic or molecular approach to accurately delineate the different stages of hepatocellular carcinoma (HCC) development is scarce. In this study, we used genome-wide allelotyping to systematically evaluate the allelic alterations in the multisteps of hepatitis B virus-associated hepatocarcinogenesis. The overall fractional allelic loss (FAL) indices of cirrhosis, dysplastic nodules (DN), and HCC were significantly different, with a clear stepwise increase (P < 0.001). Loss of heterozygosity (LOH) was uncommon in cirrhotic livers (n = 24; mean FAL index +/- SD, 0.09 +/- 0.09; median, 0.07). In contrast, LOH was common in our 74 HCC nodules, which were predominantly hepatitis B virus-associated (mean FAL index +/- SD, 0.40 +/- 0.23; median, 0.38). The 18 DNs had FAL index (mean +/- SD, 0.27 +/- 0.19; median, 0.20) in between that of cirrhosis and HCC. Importantly, high-grade DNs had FAL index significantly higher than that of low-grade DNs (P = 0.031) and close to that of HCC, indicating that high-grade DNs were genetically closer to HCC. However, there was no significant difference in FAL indices between primary HCCs and their corresponding intrahepatic metastases, but this absence of major allelic losses in this transformation to a metastatic phenotype does not exclude small-scale chromosomal losses or gene deletions. To conclude, hepatitis B virus-associated hepatocarcinogenesis is a multistep process accompanied by stepwise increase in allelic losses from cirrhosis and low- and high-grade DN to HCC. Such allelic losses contribute to promote tumor development and progression.

Perfusion-weighted MRI in evaluating the intranodular hemodynamic characteristics of dysplastic nodules and hepatocellular carcinomas in an experimental rat model

PURPOSE

To investigate the value of perfusion-weighted MRI in the evaluation of the intranodular hemodynamic characteristics of dysplastic nodules (DNs) and hepatocellular carcinomas (HCCs) in an experimental rat model.

MATERIALS AND METHODS

A total of 40 rats with chemically-induced DNs and HCCs were investigated. Single-slice gadolinium-enhanced perfusion-weighted MRI was performed to evaluate the nodules. Time to peak (Tp), maximal relative signal enhancement (REmax), and the initial slope of signal intensity (SI) vs. time curves of the nodules and cirrhotic liver were evaluated. Nodules precisely corresponding to MRI were examined histologically. Paired Student's t-tests were used to compare the difference between nodules and cirrhotic liver.

RESULTS

A total of 20 HCCs and 14 DNs were evaluated. HCCs showed a significantly higher REmax, shorter Tp, and higher slope than adjacent cirrhotic liver. The REmax and slope of DNs were significantly lower than adjacent cirrhotic liver parenchyma. Although the Tp of DNs was delayed two to three seconds compared to adjacent cirrhotic liver, there was no significant difference between them.

CONCLUSION

Perfusion-weighted MRI detected the intranodular hemodynamic characteristics of DNs and HCCs in an experimental rat model. DNs were hypovascular compared to cirrhotic liver, while HCCs were markedly hypervascular.

Radiofrequency ablation of high-grade dysplastic nodules in chronic liver disease: comparison with well-differentiated hepatocellular carcinoma based on long-term results

This retrospective study compared the long-term results of percutaneous radiofrequency (RF) ablation for high-grade dysplastic nodules (DNs) and well-differentiated hepatocellular carcinomas (HCCs). Between April 1999 and December 2006, 20 patients with 21 high-grade DNs (range, 1.2-3.0 cm; mean, 1.9 cm) (group 1) and 49 with a well-differentiated HCC (range, 1.0-5.0 cm; mean, 2.3 cm) (group 2) underwent RF ablation. The technique effectiveness, local tumor progression, cancer-free and cumulative survivals using the Kaplan-Meier method were compared. The technique effectiveness rates at 1 year after RF ablation were 100% (19/19) and 94.1% (32/34) in groups 1 and 2, respectively (P > 0.05). The local tumor progression rates in groups 1 and 2 were 0% and 20.6% (7/34), respectively (P = 0.041). The local tumor progression in group 2 was seen on follow-up computed tomography 4-58 months (mean, 17 months) after RF ablation. The 1-, 3-, and 5-year cancer-free survival rates in groups 1 and 2 were 95.0% and 76.9%, 56.2% and 44.6%, and 38.5% and 24.8%, respectively (P > 0.05). The 1-, 3-, and 5-year cumulative survival rates in groups 1 and 2 were 100% and 97.9%, 73.0% and 68.0%, and 63.8% and 51.1%, respectively (P > 0.05). Percutaneous RF ablation is effective for treating high-grade DNs and well-differentiated HCCs. The long-term results after RF ablation of high-grade DNs may be improved compared with those of well-differentiated HCCs.

Hepatic precancerous lesions and small hepatocellular carcinoma

Precancerous lesions that may be detected in chronically diseased, usually cirrhotic livers, include: clusters of hepatocytes with atypia and increased proliferative rate (dysplastic foci) that usually represent an incidental finding in biopsy or resection specimens; and grossly evident lesions (dysplastic nodules) that may be detected on radiologic examination. There are two types of small hepatocellular carcinoma (HCC) (defined as HCC that measures less than 2 cm): early HCC, which is well-differentiated and has indistinct margins; and distinctly nodular small HCC, which is well- or moderately differentiated, and is usually surrounded by a fibrous capsule. Precise diagnosis of precancerous and early cancerous lesions by imaging methods is often difficult or impossible. Detection of a dysplastic lesion in a biopsy specimen is a marker of increased risk for HCC development, and warrants increased surveillance. High-grade dysplastic nodules and small HCCs should be treated by local ablation, surgical resection, or liver transplantation.

Proposal of progression model for intrahepatic cholangiocarcinoma: clinicopathologic differences between hilar type and peripheral type

It is important to clarify the histologic progression of intrahepatic cholangiocarcinoma (ICC) in consideration of its origin from the intrahepatic large or small biliary ducts. On the basis of the gross and histologic assessment, we classified 87 cases of ICC smaller than 5 cm in diameter into hilar type (H-ICC, n=38) or peripheral type (P-ICC, n=49) to compare their clinical and histologic features. Biliary dysplasia was observed in 65.8% (25/38) of H-ICC cases, whereas hepatitis virus infection and liver cirrhosis were associated with 46.7% (21/45) and 28.6% (14/49) of P-ICC, respectively. The frequency of perineural invasion, lymph node metastasis, and extrahepatic recurrence of H-ICC was significantly higher than that of P-ICC (P<0.0001, 0.0106, and 0.0279, respectively). H-ICC cases showed frequent vascular invasion and intrahepatic metastasis even with small tumor size, compared with P-ICC cases. H-ICC showed large duct involvement within the tumor, and in the cases of large tumor size, intraductal spread was detected in the tumor periphery. P-ICC of small size contained preserved architecture of the portal tracts. The survival of patients with H-ICC was worse than that of patients with P-ICC (P=0.0121). The independent and best prognostic factor by multivariate analysis was intrahepatic metastasis for H-ICC and lymph node metastasis for P-ICC. Our results suggest that ICCs derived from a different level of biliary ducts were related to different premalignant conditions and different tumor progression. Some ICCs arising from the large biliary duct are likely to exhibit an aggressive course even in cases of small tumor size. The recognition of the above events induces the proper therapy.

EUS for detection of the hepatocellular carcinoma: results of a prospective study

BACKGROUND

Early detection of hepatocellular carcinoma (HCC) and accurate determination of the number of lesions are critical in determining eligibility for liver transplantation or resection. Current diagnostic modalities (CT and magnetic resonance imaging [MRI]) often miss small lesions.

OBJECTIVE

To compare the accuracy of the EUS with CT for the detection of primary tumors of the liver.

DESIGN

Prospective single-center study.

SETTING

Academic medical center.

PATIENTS

Subjects at high risk of HCC (hepatitis B, hepatitis C, or alcoholic cirrhosis) were enrolled.

INTERVENTIONS

US, CT, MRI, and EUS examinations of the liver were performed. Liver lesions identified during EUS underwent EUS-guided FNA (EUS-FNA).

RESULTS

Seventeen patients were enrolled in the study. Nine of these patients had liver tumors (HCC, 8; cholangiocarcinoma, 1). EUS-FNA established a tissue diagnosis in 8 of the 9 cases. The diagnostic accuracy of US, CT, MRI, and EUS/EUS-FNA were 38%, 69%, 92%, and 94%, respectively. EUS detected a significantly higher number of nodular lesions than US (P = .03), CT (P = .002), and MRI (P = .04). For HCC lesions, a trend was observed in favor of EUS for the detection of more lesions than US (8 vs 2; P = .06) and CT (20 vs 8; P = .06). No complications were observed as a result of EUS-FNA.

LIMITATIONS

Small sample size.

CONCLUSIONS

EUS-FNA is a safe and accurate test for the diagnosis of HCC. EUS increases the accuracy of intrahepatic staging of the HCC by delineation of lesions, which are missed by CT and MRI. We recommend EUS for suspected HCC, particularly in cases that are being considered for liver transplantation.

Vascular endothelial growth factor, its receptor Flk-1, and hypoxia inducible factor-1alpha are involved in malignant transformation in dysplastic nodules of the liver

Dysplastic nodules (DNs) are regarded as a premalignant lesion of hepatocellular carcinoma (HCC). Sinusoidal capillarization and unpaired arteries are reported in HCC and also to a lesser degree in DN. However, the mechanism and significance of these vascular alterations remain unclear. In this study, these vascular changes were examined with respect to vascular endothelial growth factor (VEGF) and its receptors (Flt-1 and Flk-1), hypoxia inducible factor-1alpha (HIF-1alpha), and CD34, by using 20 surgically resected cases of DNs and 36 cases of conventional HCC. The expression of these molecules was examined immunohistochemically. Although sinusoidal capillarization characterized by CD34 expression was found diffusely in HCC, such changes were found mainly in the areas around the portal tracts and also in other areas in DNs (focal in 6 cases, zonal in 7 cases, and extensive distribution in 7 cases). These capillarized areas were frequently associated with unpaired arteries, and the infiltration of neoplastic hepatocytes into the portal tracts and loss of reticulin fibers in DNs, particularly those with a zonal and extensive distribution. VEGF was diffusely expressed in neoplastic hepatocytes of DNs and HCC. Interestingly, Flk-1 and HIF-1alpha were mostly expressed in endothelial cells and neoplastic hepatocytes in the capillarized areas around portal tracts in DNs, respectively. In conclusion, the capillarized areas with increased numbers of unpaired arteries in DNs may represent an early malignant transformation. Increased expression of Flk-1 and HIF-1alpha associated with VEGF may be involved in sinusoidal capillarization and the increased numbers of unpaired arteries in these areas.

Strategies for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) generally develops as a consequence of underlying liver disease, most commonly viral hepatitis. The development of HCC follows an orderly progression from cirrhosis to dysplastic nodules to early cancer development, which can be reliably cured if discovered before the development of vascular invasion (typically occurring at a tumor diameter of approximately 2 cm). The identifiable population at risk makes screening a realistic possibility, and liver imaging is recommended every 6 months for patients with cirrhosis. For patients with preserved liver function and no portal hypertension who develop HCC that is confined to one region of the liver, resection is the preferred treatment. If resection is not possible because of poor liver function, and the HCC is within the Milan criteria (1 nodule > or =5 cm, 2-3 nodules > or =3 cm), liver transplantation is the treatment of choice. To prevent tumor progression while waiting, nonsurgical treatments including percutaneous ethanol injection, radiofrequency ablation, and transarterial chemoembolization are employed, but drop-out from the waiting list remains a problem. Living donor transplantation is an alternative that can eliminate drop-out and enable liver transplantation for patients with HCC whose disease does not fall within the Milan criteria. There is a need for more effective adjuvant therapies after resection and liver transplantation; newer antiangiogenic agents offer hope for improved outcomes in the future.

Targeting FGF19 inhibits tumor growth in colon cancer xenograft and FGF19 transgenic hepatocellular carcinoma models

Although fibroblast growth factor 19 (FGF19) can promote liver carcinogenesis in mice its involvement in human cancer is not well characterized. Here we report that FGF19 and its cognate receptor FGF receptor 4 (FGFR4) are coexpressed in primary human liver, lung and colon tumors and in a subset of human colon cancer cell lines. To test the importance of FGF19 for tumor growth, we developed an anti-FGF19 monoclonal antibody that selectively blocks the interaction of FGF19 with FGFR4. This antibody abolished FGF19-mediated activity in vitro and inhibited growth of colon tumor xenografts in vivo and effectively prevented hepatocellular carcinomas in FGF19 transgenic mice. The efficacy of the antibody in these models was linked to inhibition of FGF19-dependent activation of FGFR4, FRS2, ERK and beta-catenin. These findings suggest that the inactivation of FGF19 could be beneficial for the treatment of colon cancer, liver cancer and other malignancies involving interaction of FGF19 and FGFR4.

Hepatocyte senescence in end-stage chronic liver disease: a study of cyclin-dependent kinase inhibitor p21 in liver biopsies as a marker for progression to hepatocellular carcinoma

BACKGROUND

Histologic markers to predict hepatocellular carcinoma (HCC) include small cell change and dysplastic nodules. Hepatocyte senescence is noted in chronic liver disease and may or may not be important in progression to HCC.

AIM

The study was undertaken to compare standard histologic features of chronic liver disease as well as markers of senescence and proliferation in two groups of biopsies from patients followed for at least a year.

METHODS

Standard histologic evaluation of necroinflammatory activity, fibrosis, steatosis, and iron, internationally accepted criteria of dysplasia, and immunohistochemical markers for proliferation and hepatocyte senescence were compared in 47 liver biopsies from noncholestatic chronic liver disease patients who subsequently either underwent transplant (the Control group, n=19) or had biopsy-proven (HCC group, n=28) over a similar time period of 34.9 months (mean) and 42.5 months (mean) respectively.

RESULTS

Both groups were predominantly men; the MELD score was higher, and mean age was less in the Control group (46.9 vs 53.8 years, P=0.01). Small cell change was not significantly different in the biopsies between the two groups; neither were grade, stage (Ishak scores), nor presence or location of iron. Steatosis was more common in the group that subsequently developed HCC (P=0.04). The MIB-1 proliferation index was greater in the biopsies from the Control group. The senescence marker p21, and the ratio of p21:MIB-1 were not statistically different between the two groups. However, a Spearman's rank correlation showed a linear correlation of p21/MIB-1 with a greater amount of dyplasia in the explant livers of Controls.

CONCLUSIONS

These findings suggested the Control groups' livers maintained effective removal of cells from the cell cycle by overexpression of p21 and, while not 'protected' from significant involvement by dysplasia, may have been precluded from development of HCC.

Diffusion-weighted magnetic resonance imaging of focal hepatic nodules in an experimental hepatocellular carcinoma rat model

RATIONALE AND OBJECTIVES

We sought to investigate the value of diffusion-weighted MR imaging in evaluating focal hepatic nodules in an experimental hepatocellular carcinoma (HCC) rat model.

MATERIALS AND METHODS

Forty rats with chemically induced primary hepatic nodules ranging pathologically from regenerative nodules (RNs) to dysplastic nodules (DNs) to HCC were examined with diffusion-weighted imaging. The apparent diffusion coefficient (ADC) values of hepatic nodular lesions were calculated. Tukey's HSD post hoc test was used to compare the difference in ADC values between different hepatic nodular lesions.

RESULTS

Eight RNs, 16 DNs, 7 well-differentiated HCCs (HCCwell), 11 moderately differentiated HCCs (HCCmod), and 14 poorly differentiated HCCs (HCCpoor) were evaluated. There was no significant difference between RNs and DNs (P > 0.05). Although the ADC values of HCCwell were slightly lower than those of DNs, there was no significant difference between them (P > 0.05). The ADC values of HCCmod and HCCpoor were significantly higher (P < 0.05) than those of other nodules, and no significant difference was seen between HCCmod and HCCpoor (P > 0.05).

CONCLUSION

Diffusion-weighted magnetic resonance imaging can be useful in characterizing focal hepatic nodular lesions, but ADC values cannot be used efficiently to distinguish HCCwell from DNs.

Early occurrence of hepatocellular carcinoma in biliary atresia treated by liver transplantation

A case of liver transplantation for HCC complicating BA in an eight-month old infant is reported. HCC in BA is extremely rare. Screening of AFP and ultrasonographic examination should be performed regularly in patients with secondary biliary cirrhosis for early detection of HCC.