Multicentric hepatocellular carcinoma following phosphate diethylstilbestrol therapy for prostatic cancer

This paper reports an autopsy case of a 78-year-old male with multiple nodules in the liver developed after long-termed administration of phosphate diethylstilbestrol (PDES) for prostatic cancer. Large part of these nodules were suspected to be well differentiated hepatocellular carcinoma with high level of serum alpha-fetoprotein (AFP) up to 3,400 ng/ml, but a part of them was evaluated to be a borderline between hepatocellular carcinoma and adenoma with mild cellular atypism. The liver other than the nodules showed liver fibrosis associated with liver cell dysplasia and peliosis hepatis-like change. This is a unique autopsy case of hepatocellular carcinoma closely related to diethylstilbestrol (DES) therapy for prostatic cancer.     

MULTICENTRIC HEPATOCELLULAR CARCINOMA FOLLOWING PHOSPHATE DIETHYLSTILBESTROL THERAPY FOR PROSTATIC CANCER

This paper reports an autopsy case of a 78-year-old male with multiple nodules in the liver developed after longtermed administration of phosphate diethylstilbestrol (PDES) for prostatic cancer. Large part of these nodules were suspected to be well differentiated hepatocellular carcinoma with high level of serum alpha-fetoprotein (AFP) up to 3,400 ng/ml, but a part of them was evaluated to be a borderline between hepatocellular carcinoma and adenoma with mild cellular atypism. The liver other than the nodules showed liver fibrosis associated with liver cell dysplasia and peliosis hepatis-like change. This is a unique autopsy case of hepatocellular carcinoma closely related to diethylstilbestrol (DES) therapy for prostatic cancer.     

Adenomatous hyperplasia of the liver resembling focal nodular hyperplasia in patients with chronic liver disease

Two nodules of hepatic adenomatous hyperplasia (AH) resembling focal nodular hyperplasia were found in two patients with cirrhosis or chronic active hepatitis. Imaging techniques suggested that the nodules were hepatocellular carcinoma. Pathological examination showed that the nodules (approximately 1.0 cm in diameter) were clearly demarcated from the surrounding liver tissue, and contained foci of scar-like fibrosis in the centre of the nodules. Microscopically, they contained portal tracts and fulfilled the criteria of AH. A large number of arteries were present in the central scarlike fibrosis as well as in the parenchyma of the nodules. There were foci of mildly atypical hepatocytes in one nodule but no cellular atypia in the other. Morphometric analysis showed that the cumulative luminal area of arteries per unit area was much greater in the nodules than in the extranodular liver tissues, while the cumulative luminal area of portal veins per unit area was much less in the nodules than in the extranodular liver tissues. Although the pathogenesis is unclear, these nodules might have developed through localized vascular changes associated with chronic liver disease, may have arisen from pre-existing arterial malformation, or may represent the early stages of angiogenesis in hepatocarcinogenesis.     

ADENOMA WITH MULTIPLE HYPERPLASTIC NODULES IN NONCIRRHOTIC LIVER POSSIBLY RELATED TO LONG-TERM ADMINISTRATION OF A HYPOLIPIDEMIC DRUG

Described here is an autopsy case of a 76-year-old woman with preneoplastic and other adenomatous hepatocellular lesions. Multiple small hyperplastic liver foci with PAS positive reaction and adenomatous nodular lesions were noted in a non-cirrhotic liver. These lesions resembled altered foci or neoplastic nodules which are currently regarded as premalignant changes in experimental animal models. It is suggested that the liver lesions of this woman may be related to long-term administration of hypolipidemic drug cloflbrate for hypercholesteremia and the lesions could be one of the precursor changes of human hepatocellular carcinoma.     

Adenoma with multiple hyperplastic nodules in noncirrhotic liver possibly related to long-term administration of a hypolipidemic drug

Described here is an autopsy case of a 76-year-old woman with preneoplastic and other adenomatous hepatocellular lesions. Multiple small hyperplastic liver foci with PAS positive reaction and adenomatous nodular lesions were noted in a non-cirrhotic liver. These lesions resembled altered foci or neoplastic nodules which are currently regarded as premalignant changes in experimental animal models. It is suggested that the liver lesions of this woman may be related to long-term administration of hypolipidemic drug clofibrate for hypercholesteremia and the lesions could be one of the precursor changes of human hepatocellular carcinoma.     

COMPARATIVE STUDY OF ABNORMALITY IN GLYCOGEN STORING CAPACITY AND OTHER HISTOCHEMICAL PHENOTYPIC CHANGES IN CARCINOGEN-INDUCED HEPATOCELLULAR PRENEOPLASTIC LESIONS IN RATS

A sequential comparison was made between abnormal glycogen storage and other histochemical phenotypic changes in hepatocellular precancerous lesions (altered foci and neoplastic nodules) during various stages in the process of development of cancer in rat liver. N-2-fluorenylacetamide was fed to male rats for 8 weeks and groups of rats were killed at the end of carcinogen feeding and at 12 and 24 weeks on control diet. Foci rich in glycogen storage accounted for a majority of all foci over the course of experiment, while foci devoid of glycogen storage, which were absent at the end of carcinogen feeding, gradually increased in number during maintenance. Glycogen-deficient lesions that might appear to arise from glycogen-rich lesions displayed hyper-basophilia demonstrated by toluidine blue reaction, but often lacked gamma-glutamyl transpeptidase activity. Resistance to iron accumulation was consistently shown in all precursor lesions for hepatocellular carcinoma in the siderotic liver regardless of abundance or absence of cellular glycogen. It was suggested that properties such as loss of glycogen storing capacity, hyperbaso-philia, and some cellular atypicality resembling those of carcinoma cells might be essential elements for malignant progression.     

The slow induction of resistant hepatocytes during initiation of hepatocarcinogenesis by the nongenotoxic carcinogen clofibrate

This study was designed to explore whether a well-known nongenotoxic liver carcinogen, clofibrate, would induce rare resistant hepatocytes similar to those seen during initiation of hepatocarcinogenesis with many genotoxic carcinogens. Male young adult F344 rats were exposed to a control diet containing 0.5% (w/w) clofibrate for 3, 6, or 10 months. After 1 month on a diet free of clofibrate, the animals were assayed for resistant hepatocytes by a standardized selection procedure using 2-acetylaminofluorene as the inhibitor and partial hepatectomy as a strong stimulus for cell proliferation. No resistant hepatocytes were found in the animals exposed to clofibrate for 3 months or in any of a series of control animals. However, animals on the clofibrate for 6 and 10 months contained resistant hepatocytes that were clonally expanded to produce hepatocyte nodules. These nodules were indistinguishable on gross and microscopic examination from hepatocyte nodules seen in animals in which nodules are induced with one of many different genotoxic carcinogens. Also, like those nodules, the nodules seen in the animals exposed to clofibrate stained positively for glutathione S-transferase 1-1 and gamma-glutamyl transpeptidase and negatively for ATPase. The evidence from this study indicates that the nongenotoxic carcinogen, clofibrate, induces early cellular changes in the liver that are very similar to those induced by many different genotoxic carcinogens. These changes are manifest as a resistance phenotype in a few scattered hepatocytes that now can be clonally expanded selectively to form hepatocyte nodules. However, the resistant hepatocytes are induced by clofibrate much more slowly. Whether this basic similarity pertains to the later steps in the hepatocarcinogenic process remains to be studied.     

Comparative study of abnormality in glycogen storing capacity and other histochemical phenotypic changes in carcinogen-induced hepatocellular preneoplastic lesions in rats

A sequential comparison was made between abnormal glycogen storage and other histochemical phenotypic changes in hepatocellular precancerous lesions (altered foci and neoplastic nodules) during various stages in the process of development of cancer in rat liver. N-2-fluorenylacetamide was fed to male rats for 8 weeks and groups of rats were killed at the end of carcinogen feeding and at 12 and 24 weeks on control diet. Foci rich in glycogen storage accounted for a majority of all foci over the course of experiment, while foci devoid of glycogen storage, which were absent at the end of carcinogen feeding, gradually increased in number during maintenance. Glycogen-deficient lesions that might appear to arise from glycogen-rich lesions displayed hyperbasophilia demonstrated by toluidine blue reaction, but often lacked gamma-glutamyl transpeptidase activity. Resistance to iron accumulation was consistently shown in all precursor lesions for hepatocellular carcinoma in the siderotic liver regardless of abundance or absence of cellular glycogen. It was suggested that properties such as loss of glycogen storing capacity, hyperbasophilia, and some cellular atypicality resembling those of carcinoma cells might be essential elements for malignant progression.     

Enhancement of chemical hepatocarcinogenesis by the HIV-1 tat gene

The human immunodeficiency virus-1 Tat protein is suspected to be involved in the neoplastic pathology arising in AIDS patients. tat-transgenic (TT) mice, which constitutively express Tat in the liver, develop liver cell dysplasia (LCD) that may represent a preneoplastic lesion. To test if TT mice are predisposed to liver carcinogenesis, we treated them with diethylnitrosamine, a hepatotropic carcinogen. Diethylnitrosamine-treated TT mice developed both preneoplastic and neoplastic lesions in the liver. They showed an enhancement of LCD and developed basophilic liver cell nodules (BLCN), hepatocellular adenomas (HA), and hepatocellular carcinomas (HC). Both preneoplastic (LCD and BLCN) and neoplastic (HA and HC) lesions were significantly more frequent in TT than in control mice: 29.7% versus 12.7% for LCD, 57.9% versus 23.3% for BLCN, 40.6% versus 10.0% for HA, and 50.0% versus 12.7% for HC. These results indicate that Tat expression in the liver predisposes to both initiation of hepatocarcinogenesis and to malignant progression of liver tumors. This study supports a role for Tat in enhancing the effect of endogenous and exogenous carcinogens in human immunodeficiency virus-1-infected patients, thereby contributing to tumorigenesis in the course of AIDS.     

‘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.     

Oncogene activation and hepatocarcinogenesis

Dominant-transforming oncogenes are frequently detected in mouse liver tumors, but are rare or inconsistently detected in rat liver tumors. Most of those that have been identified are members of the ras family. While altered expression of many oncogenes has been reported, an increase in the expression of the c-myc gene is consistently observed in both rat and mouse hepatocellular tumors. Both hepatocytes and liver epithelial cells have been immortalized or transformed with viral or cellular oncogenes. Immortalization of cells occurs without the loss of differentiated functions, while transformation induces the expression of many genes/gene products associated with liver cancer in vivo. Cells transformed with chemical carcinogens or oncogenes display a phenotype of growth factor independence or greatly reduced growth factor requirements. Transformation is frequently associated with a substantial decrease in the expression of the exogenous growth factor receptor in the hepatocellular tumors.     

Liver cell atypias: a comparative study in cirrhosis with and without hepatocellular carcinoma

Various criteria have been proposed for the identification of early neoplastic changes in the setting of both small hepatocellular carcinomas and macroregenerative nodules. In this study we have applied those criteria to cases of liver cirrhosis without tumour (group I) and hepatocellular-carcinoma-associated cirrhosis (group II) to assess their discriminatory value in these two situations. Group I included 50 liver biopsies with uncomplicated cirrhosis while group II encompassed 48 liver biopsies of cirrhotic nodules adjacent to hepatocellular carcinomas. The histological changes sought were large cell dysplasia, small cell dysplasia, cytoplasmic basophilia, small microacinar structures, peripheral distribution of nuclei, nuclear irregularities and thickened liver cell plates. These changes were also assessed in macroregenerative nodules (nine in group I and seven in group II). None of these changes was useful to discriminate between group I and group II cirrhotic nodules when assessed separately. On the other hand, cirrhotic nodules showing three or fewer changes were never associated with malignancy, whereas those exhibiting four or more alterations were often located in the vicinity of a tumour. Acinar structures, thickened cell trabeculae, peripheral distribution of nuclei and nuclear irregularities seem to be the most specific indicators of proximity to a hepatocellular carcinoma. Similar results were obtained for macroregenerative nodules. These results may be helpful as guidelines to the probability of having a hepatocellular carcinoma elsewhere in livers containing atypical cirrhotic nodules, and may also prove valuable in the selection of appropriate material for investigating early molecular events in hepatic carcinogenesis.     

原发性肝癌和慢性肝病血清HBsAg特异性免疫复合物的检测比较

采用捕捉法ELISA,检测31例HBV感染指标阳性的原发性肝癌患者血清四类HBsAg特异性免疫复合物。结果表明,各类的阳性率均非常显著低于慢性活动性乙肝和乙肝后肝硬化,而与慢性迁延性乙肝无明显差异。提示患者的免疫抑制程度与慢迁肝基本一致。     

Comparative effects of carcinogens on the induction of placental glutathione S-transferase-positive liver nodules in a short-term assay and of hepatocellular carcinomas in a long-term assay

The dose-dependent effects of three hepatocarcinogens were investigated by measuring the number and area of glutathione S-transferase placental form (GST-P)-positive foci and nodules appearing in the liver under short-term conditions (Experiment I) and evaluating the incidence of hepatocellular carcinoma after long-term chronic administration (Experiment II). For these purposes, three different doses of 2-acetylaminofluorene (2-AAF), 3'-methyl-4-dimethy-laminoazobenzene (3'-Me-DAB), and DL-ethionine (ethionine) were given to male F344 rats for 6 weeks after a single injection of diethylnitrosamine (DENA) in Experiment I or for 104 weeks without initiation by DENA in Experiment II. In Experiment I, the induction of GST-P-positive foci and nodules by 2-AAF and 3'-Me-DAB was clearly dose-dependent. In contrast, ethionine showed enhancing effects inducing GST-P-positive foci and nodules only in groups given the highest dose level. Similarly, in Experiment II, induction of hepatocellular carcinomas by 2-AAF and 3'-Me-DAB was clearly dose-dependent, whereas liver neoplasms were only induced by the highest dose level of ethionine. These results indicate that degree of induction of GST-P positive foci and nodules in a short-term in vivo test for liver carcinogens corresponds with the incidences of hepatocellular carcinomas revealed in a long-term in vivo assay.     

Focal nodular hyperplasia-like areas in cirrhosis

AIMS: Focal nodular hyperplasia-like lesions have rarely been described in cirrhotic livers. We describe five cases of such lesions. METHODS AND RESULTS: Between 1998 and 2001, 146 liver transplants were performed at the Royal Free Hospital for cirrhosis of the liver. Nodular lesions identified in the livers removed at transplantation were defined histologically according to the International Working Party classification (Hepatology 1995; 22; 983). They were present in 63 of these livers, as follows: 36 dysplastic nodules, 121 macroregenerative nodules, and 71 hepatocellular carcinomas. In five patients, an additional 12 nodules (size range 4-23 mm, median 10.5 mm) showed histological features suggestive of focal nodular hyperplasia including mildly inflamed vascular fibrous septa, and ductular proliferation. Pre-transplantation imaging showed features suspicious for hepatocellular carcinoma, in three of these lesions (12, 23 and 23 mm diameter) from two different patients. These lesions were histologically indistinguishable from focal nodular hyperplasia occurring in non-cirrhotic livers, with fibrous scars and septa which contained vascular and ductular structures. CONCLUSIONS: It is important to recognize that these lesions may occur in the context of cirrhosis and that they should be considered in the differential diagnosis with hepatocellular carcinoma, dysplastic nodules and macroregenerative nodules.     

Prediction of rodent carcinogenesis: an evaluation of prechronic liver lesions as forecasters of liver tumors in NTP carcinogenicity studies

The National Toxicology Program (NTP) developed the chronic 2-year bioassay as a mechanism for predicting the carcinogenic potential of chemicals in humans. The cost and duration of these studies has limited their use to small numbers of selected chemicals. Many different short-term methods aimed at increasing predictive accuracy and the number of chemicals evaluated have been developed in attempts to successfully correlate their results with evidence of carcinogenicity (or lack of carcinogenicity) are assessed. Using NTP studies, the effectiveness of correlating prechronic liver lesions with liver cancer encompassing multiple studies using mice (83 compounds) and rats (87 compounds). These lesions include hepatocellular necrosis, hepatocellular hypertrophy, hepatocellular cytomegaly, bile duct hyperplasia, and hepatocellular degeneration, along with increased liver weight. Our results indicate that pooling 3 of these prechronic data points (hepatocellular necrosis, hepatocellular hypertrophy, and hepatocellular cytomegaly) can be very predictive of carcinogenicity in the 2-year study (p < 0.05). The inclusion of increased liver weight as an endpoint in the pool of data points increases the number of rodent liver carcinogens that are successfully predicted (p < 0.05), but also results in the prediction of increased numbers of noncarcinogenic chemicals as carcinogens. The use of multiple prechronic study endpoints provides supplementary information that enhances the predictivity of identifying chemicals with carcinogenic potential.     

Arterial elements and perisinusoidal cells in borderline hepatocellular nodules and small hepatocellular carcinomas

Borderline hepatocellular nodule in the human cirrhotic liver is considered a preneoplastic lesion of hepatocellular carcinoma (HCC). However, the angiogenetic process and changes in perisinusoidal cells (fat-storing cells or Ito cells) during the borderline nodule-HCC sequence have not been investigated. We have investigated intraparenchymal arterial elements and perisinusoidal cells in normal livers, chronic hepatitis, borderline nodules and small HCC, using an immunohistochemical staining for α-smooth muscle actin. In normal livers, chronic hepatitis, cirrhotic nodules and large regenerative nodules, no or few arterial elements were present in the parenchyma, and α-smooth muscle actin-positive perisinusoidal cells were not increased. In borderline nodules, however, there were many intranodular arterial elements, and perisinusoidal cells were significantly increased. In small HCC, there were much more arterial elements, and perisinusoidal cells were increased further. These data suggest that angiogenesis first occurs in borderline hepatocellular nodules and it gradually proceeds during the nodule to HCC sequence along with an increase in perisinusoidal cells. The demonstration of arterial elements and perisinusoidal cells may be useful for the differential diagnosis of large regenerative nodule, borderline hepatocellular nodule and small HCC.     

Morphometric evaluation of hepatocellular proliferative lesions in the rat liver

Classification of rat hepatocellular proliferative lesions can vary between pathologists as the many qualitative histologic criteria have not been satisfactorily evaluated and ranked for prognostic value. Computer-assisted morphometry offers an objective method to evaluate certain cellular features. The Solt-Farber resistant hepatocyte model was used in this study to produce populations of rats with a full range of hepatocellular proliferative lesions. Cellular features within the lesions were then measured morphometrically and the data were analyzed by animal age and by subjective lesion diagnosis. The nuclear/cytoplasmic ratio followed by the cell area and nuclear area were found to be the most important parameters for separating microscopic foci and islands of cellular alteration, an early hyperplastic lesion, from other hepatocellular proliferative lesions. The coefficient of variation, as a relative measure of heterogeneity, increased in a linear manner for cell, nuclear and nucleolar areas as the animals aged and was significantly higher for cell and nuclear area in hepatocellular carcinoma compared to other hepatocellular proliferative lesions. Hepatocyte nodules (representing primarily late hyperplastic lesions) and persistent hepatocyte nodules (lesions with similarities to hepatocellular adenoma) could not be satisfactorily separated within the limits of this study. As these borderline lesions show a continuum of cytologic change, other features, such as architectural change, are necessary to satisfactorily classify them on a subjective basis. An alternative approach is to use discriminant functions derived from morphometric studies.