Prevalence of liver cell dysplasia and association with HCC in a series of 100 cirrhotic liver explants

Hepatic Precancerous Lesions and Early Hepatocellular Carcinoma

This review discusses the diagnostic challenges of diagnosing and treating precursor lesions of hepatocellular carcinoma (HCC) in both cirrhotic and non-cirrhotic livers. The distinction of high-grade dysplastic nodule (the primary precursor lesion in cirrhotic liver) from early HCC is emphasized based on morphologic, immunohistochemical, and genomic features. The risk factors associated with HCC in hepatocellular adenomas (precursor lesion in non-cirrhotic liver) are delineated, and the risk in different subtypes is discussed with emphasis on terminology, diagnosis, and genomic features.

Significance of hepatocyte atypia in liver fine needle aspiration

Fine needle aspiration (FNA) of the liver is frequently the diagnostic procedure of choice for sampling hepatic lesions. One of the main diagnostic challenges in the interpretation of liver FNA is distinguishing dysplastic lesions and well-differentiated hepatocellular carcinoma (WD-HCC) from benign processes, as they share significant cytomorphologic overlap. Furthermore, the diagnosis of HCC often requires evaluation of stroma for invasion, which may not be present on cytology and small needle biopsy specimens. A reporting system for liver cytopathology has yet to be instituted. Without standardized and well-defined criteria for hepatocyte atypia, we recommend limiting the use of atypia in evaluation of liver FNA specimens to describe a diagnosis of exclusion, in which all known benign and neoplastic processes have been ruled out. The cytologic findings on the FNA of a liver nodule may be best reported as atypical hepatocytes in the absence of a core needle biopsy or cell block sufficient to render a definitive diagnosis of HCC.

The Apoptotic Effect of Trichinella spiralis Infection Against Experimentally Induced Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer. Prognosis of HCC remains unsatisfactory. Therefore, developing new therapeutic modalities is still mandatory. Tumor biotherapy is a novel concept developed as a therapeutic strategy for cancer treatment. There is a similarity between the regulatory mechanism of Trichinella spiralis nurse cell formation and tumor cell apoptosis signal regulation.

OBJECTIVES

Induction of apoptosis by T. spiralis can represent a new strategy for tumor treatment.

METHODS

Experimental animals were divided in four groups; negative control (GI), T. spiralis infected (GII), induced HCC (GIII) and HCC then infected with T. spiralis (GIV). The apoptotic effect of T. spiralis infection was assessed by histopathological and immunohistochemical staining of B-cell lymphoma 2 (Bcl-2).

RESULTS

We found higher survival rate of rats and decreased weight of their livers with no nodules in HCC- T. spiralis group as compared to HCC group. Improvement of the dysplastic changes and increased apoptotic bodies which was confirmed by decreased expression of Bcl-2 reported in HCC- T. spiralis group.

CONCLUSION

Trichinella-induced apoptosis can be a contributing mechanism of the anti-tumor effect of T. spiralis infection. Our results showed a certain level of decreased progression of the tumor in HCC-T. spiralis group as indicated by increased rate of apoptosis and subsequently had a positive impact on the survival of rats.
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[Hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) belongs to the most prevalent and deadliest cancers worldwide. It can be attributed to well-defined risk factors (mainly chronic viral hepatitis and alcoholic/nonalcoholic steatohepatitis) leading to liver cirrhosis, a premalignant condition for the development of preneoplastic hepatocellular lesions and finally liver cancer. By applying strict morphological criteria and a panel of immunohistological markers, early HCC can be differentiated from its precursor lesions and other highly differentiated hepatocellular lesions even in most biopsy specimens. Integrative characterization led to the association of histological features and molecular subgroups of human HCC. This potentially relevant clinical development was recognized by the recently updated WHO classification of liver cancer resulting in the introduction of several HCC subtypes. These are characterized by a distinct combination of histological and molecular features, biological behavior, and clinical characteristics, allowing for a distinction from other HCC without specified features. Whether this development sets the corner stone for precision oncology of human HCC patients must be monitored.

The Evaluation of Angiogenesis Markers in Hepatocellular Carcinoma and Precursor Lesions in Liver Explants From a Single Institution

Hepatocellular carcinoma (HCC) is a global health problem associated with chronic liver disease. Precursor lesions are described, and the correct diagnosis of liver nodules is paramount when considering liver transplantation. We evaluated the immunohistochemical expression of vascular endothelial growth factor (VEGF) and angiopoietin-2 in HCC and precursors lesion in a single institution series of whole liver explants between 2013 and 2015, evaluating morphologic and clinical variables. The study comprised 67 patients (32.8% female) and 107 nodules. The mean age of the patients was 52.7 years (29 to 70 y). There were no significant epidemiologic differences among malignant lesions, dysplastic nodules, and regenerative nodules. Angiopoietin-2 expression was significantly more expressed in carcinoma when compared with regenerative lesions (P<0.0001). A statistically significant relationship was noted between the expression of VEGF in hepatocytes and Ang-2 expression in the small vasculature (P=0.006). VEGF expression also correlated significantly with the number of nonpaired arteries (P=0.03), although it was not useful in separating benign from malignant cases. We identified a sensitivity of 54% and a specificity of 96% using angiopoietin-2, and a sensitivity of 68.7% and a specificity of 31.2% when using VEGF for the diagnosis of HCC. There was no significant correlation between the immunohistochemical parameters and the clinical staging, the number of gross lesions, and the histologic grade in cases of HCC. Angiopoietin-2 may be a candidate biomarker in assessing liver nodules in transplant patients, and may assist in the diagnosis of difficult lesions and in small biopsies pretransplant.

Role of Glypican-3 in the growth, migration and invasion of primary hepatocytes isolated from patients with hepatocellular carcinoma

BACKGROUND

Recently, Glypican-3 (GPC3) has been identified as a potential hepatocellular carcinoma (HCC) diagnostic and/or therapeutic target. GPC3 has been found to be up-regulated in HCC and to be absent in normal and cirrhotic liver. As yet, however, the molecular characteristics of GPC3 and its role in HCC cell physiology and development are still undefined.

METHODS

Human hepatocyte cultures were established from 10 HCC patients. Additional liver samples were obtained from 5 patients without cirrhosis and/or HCC. Soft agar colony formation, (co-)immunofluorescence and Western blot assays were used to characterize the hapatocyte cultures. The expression of GPC3 in the hepatocytes was silenced using siRNA, after which, apoptosis, scratch wound migration and transwell invasion assays were performed.

RESULTS

We found that in HCC precursor hepatocytes GPC3 is increasingly expressed in different forms and at different locations, i.e., a non-cleaved form (70 kDa) was found to be localized in the cytoplasm while a N-terminal cleaved form (N-GPC3: 40 kDa) was fond to be localized in the cytoplasm and at the extracellular side of hepatocyte membranes. In addition, we found that the non-cleaved form of GPC3 co-localizes with Furin-Convertase in the Golgi apparatus. We also found that, similar to GPC3, Furin-Convertase is expressed in HCC precursor cells, suggesting a role in GPC3 processing. Subsequent siRNA-mediated GPC3 silencing resulted in a temporary inhibition of cell proliferation, migration and ivasion, while inducing apoptosis in transformed hepatocytes.

CONCLUSION

Our data reveal new aspects of the role of GPC3 in early hepatocyte transformation. In addition we conclude that GPC3 may serve as a new HCC immune-therapeutic target.

Transjugular intrahepatic porto-systemic shunt is a risk factor for liver dysplasia but not hepatocellular carcinoma: a retrospective study of explanted livers

BACKGROUND

Conflicting data exist regarding the risk for hepatocellular carcinoma after transjugular intrahepatic porto-systemic shunt (TIPS) insertion in cirrhotic patients.

METHODS

We retrospectively analysed histopathological data from 214 patients who were transplanted in our Institution including 68 patients who underwent TIPS placement before transplantation. Pathological lesions from explanted livers, including incidental hepatocellular carcinoma, small cell dysplasia and large cell dysplasia were recorded.

RESULTS

Pathological lesions were found in 36.4% of explanted livers. TIPS insertion was an independent risk factor for pathological lesion (HR = 2.11, p < 0.05), concurrently with age (HR = 1.10 per year, p < 0.001) and viral aetiology of cirrhosis (HR = 3.05, p < 0.001). When considering the different type of lesions, TIPS insertion was not associated with an increased risk for hepatocellular carcinoma but was an independent risk factor for liver dysplasia (HR = 2.15, p = 0.042).

CONCLUSION

Although a direct relationship between TIPS insertion and hepatocellular carcinoma risk was not demonstrated in this study, the increased frequency of liver dysplasia observed in TIPS-bearing explanted livers deserves further prospective investigations with adequate follow-up.

Expression of glypican 3 enriches hepatocellular carcinoma development-related genes and associates with carcinogenesis in cirrhotic livers

Glypican-3 (GPC3) protein expression was determined by immunohistochemical analysis from 29 normal livers, 80 cirrhotic livers sample taken near hepatocellular carcinoma (HCC), and 87 cirrhotic livers without HCC. The levels for miR-657 and HCC-related gene mRNAs were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Also, a published microarray dataset was used for gene set enrichment analysis (GSEA) to investigate the relationship between GPC3- and HCC-related gene signatures. Kaplan-Meier analysis was used to evaluate the relationship between GPC3 and HCC recurrence. GPC3 protein expression was not detected in any of the 29 (0%) normal livers, but was detected in 32 of 87 (37%) cirrhotic livers without HCC, and 51 of 80 (64%) cirrhotic liver samples taken near HCC sites (P < 0.001). The GPC3-positive rate in cirrhotic livers of viral origin was 68% (27/40), which was significantly higher than for non-viral cirrhotic livers (11%, 5/47) (P < 0.001). Also, GPC3 expression positively correlated with mRNA expression of HCC-related genes in the qRT-PCR and GSEA evaluations. Furthermore, HCC recurrence in cirrhotic liver samples taken near HCC sites was significantly higher in the GPC3-positive group than the GPC3-negative group (Log-rank P = 0.02, HR = 3.26; 95% CI = 1.20-10.29). This study demonstrated that highly expression of GPC3 could enrich HCC-related genes' mRNA expression and positive associate with dysplasia in cirrhotic livers. Therefore, GPC3 may serve as a precancerous biomarker in cirrhotic livers.

The status of zinc in the development of hepatocellular cancer: an important, but neglected, clinically established relationship

Liver cancer (hepatocellular carcinoma, HCC) is increasing worldwide. About 75% of HCC cases result in death generally within one year. The factors responsible for the initiation and progression of HCC remain largely unknown and speculative, thereby impeding advancements in the development of effective therapeutic agents and biomarkers for early detection of HCC. A consistent marked decrease in zinc in HCC tumors compared with normal liver is an established clinical relationship, which occurs in virtually all cases of HCC. However, this relationship has been largely ignored by the contemporary clinical and research community. Consequently, the factors and mechanisms involved in this relationship have not been addressed. Thus, the opportunity and potential for its employment as biomarkers for early identification of malignancy, and for development of a chemotherapeutic approach have been lacking. This presentation includes a review of the literature and the description of important recent and new data, which provide the basis for a concept of the role of zinc in the development of HCC. The basis is presented for characterizing HCC malignancy as ZIP14-deficient tumors, and its requirement to prevent zinc cytotoxic effects on the malignant cells. The potential for an efficacious zinc treatment approach for HCC is described. The involvement of zinc in the predisposition for HCC by chronic liver disease/cirrhosis is presented. Hopefully, this presentation will raise the awareness, interest, and support for the much needed research in the implications of zinc in the development and progression of HCC.

Schistosoma mansoni infection: is it a risk factor for development of hepatocellular carcinoma?

The burden of hepatocellular carcinoma (HCC) in Egypt has been increasing with a doubling in the incidence rate in the past 10 years, which necessitates the investigation of the possible risk factors to its development. The present study aimed at investigating the role of Schistosoma mansoni infection as a risk factor for development of HCC. Five hundred parasite free mice were categorized into four groups: Group I (induction of carcinoma by diethylnitrosamine (DEN)), Group II (DEN+Infection), Group III (Infection) and Group IV (Control). Groups I and II were further subdivided into 4 subgroups according to the dose of DEN given. Serum samples from each group were examined for levels of tumor markers alpha fetoprotein (AFP) and ferritin by ELISA, then mice were sacrificed and subjected to histopathological examination of their livers. These were repeated every week till the end of the experiment. The results of the histopathological examination clarified the role of S. mansoni in enhancing and aggravating the carcinogenic effect of DEN; dysplastic changes appeared earlier, with a higher grade and with a smaller dose of DEN in Group II compared to Group I. Serum levels of tumor markers showed earlier statistically significant differences in Group II than in Group I when compared to Group IV. We conclude that S. mansoni accelerates hepatic dysplastic changes in the presence of other risk factors making cancer appear early and with a more aggressive nature, compared to the same risk in absence of schistosomiasis.

ZIP14 zinc transporter downregulation and zinc depletion in the development and progression of hepatocellular cancer

PURPOSE

Hepatocellular cancer (HCC) is a deadly and most rapidly increasing cancer in the USA and worldwide. The etiology and factors involved in development of HCC remain largely unknown. A marked decrease in zinc occurs in HCC. Its role and involvement in HCC has not been identified. We investigated the relationship of cellular zinc changes to the development of malignancy, and the identification of potential zinc transporters associated with the inability of hepatoma cells to accumulate zinc.

METHODS

The detection of relative zinc levels in situ in normal hepatic cells vs. hepatoma was performed on normal and HCC tissue sections. ZIP1, 2, 3, and 14 transporters were identified by immunohistochemistry.

RESULTS

Intracellular zinc levels are markedly decreased in HCC hepatoma cells vs. normal hepatic cells in early stage and advanced stage malignancy. ZIP14 transporter is localized at the plasma membrane in normal hepatocytes, demonstrating its functioning for uptake and accumulation of zinc. The transporter is absent in the hepatoma cells and its gene expression is downregulated. The change in ZIP14 is concurrent with the decrease in zinc. ZIP1, 2, 3 are not associated with normal hepatocyte uptake of zinc, and HCC zinc depletion. HepG2 cells exhibit ZIP14 transporter. Zinc treatment inhibits their growth.

CONCLUSIONS

ZIP14 downregulation is likely involved in the depletion of zinc in the hepatoma cells in HCC. These events occur early in the development of malignancy possibly to protect the malignant cells from tumor suppressor effects of zinc. This provides new insight into important factors associated with HCC carcinogenesis.

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.

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.

Fine needle aspiration biopsy of hepatocellular carcinoma and hepatocellular nodular lesions: role, controversies and approach to diagnosis

The role of fine needle aspiration (FNA) biopsy of the liver has evolved. Advances in imaging modalities have obviated the need for tissue confirmation in clinically classic hepatocellular carcinoma (HCC). The risks of needle tract seeding and haematogenous dissemination have been actively debated. Nowadays, cytopathologists are confronted by smaller and smaller nodules, detected due to increased surveillance of high-risk cirrhotic patients. Tissue characterization of small well-differentiated hepatocellular nodular lesions (size less than and equal to 2 cm) is extremely challenging and has therapeutic implications. Major issues in the cytodiagnosis of HCC include: (i) distinguishing benign hepatocellular nodular lesions, namely, large regenerative nodules, dysplastic nodules, focal nodular hyperplasia and hepatocellular adenoma from reactive hepatocytes; (ii) distinguishing well-differentiated HCC from benign hepatocellular nodular lesions; (iii) distinguishing poorly differentiated HCC from intrahepatic cholangiocarcinoma and metastatic carcinomas; (iv) determining the histogenesis of a malignant tumour; and (v) determining the site of origin of a malignant tumour. An overview of the biological evolution and histopathological aspects of dysplastic nodules, small HCCs and 'nodule-in-nodule' lesions is presented in tandem with clinically relevant nomenclature. An algorithmic approach to FNA diagnosis of HCC and hepatocellular nodular lesions is outlined. Optimal results depend on (i) a dedicated radiologist-cytopathologist team; (ii) an on-site cytology service, (iii) a combined cytohistological approach, (iv) immunohistochemistry, and (v) clinicopathological correlation. As we move towards personalized medicine, it is envisaged that hepatic FNA is likely to become a point of care in the management protocol as it takes on the additional role of procurement of tumour and peritumoural tissues for genomic and proteomic profiling to enable targeted molecular therapy.

Fine-needle aspiration biopsy of hepatocellular carcinoma and related hepatocellular nodular lesions in cirrhosis: controversies, challenges, and expectations

The role of hepatic fine-needle aspiration (FNA) biopsy has evolved. Advances in imaging modalities have obviated the need for tissue confirmation in most hepatocellular carcinomas (HCCs). There is risk of needle-tract seeding. Increasingly, small nodules are being detected on ultrasound surveillance of high-risk patients. Diagnostic challenges associated with cirrhosis include distinction of benign hepatocellular nodules, namely, large regenerative nodules and dysplastic nodules, from reactive hepatocytes; and distinction of well-differentiated HCCs from benign hepatocellular nodules. This paper will discuss (i) controversies regarding preoperative/pretransplantation FNA diagnosis of HCC, (ii) update of biological evolution, nomenclature, and histopathologic criteria for diagnosis of precancerous nodules and small HCCs, and (iii) algorithmic approach to FNA diagnosis of hepatocellular nodules. Optimal results depend on dedicated radiologist-cytopathologist team, on-site cytology service; combined cytohistologic approach, immunohistochemistry, and clinicopathologic correlation. Hepatic FNA is likely to be incorporated as a point of care as we move towards personalized medicine.

Chronic viral hepatitis: the histology report

In chronic viral hepatitis, the role of liver biopsy as a diagnostic test has seen a decline, paralleled by its increasing importance for prognostic purposes. Nowadays, the main indication for liver biopsy in chronic viral hepatitis is to assess the severity of the disease, in terms of both necro-inflammation (grade) and fibrosis (stage), which is important for prognosis and therapeutic management. Several scoring systems have been proposed for grading and staging chronic viral hepatitis and there is no a general consensus on the best system to be used in the daily practice. All scoring systems have their drawbacks and all may be affected by sampling and observer variability. Whatever the system used, a histological score is a reductive approach since damage in chronic viral hepatitis is a complex biological process. Thus, scoring systems are not intended to replace the detailed, descriptive, pathology report. In fact, lesions other than those scored for grading and staging may have clinical relevance and should be assessed and reported. This paper aims to provide a systematic approach to the interpretation of liver biopsies obtained in cases of chronic viral hepatitis, with the hope of helping general pathologists in their diagnostic practice.

Proliferative drive and liver carcinogenesis: too much of a good thing?

There have been innumerable studies published in the attempt to identify gene expression signatures in hepatocellular carcinoma (HCC). When all the regulators and targets of the differentially expressed genes are analyzed from larger studies, the most striking theme is upregulation of mitosis-promoting and cell proliferation genes in HCC compared with 'liver-specific gene clusters' in non-tumorous tissue. A major limitation of expression profiling is that it only provides a 'snapshot' of what is an evolving process and thus cannot distinguish the differences in gene expression that are primary effectors of dysregulated growth from those that represent downstream consequences. The development of HCC in a chronically diseased liver, often referred to as hepatocarcinogenesis, is a multistep process characterized by the progressive accumulation and interplay of genetic alterations causing aberrant growth, malignant transformation of liver parenchymal cells, followed by vascular invasion and metastasis. This review will discuss HCC precursor lesions, draw on the 'proliferation cluster' genes highlighted from HCC expression profiling studies, relate them to a selection of regulatory networks important in liver regeneration, cell cycle control and their potential significance in the pathogenesis of HCC or primary liver cancer.

Large liver cell change in hepatitis B virus-related liver cirrhosis

Large liver cell change (LLCC) refers to microscopic lesions often found in various chronic liver diseases; however, its nature is still controversial. Thirty-four formalin-fixed and 19 fresh frozen hepatitis B virus (HBV)-related cirrhosis samples were examined for the presence of LLCC, small liver cell change (SLCC), and hepatocellular carcinoma (HCC). The cell cycle checkpoint status (p21, p27, p16, Tp53), cell dynamics (proliferating cell nuclear antigen, Ki-67, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling, M30), DNA damage (gamma-H2AX [H2A histone family, member X]), telomere lengths, chromosomal instability (micronuclei index), and senescence-associated beta-galactosidase (SA-beta-Gal) activity were evaluated using an in situ approach and compared to those in normal liver (n = 5) and liver with chronic cholestasis (34 cases of hepatolithiasis and three cases of primary biliary cirrhosis). In HBV-related cirrhosis, the p21, p27, and p16 cell cycle checkpoint markers were activated in normal-looking cirrhotic hepatocytes (NLCH), but diminished gradually from LLCC, SLCC, to HCC, with an increase in Tp53 expression. There was a general decrease in telomere length from NLCH, LLCC, SLCC, to HCC. Micronuclei, gamma-H2AX foci, and net cellular gain were significantly increased from normal hepatocytes, NLCH, LLCC, SLCC, to HCC. The SA-beta-Gal activity was weaker in LLCC compared to NLCH and absent in SLCC and HCC. In contrast, cholestatic LLCC showed retained expression of cell cycle checkpoint markers and decreased net cellular gain compared to adjacent normal-looking hepatocytes. HBV-related LLCC showed significantly higher Tp53 labeling index, gamma-H2AX labeling index, and micronuclei index; shorter telomere length; decreased SA-beta-Gal activity; and increased net cellular gain compared to cholestatic LLCC.

CONCLUSION

The nature of LLCC is rather heterogeneous depending on the biological setting. The characteristics of HBV-related LLCC are more consistent with dysplastic rather than merely reactive hepatocytes, whereas cholestatic LLCC more likely represents reactive change with more stringent cell cycle checkpoint control.

Predictive value of liver cell dysplasia for development of hepatocellular carcinoma in patients with chronic hepatitis B

GOALS

We aimed to determine whether the presence of large liver cell dysplasia (LLCD) and/or small LCD (SLCD) in chronic hepatitis B is a risk factor for hepatocellular carcinoma (HCC) development.

BACKGROUND

A close relationship between LLCD/SLCD and hepatitis B virus has been observed and SLCD has been proposed to be a putative precursor of HCC, whereas the significance of LLCD is still controversial.

STUDY

One hundred eighty-one patients with chronic hepatitis B who underwent needle liver biopsy were evaluated for the presence of LLCD/SLCD. The predictive value of LLCD/SLCD for HCC development was assessed.

RESULTS

LLCD and SLCD were present at initial biopsy in 82 (45%) and 17 (9%) patients, respectively. During the mean follow-up of 115+/-48 months, 19 (10%) cases were diagnosed of HCC, of which 13 (76%) and 3 (17%) cases had demonstrated LLCD and SLCD, respectively, at initial evaluation. The patients with LLCD showed a significantly higher cumulative probability of HCC development than those without LLCD (P=0.016). The risk of HCC development in the presence of LLCD was approximately 3-fold, with positive and negative predictive values of 15.9% and 94.9%, respectively. The patients with SLCD showed no significant difference in cumulative probability of HCC development compared with those without (P>0.05).

CONCLUSIONS

LLCD in chronic hepatitis B is considered to be one of the risk factors for HCC development and its presence may help to identify a high-risk subgroup of patients requiring more intensive screening for HCC.

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.

Large liver cell dysplasia: a controversial entity

Large cell change (LCC) is a noncommittal term used today to indicate liver cell dysplasia of the large cell type. Dysplasia was deleted from the original definition because not enough evidence has been collected over time to support premalignancy. LCC is a microscopically well-defined lesion, usually found in cirrhosis, whose origin, natural history, and fate are still debated. Different morphologic, phenotypic, molecular and clinical studies have been performed to address the issue of the dysplastic versus reactive nature of this lesion. The aim of this review is to critically evaluate the contributions to the topic and to underline that the heterogeneity of the lesion is an important issue to be taken into account for our biological understanding of it. While LCC has important morphologic analogies in experimental liver carcinogenesis, no comparable lesions are known in solid non-liver parenchymal human tissues that morphologically feature dysplasia, but in which it is uncertain whether the lesions are reactive or preneoplastic. The debate over the lesion may be useful in learning the actual limits of morphology and how additional information can be gained by looking inside the cells.

A stable model of cirrhotic portal hypertension in the rat: thioacetamide revisited

BACKGROUND

Cirrhotic animal models are vital to investigate complications of chronic liver disease. We chronologically characterized the effect of thioacetamide, administrated orally and adapted weekly to weight changes, focusing on the optimal moment to obtain all typical features of portal hypertension and cirrhosis.

MATERIALS AND METHODS

Male Wistar rats, 200-250 g, were intoxicated for 6, 12 or 18 weeks (n = 8 per group), respectively, and compared with age-matched controls (n = 4 per group). An in-situ perfusion model was used to evaluate intrahepatic resistance and endothelial function. Splanchnic blood flow and portosystemic shunting were assessed by a perivascular flow probe.

RESULTS

Rats intoxicated for 6 or 12 weeks had no mortality and histologically showed hepatitis and advanced fibrosis, respectively. At 18 weeks, mortality was 16% (on a total of 56 animals) and only at that moment all animals showed homogenous macronodular cirrhosis with signs of high-grade hepatocellular dysplasia. Portal hypertension was present at 12 weeks (11 +/- 0.4 vs. 5.9 +/- 0.4 mmHg, P < 0.001), but was not associated with the hyperdynamic state until 18 weeks (12.1 +/- 0.8 vs. 5.6 +/- 0.5 mmHg, P < 0.001). At this latter time-point, we also observed increased intrahepatic resistance associated with endothelial dysfunction, hyperresponsiveness to vasoconstrictors, splanchnic hyperaemia and portosystemic shunting. These alterations were associated with increased systemic levels of nitrate/nitrite and thromboxane A(2).

CONCLUSION

Thioacetamide, adapted to weekly weight changes, leads to a homogenous, reproducible model of cirrhosis in the rat in 18 weeks, which is associated with all the typical characteristics of portal hypertension, including endothelial dysfunction.

Hepatic expression of the proliferative marker Ki-67 and p53 protein in HBV or HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma

To evaluate hepatic expression of the nuclear proliferative marker Ki-67 and the p53 oncoprotein in hepatitis B virus (HBV)/HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma (HCC). We studied needle liver biopsies from 107 patients with cirrhosis and no HCC (52 HBV, 55 HCV) who had been assessed for protocol studies, and 57 cirrhotic patients with HCC (40 HBV, 17 HCV). We evaluated small and large cell dysplastic changes along with the expression of Ki-67 and p53 by immunohistochemistry. The labelling index (LI) was defined as the proportion (%) of positive-stained nuclei of the 500 measured. Large and small cell dysplastic changes were observed in 12 and 9% of specimens respectively. Only small cell changes were associated with Ki-67 expression. Ki-67 LI was 5.50 +/- 5.7 in cirrhosis (13.90 +/- 3.84 in those with small cell dysplastic changes vs 4.64 +/- 4.98 in those without, P < 0.01), 10.2 +/- 5.95 in cirrhosis with HCC (P < 0.05) and 18.56 +/- 10 in HCC (P < 0.01). Neither the presence of small cell dysplastic changes nor the expression of Ki-67 was related to severity or aetiology of cirrhosis. Expression of p53 was observed in 30% of the non-tumorous and in 53% of the neoplastic tissue obtained from patients with HCC, with no differences between HCV and HBV. Ki-67 and p53 expression was associated with the tumour grade (P < 0.001). Our observations clearly demonstrate the association between the proliferation activity and the morphological changes in the cirrhotic liver from the non-dysplastic to dysplastic lesion to HCC. They also support the hypothesis that p53 alterations are a rather late event in carcinogenesis and related to HCC grade. And finally, they suggest that the final steps of hepatocarcinogenesis are common and independent of the aetiology of the chronic viral infection.

Large liver cell dysplasia in hepatitis B virus x transgenic mouse liver and human chronic hepatitis B virus-infected liver

OBJECTIVES

Large liver cell dysplasia (LCD) is frequently associated with hepatitis B virus (HBV), but it remains uncertain whether it is reactive, senescent or preneoplastic.

METHODS

The HBX transgenic mice and normal control mice were sacrificed at 1, 3, 5, 7, 9, 11, 13 and 15 months after birth. Twenty-three cases of human B viral chronic hepatitis/cirrhosis with prominent LCD were selected. The immunohistochemical stain of proliferating cell nuclear antigen (PCNA), transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and senescence-associated beta-galactosidase (SA-beta-Gal) were evaluated.

RESULTS

In HBX transgenic mice, LCD was developed since 3 months and formed small nodules of hepatocellular adenoma, which progressed to hepatocellular carcinoma. The hepatocytes with LCD in HBX transgenic mice showed significantly higher PCNA-labeling index (LI) and lower TUNEL-LI than normal hepatocytes of control mice (p < 0.05). In the majority of human B viral chronic hepatitis/cirrhosis, the hepatocytes with LCD revealed higher PCNA-LI and lower TUNEL-LI than those without, when compared in each case using the same tissue block. SA-beta-Gal staining showed no difference between hepatocytes with and without LCD.

CONCLUSION

It is suggested that LCD, related to HBV, might not be just an innocent bystander, but closely related to hepatocarcinogenesis.

Preneoplastic lesions in human hepatocarcinogenesis

The early stages of hepatocarcinogenesis in human chronic liver diseases are characterized by the emergence of preneoplastic lesions of which some will eventually develop into hepatocellular carcinoma (HCC). Basic studies on the genetic and epigenetic alterations of these preneoplastic lesions may eventually lead to new therapeutic strategies. Clinicopathological studies are also important in order to determine optimal management of patients with a preneoplastic lesion. This article aims to provide a comprehensive review of the current concepts of preneoplastic lesion in chronic liver diseases. The microscopical small-cell dysplastic focus is the smallest morphologically recognizable precursor lesion of HCC and therefore is a logical target of study to elucidate the earliest events in hepatocarcinogenesis. In contrast, large-cell dysplasia is not a precursor lesion, but appears to be of clinical value because of its good predictive value for development of HCC. Dysplastic nodules (DNs) are macroscopically recognizable precursor lesions of HCC and high-grade DNs (HGDNs) have a risk of malignant transformation. Detection of DNs and correct differentiation from small HCC (<2 cm) is sometimes difficult, especially when only imaging techniques are used. Additional clinicopathological studies on identification and optimal treatment of DNs are necessary. Molecular studies on HGDNs and small HCCs may yield much information on the genetic mechanisms involved in the transition from severe dysplasia to early malignancy. In contrast, currently available data indicate that (large) regenerative nodules do not represent a distinct step in hepatocarcinogenesis. Animal models will be helpful in the further unravelling of human HCC development, provided that studies are performed on models that are good representatives of human hepatocarcinogenesis. We propose three criteria by which good mimickers can be identified.

Genetic evaluation of the dysplasia-carcinoma sequence in chronic viral liver disease: a detailed analysis of two cases and a review of the literature

Hepatocellular carcinoma (HCC) is one of the most frequent human malignancies, especially in Asia and Africa, but also in the Western world its incidence is increasing. HCC is a complication of chronic liver disease with cirrhosis as the most important risk factor. Viral co-pathogenesis due to hepatitis B virus (HBV) and hepatitis C virus (HCV) infection seems to be an important factor in the development of HCC. Curative therapy is often not possible due to the late detection of HCC. Thus, it is attractive to find parameters which predict malignant transformation in HBV- and HCV-infected livers. In the past decade, preneoplastic lesions, i.e. dysplastic foci or nodules, have gained interest as possible markers for imminent malignancy. Noteworthy, dysplastic liver lesions are increasingly detected by imaging techniques. We describe here two cases of chronic viral liver disease, one HBV-and one HCV-related, in which dysplastic lesions were present adjacent to HCC. In the HBV case, a (smaller) satellite of HCC was present as well. The neoplastic specimens were investigated by comparative genomic hybridization (CGH) and in situ hybridization (ISH). Both methods revealed multiple genetic alterations in the HCCs. The genetic patterns of the HBV-related HCC and the satellite tumor showed many shared alterations suggesting a clonal relationship. A subset of genetic changes were already present in dysplasias illustrating their preneoplastic nature. Surrounding liver cirrhosis samples did not display chromosomal aberrations. A literature survey illustrates the relative paucity of information concerning genetic alterations in preneoplastic liver lesions. However, all the data strongly suggests a role for liver cell dysplasia as a precursor condition of liver cell cancer.

Quantitative RT-PCR in cirrhotic nodules reveals gene expression changes associated with liver carcinogenesis

Cirrhosis is considered to be the precursor of most hepatocellular carcinomas. To gain insight into the early molecular mechanisms of liver carcinogenesis, this study compared, using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), the expression levels of 31 selected genes in normal livers, cirrhotic nodules, and hepatocellular carcinomas. Since cirrhosis is composed of a mixture of polyclonal and monoclonal nodules, gene expression levels were also compared according to the clonal status of the cirrhotic nodules. The expression of eight of the 31 genes studied was significantly increased (NEGF2, ANGPT1, ARF, KRT19, SFN, CLDN4, MMP7, and ETV4) in cirrhotic nodules compared with normal liver, while only one was decreased (LYVE1). The same trend of variation was observed in cirrhosis and hepatocellular carcinomas for all of these genes except KRT19. When gene expression variation was compared according to the clonal status of cirrhotic nodules, only the LYVE1 expression level was significantly different. The LYVE1 gene expression level decreased progressively from polyclonal cirrhotic nodules to monoclonal cirrhotic nodules (polyclonal nodules 0.39 +/- 0.25; monoclonal nodules 0.20 +/- 0.14; p < 0.05) and to hepatocellular carcinoma (0.07 +/- 0.1). In conclusion, this study highlights the fact that among genes strongly dysregulated in hepatocellular carcinoma, some are already abnormally expressed in cirrhosis. The decrease in the expression level of one of these genes, LYVE1, was associated with monoclonality in cirrhotic nodules.

Liver pathology and hepatocarcinogenesis in a long-term mouse model of erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is an inherited disease of haem synthesis caused by a mutation in one of the alleles of the enzyme ferrochelatase. This mutation leads to partial deficiency of the enzyme, resulting in increased concentrations of protoporphyrin (PP) in blood, liver, and faeces. Five to ten per cent of patients with EPP develop severe liver disease characterized by the presence of PP deposits. This study used histochemistry and immunohistochemistry to investigate the histopathological features present in the livers of 44 mice with a heterozygous or homozygous point mutation in the ferrochelatase gene (fch/+ and fch/fch mice, respectively). Some fch/+ mouse livers showed mixed steatosis and large cell dysplasia. The livers of fch/fch mice showed periportal or septal fibrosis accompanied by an atypical ductular reaction. These findings suggest that the obstruction and damage of a proportion of large and small bile ducts by PP deposits cause an accumulation of PP in the parenchyma, which leads to damage and loss of hepatocytes due to the toxic effects of PP. The classical stages of hepatocarcinogenesis were observed and hepatic progenitor cells appear to be involved in this process. PP acts as the promoting agent and is probably also the initiating agent.

Nucleolar hypertrophy correlates with hepatocellular carcinoma development in cirrhosis due to HBV infection

Patients with cirrhosis are at significant risk for hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the relationship between the percentage of hepatocytes showing nucleolar hypertrophy and the development of HCC in cirrhosis of different causes. A total of 111 cirrhotic patients were studied, with a mean follow-up period of 83.3 months. Histologic sections from liver biopsy specimens were silver stained for selective visualization of the nucleolus; the nucleolar area was measured by image cytometry. Nucleoli with a size of 7 microm(2) or greater were considered to be hypertrophic. The nucleolar index was obtained by calculating the percentage of hepatocytes disclosing a nucleolar area of 7 microm(2) or greater. During the observation time, HCC was diagnosed in 39 of 111 patients. The incidence rate of HCC was greater in patients with nucleolar indexes of 2.5 or greater than in patients with nucleolar indexes of less than 2.5 (16.49%/y vs. 3.41%/y, respectively; P <.0001). The capacity of the nucleolar index to predict HCC development was separately tested in groups of patients divided by etiology, and it was found to be particularly relevant in hepatitis B virus (HBV)-related cirrhosis (P =.0006). Among patients with hepatitis C virus (HCV) infection, high nucleolar-index values were associated with a greater risk for HCC development, but the difference in the incidence rate of HCC between groups with a nucleolar index of 2.5 or greater and less than 2.5 was not statistically significant (P =.0944). In conclusion, our results have shown that high percentages of hepatocytes showing nucleolar hypertrophy significantly predict HCC development in patients with HBV infection, whereas their predictive value in HCV-related cirrhosis seems to be lower.

Diagnosis of hepatocellular carcinoma: fine needle aspiration cytology or needle core biopsy

Needle core biopsy (NCB) has been the standard procedure for histopathologic diagnosis of hepatic lesions for more than 50 years. In recent years fine needle aspiration cytology (FNAC) has emerged as a minimally invasive, relatively inexpensive and a rapid method of pathologic evaluation of primary or metastatic hepatic masses. The specificity and the positive predictive value of FNAC is very high however, the sensitivity of the procedure widely ranges between 67% to 93%. The two major areas of diagnostic difficulties are differentiation of benign and non-neoplastic hepatic nodules from well differentiated HCC and identification of obviously malignant cells as HCC, cholangiocarcinoma, or metastasis. Preparation of cell blocks, immunohistochemical stains and application of other ancillary techniques are often helpful in difficult cases. In presence of characteristic features a diagnosis of HCC can be established on FNAC however, a negative result does not exclude malignancy. The role of pathologic diagnosis in the assessment of large hepatic masses is well established however, its role in the evaluation of small hepatic nodules (<3 cm) detected during surveillance of high risk patients is still evolving. Considering the overall advantages and cost-analysis, FNAC can be suggested as the initial method of choice for evaluation of hepatic masses in most clinical settings. However, the final choice of the diagnostic procedure should be decided on the basis of working clinical diagnosis and the institutional experience.

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.

Expression of bile duct-type cytokeratin in hepatocellular carcinoma in patients with hepatitis C virus and prior hepatitis B virus infection

The clinicopathologic findings in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) positive for biliary markers, those related to the hepatic progenitor cells, were investigated. Cytokeratin (CK) 19 was reactive for HCCs only in patients with prior hepatitis B virus (HBV) infection. The proportions of patients with prior HBV infection and poorly differentiated HCC were significantly higher among those with CK 19-positive HCC than among those with CK 19-negative HCC. Some HCCs develop from the hepatic progenitor cells in patients with HCV infection and prior HBV infection, which may affect the clinicopathologic findings of HCV-related HCCs.

Hepatocellular carcinoma: an overview

Hepatocellular carcinoma remains widely prevalent in tropical Africa and south-east Asia and is largely related to chronic hepatitis B virus (HBV) infection. Primary prevention by vaccination of infants at or near birth is effective but any reduction in tumour incidence cannot be expected for decades to come yet, even in those countries in which the necessary resources exist, as millions of adults remain chronically infected. Meanwhile, the incidence is rising in Japan, Mediterranean countries of Europe, Middle East and North Africa and in the USA, largely due to chronic hepatitis C virus (HCV) infection introduced by the indiscriminate use of unscreened blood and blood products in the recent past. Much has been learned from molecular biological studies on hepatocarcinogenesis incriminating the HBX gene of HBV, the core protein of HCV and a unique guanine to thymine transversion at codon 249 has been observed in cases due to aflatoxin exposure. The subject of precancerous lesions, notably adenomatous/dysplastic nodules and large-cell/small-cell change continues to be a source of much debate and the distinction of nodular lesions in cirrhosis from early carcinoma remains uncertain. Spontaneous regression of hepatocellular carcinoma is rare but it is probably immunologically mediated and treatment by activated T-lymphocytes may reduce recurrence rates after surgery. The positive identification of hepatocellular carcinoma by a liver-specific antibody has greatly facilitated the diagnosis in difficult cases.

Chromosomal abnormalities in liver cell dysplasia detected by comparative genomic hybridisation

BACKGROUND/AIM

The pathogenetic relation between liver cell dysplasia and hepatocellular carcinoma (HCC) is poorly understood. The aim of this study was to determine whether there is a genetic link between liver cell dysplasia and HCC that could support the role of dysplasia as a tumour precursor lesion.

METHODS

Microdissection from paraffin wax embedded sections and degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR) were combined to analyse chromosomal imbalances by comparative genomic hybridisation (CGH) in nine HCCs and nodules containing liver cell dysplasia and cirrhosis adjacent to the tumours. Seven cases of large cell changes (LCC) and three cases of small cell changes (SCC) were analysed. The genetic abnormalities detected in liver cell dysplasia were then compared with those present in the corresponding HCC.

RESULTS

No abnormalities were detected in LCC and cirrhotic nodules, arguing against the preneoplasic nature of these cell foci. In contrast, a subset of chromosomal alterations present in HCCs was found in the adjacent SCC.

CONCLUSIONS

These findings support the preneoplastic status of SCC in human hepatocarcinogenesis.

Predictive value of liver cell dysplasia for development of hepatocellular carcinoma in patients with non-cirrhotic and cirrhotic chronic viral hepatitis

AIMS

Hepatocellular carcinoma (HCC) frequently develops in patients with chronic viral hepatitis, especially in the cirrhotic stage. We retrospectively studied whether the presence of the putative preneoplastic lesions large liver cell dysplasia (LLCD) and/or small liver cell dysplasia (SLCD) in a needle liver biopsy of these patients are a risk factor for the development of HCC.

METHODS AND RESULTS

The presence of LLCD and SLCD in the needle liver biopsy taken at the initial work-up of 115 patients with chronic hepatitis B or C was assessed retrospectively. LLCD and SLCD were present in the initial biopsy of, respectively, 35 (30%) and 25 patients (22%). During a mean follow-up of 107 months, 16 patients (14%) developed HCC and this occurred significantly more frequently in patients with cirrhosis, age > or = 55 years, LLCD or SLCD. Cirrhosis and LLCD were independent risk factors for HCC development.

CONCLUSIONS

Our findings indicate that the presence of LLCD in a needle liver biopsy of patients with viral-induced chronic liver disease is an independent risk factor for the development of HCC. If these results are confirmed, the presence of LLCD can be used to identify a subgroup of patients at high risk for HCC requiring more intensive screening.

Endothelial cell marker expression in dysplastic lesions of the liver: an immunohistochemical study

BACKGROUNDS/AIMS

Hepatocellular carcinoma usually contains continuous capillary vessels lacking the differentiation markers specific for normal sinusoidal endothelial cells. We therefore aimed to search for alterations in endothelial cell marker expression in precancerous liver lesions.

METHODS

Expression of the endothelial cell markers CD31, CD34 and BNH9 was analyzed in 138 dysplastic lesions from 40 cirrhotic patients (20 with and 20 without hepatocellular carcinoma).

RESULTS

No expression of the three endothelial cell markers was detected in cirrhotic nodules and in non dysplastic regenerative macronodules. The three markers were detected in 29.8% of dysplastic lesions and 47% of hepatocellular carcinomas. At least one marker was detected in 75% of dysplastic lesions and 100% of hepatocellular carcinomas. The three markers were more frequently expressed in areas of small cell than of large cell change (34 vs 10%). No correlation was found with the grade of dysplasia, the occurrence of arterialization and the association with hepatocellular carcinoma.

CONCLUSIONS

Alterations in the hepatic microcirculation comparable to those observed in hepatocellular carcinoma are present in a significant proportion of dysplastic lesions of the liver and may be indirect markers of the process of liver carcinogenesis.

The immunohistochemical phenotype of dysplastic foci in human liver: correlation with putative progenitor cells

BACKGROUND/AIMS

In previous studies we found strong evidence for the existence and activation in human liver of putative progenitor cells resembling oval cells in rat liver. In view of the known role of rat oval cells in regeneration and hepatocarcinogenesis, we investigated a possible correlation between human putative progenitor cells and different types of dysplastic foci.

METHODS

We determined the immunohistochemical phenotype of dysplastic foci found in 20 cirrhotic liver explants of various etiology, using specific antibodies against hepatocyte-type cytokeratin (CK) 8 and CK18, bile duct-type CK7 and CK19, chromogranin-A (chrom-A) and rat oval cell marker OV-6.

RESULTS

All 12 foci of large cell dysplasia had a phenotype similar to that of surrounding parenchyma. Oncocytic foci showed a strong cytoplasmic staining for CK7. Three out of six of these foci contained "progenitor cells", which are small cells immunoreactive for CK18, CK7, CK19, OV-6, chrom-A and stained more intensely for CK8 than surrounding hepatocytes. Four out of eight glycogen-storing foci contained CK7-positive intermediate hepatocyte-like cells and "progenitor cells". Sixteen out of 29 small cell dysplastic foci consisted of "progenitor cells" and intermediate hepatocyte-like cells which were immunoreactive for CK7, CK18, OV-6, chrom-A and showed a stronger cytoplasmic positivity for CK8 than surrounding hepatocytes.

CONCLUSIONS

Foci of large cell dysplasia show no correlation with putative progenitor cells. Half of the oncocytic and glycogen-storing foci contain "progenitor cells", while more than half of the foci of small cell dysplasia consist of small cells with the same immunohistochemical phenotype as putative progenitor cells and intermediate hepatocyte-like cells, suggesting that differentiating putative progenitor cells can give rise to foci of small cell dysplasia.

Focal nodular hyperplasia of the liver: a comprehensive pathologic study of 305 lesions and recognition of new histologic forms

Atypical histologic variants of focal nodular hyperplasia have been reported and are sometimes difficult to recognize. To characterize the morphologic spectrum of focal nodular hyperplasia, we studied 305 lesions surgically resected from 168 patients. Clinicomorphologic correlations were established by statistical analyses. The patients included 150 women and 18 men (sex ratio, 8:1; median age, 38 years). One hundred twenty-eight (76.2%) patients had solitary lesions, and 40 (23.8%) had 2 to 30 lesions. All 305 lesions measured 1 mm to 19 cm in diameter. Only 49% of these lesions had one to three macroscopic scars. Histologically, 245 (80.3%) lesions were of classical form, and 60 (19.7%) lesions were nonclassical. The latter were classified as focal nodular hyperplasia of telangiectatic form (47 lesions), of mixed hyperplastic and adenomatous form (five lesions), and with atypia of large cell type (eight lesions). Several benign or malignant tumors were found in association with these lesions. This large retrospective series of focal nodular hyperplasia shows the relative incidence of its classical and nonclassical forms. The absence of a central scar could explain the difficult preoperative diagnosis of some of the cases. The morphologic diagnostic criteria in this study require further prospective evaluation.

Hepatocellular carcinoma

Hepatitis C infection is associated with the development of hepatocellular carcinoma, and progress has been made in a number of areas. Transgenic mice lines expressing the hepatitis C core protein develop hepatic steatosis, adenomas, and hepatocellular carcinomas, with no significant hepatitis or fibrosis. This implies that hepatitis C can lead directly to malignant transformation. A new lesion, irregular regeneration, has been described in chronic hepatitis C infection and is associated with a 15-fold increase in the relative risk of developing hepatocellular carcinoma. A minority of patients with hepatitis C-related hepatocellular carcinoma have intense lymphocytic infiltration of the cancer, a feature associated with a better prognosis. Several studies have confirmed the association between large cell dysplasia and hepatocellular carcinoma. However, large cell dysplasia may not be a premalignant lesion and instead may be a marker for premalignant alterations elsewhere in the liver. Oral contraceptives previously have been linked to an increased risk of hepatocellular carcinoma. A large multicenter European case-control study has shown minimal increased risk of hepatocellular carcinoma with use of steroidal contraception. Tamoxifen had shown promise in the management of advanced hepatocellular carcinoma. However, a randomized placebo-controlled study of 477 patients with hepatocellular carcinoma found no benefit from tamoxifen. In a preliminary study, however, octreotide has shown improved survival and quality of life in patients with advanced hepatocellular carcinoma. Finally, interferon treatment continues to be linked to a reduced risk of hepatocellular carcinoma in patients with hepatitis C. These studies generally are not randomized, and a randomized prospective study is required to address this issue.