Macroregenerative nodules and hepatocellular carcinoma in forty-four sequential adult liver explants with cirrhosis

Precision pathology analysis of the development and progression of hepatocellular carcinoma: Implication for precision diagnosis of hepatocellular carcinoma

Outcomes for patients with hepatocellular carcinoma (HCC) remain poor because the condition is often unresponsive to the available treatments. Consequently, the early and precise diagnosis of HCC is crucial to achieve improvements in prognosis. For patients with chronic liver disease, the assessment of liver fibrosis is also important to ascertain both the staging of fibrosis and the risk of HCC occurrence. Early HCC was first described in 1991 in Japan and was defined internationally in 2009. As the concept of early HCC spread, the multistage hepatocarcinogenesis process became accepted. Consequently, improvements in imaging technology made the early diagnosis of HCC possible. At present, the most appropriate therapeutic strategy for HCC is determined using an integrated staging system that assesses the tumor burden, the degree of liver dysfunction and the patient performance status; however, pathological and molecular features are not taken into account. The recent introduction of several new therapeutic agents will change the treatment strategy for HCC. Against this background, HCC subclassification based on tumor cellular and microenvironmental characteristics will become increasingly important. In this review, we give an overview of how pathological analysis contributes to understanding the development and progression of HCC and establishing a precision diagnosis of HCC.

Risk assessment of hepatocellular carcinoma development for indeterminate hepatic nodules in patients with chronic hepatitis B

Background/Aims

A risk prediction model for the development of hepatocellular carcinoma (HCC) from indeterminate nodules detected on computed tomography (CT) (Rad_CT score) in patients with chronic hepatitis B (CHB)-related cirrhosis was proposed. We validated this model for indeterminate nodules on magnetic resonance imaging (MRI).

Methods

Between 2013 and 2016, Liver Imaging Reporting and Data System (LI-RADS) 2/3 nodules on MRI were detected in 99 patients with CHB. The Rad_CT score was calculated.

Results

The median age of the 72 male and 27 female subjects was 58 years. HCC history and liver cirrhosis were found in 47 (47.5%) and 44 (44.4%) patients, respectively. The median Rad_CT score was 112. The patients with HCC (n=41, 41.4%) showed significantly higher Rad_CT scores than those without (median, 119 vs. 107; P=0.013); the Chinese university-HCC and risk estimation for HCC in CHB (REACH-B) scores were similar (both P>0.05). Arterial enhancement, T2 hyperintensity, and diffusion restriction on MRI were not significantly different in the univariate analysis (all P>0.05); only the Rad_CT score significantly predicted HCC (hazard ratio [HR]=1.018; P=0.007). Multivariate analysis showed HCC history was the only independent HCC predictor (HR=2.374; P=0.012). When the subjects were stratified into three risk groups based on the Rad_CT score (<60, 60–105, and >105), the cumulative HCC incidence was not significantly different among them (all P>0.05, log-rank test).

Conclusions

HCC history, but not Rad_CT score, predicted CHB-related HCC development from LI-RADS 2/3 nodules. New risk models optimized for MRI-defined indeterminate nodules are required.

Different Nodules Identified during Liver Explant Gross Examination: Relevance and Need for Sectioning-Experience from India

Objective. The goal of this study was to determine the etiopathological association of various hepatic nodules identified during gross examination of liver explants specimen and the grossing aspects of these abnormal nodules especially those smaller than 1 cm in diameter. Our aim was to analyze whether there is any association of macroregenerative and dysplastic nodule with hepatocellular carcinoma. Materials and Methods. Fifty consecutive liver explants specimens were analyzed for the presence of any abnormal nodule (abnormal nodule defined as any nodule different in color, texture, and appearance from adjacent liver tissue). Results. Of the total 40 abnormal nodules identified in 50 liver explant specimens, there were 12 (30%) HCC [including 5 small HCC (41% of total HCC) and 1 steatohepatitic HCC (8% of total HCC)], 11 (27%) MRNs, 8 (20%) dysplastic nodules, and 9 (22%) necrotic nodules. Most cases (72%) of MRN are seen in hepatitis C virus related cirrhosis with only 2 cases having associated HCC. Most cases of HCC were seen in cases of HBV associated cirrhosis (60%). The association of MRN was not found to be significantly associated with HCC with a p value of 1.0. Dysplastic nodules were found to be significantly associated with HCC with a p value of 0.02. Conclusion. In hepatic carcinogenesis, the role of MRN does not appear to be significant. However, the presence of dysplastic nodules is significantly associated with HCC. The study identified another variant of cirrhotic nodules herein called necrotic nodules that are mostly tan greenish in color and <0.5 cm in diameter. No dysplastic changes were identified in any of these nodules disqualifying the need of sectioning in such nodules.

Characterization of hepatocellular carcinoma (HCC) lesions using a novel CT-based volume perfusion (VPCT) technique

OBJECTIVE

To characterize hepatocellular carcinoma (HCC) in terms of perfusion parameters using volume perfusion CT (VPCT) and two different calculation methods, compare their results, look for interobserver agreement of measurements and correlation between tumor arterialization and lesion size.

MATERIAL AND METHODS

This study was part of a prospective monitoring study in patients with HCC undergoing TACE, which was approved by the local Institutional Review Board. 79 HCC-patients (mean age, 64.7) with liver cirrhosis were enrolled. VPCT was performed for 40s covering the involved liver (80 kV, 100/120 mAs) using 64 mm × 0.6 mm collimation, 26 consecutive volume measurements, 50 mL iodinated contrast IV and 5 mL/s flow rate. Mean/maximum blood flow (BF; ml/100mL/min), blood volume (BV) and k-trans were determined both with the maximum slope+Patlak vs. deconvolution method. Additionally, the portal venous liver perfusion (PVP), the arterial liver perfusion (ALP) and the hepatic perfusion index (HPI) were determined for each tumor including size measurements. Interobserver agreement for all perfusion parameters was calculated using intraclass correlation coefficients (ICC).

RESULTS

The max. slope+Patlak method yielded: BFmean/max=37.8/57 mL/100g-tissue/', BVmean/max=9.8/11.1 mL/100g-tissue, k-trans-mean/max=34.4/44.5 mL/100g-tissue/'. For the deconvolution method BFmean/max, BVmean/max and, k-trans-mean/max were 68.3/106.1 mL/100g-tissue/', 12.6/15.5 mL/100g-tissue and 24/33.8 mL/100g-tissue/'. Mean ALP, PVP, HPI and size were 53.7 mL/100g-tissue/', 2.4 mL/100g-tissue/', 96.4 and 3.5 cm, respectively. Interobserver agreement measured with intraclass coefficient correlation (ICC) was very good for all perfusion parameters (≥ 0.99). Best correlation between calculation methods was achieved for measurements of BF, while BV and k-trans values were less correlated. There was no relationship between HPI and lesion size.

CONCLUSION

VPCT can measure tumor volume perfusion non-invasively and enables quantification of the degree of HCC arterialization. Results are dependent on the technique used with best inter-method correlation for BF. Tumor HPI did not proved size-dependent.

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.

Hepatocellular carcinoma: epidemiology, biology, diagnosis, and therapies

Hepatocellular carcinoma is the fifth most common cancer in men and the seventh in women, as is diagnosed in more than half a million individuals worldwide every year. In Portugal, its incidence and mortality rates are low compared to other types of cancers. In Brazil, in the city of São Paulo, according to data released by the Brazilian Unified Health System (Sistema Único de Saúde - SUS), the incidence of primary liver cancer was 2.07/100,000 inhabitants. Although the vast majority of cases (85%) mainly affect developing countries, especially where infection by hepatitis B virus (HBV) is endemic, the incidence in developed countries is increasing. This pathology is associated with several risk factors, not only environmental but also genetic, generating an increasing interest in attaining a better understanding of this disease, which is still associated with very late diagnosis and poor prognosis. Of the available treatments, few patients benefit from their scanty advantages, increasingly stimulating research of new forms of treatment against this disease. This review aimed to briefly but fully identify risk factors, molecular and biochemical pathways, pathophysiology, diagnosis, and possible clinical approaches of hepatocellular carcinoma.

Predictors of dysplastic nodule diagnosis in patients with liver cirrhosis on unenhanced and gadobenate dimeglumine-enhanced MRI with dynamic and hepatobiliary phase

OBJECTIVE

The purpose of this article is to assess whether unenhanced and gadobenate dimeglumine-enhanced MRI with dynamic and hepatobiliary phase may predict the diagnosis of dysplastic nodules in patients with liver cirrhosis.

MATERIALS AND METHODS

We retrospectively analyzed 75 cirrhotic patients (47 men and 28 women; mean [± SD] age, 55 ± 12 years) with 82 hepatocellular nodules, including histology-proven dysplastic nodules (n = 25; diameter, 1-3 cm) and hepatocellular carcinomas (n = 57; diameter, 2-3 cm) scanned by MRI before and after gadobenate dimeglumine injection during hepatic arterial phase (HAP), portal venous phase (PVP), equilibrium phase, and hepatobiliary phase. Nodule T1 and T2 intensities before contrast agent injection and nodule HAP, PVP, equilibrium phase, and hepatobiliary phase intensities were compared with the adjacent liver. Univariate and multivariate logistic regression analysis was conducted to assess how the nodule could predict dysplastic nodule diagnosis.

RESULTS

Some imaging findings were independent predictors of dysplastic nodule diagnosis-namely, nodule T2 isohypointensity (odds ratio [OR], 12.28; 95% CI, 3.88-38.82), T1 isohyperintensity (OR, 26.74; 95% CI, 7.53-94.90), HAP isohypointensity (OR, 97.16; 95% CI, 20.06-470.49), PVP-equilibrium phase isohyperintensity (OR, 20.53; 95% CI, 5.36-78.62), and hepatobiliary phase isohyperintensity (OR, 119.6; 95% CI, 21.59-662.40). Nodule T2 and HAP isohypointensity (OR 31.47; 95% CI, 7.88-125.58), nodule T2 isohypointensity and hepatobiliary phase isohyperintensity (OR, 28.77; 95% CI, 7.79-106.19), nodule T1 isohyperintensity and HAP isohypointensity (OR, 17.22; 95% CI, 4.85-61.14), and nodule T1 and hepatobiliary phase isohyperintensity (OR, 19.39; 95% CI, 5.38-69.90) were also predictors of dysplastic nodule diagnosis.

CONCLUSION

The combination of nodule appearance on T2-weighted MRI and nodule enhancement after gadobenate dimeglumine injection may predict dysplastic nodule diagnosis in patients with liver cirrhosis.

Histopathology of hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the most frequent primary liver malignancy, mostly occurring in the context of chronic liver diseases leading to cirrhosis. Epidemiological data demonstrate the increasing incidence of HCC worldwide, mainly related to viral hepatitis and metabolic syndrome. Pathological analysis recognizes several types of HCC according to macroscopic and microscopic features. A subset of HCC can develop on normal liver and usually corresponds to specific variants, including fibrolamellar carcinoma mostly encountered in young population. Prognosis of HCC remains poor, depending on delayed tumor diagnosis, the clinical status of the patient but also tumor behavior with a great propensity for angioinvasion.

Accuracy and disagreement of computed tomography and magnetic resonance imaging for the diagnosis of small hepatocellular carcinoma and dysplastic nodules: role of biopsy

Liver macronodules, ranging from benign to low-grade or high-grade dysplastic nodules (LGDNs/HGDNs) and hepatocellular carcinoma (HCC), may develop during chronic liver diseases (CLDs). Current guidelines were recently updated and the noninvasive criteria for the diagnosis of small HCC are based on a single typical radiological pattern and nonconclusive coincidental findings with two techniques. This study aimed to assess the accuracy and disagreements of noninvasive multiphasic examinations for the diagnosis of HCC and dysplastic nodules (DNs) and the role of biopsy. Seventy-four consecutive patients with CLD with ultrasound-detected 1-2-cm nodules underwent, within 1 month, multiphasic computed tomography (CT), magnetic resonance imaging (MRI), and biopsy of the nodule. Median age was 60 years; 33 patients (45%) had hepatitis C virus, 20 (27%) had hepatitis B virus, and 13 (18%) patients had no cirrhosis. Biopsy revealed 47 HCCs, 6 HGDNs, 1 LGDNs, 1 cholangiocarcinoma, and 1 epithelioid hemangioendothelioma. There were no tumors in the other 18 patients. All patients (31 of 31; 100%) who had conclusive coincidental findings (i.e., arterial enhancement and washout) on both examinations had HCC or HGDN (sensitivity, 57%; specificity, 100%). All patients (51 of 51; 100%) who had conclusive findings on at least one of the two examinations had HCC or HGDN (sensitivity, 96%; specificity, 100%). There was a disagreement regarding imaging findings between CT and MRI in 21 of 74 (28%) patients and no washout on both examinations in 23 of 74 patients (31%). In these 44 patients, liver biopsy provided an initial accurate diagnosis.

CONCLUSION

The noninvasive diagnosis of HCC or HGDN can be obtained if arterial enhancement and washout are found in a single dynamic imaging examination. These findings are frequently discordant on both CT and MRI, supporting the place of biopsy for the diagnosis of small HCCs.

Well-differentiated hepatocellular carcinoma detected as hypovascularity by only CT during hepatic arteriography

We describe a well-differentiated hepatocellular carcinoma (HCC) with alcohol-related liver cirrhosis in a 69-year-old man. Ultrasonography (US) disclosed a 10 mm hypoechoic nodule in segment 4; Sonazoid contrast-enhanced US and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) revealed no defect in either the Kupffer phase or the hepatobiliary phase. Computed tomography during hepatic arteriography (CTHA), however, revealed a hypovascular nodule, but CT during arterial portography showed no perfusion defect. Histological analysis indicated a well-differentiated HCC. Thus, our detection of well-differentiated HCC disclosed by only CTHA attested to the efficiency of this modality, suggesting that it is more sensitive than Gd-EOB-GTPA-enhanced MRI.

The changing role of liver biopsy in diagnosis and management of haemochromatosis

Liver biopsy with histological examination of liver tissue was for many years the cornerstone of the diagnosis of haemochromatosis, allowing assessment of the degree of iron overload and examination of liver histology for the acute and chronic effects of iron overload. In the past two decades the role of liver biopsy in haemochromatosis has changed dramatically. Liver biopsy is rarely requested for two main reasons: (1) genetic testing for human haemochromatosis (HFE) mutations has proved to be very reliable in the diagnosis of haemochromatosis in Caucasian populations, and (2) the majority of patients with haemochromatosis are now diagnosed at an early stage well before permanent tissue damage occurs, so the need to assess tissue and organ damage has diminished. Liver biopsy continues to have a very important role in a small number of haemochromatosis patients for whom it has both diagnostic and prognostic implications. Liver biopsy is essential for the accurate assessment of patients with non-HFE haemochromatosis and in patients who have dual pathology. It is also useful where there appears to be a discrepancy between HFE genotypes and iron studies, particularly in HFE heterozygotes. Finally, liver biopsy is currently the 'gold standard' for the diagnosis of fibrosis and cirrhosis, although this is changing as non-invasive methods for assessing fibrosis become more reliable and available. Therefore, it is important that pathologists maintain their knowledge and skills in the use of liver biopsy in haemochromatosis and other iron storage disorders.

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.

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.

Diagnostic sensitivity of imaging modalities for hepatocellular carcinoma smaller than 2 cm

AIM

To compare the imaging results with histology and to evaluate the diagnostic sensitivity of imaging modalities for hepatocellular carcinoma (HCC) smaller than 2 cm.

METHODS

Nodules smaller than 2 cm (n = 34) revealed by ultrasonography (US) in 29 patients with liver cirrhosis were analyzed. Histological diagnosis of HCC was performed by ultrasonographic guidance: moderately-differentiated HCC (n = 24); well-differentiated HCC (n = 10). The patterns disclosed by the four imaging modalities defined the conclusive diagnosis of HCC: (1) contrast-enhanced computed tomography (CECT), hypervascularity in the arterial phase and washout in the equilibrium phase; (2) Sonazoid contrast-enhanced US (CEUS), hypervascularity in the early vascular phase and defect in the Kupffer phase; (3) gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI), hypervascularity in the arterial phase and/or defect in the hepatobiliary phase; and (4) CT arterioportal angiography: hypervascularity by CT during arteriography and/or perfusion defect by CT during arterial portography.

RESULTS

Overall, the sensitivity of diagnosing HCC smaller than 2 cm was 52.9% (18/34) (95% CI: 35.1-70.2) by CECT; 67.6% (23/34) (95% CI: 49.5-82.6) by Sonazoid CEUS; 76.5% (26/34) (95% CI: 58.8-89.3) by Gd-EOB-DTPA MRI; and 88.2% (30/34) (95% CI: 72.5-96.7) by CT arterioportal angiography. The diagnostic sensitivity of detecting moderately-differentiated HCC by CECT, Sonazoid CEUS, Gd-EOB-DTPA MRI and CT arterioportal angiography was 62.5% (15/24) (95% CI: 40.6-81.2), 79.2% (19/24) (95% CI: 57.8-92.9), 75.0% (18/24) (95% CI: 53.3-90.2) and 95.8% (23/24) (95% CI: 78.9-99.9), respectively. A significant difference (P < 0.05) was observed between CECT and CT arterioportal angiography in all nodules. There was no difference between Sonazoid CEUS, Gd-EOB-DTPA MRI, and CT arterioportal angiography. The combined sensitivity of Sonazoid CEUS and Gd-EOB-DTPA MRI was 94.1% (32/34).

CONCLUSION

Changing the main diagnostic modality for HCC smaller than 2 cm from CT arterioportal angiography to Sonazoid CEUS and Gd-EOB-DTPA MRI is recommended.

Hepatocellular carcinoma: epidemiology, surveillance, and diagnosis

Hepatocellular carcinoma (HCC) is increasing in incidence in many countries, and is the most common cause of death in patients with cirrhosis. With regular surveillance, small early HCC lesions can be identified. An algorithm has been developed that allows for diagnosis of these lesions. Very early HCC lesions have high cure rates with appropriate treatment. If all these factors are in place most HCCs can be cured.

Association between hypothyroidism and hepatocellular carcinoma: a case-control study in the United States

Thyroid hormones play an essential role in lipid mobilization, lipid degradation, and fatty acid oxidation. Hypothyroidism has been associated with nonalcoholic steatohepatitis; however, the association between thyroid diseases and hepatocellular carcinoma (HCC) in men and women has not been well established. We investigated the association between hypothyroidism and HCC risk in men and women in a case-control study, which included 420 eligible patients with HCC and 1104 healthy controls. We used multivariate unconditional logistic regression models to control for the confounding effects of established HCC risk factors. A long-term history of hypothyroidism (>10 years) was associated with a statistically significant high risk of HCC in women; after adjusting for demographic factors, diabetes, hepatitis, alcohol consumption, cigarette smoking, and family history of cancer, the odds ratio (OR) was 2.9 (95% confidence interval [CI], 1.3-6.3). Restricted analyses among hepatitis virus-negative subjects, nondrinkers, nondiabetics, nonsmokers, and nonobese individuals indicated a significant association between hypothyroidism and HCC, with an approximate two-fold to three-fold increased risk of HCC development. We observed risk modification among women with diabetes mellitus (OR = 9.4; 95% CI = 2.7-32.7) and chronic hepatitis virus infection (OR = 31.2; 95% CI = 6.3-153.2). A history of hyperthyroidism was not significantly related to HCC (OR = 1.7; CI = 0.6-5.1). We noted significant elevated risk association between hypothyroidism and HCC in women that was independent of established HCC risk factors. Experimental investigations are necessary for thorough assessment of the relationship between thyroid disorders and HCC.

Histological features of early hepatocellular carcinomas and their developmental process: for daily practical clinical application : Hepatocellular carcinoma

Based on clinical and pathological experience, indistinct margin-type hepatocellular carcinomas (HCCs) were considered to be typical early-stage HCCs with good prognosis. For histological diagnosis, the assessment of stromal invasion (tumor invasion into portal tracts and fibrous septa) is very important. In differentiating stromal invasion from pseudoinvasion (benign hepatic tissue in the fibrous stroma), the following 5 items are useful: (1) macroscopic or panoramic views of the histological specimen, (2) amount of fibrous components of the stroma, (3) destruction of the structure of portal tracts, (4) loss of reticulin fibers around cancer cells, and (5) cytokeratin 7 immunostaining for ductular proliferation. Parenchymal features of early HCCs are summarized as follows: (1) thin trabecular structure, (2) hypercellularity, (3) hyperstainability of cytoplasm, and (4) microacinar formation. Detailed understanding of the total biopsy procedure and various difficult lesions is necessary for a correct biopsy diagnosis. Evaluation of noncancerous tissue is also required to attain a better understanding of the developmental process and clinical stages of 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.

Malignant progression of a small HCC nodule: hypovascular 'early HCC' converted to hypervascular 'small HCC' within six months

We report a case of hepatocellular carcinoma superimposed on chronic hepatitis C virus (HCV) hepatitis in which final diagnosis of hepatocellular carcinoma was delayed because there was no consensus on hypervascularity with two diagnostic methods at the time of presentation. A 3 cm lesion was initially observed as hypovascular at multidetector-row computed tomography. Conversely, two months later the lesion appeared hypervascular at contrast-ultrasonography and gadolinium-enhanced dynamic magnetic resonance, and hyperintense after superparamagnetic iron oxide-enhanced T2W studies. Only in the late follow-up it was definitively confirmed as hypervascular in the arterial phase of multidetector-row computed tomography. This case clearly highlights some pitfalls in the European Association for the study of the liver guidelines for hepatocellular carcinoma management, which were readdressed in the last American Association for the Study of Liver Diseases (AASLD) and in the forthcoming international proposals, leading to more pragmatic suggestions for clinical practice.

Hepatocellular dysplastic nodules

The multistep process of hepatic carcinogenesis is mirrored by the morphologic classification of lesions detectable in cirrhosis, which include large regenerative nodules (LRN), low grade dysplastic nodules (LGDN), and high grade dysplastic nodules (HGDN). The latter belong to the "bordeline malignancy" category requiring accurate distinction from well-differentiated and early hepatocellular carcinoma (HCC). Nodules in cirrhosis are usually detected by non-invasive imaging techniques, which are unable to discriminate malignant from non-malignant forms, particularly in the 1-2-cm sized group. Liver biopsy is essential in providing practical diagnostic information to hepathologists in the management of cirrhotic patients with ultrasound (US)-detectable nodules. Histologic diagnosis on liver samples is based on the accurate search of a set of cyto-architectural features (e.g. cell atypia, cell crowding, trabecular thickness, microacini) and by a supplement of histochemical (Gomori staining) and immunocytochemical stainings. The latter rely upon the search of both well established and novel markers, targeted to evaluate stromal invasion (CK7/19), the vascular pattern (ASMA and CD34), or tumor markers (including HSP70 and glipican-3). Still, the diagnostic sensitivity is limited by the type and size of sampling and by its representativity of the entire lesion. Thus, the best diagnostic approach requires the integration ofclinical, morphological, and immunocytochemical information with imaging data (i.e. US pattern, perfusional pattern, helical computed tomography/magnetic resonance pattern). Molecular data are still under evaluation as to their diagnostic efficacy in this controversial field. Discrepancies have emerged recently between Eastern and Western interpretation of these lesions, particularly in the category of "borderline" nodules that are mostly labelled as early, well differentiated HCC by Eastern pathologists and as HGDN by Western pathologsts. Novel and more objective phenotypical and molecular markers are needed to discriminate within the grey area of borderline lesions that, epidemiologically, are likely distinct between Eastern and Western geographic areas. These tools might allow a better understanding of the boundaries of the process going from high grade dysplasia to in situ HCC and from the latter to microinvasive HCC and advanced HCC, for proper clinical management and optimal therapy.

Newly Developed Hepatocellular Carcinoma (HCC) in Chronic Liver Disease

PURPOSE

The purpose of this work was to describe the initial magnetic resonance (MR) imaging findings obtained before an imaging diagnosis of overt hepatocellular carcinoma (HCC) in the chronically damaged liver.

METHODS

One hundred fifty-two newly diagnosed HCCs diagnosed by dynamic computed tomography (n = 111) or by MR imaging (n = 41), in addition to digital subtraction hepatic arteriography, in 96 patients were subjected to analysis of their MR imaging features within the previous 2 years.

RESULTS

Ninety-seven (64%) HCC cases showed no focal lesions distinguishable from background hepatic parenchyma in MR images taken before the indication of typical HCC. The remaining 55 (36%) lesions were readily identified in earlier images and were categorized into 3 groups: nonhypervascular lesions (category I, n = 6), lesions with partially hypervascular foci of "nodule-within-nodule" appearance (category II, n = 12), and homogeneously hypervascular and/or T2-weighted hyperintense lesions (category III, n = 37). The size and doubling time of category III lesions (0.7 cm, 154 days) were smaller and shorter than those of the other lesions (1.2 cm, 377 days).

CONCLUSIONS

Before the imaging diagnosis of HCCs, the premalignant or early malignant lesions can be found on the prior MR images just in the minority of the lesions in the cirrhotic liver.

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

BACKGROUND

Advances in imaging technology have enhanced the detection of small nodular lesions during the course of chronic liver disease.

METHODS

Between 1995 and 2002, the authors examined 154 consecutive patients with small hepatic nodules without hepatocellular carcinoma (HCC) over a median duration of 2.8 years. The median size of these nodules was 14 mm (range, 7-40 mm). The initial histopathologic diagnosis included high-grade dysplastic nodule (HGDN) (n=13), low-grade dysplastic nodule (LGDN) (n=42), and regenerative nodule (RN) (n=99).

RESULTS

A total of 29 (18.8%) nodules developed into HCC during the observation period. Cumulative HCC development rates at the first, third, and fifth year were 46.2%, 61.5%, and 80.8% for HGDN; 2.6%, 30.2%, and 36.6% for LGDN; and 3.3%, 9.7%, and 12.4% for RN, respectively. The rate of HCC development was significantly higher in the HGDN group than for other types (P<0.001). Multivariate analysis disclosed that histopathologic diagnosis (P<0.001) and findings on computed tomographic arterial portography (CT-AP) (P=0.004) were significantly associated with future HCC development. The hazard ratios of HGDN and LGDN were 16.8 (95% confidence interval [CI], 6.19-45.6) and 2.96 (95% CI, 1.20-7.31), respectively. A decrease in portal blood flow also showed a significantly high hazard ratio of 3.04 (95% CI, 1.42-6.50). Approximate annual development rate to HCC was 20% in patients with HGDN and 10% in LGDN.

CONCLUSION

HGDN should be considered a precancerous lesion when it appears during follow-up of chronic viral hepatitis or cirrhosis. Reduced portal blood flow in the nodule on computed tomography-AP is also an important predictor for development of hepatocellular carcinoma.

Characterization of small nodules in cirrhosis by assessment of vascularity: the problem of hypovascular hepatocellular carcinoma

In a prospective study, we examined the impact of arterial hypervascularity, as established by the European Association for the Study of the Liver (EASL) recommendations, as a criterion for characterizing small (1-3 cm) nodules in cirrhosis. A total of 72 nodules (1-2 cm, n = 41; 2.1-3 cm, n = 31) detected by ultrasonography in 59 patients with cirrhosis were included in the study. When coincidental arterial hypervascularity was detected at contrast perfusional ultrasonography and helical computed tomography, the lesion was considered to be hepatocellular carcinoma (HCC) according to EASL criteria. When one or both techniques showed negative results, ultrasound-guided biopsy was performed. In cases with negative results for malignancy or high-grade dysplasia, biopsy was repeated when an increase in size was detected at the 3-month follow-up examination. Coincidental hypervascularity was found in 44 of 72 nodules (61%; 44% of 1-2-cm nodules and 84% of 2-3-cm nodules). Fourteen nodules (19.4%) had negative results with both techniques (hypovascular nodules). Biopsy showed HCC in 5 hypovascular nodules and in 11 of 14 nodules with hypervascularity using only one technique. All nodules larger than 2 cm finally resulted to be HCC. Not satisfying the EASL imaging criteria for diagnosis were 38% of HCCs 1 to 2 cm (17% hypovascular) and 16% of those 2 to 3 cm (none hypovascular). In conclusion, the noninvasive EASL criteria for diagnosis of HCC are satisfied in only 61% of small nodules in cirrhosis; thus, biopsy frequently is required in this setting. Relying on imaging techniques in nodules of 1 to 2 cm would miss the diagnosis of HCC in up to 38% of cases. Any nodule larger than 2 cm should be regarded as highly suspicious for HCC.

Approaches to the diagnosis of hepatocellular carcinoma

The advent of screening programs for hepatocellular carcinoma in patients with chronic viral hepatitis and cirrhosis has resulted in detection of smaller and smaller lesions in the liver. Some of these are small carcinomas, but many are not malignant in nature or are potential precursors to malignancy. Neither radiology nor biopsy can be used confidently to distinguish between these possibilities when the lesions are smaller than approximately 1.5 cm in diameter. Therefore, diagnostic algorithms must be developed to assist physicians in investigating these small lesions and deciding when they are truly malignant, when treatment is necessary, or whether a watchful waiting course is appropriate. The diagnostic difficulties are presented, with examples of diagnostic algorithms that may be helpful in managing these patients.

Histopathology of liver cancers

Recently, new pathomorphologic information about early-stage small hepatocellular carcinoma (HCC) and the multi-step process of human hepatocarcinogenesis has been obtained, along with advances in the development of diagnostic modalities. The most valuable information is that in the majority of cases HCC arises as a very well differentiated cancer and proliferates with a stepwise process of dedifferentiation. In addition, it has been suggested that many HCCs seem to arise from dysplastic nodules (DNs) on the basis of the following evidence: the presence of DNs containing HCC foci, frequent association of DNs in the vicinity of HCC, and clinical progression from DN to HCC. However, as many HCCs are still detected at an advanced stage, it is also important to understand not only the classical pathologic features of HCC but also unusual features such as scirrhous change, sarcomatous change, fibrolamellar variant, and intra-bile duct or intra-atrial tumor growth.

Dysplastic nodules in liver cirrhosis: detection with triple phase helical dynamic CT

The purpose of this study was to determine the sensitivity of triple phase helical dynamic CT for detecting dysplastic nodules in patients with liver cirrhosis. 76 dysplastic nodules were confirmed by histopathological examination of the liver specimens after surgical resection in 21 patients or after explantation of the whole liver in 20 patients. Triple phase helical dynamic CT including arterial, portal venous and delayed phases was performed as a pre-operative evaluation for hepatocellular carcinoma. Two readers retrospectively evaluated the images. The presence of dysplastic nodules was determined by one-to-one correlation of the CT images and the pathological results in terms of the anatomical location and size of each nodule. Helical dynamic triple phase CT depicted eight of 76 dysplastic nodules (10%): five of 35 high grade dysplastic nodules (14%) and three of 41 low grade dysplastic nodules (7%). Triple phase helical dynamic CT is insensitive for detection of dysplastic nodules in cirrhotic livers.

Unique hypervascular nodules in alcoholic liver cirrhosis: identical to focal nodular hyperplasia-like nodules?

BACKGROUND/AIMS

Currently, focal nodular hyperplasia (FNH)-like nodules in cirrhotic liver is spotlighted. Unique hypervascular nodules mimicking FNH-like nodule in alcoholic liver cirrhosis were clinicopathologically clarified.

METHODS

Six resected and six biopsy cases of small hypervascular nodules found in alcoholic cirrhosis were studied clinicopathologically.

RESULTS

All cases were male and consumed 90-150 g/day of ethanol for longer than 20 years, and hepatitis virus markers were negative. The nodules, 9-21 mm in diameter, were detected by ultrasonography during follow-up of alcoholic cirrhosis, and showed hypervascularity on angiography. Six patients were diagnosed as hepatocellular carcinoma and six were as hyperplastic nodule by biopsy, and the former six cases received partial hepatectomy. All of the resected nodules were completely or incompletely encapsulated. Histologically, all resected and biopsy nodules showed moderate increase of cell-density with an irregular trabecular pattern, and scar-like fibrosis with anomalous blood vessels, and unpaired arteries. All nodules showed marked or mild iron deposits in hepatocytes and/or kupffer cells, and a diffuse capillarization of the sinusoids.

CONCLUSIONS

The nodules in the present series seem to fall in the same category as FNH-like nodules in cirrhotic liver, and should be taken account in screening programs including patients with alcoholic cirrhosis.

Usefulness of contrast-enhanced perfusional sonography in the assessment of hepatocellular carcinoma hypervascular at spiral computed tomography

BACKGROUND/AIMS

Diagnosis of hepatocellular carcinoma (HCC) relies strongly on the detection of hypervascularity in the arterial phase and, in this setting, spiral computed tomography (CT) is the most widely used method. This prospective study aimed to investigate the usefulness of low mechanical index harmonic ultrasound (US), using a second generation contrast-enhanced technique, in the assessment of vascular pattern of HCC shown to be hypervascular at spiral CT.

METHODS

A total of 79 cirrhotic patients with 103 nodules (mean+/-SD 28+/-13 mm) with arterial hypervascularity at spiral CT were studied. US examination was performed by perfusional sonography, using a new dedicated technology (CnTI-Esaote trade mark ), operating at low mechanical index, after injection of a second generation contrast agent (SonoVue trade mark -Bracco), allowing detection of tumoral flow during arterial phase.

RESULTS

Selective arterial enhancement on perfusional sonography was observed in 94 /103 nodules (91.3%), with a sensitivity of 66.6, 87.5, 91.7, and 97.3% in nodules </=1 cm, >1</=2 cm, >2</=3 cm, and >3 cm respectively.

CONCLUSIONS

Perfusional sonography shows good diagnostic agreement with spiral CT in hypervascular HCC and may be proposed for the immediate vascular characterization of nodules detected at US and used as second imaging technique to confirm hypervascularity in cirrhotic nodules.

Focus on dysplastic nodules and early hepatocellular carcinoma: an Eastern point of view

Although increasing numbers of equivocal nodular lesions have been detected in patients with liver cirrhosis with the development of various diagnostic imaging modalities, the pathological diagnosis of small, well-differentiated hepatocellular carcinoma (HCC) in the early stage and of high-grade dysplastic nodules (DNs) is a controversial issue among both Japanese and Western pathologists. In particular, many of the vaguely nodular HCCs of well-differentiated HCC diagnosed by Japanese pathologists tend to be interpreted as high-grade DNs rather than HCC by Western pathologists. In contrast, many of the high-grade DNs diagnosed by Western pathologists are interpreted as well-differentiated HCC by Japanese pathologists. The reasons for the discrepancy between Japanese and Western pathologists can be explained by the following: for Western pathologists, most information comes from the study of HCC and advanced cirrhosis explanted at liver transplantation without detailed clinical information about the nodules; for Japanese pathologists, most information comes from the examination of surgical and biopsy materials together with detailed clinical information that includes meticulous follow-up data on the clinical course of the nodular lesions. To resolve the diagnostic confusion concerning equivocal nodular lesions in the cirrhotic liver, it is necessary to promote the active exchange of clinicopathologic information between Japan and Western countries.

Improved diagnosing of small hepatocellular carcinomas by echo-enhanced power Doppler sonography in patients with cirrhosis

BACKGROUND AND AIMS

Echo-enhanced power Doppler sonography is an increasingly used procedure for the differentiation of liver tumours. The aim of this prospective study was to investigate the accuracy of echo-enhanced power Doppler sonography in comparison with conventional ultrasound and fundamental power Doppler sonography in diagnosing hepatocellular carcinomas and regenerative nodules in patients with cirrhosis.

SUBJECTS AND METHODS

Eighty-seven patients with cirrhosis and 90 liver tumours at conventional ultrasound were included in the study, selected from 103 consecutive patients with a mean age of 60 years (range 23-87 years) who presented to our department from January 1998 through January 2002. Sonography was performed by an experienced examiner, who was unaware of the clinical diagnosis. The exact diagnosis was based upon histological evidence from biopsy examination, laboratory results, and/or a follow-up of at least 18 months.

RESULTS

There were 65 hepatocellular carcinomas, 21 regenerative nodules, and four metastases in the study group. Only 43% of the carcinomas (mainly nodules > 3 cm in diameter) could be classified correctly by conventional ultrasound or fundamental power Doppler sonography. However, 46% of the malign lesions (mainly nodules < 3 cm in diameter) were not differentiable. All non-differentiable tumours were classified correctly by echo-enhanced power Doppler sonography. The overall sensitivity of echo-enhanced power Doppler sonography with respect to diagnosing hepatocellular carcinoma was 89%; its specificity was 60%. The corresponding values for regenerative nodules were 71% and 100%, respectively.

CONCLUSIONS

Only hepatocellular carcinomas greater than 3 cm in size can be diagnosed with a high accuracy by conventional ultrasound or fundamental power Doppler sonography. However, small malignant lesions in cirrhotic livers are often not differentiable with these techniques. With echo-enhanced power Doppler sonography, the differentiation of small hepatocellular carcinomas can be improved. However, histology is the standard of reference.

Scirrhous changes in dysplastic nodules do not indicate high-grade status

BACKGROUND AND AIMS

Dysplastic nodules (DN) may be divided into high-grade and low-grade, and the former has been known as a precancerous or borderline lesion. Recently many morphological characteristics concerning these types of DN have been reported. In the present study we attempted to evaluate the scirrhous change in DN as an indicative feature of high-grade DN, based on the morphological and cell-kinetic analyses using immunohistochemical stains for Ki-67.

METHODS

We reviewed 35 livers with DN and selected 15 DN with scirrhous change. We stained DN-bearing sections of each case with hematoxylin and eosin, trichrome, reticulin and Perls' stain. We tried to subclassify and characterize the scirrhous change according to the fibrosis pattern. We also stained with Ki-67 immunohistochemically to assess the proliferative activity of DN with scirrhous change.

RESULTS

We found two types of scirrhous change, that is, pericellular and stellate. The pericellular type was related to the Mallory body-forming cholestatic degeneration, whereas the stellate type was associated with extensive portal fibrosis probably induced by ischemic damage. Among DN with scirrhous change, high-grade DN comprised five nodules (33%) and there were 10 (67%) low-grade nodules. There was no significant relationship between the presence or the types of scirrhous change and the grade of DN. The significant differences of Ki-67 labeling indices between types of scirrhous change were not shown in this study. We also could not find the differences between Ki-67 labeling indices of scirrhous DN (high and low grades) and those of surrounding regenerative nodules.

CONCLUSIONS

This evidence indicated that the scirrhous change in DN was not a specific feature of high-grade DN. We also found that scirrhous DN have two morphological varieties that may represent biologically different processes, that is, pericellular scirrhous type and stellate scirrhous type.

Transplantation for hepatocellular carcinoma and cirrhosis: sensitivity of magnetic resonance imaging

The sensitivity of magnetic resonance imaging (MRI) in patients who undergo transplantation for hepatocellular carcinoma (HCC) and cirrhosis is not known. We prospectively evaluated 24 patients with known HCC who underwent MRI and subsequent transplantation within 60 days (mean, 20 days). Using a phased-array coil at 1.5T, breath-hold turbo STIR and T2-weighted MR images were performed. Dynamic gadolinium-enhanced MRI was performed using a two- or three-dimensional gradient echo pulse sequence with images obtained in the hepatic arterial, portal venous, and equilibrium phases. The prospective interpretation of the MR study was directly compared with thin-section pathology evaluation of the explanted livers. All 24 patients had at least one HCC, and MR diagnosed tumor in 21 (88%) of these patients. On a lesion-by-lesion basis, MRI depicted 39 of 118 HCC for an overall sensitivity of 33%. MRI detected five (100%) of five lesions >5 cm, 20 (100%) of 20 lesions >2 cm but not exceeding 5 cm, 11 (52%) of 21 lesions between 1 and 2 cm, and three (4%) of 72 lesions <1 cm. Of the nine patients with carcinomatosis (innumerable lesions less than 1 cm), MR detected three lesions in one patient. Of the 15 dysplastic nodules found at pathology, MRI depicted a single 1.8-cm high-grade lesion, for a sensitivity of 7%. In conclusion, MRI is sensitive for the detection of HCC measuring at least 2 cm in diameter but is insensitive for the diagnosis of small HCC (<2 cm) and carcinomatosis.

Is obesity an independent risk factor for hepatocellular carcinoma in cirrhosis?

Recently, several epidemiologic observations have suggested that obesity might be an independent risk factor for certain malignancies such as breast cancer, colon cancer, renal cell carcinoma, and esophageal adenocarcinoma. However, there are no studies examining the risk of hepatocellular carcinoma (HCC) in obesity. The aim of the present study was to determine whether obesity is an independent risk factor for HCC in patients with cirrhosis. Explanted liver specimens from a national database on patients undergoing liver transplantation were examined for HCC, and the incidence was compared among patients with varying body mass indices according to the etiology of cirrhosis. A multivariate analysis was used for controlling other potentially confounding variables such as age and sex. Among 19,271 evaluable patients, the overall incidence of HCC was 3.4% (n = 659) with a slightly higher prevalence among obese patients compared with lean patients. Obesity was an independent predictor for HCC in patients with alcoholic cirrhosis (odds ratio [OR], 3.2; 95% CI, 1.5-6.6; P =.002) and cryptogenic cirrhosis (OR, 11.1; 95% CI, 1.5-87.4; P =.02). Obesity was not an independent predictor in patients with hepatitis C, hepatitis B, primary biliary cirrhosis, and autoimmune hepatitis. The higher risk of HCC in obese patients is confined to alcoholic liver disease and cryptogenic cirrhosis. In conclusion, more frequent surveillance for HCC may be warranted in obese patients with alcoholic and cryptogenic cirrhosis. However, as this study is based on patients with advanced cirrhosis, our findings need to be confirmed in a broader population of individuals with cirrhosis.

Hepatocellular carcinoma: predisposing conditions and precursor lesions

The global incidence of HCC is rising; in the United States, its rise is in parallel to that of cirrhosis due to the HCV and obesity epidemics. The lack of adequate treatment for advanced HCC mandates both prevention and early detection of these lesions. The limitations of currently available histopathologic evaluations, serologic markers, and radiographic imaging modalities in detecting HCC and its precursors have been outlined in this review. Refinements of all of these may lead to better HCC detection, earlier intervention, and successful treatment. Randomized controlled trials are necessary to evaluate the most efficacious and cost-effective approach to screening.

Dysplastic nodules and hepatocarcinogenesis

In the last decade, careful examination of explanted cirrhotic livers in liver transplant centers around the world has confirmed the findings of the earlier Japanese investigators: DNs (by this or any other name) represent hepatic, premalignant lesions in chronic liver disease. Careful examination of their gross and microscopic morphologies has led to the hypothesis of precirrhotic, spreading clonal expansions that are resistent to scarring, and that result in neoplastic islands of hepatic parenchyma. The resultant distinctive nodules, often marked by features suggestive of their clonality (such as increased pigment), are at increased risk for subsequent carcinomatous events, thereby giving rise to HCC. Specialized molecular and immunohistochemical studies confirm many aspects of this hypothesis. In suggesting that some aspects of DN pathophysiology are not integral to the carcinogenetic pathway (i.e., inhibition of HSC inactivation), this hypothesis serves a broader purpose, explaining the various settings in which early HCCs are found in cirrhotic explants and in wedge resections of radiographically defined lesions. Discrepancies between Japanese and non-Japanese investigations regarding dysplasia and early HCCs reflect not different biologic pathways but differences in detection, interpretation, and application of nomenclature. These differences may fade away as more international collaborative work brings investigators of diverse nationalities into regular contact, supporting movement toward a commonly acceptable nomenclature and set of diagnostic criteria. Ultimately, an understanding of the pathophysiology of these lesions, through more detailed molecular and physiologic studies, should lead to more efficient and available early detection, and perhaps chemoprevention approaches to hepatic malignancy.

Huge adenomatous hyperplasia of the liver

Adenomatous hyperplasia (AH) of the liver is defined as a regenerative overgrowth with limited growth potential. Patients with AH of the liver usually have cirrhosis of the liver as well. Adenomatous hyperplasia is also described as a benign nodule more than 8 mm, which is the main differentiation between AH and regeneration nodules (which are less than 8 mm). Adenomatous hyperplasias more than 20 mm is extremely rare in the clinicopathologic studies. We present two cases of extraordinarily large AH (one was 100 mm and the other, 30 mm). Both patients were alcoholic, and one also had viral hepatitis B. By clinical, biochemical, and upper gastrointestinal endoscopic examinations, we diagnosed liver cirrhosis in both. Sizable nodules were discovered in their livers using imaging studies (including ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography), and percutaneous liver biopsies of the nodules showed their cirrhotic background. However, neither of the patients developed hepatocellular carcinoma during the follow-up period.

Hepatocellular carcinoma and dysplastic nodules in patients with cirrhosis: prospective diagnosis with MR imaging and explantation correlation

PURPOSE

To determine the sensitivity and specificity of magnetic resonance (MR) imaging for detection of hepatocellular carcinoma (HCC) and dysplastic nodules (DNs) by using explantation correlation in patients with cirrhosis and no known HCC.

MATERIALS AND METHODS

Seventy-one patients without a known history of HCC who underwent MR imaging and subsequent transplantation within 90 days were examined. Breath-hold turbo short inversion time inversion-recovery and/or T2-weighted turbo spin-echo MR images were obtained. Dynamic two- or three-dimensional gadolinium-enhanced gradient-echo MR images were obtained in the hepatic arterial, portal venous, and equilibrium phases. Prospective MR image interpretations were compared directly with explanted liver pathologic results.

RESULTS

Eleven (15%) of 71 patients had hepatic malignancies; MR imaging enabled diagnosis of tumor in six (54%) of 11 patients. On a lesion-by-lesion basis, MR imaging depicted 11 of 20 hepatic neoplasms, for an overall sensitivity of 55%. MR imaging depicted four (80%) of five lesions larger than 2 cm, six (50%) of 12 lesions 1-2 cm, and one (33%) of three lesions smaller than 1 cm. MR imaging depicted only nine (15%) of 59 DNS: The specificities of MR imaging for detection of HCC and DNs on a per patient basis were 60 (86%) of 70 patients and 53 (85%) of 62 patients, respectively.

CONCLUSION

MR imaging is insensitive for the diagnosis of small (<2-cm) HCCs and DNS:

Siderotic nodules in the cirrhotic liver at MR imaging with explant correlation: no increased frequency of dysplastic nodules and hepatocellular carcinoma

PURPOSE

To determine the sensitivity of magnetic resonance (MR) imaging for detection of siderotic nodules in patients with cirrhosis and whether the frequency of hepatocellular carcinoma (HCC) and dysplastic nodules is greater if siderotic nodules are present.

MATERIALS AND METHODS

MR imaging (1.5 T) was performed within 0-117 days (mean, 30 days) before liver transplantation in 77 patients. Two readers retrospectively evaluated gradient-echo (GRE) (echo time [TE], > or = 9 and 4-5 msec) and turbo short inversion time inversion-recovery or T2-weighted images for low-signal-intensity nodules. Whole-explant pathologic correlation was available in every case.

RESULTS

At explantation, 28 (36%) of 77 patients had HCC, 25 (32%) had dysplastic nodules, and nine (12%) had both; 35 (45%) patients had siderotic nodules. The sensitivity of GRE imaging with 9-msec or longer TE for the detection of siderotic nodules was 80% (28 of 35) but decreased to 31% (11 of 35) with 4-5-msec TE. Frequency of HCC was not significantly higher (P =.27) in patients with (43% [15 of 35]) than in patients without (31% [13 of 42]) siderotic nodules. Frequency of dysplastic nodules also was not significantly higher (P =.42) in patients with (37% [13 of 35]) than in patients without (29% [12 of 42]) siderotic nodules.

CONCLUSION

Sensitivity of MR imaging for the detection of siderotic nodules was improved with use of GRE pulse sequences with longer TEs of 9 msec or greater (80%) versus 4-5 msec (31%); however, there was no significant increased frequency of HCC or dysplastic nodules in patients with pathologically proved siderotic nodules.

Clonal analysis of micronodules in virus C-induced liver cirrhosis using laser capture microdissection (LCM) and HUMARA assay

Most hepatocellular carcinomas (HCC) arise from malignant transformation of regenerative cirrhotic nodules. Because HCC has a very poor prognosis, detection of these premalignant lesions may improve the management of patients with cirrhosis. In this regard, clonal analysis of liver micronodules should be of particular interest in order to differentiate polyclonal regenerative micronodules from monoclonal neoplastic potentially malignant micronodules. To address this issue, 112 micronodules from 15 cases of explanted liver cirrhosis were carefully microdissected from paraffin-embedded tissue using a laser capture microscopy system. Clonal analysis was performed by analyzing X-chromosome inactivation, as indicated by the methylation status of the human androgen receptor gene (HUMARA). For each microdissected micronodule, a large set of pathological features was evaluated and correlated with their clonal status. Clonal analysis showed that 57 micronodules (51%) were monoclonal and 55 (49%) were polyclonal. Prevalence of monoclonal nodules ranged from 25% to 71% according to cases. In all cases, mono- and polyclonal nodules were randomly distributed in the cirrhotic liver. Although the clonal status was not significantly affected by the presence or absence of macronodules in the adjacent liver, size of monoclonal micronodules was significantly larger than size of polyclonal micronodules (mean size of the monoclonal nodules: 3 + 0.1 mm vs mean size of the polyclonal nodules: 2.5 +/- 0.1 mm, p = 0.007). Among the elementary pathological features evaluated, only the presence of iron overload was correlated with a monoclonal status (p = 0.04). In conclusion, clonal analysis of liver cirrhosis shows that 51% of micronodules are monoclonal lesions, supporting the notion that liver cirrhosis is a multineoplastic lesion. Because monoclonality is a marker of neoplasia, cirrhosis with accumulation of monoclonal nodules may be carefully followed, and monoclonal nodules should be screened for additional markers to assess their biological behavior.

Siderotic nodules at MR imaging: regenerative or dysplastic?

OBJECTIVE

To determine if iron containing "siderotic" nodules detected at magnetic resonance (MR) imaging are regenerative (RN) or dysplastic (DN) and to attempt to identify features that may distinguish them.

MATERIAL AND METHODS

MR imaging (1.5 T) was performed on 77 cirrhotic patients who underwent orthotopic liver transplantation within 0-117 days (mean 30 days) of MR imaging. Two readers retrospectively evaluated breath-hold gradient-echo pulse sequences (echo time > or =9.0 ms, flip angle < or =45 degrees) for the presence of hypointense nodules, which were classified as micronodular (< or =3 mm), macronodular (>3 mm), or mixed. Nodule distribution was classified as focal (<5), scattered (5-20), or diffuse (>20) per slice. Thin section pathologic correlation was available in all cases, and Prussian blue iron stains were performed.

RESULTS

Of 35 patients with pathologically proven siderotic nodules, 10 (29%) had at least 2 siderotic DN. MR detected siderotic nodules in 10 of 10 (100%) patients with siderotic DN and RN, and in 18 of 25 patients (72%) with siderotic RN only.

CONCLUSION

Siderotic RN cannot be reliably distinguished from siderotic DN with MR imaging, and therefore the widely used term "siderotic regenerative nodule" should be avoided and replaced by "siderotic nodule."

Hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is increasing in many countries as a result of an increase in hepatitis C virus (HCV) infection since World War II. The epidemiology of HCC varies with the global region. There have been conflicting observations from different parts of the world concerning the frequency of HCC in patients who in the distant past had post-transfusion non-A, non-B hepatitis. The genetic basis of hepatocarcinogenesis is still poorly understood. In hepatitis B virus (HVB) associated HCC, codon 249 mutation in the p 53 gene seems more related to exposure to aflatoxin B1 than to hepatocarcinogenesis itself. HCC that occurs in children in high HBV endemic regions could be associated with germ-line mutations, but little information is available; not much is known about chemical hepatocarcinogens in the environment other than aflatoxins. The X gene of HBV seems to play an important role in HBV-associated hepatocarcinogenesis. There are preliminary observations on the molecular mechanism of HCV-associated HCC, such as HCV core protein inducing HCC in transgenic mice and the NS3 genome transforming NIH 3T3 cells. Pathological distinction between preneoplastic and very early transformed lesions still depends on classical morphology, and a more genetically oriented differential diagnosis is required. Clinical diagnosis based on modern imaging has improved greatly, but is still unsatisfactory in the differential diagnosis of preneoplastic and early transformed nodules, because the vasculature changes that occur within the nodule are not accurately discerned with the current imaging. Use of sensitive des-gamma-carboxy prothrombin (PIVKA II) assay, and lectin affinity chromatography separating HCC specific subspecies of AFP molecules with a more practical biochemical technique will further improve diagnosis. Early diagnosis and transplantation are the best treatment at the moment, but transplantation is not widely available because of the donor shortage. Despite successful resection, the remnant cirrhotic liver frequently develops new HCC lesions, seriously curtailing long-term survival. All-out efforts should be directed to the prevention of HCC, through prevention of viral hepatitis, prevention of acute hepatitis from becoming chronic, prevention of chronic hepatitis from progressing to cirrhosis, and prevention of the cirrhotic liver from developing HCC (chemoprevention). At the moment, very few such studies exist.

The vascular profile of regenerative and dysplastic nodules of the cirrhotic liver: implications for diagnosis and classification

We investigated the angiogenic phenotype of regenerative and dysplastic hepatocellular nodules to assess whether these lesions have distinct vascular profiles compared with the adjacent nonneoplastic or malignant liver. Forty-three liver nodules surgically removed from 18 patients were classified into regenerative and dysplastic categories. Serial sections of each nodule, adjacent cirrhotic liver (16 patients), and associated hepatocellular carcinoma (HCC) (6 patients), have been immunostained against CD31 and alpha-smooth muscle actin (alphaSMA) to detect capillary and muscular vessels. The study included 20 large regenerative nodules (LRNs), 13 low-grade dysplastic nodules (LGDNs), and 10 high-grade dysplastic nodules (HGDNs). The number of both capillary units and unpaired arteries was significantly increased in HGDNs and malignant lesions over LGDNs, regenerative, and cirrhotic nodules (P <.01), which showed an overlapping vascular profile. In addition, the number of capillary units, but not that of unpaired arteries, was significantly increased in HCC compared with HGDNs (P <.01). These results show that certain angiogenic features segregate HGDNs from other nonmalignant nodules such as LRNs and LGDNs. The former group of lesions is similar to HCC whereas the latter group is undistinguishable from the adjacent cirrhosis as far as their vascular profile is concerned. The adopted investigative approach does not support the morphological distinction between LRNs and LGDNs although it suggests that HGDNs are likely advanced precursors of HCC. An abnormal number of capillary units and/or unpaired arteries in a nonmalignant hepatocellular nodule can be diagnostically helpful to identify a precancerous lesion.

Proliferating cell nuclear antigen and Ki-67 labeling in hepatocellular nodules: a comparative study

AIMS/BACKGROUND

The morphologic differential diagnosis of hepatocellular nodules (HCN) is frequently difficult and objective criteria would be useful in the categorization of such lesions. This study evaluated the proliferative activity of HCN, including regenerative, macroregenerative (MRN), cirrhotic, dysplastic, and hepatocellular carcinoma (HCC), as well as intranodular cytologic changes such as bile-stained hepatocytes, eosinophilia, clear, large cell (LCC) and small cell (SCC) change, by comparing the cellular density (CD), labeling indices (LI) and density (DP) of two proliferation markers.

METHODS

Routinely processed tissue sections from 45 HCN from 17 adult liver explants were studied by immunohistochemistry for PCNA and Ki-67 (MIB-1).

RESULTS

A progressive increase in LI from regenerative to dysplastic nodules to HCC was observed with both proliferation markers. The values of the two markers were significantly correlated (p<0.001). CD, PCNA and MIB-1 LI and DP values were significantly lower in regenerative compared to dysplastic nodules or HCC. MRNs had lower PCNA and MIB-1 LI and DP than regenerative nodules, but similar CD. There were no statistically significant differences in CD, PCNA, and MIB-1 LI and DP between dysplastic nodules and HCC, comparing high versus low grade dysplasia, or HCC smaller than 2 cm with those larger than 2 cm. The CD and proliferation indices LI and DP were higher in HCC than in the surrounding non-neoplastic parenchyma. Lesions with clear cell, eosinophilic and large cell change had CD, PCNA and MIB-1 indices similar to those of regenerative nodules, while these were lower in bile-stained hepatocellular lesions (p<0.01). SCC showed CD, PCNA and MIB-1 LI and DP similar to HCC and higher than surrounding regenerative lesions (p<0.003).

CONCLUSIONS

Our results suggest that PCNA and MIB-1 values are closely correlated in HCN. Regenerative nodules are characterized by low cellular proliferation, while dysplastic nodules are usually highly proliferative lesions and may represent an early stage in hepatocarcinogenesis. Hepatocellular lesions characterized by bile stained hepatocytes, eosinophilic, clear and large cell change have low proliferation rates and may not be significant for the development of malignancy.

Hepatocellular carcinoma: MR imaging findings in cirrhotic livers and noncirrhotic livers

PURPOSE

To compare the magnetic resonance (MR) imaging findings of primary hepatocellular carcinoma (HCC) in cirrhotic versus noncirrhotic livers.

MATERIALS AND METHODS

MR images in 36 patients with HCC (30 men and she women aged 42-84 years [mean age, 65 years]) were retrospectively reviewed. The number and size of hepatic lesions were assessed. Lesion margins were categorized as well circumscribed or ill defined. The presence of a capsule, intratumoral high signal intensity on T1-weighted MR images, and a stellate scar were determined.

RESULTS

Eleven (31%) patients had MR imaging evidence of cirrhosis, and 25 (69%) did not: Lesions in cirrhotic livers differed significantly from those in noncirrhotic livers in terms of size (22 cm2 vs 99 cm2, P < .05), frequency of a solitary lesion (27% vs 72%, P < .05), and frequency of a central scar (6% vs 50%, P < .05). There was no difference between the cirrhotic and noncirrhotic livers with regard to tumor margin, intratumoral high signal intensity on T1-weighted images, or tumor capsule.

CONCLUSION

Differences exist in the MR imaging appearance of HCC between patients with and those without cirrhosis, although there is overlap of imaging findings.

Broadsheet number 47: Chronic hepatitis: an update with guidelines for histopathological assessment of liver biopsies. Board of Education of The Royal College of Pathologists of Australasia

The liver biopsy remains the 'gold standard' for the diagnosis of chronic hepatitis, particularly since it is the only investigation that permits assessment of the severity (grade of histological activity and stage of fibrosis) of liver injury. As outlined below, the liver biopsy is invaluable for both diagnosis and the monitoring of therapy. To optimise the value of the liver biopsy, a standardised approach for assessment and reporting of chronic hepatitis is recommended.

Clonal analysis of macronodules in cirrhosis

Several arguments suggest that most hepatocellular carcinomas (HCCs) occurring in human cirrhotic livers arise from large hepatocellular nodules or macronodules. Except for nodules with obvious features of HCC, there exist no consistent criteria enabling the differentiation between benign regenerative and neoplastic, potentially malignant macronodules. Surrogate markers able to accurately discriminate those lesions that will evolve toward a HCC are required. In this study, we investigated the clonality of 26 macronodules isolated from eight cases of explanted cirrhotic livers in women by analyzing X-chromosome inactivation, as indicated by the methylation status of the human androgen receptor gene (HUMARA). For each macronodule, a large set of pathological features was evaluated and used to classify the macronodules into four groups: entirely benign-looking nodule (type 1), low-grade dysplastic nodule (type 2), high-grade dysplastic nodule (type 3), and HCC (type 4). Clonal analysis showed that 14 macronodules (54%) were monoclonal and 12 (46%) were polyclonal. Monoclonality was detected in 5 of 11 (45%) nodules from groups of entirely benign-looking and low-grade dysplastic nodules (types 1 and 2) and in 9 of 15 (60%) nodules from the group of high-grade dysplastic nodule and HCC (types 3 and 4). Neither the etiology of cirrhosis nor the size or histological classification of macronodules was correlated with the clonal status. In conclusion, clonal analysis of macronodules enables the differentiation between mono- and polyclonal macronodules in cirrhosis. Because monoclonal macronodules are prone to evolve to HCC, the determination of the clonal status of a macronodule could provide additional information for evaluating the prognosis of these lesions.