Hepatocarcinogenesis in liver cirrhosis: imaging diagnosis.

Hepatocellular carcinoma (HCC) frequently occurs in association with liver cirrhosis, as chronic liver disease is one of the most important factors in carcinogenesis. In addition to HCCs, recent reports of pathologic studies of resected specimens from cirrhotic liver describe associated small nodular lesions such as regenerative nodule, dysplastic nodule (adenomatous hyperplasia), and dysplastic nodule with subfocus of HCC (early HCC). In hepatocarcinogenesis of the cirrhotic liver, a regenerative nodule might be the first step in the development of HCC, going through phases of dysplastic nodule, early HCC and early advanced HCC in a multistep fashion. Fortunately, recent advances in various imaging techniques have facilitated the verification of these nodules. In this review, new nomenclature of small hepatocellular nodules, and detection and characterization of hepatic nodules in carcinogenesis with various imaging techniques are described with focus on the premalignant lesions and early stage of HCC. In addition, the efficacy of various imaging techniques for diagnosing them is discussed. Although the terms and definitions of these nodules are still variable and controversial, familiarity with the concept of these borderline lesions is important.     

‘Atypical adenomatous hyperplasia’ in liver cirrhosis: low-grade hepatocellular carcinoma or borderline lesion?

Adenomatous hyperplasia, defined as a sizable parenchymal nodule in cirrhosis, was examined morphologically. Ninety-seven nodules of adenomatous hyperplasia were obtained from 47 cirrhotic livers and were divided into 'ordinary' (44 nodules) and 'atypical' (53 nodules) types. The former consisted of hepatocytes similar to those of the surrounding liver, and showed regularly distributed portal tracts. The latter type was composed of hepatocytes showing nuclear atypia, relative to the surrounding liver, and showed irregular or sparse portal tracts. Atypical nodules were histologically heterogeneous, possessing areas of normo-trabecular, compact, pseudoglandular and/or scirrhous patterns. Several cytological changes, such as clear cell change, small or large cell change and fatty change, were intermingled variably within a given nodule. Atypical nodules showed expansive and/or replacing growth into the surrounding liver. Atypical hepatocytes also infiltrated into the fibrous septa and portal tracts. Foci of overt hepatocellular carcinoma were found in 11 of the 53 atypical nodules. These findings suggest that ordinary adenomatous hyperplasia may be a large-sized regenerative nodule, while atypical adenomatous hyperplasia may be a hepatocellular neoplasm, a peculiar form of low-grade hepatocellular carcinoma or borderline lesion, in which overt hepatocellular carcinoma is likely to evolve through multiple steps.     

Minute scirrhous hepatocellular carcinomas undergoing different carcinogenetic processes

Scirrhous hepatocellular carcinoma (scirrhous HCC) is a rare histological subtype of HCC characterized by marked fibrosis along the sinusoid spaces. Carcinogenetic processes and pathological features at earlier stages of scirrhous HCC remain unclarified. In the present report two cases of minute scirrhous HCC suggesting different carcinogenesis, are described. The first case involved a 54-year-old man with liver cirrhosis related to HCV infection. This patient died of ruptured splenic aneurysm. At autopsy a hepatic tumor measuring 1.8 cm was found, and this tumor had a nodule-in-nodule appearance. Histologically, the inner part of the tumor was well-differentiated HCC with prominent collagen fiber deposition along the sinusoids (scirrhous HCC), whereas the outer part was a high-grade dysplastic nodule. The other patient was a 75-year-old woman who died of hepatic failure due to liver cirrhosis probably related to non-alcoholic steatohepatitis. At autopsy a hepatic tumor (1.2 cm in diameter) was incidentally found in the cirrhotic liver, and was histologically scirrhous HCC without dysplastic nodule elements. Carcinoma cells proliferated along the cirrhotic fibrous septa and replaced regenerative nodules. These two cases suggested that scirrhous HCC could occur in dysplastic nodules (the former case) and also develop de novo in cirrhotic liver (the latter case).     

Multiple occurrence of borderline hepatocellular nodules in human cirrhotic livers: possible multicentric origin of hepatocellular carcinoma

Borderline hepatocellular nodules (BHN), atypical adenomatous hyperplasia, macroregenerative nodule type II or dysplastic nodules in the cirrhotic liver are considered to be important prcancerous lesions transforming to hepatocellular carcinoma (HCC). In order to evaluate the uni- or multicentric origin of BHN and HCC arising from BN, we surveyed 30 cirrhotic livers with BHNs that had been surgically resected or autopsied during 1973–1993. Among the 30 cirrhotic livers with BHNs, two or more BHNs were present in a single cirrhotic liver in 10 (33%) cases, while only one BHN was present in a single cirrhotic liver in the remaining 20 (67%) cases. The mean number of BHN in a cirrhotic liver with multiple BHNs was 3.5. Carcinomatous foci were present within BHN in 6 (60%) of the 10 cirrhotic livers with multiple BHNs, while they were present in 4 (20%) of the 20 cirrhotic livers with a single BHN; this difference was statistically significant (P<0.05). Coexistance of HCC was noted in 8 (80%) of the 10 cirrhotic livers with multiple BHNs, and in 3 (15%) of the 20 cirrhotic livers with a single BHN; this difference was statistically significant (P<0.01). There were no significant differences in age, sex, aetiology and morphology between cirrhotic livers with multiple BHNs and those with a single BHN. These data suggest that BHN and HCC arising from BHN may be of multicentric origin.     

Synchronous hepatocellular carcinoma and cholangiocarcinoma arising in two different dysplastic nodules.

We present the first reported case of explant cirrhotic liver that had synchronous cholangiocarcinoma and hepatocellular carcinoma arising in two different high-grade dysplastic nodules. The patient was a 55-year-old woman who had hepatitis B virus-associated liver cirrhosis for 3 years. The moderately differentiated cholangiocarcinoma occurred in high-grade dysplastic nodule with a 1.7-fold cell density compared with that of cirrhotic nodule. The hepatocellular carcinoma arose in a nodule-in-nodule pattern within a peripherally low-grade and centrally high-grade dysplastic nodule and had a 2.7-fold cell density compared with that of cirrhotic nodule. By immunohistochemistry, the tumor cells of the cholangiocarcinoma as well as bile ductular cells in dysplastic nodule were diffusely positive for cytokeratin 7, whereas hepatocellular carcinoma cells and dysplastic hepatocytes were negative for cytokeratin 7. The c-kit-positive hepatic progenitor cells were singly scattered between hepatocytes, and their number was highest in cirrhotic nodule and decreased in dysplastic nodule, whereas they were absent in cholangiocarcinoma and hepatocellular carcinoma arising in dysplastic nodules. Proliferation indices were progressively increased in cirrhotic nodule, dysplastic nodule, and cholangiocarcinoma or hepatocellular carcinoma, sequentially. These observations indicate that cholangiocarcinoma as well as hepatocellular carcinoma can develop in dysplastic nodule and that hepatic progenitor cells might play a role in the early stage of cholangiocarcinogenesis and hepatocarcinogenesis.     

Morphometric analysis of hepatocellular nodular lesions in HCV cirrhosis

We generated a computerized morphometric model to evaluate and quantify the morphological features in large regenerative nodules (LRN), high-grade dysplastic nodules (HGDN) and hepatocellular carcinoma (HCC). Sixteen LRN, 10 HGDN and 16 HCC in HCV-cirrhotic livers were stained with H&E, smooth muscle actin, CD34, CD31 and reticulin to evaluate volume and surface fractions. On H&E stains, the most discriminatory features between LRN, HGDN and HCC were volume fraction and the number of hepatocyte nuclei in unit volume and hepatocyte nuclear/cytoplasmic ratio. On immunohistochemistry, volume fractions of capillarised sinusoids, capillary units and isolated arteries were significantly different among all groups and highest in HCC; surface fraction of reticulin was markedly decreased in HCC. Our morphometric model is an objective method for quantification of the morphological changes of the nodular lesions, and it could be applied to studies involving histological evaluation of the spectrum of nodular lesions arising in the cirrhotic liver.     

Quantitative morphology of mitochondria in hepatocellular carcinoma and chronic liver disease

A morphometric method was applied to measure the size, number, and surface membranes of the mitochondria in cells obtained from hepatitis B-associated hepatocellular carcinoma (HCC), from cirrhotic portions of livers with and without HCC, and from alcoholic liver disease (ALD). The mitochondria in HCC cells showed a significantly higher numerical density and surface density of internal membranes and cristae than mitochondria in cirrhosis and ALD. The findings suggest an increased functional activity of mitochondria in HCC.     

Detection of micronuclei formation and nuclear anomalies in regenerative nodules of human cirrhotic livers and relationship to hepatocellular carcinoma

Human cirrhosis is considered an important factor in hepatocarcinogenesis. The lack of substantial genetics and cytogenetics data in human cirrhosis led us to investigate spontaneous micronuclei formation, as an indicator of chromosomal damage. The analysis was performed in hepatocytes of regenerative, macroregenerative, and tumoral nodules from 30 cases of cirrhosis (paraffin-embedded archival material), retrospectively selected: cryptogenic, hepatitis C virus, and hepatitis C virus associated with hepatocellular carcinoma (HCC). Thirteen control liver samples of healthy organ donors were included. Micronucleated hepatocytes were analyzed with Feulgen-fast-green dyeing techniques. The spontaneous frequency of micronucleated hepatocytes in both regenerative and macroregenerative nodules of all cirrhotic patients was significantly higher than for the normal control group. There was no significant difference in frequency of micronucleated hepatocytes in regenerative nodules compared with macroregenerative nodules for all cases analyzed, whereas a significantly higher frequency of micronucleated hepatocytes was detected in tumoral nodules, compared with cirrhotic regenerative nodules and normal parenchyma. A higher frequency of the nuclear anomalies termed broken-eggs was observed in hepatitis C virus-related samples. Chromatinic losses and genotoxicity already existed in the cirrhotic regenerative nodules, which might predispose to development of HCC.     

A case of hypervascular hyperplastic nodules in a patient with alcoholic liver cirrhosis

Most hypervascular nodules in a cirrhotic liver are hepatocellular carcinomas (HCCs); however, some are benign hypervascular hyperplastic nodules. We report a case of benign hypervascular hyperplastic nodules in a 41-year-old male patient without hepatitis B or C virus infection, with a history of alcohol abuse, and diagnosed with an aortic aneurysm. The dynamic computerized tomography of the liver demonstrated multiple nodular lesions on both liver lobes with arterial enhancement and delayed washout. The hepatic angiography showed multiple faint nodular staining of both lobes in the early arterial phase. Magnetic resonance imaging revealed numerous nodules showing high signals on T1 weighted images, with some nodules showing a low central signal portion. The clinical impression was HCC. The ultrasonography-guided liver biopsy, which was performed on the largest nodule (2.5 cm in size), revealed hepatocellular nodules with slightly increased cellularity, unpaired arteries, increased sinusoidal capillarization, and focal iron deposition. However, both cellular and cytological atypia were unremarkable. Although the clinical impression was HCC, the pathological diagnosis was hypervascular hyperplastic nodules in alcoholic cirrhosis. Differential diagnosis of hypervascular nodules in cirrhosis and HCC is difficult with imaging studies; thus, histological confirmation is mandatory.     

Expression of alpha-smooth muscle actin in liver diseases.

To evaluate the distribution of alpha-smooth muscle actin (alpha-SMA) positive cells in various liver diseases, we undertook an immunohistochemical study of liver diseases including chronic persistent hepatitis, chronic active hepatitis, liver cirrhosis, intrahepatic cholelithiasis and hepatocellular carcinoma. As a control, fetal livers (gestational age: 22-26 weeks) showed alpha-SMA positive cells along the blood vessels of the portal area, terminal hepatic venules and at perisinusoidal spaces. Perisinusoidal alpha-SMA positive cells were bipolar shaped and had round nuclei. In chronic persistent hepatitis, a few alpha-SMA positive cells were admixed with the inflammatory infiltrates mostly along the intact limiting plate. They were also detected multifocally in a linear pattern along the dilated sinusoid. In chronic active hepatitis, very strong alpha-SMA staining was detected at the site of piecemeal necrosis and adjacent lobules. A-SMA expression was decreased in some cases after interferon treatment. In cases of transplanted liver biopsies, expression of intralobular alpha-SMA was diffusely increased but showed no correlation with degree of acute rejection. Cirrhotic livers revealed strong alpha-SMA positivity in fibrous septae as well as in the perisinusoidal space of intact hepatocytes at the leading edge of fibrosis. Interlobular bile ducts were concentrically circumscribed by alpha-SMA positive cells in cases of intrahepatic cholelithiasis. In trabecular type hepatocellular carcinomas, most sinusoidal lining cells were positive for alpha-SMA. Most intralobular alpha-SMA positive cells represent, if not all, perisinusoidal cells (PSCs) which are involved in intralobular fibrogenesis in various liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Focal hyperplastic hepatocellular nodules in hepatic venous outflow obstruction: a clinicopathological study of four patients and 24 nodules

AIMS: In hepatic venous outflow obstruction (Budd-Chiari syndrome), focal hepatocellular nodules are occasionally discovered showing variable morphology. These could be interpreted either as neoplastic (adenoma), regenerative (large regenerative nodule) or reactive to abnormal vasculature (focal nodular hyperplasia). The aim of this study was to investigate their histogenesis and to determine their morphological characteristics in order to provide diagnostic criteria. MATERIAL AND METHODS: Twenty-four hepatocellular nodules were studied, which were found in three explanted livers and in one additional autopsied liver from four patients with Budd-Chiari syndrome. As controls, we employed three explanted livers without nodules from patients who also suffered from Budd-Chiari syndrome. We attempted to classify the nodules morphologically as either adenoma-like, large regenerative nodule or focal nodular hyperplasia-like, using criteria from the literature. RESULTS: Out of the four cases, we observed two nodules in each of two livers, five in the third one and up to 15 in the remaining one. The size of the nodules ranged from 4 to 25 mm. Eleven nodules could be categorized as large regenerative nodules (two of them with a central scar), seven as focal nodular hyperplasia-like and six as adenoma-like. Some large regenerative nodules showed proliferated arteries with muscular hyperplasia similar to that seen in focal nodular hyperplasia. In the individual livers we could find nodules of various categories. Patchy or diffuse monoacinar regeneration was seen in most cases (six out of seven cases) in the macroscopically non-nodular liver parenchyma. In addition, thrombotic obstruction of portal vein branches was present in all except one of the nodular cases, but in none of the controls. Thus, it appears that portal venous obstructions are frequently, but not invariably associated with the development of nodules. CONCLUSIONS: The hepatocellular nodules seen in livers from patients with Budd-Chiari syndrome share morphological characteristics with large regenerative nodules, focal nodular hyperplasia and hepatocellular adenomas. Their multiplicity, the existence of mixed lesions, the frequent hepatocellular regenerative background as well as the frequently associated portal venous obstructions suggest that these nodules are regenerative in nature and conditioned by an uneven blood perfusion throughout the liver. In their differential diagnosis, the clinicopathological context in which they occur is of paramount importance and should allow recognition that those resembling adenomas may not be true neoplasms.     

Global proteomic analysis of microdissected cirrhotic nodules reveals significant biomarkers associated with clonal expansion

Cirrhosis is a heterogeneous tissue composed of polyclonal regenerative and monoclonal neoplastic, potentially malignant nodules from which hepatocellular carcinoma (HCC) might develop. The aim of this study was to investigate proteomic profile changes associated with clonal expansion of cirrhotic nodules and malignant transformation of monoclonal nodules. Seventy-one cirrhotic nodules from 10 female patients with six HCC were dissected from liver surgical specimen by laser capture microdissection. Clonal status of each nodule was assessed by the study of X-chromosome inactivation pattern using the human androgen receptor. Protein profiles were determined by surface-enhanced laser desorption ionisation-time-of-flight technology using Q10 arrays (Cyphergen ProteinChip). Molecular weight of differentially expressed protein peaks was assessed. An average of 50 protein peaks was obtained for each nodule's profile. Comparison of protein profiles in polyclonal (n=45) and monoclonal cirrhotic nodules (n=26) identified three differentially expressed protein peaks (10,092, 54,025 and 62,133 Da). All were upregulated in monoclonal nodules. Twelve peaks were differentially expressed between monoclonal nodules and HCC with nine proteins upregulated in cancer samples. This study confirms that proteome analysis can be achieved from a limited number of microdissected cells, and provides further insight into the process of clonal expansion and malignant transformation of cirrhotic nodules.     

Quantitative analysis of macrophages and perisinusoidal cells in primary biliary cirrhosis

Immunohistochemistry and image analysis were used to quantify alterations in the Kupffer cell and 'activated' perisinusoidal cell populations in the different stages of primary biliary cirrhosis. Anti-CD68 macrophage antibodies were used to detect Kupffer cells, and anti-α-smooth muscle actin (α-SMA), PR 2D3 and anti-desmin antibodies to detect perisinusoidal cells. Liver biopsy material was available from 26 patients with primary biliary cirrhosis and 23 patients with histologically normal liver. Increased Kupffer cell numbers were observed in periportal/periseptal zones of stage 3 primary biliary cirrhosis ( n = 9), and in random parenchymal areas of stage 3 and stage 4 cases. Significantly increased 'activated' perisinusoidal cell numbers were seen only in periportal/periseptal zones of stage 3 and stage 4 primary biliary cirrhosis. Neither Kupffer cell nor perisinusoidal cell numbers altered significantly in stage 1 and 2 primary biliary cirrhosis ( n = 6). PR 2D3 positivity and increased α-SMA immunoreactivity by perisinusoidal cells in primary biliary cirrhosis support myofibroblastic differentiation of these cells. Human perisinusoidal cells, unlike their rodent counterparts, did not express desmin in primary biliary cirrhosis or control liver. Kupffer cell and 'activated' perisinusoidal cell accumulation in periportal/periseptal zones of the precirrhotic and cirrhotic primary biliary cirrhosis liver support the concept of Kupffer cell-mediated stimulation of perisinusoidal cells. Furthermore, these findings indicate that Kupffer cell–perisinusoidal interactions play an important role in the development of liver fibrosis and cirrhosis in primary biliary cirrhosis.     

The formation of capsule and septum in human hepatocellular carcinoma

The formation of fibrous capsule around the cancer nodule and of the septum in the tumor is frequently observed with the development of hepatocellular carcinoma (HCC). We aimed to clarify how the capsule and septum were formed during the growth of HCC. Liver samples surgically resected from 25 patients with HCC were studied with in situ hybridization for type-I, -III, and -IV procollagen. Type-I and -III procollagen-expressing cells, mostly alpha-smooth muscle actin (SMA)-positive, were increased in the fibrous capsule and in the septum between HCC nodules. These cells were also found at the invasion front of HCC and around the necrotic cancer tissues. Type-IV procollagen gene expression was mainly observed in mesenchymal cells localized in both HCCs and non-cancerous liver. Cancer cells or hepatocytes did not express any of these procollagen genes. The present study reveals that the capsule and septum are mainly formed by alpha-SMA-positive mesenchymal cells at the interface between two different tissues (e.g., cancer nodule vs non-cancerous liver or another cancer nodule). The wound healing occurs even in HCC. The capsule formation may result from interaction between tumor and host liver and interfere the growth and invasion of HCC.     

Hepatitis B virus antigens in liver resections from patients with hepatocellular carcinoma

A high rate of hepatitis B virus (HBV) antigen carriers among patients with hepatocellular carcinoma (HCC) has been recorded from areas of endemic HBV infections in Africa and Asia, but there are only rare and contradictory data for Europe. 12 specimens of resected liver tissue were immunohistologically investigated for hepatitis B surface antigen (HBsAg) as well as for hepatitis B core antigen (HBcAg). HBsAg was contained in non-tumorous liver tissue in 66 per cent of these cases. In two cases detection of HBcAg in the liver provided evidence to replication of the virus. HBcAg plus HBsAg were present in tumour tissue in one case. All of the HBV antigen carriers did not have chronic hepatitis. On the other hand, all patients with chronic hepatitis had HBV antigens in their liver tissue. HBV antigens were detectable in 7 non-cirrhotic livers, but were contained in only one of two cirrhotic livers. These results are likely to suggest a possible relevance of HBV infection to the aetiology of HCC even in central Europe without customary liver cirrhosis.     

Iron-negative foci in siderotic macroregenerative nodules in human cirrhotic liver. A marker of incipient neoplastic lesions

Resistance to iron accumulation is known as a phenotypic marker of neoplasia and preneoplasia in experimental hepatocarcinogenesis in rodents overloaded by iron. This study was aimed to evaluate whether such iron-free foci are present and valuable for identification of preneoplastic and incipient neoplastic lesions in human cirrhotic livers, especially within macroregenerative nodules in which hepatocellular carcinoma is known to arise. Iron-free foci were found in siderotic macroregenerative nodules in liver cirrhosis. These foci were classic and overt carcinoma or borderline lesions showing an expansive growth pattern. Borderline lesions were composed of hyperplastic or small basophilic hepatocytes with hyperchromasia and distinct nuclear membrane showing pseudoglandular, trabecular, compact, and scirrhous patterns. These data suggest that iron stain is valuable for identification of neoplastic or borderline lesions representing a transition from hyperplastic nodule to carcinoma in human liver cirrhosis.     

Immunohistochemical identification of Ito cells and their myofibroblastic transformation in adult human liver

To identify Ito cells in normal and pathological adult human livers, immunohistochemical studies were performed by the avidin-biotin-peroxidase complex method using monoclonal antibodies for -smooth muscle actin (ASMA), desmin, and vimentin. Fifty one needle biopsies, 7 surgically resected specimens, and 5 autopsy specimens were studied. In the normal adult liver vascular smooth muscle cells and pericytes, together with perisinusoidal cells with thin cytoplasmic processes were positive for ASMA. These latter cells formed a loose and discontinuous layer along the sinusoidal walls. Immunoelectron microscopy showed that the ASMA-positive perisinusoidal cells were Ito cells containing fat droplets. The other sinusoidal lining cells were negative for ASMA. In chronic liver disease, ASMA-positive Ito cells showed an increase in number, size, and the intensity of immunostaining in areas of piecemeal necrosis), and formed a continuous cellular network. These cells were dendritic in shape with irregularly elongated cytoplasmic processes and contained an increased amount of microfilaments, in association with loss of the characteristic fat droplets. Thus, their ultrastructural features corresponded to those of myofibroblastic cells. Ito cells showed no staining for desmin in both normal and pathological livers. These results indicate that immunohistochemistry using an anti-ASMA antibody is a sensitive and reliable method for the identification of both normal and transformed Ito cells in adult human livers.     

Unusual hepatocellular lesions in primary biliary cirrhosis resembling but unrelated to hepatocellular neoplasms

Summary Structural, cellular and nuclear abnormalities of hepatocytes are a histological hallmark of well-differentiated, small hepatocellular carcinoma (HCC) or its borderline lesion. This study revealed that several hepatocellular abnormalities found in these hepatocellular neoplasms were also found in non-cirrhotic stages of primary biliary cirrhosis (PBC) in which HCC is unlikely to develop. These changes are small cell changes, consisting of the appearance of small hepatocytes arranged in thin trabecular or compact patterns with increased cellularity and basophilic cytoplasm. This was found in 36%, 71% and 100% in specimens of stages 1, 2 and 3, respectively. Large cell changes occurred and consisted of large hepatocytes with large nuclei and prominent nucleoli, found in 27%, 47% and 22% of the stages, respectively. Finally, liver cell rosettes were seen, showing variable acinar formation and present in 0%, 41% and 33% of the stages, respectively. These lesions were identified microscopically as irregularly shaped areas or vague nodules of hepatocytes without a fibrous rim, in the hepatic lobules. They showed an expansive growth or shaggy border against the surrounding hepatic parenchyma. Follow-up studies, including autopsies, failed to show development of HCC or its borderline lesion in PBC cases. Pathologists must make a diagnosis of HCC and its borderline lesion bearing in mind the occurrence of such unusual hepatocellular lesions probably of a reactive nature.     

Replicative senescence in normal liver, chronic hepatitis C, and hepatocellular carcinomas

There is growing evidence that senescent cells accumulate in vivo and are associated with the aging process in parallel with the progressive erosion of telomeres. Because recent data show that telomere shortening is involved in the pathogenesis of liver cirrhosis, we looked for replicative senescence cells in normal livers, chronic hepatitis C, and hepatocellular carcinoma (HCC). Replicative senescent cells were detected on liver tissue cryosections using expression of a specific marker, senescence-associated beta-galactosidase, a cytoplasmic enzyme detected at pH 6. A total of 57 frozen liver samples (15 normal liver, 32 chronic hepatitis C, and 10 HCCs) were studied. Replicative senescence was graded as absent in 56% of cases (32 of 57) and present in 44% (25 of 57). Replicative senescence was considered present in 3 of 15 normal livers (20%), 16 of 32 chronic hepatitis cases (50%), and 6 of 10 HCCs (60%). In the group of nontumoral livers, the presence of senescent cells in liver was associated with older age (P =.03). In the group with chronic hepatitis C, fibrosis stage, but not activity grade, was significantly correlated with the accumulation of replicative senescent cells (P <.001). Finally, beta-Gal staining in nontumoral tissue was strongly correlated with the presence of HCC in the surrounding liver (P <.001). These results suggest that chronic hepatitis C represents a relevant model of accelerated replicative senescence and that accumulation of replicative senescent cells predispose to HCC development. Detection of replicative senescent cells may then serve as a predictive marker of a hepatocellular carcinoma in the surrounding tissue. HUM PATHOL 32:327-332.