Vascular supply in adenomatous hyperplasia of the liver and hepatocellular carcinoma: a morphometric study.

Vascular supply of adenomatous hyperplasia (AH) of the liver, a preneoplastic or early neoplastic lesion of hepatocellular carcinoma (HCC), and that of HCC were morphometrically examined. Seventy-three nodules of AH were divided into 43 ordinary and 30 atypical AHs. The latter showed a variety of hepatocellular atypias that were, however, insufficient to make a diagnosis of HCC, while the former lacked such atypias. Arteries were slightly more numerous and portal veins were slightly less frequent in both ordinary and atypical AHs compared with the surrounding liver. In ordinary AHs, cumulative areas of arterial lumen and portovenous lumen were almost equal to or less than those in the surrounding liver in two thirds of our cases. The cumulative area of arterial lumen was equal to, and that of portovenous lumen was less than, the cumulative area in the surrounding liver in the remaining one third of our cases. In a majority of atypical AHs, the cumulative area of arterial lumen was equal to, and that of portovenous lumen was less than, the cumulative area in the surrounding liver. In most HCC nodules, the number and cumulative luminal area of arteries were much more, and those of portal veins were much less, than the number and cumulative area in the surrounding liver. The relative number and cumulative luminal area of abnormal arteries compared with all arteries showed a stepwise increase in the following order: ordinary AH (20.7% and 17.5%), atypical AH (46.8% and 52.5%), and HCC (93.6% and 92.0%). These data suggest that ordinary AH, atypical AH, and HCC are different in vascular supply, and that these differences may reflect sequential changes in the hemodynamic state during hepatocarcinogenesis.     

Histological study of PIVKA-II expression in hepatocellular carcinoma and adenomatous hyperplasia

Although serum concentration of protein induced vitamin K absence or antagonist II (PIVKA-II) has been widely used for diagnosing hepatocellular carcinoma (HCC), little information is available concerning tissue PIVKA-II as an immunohistochemical marker for liver histology. In this study, we examined the expression of PIVKA-II in precancerous nodules (adenomatous hyperplasia) and various differentiation grades of HCC by immunohistochemical study using the monoclonal anti-PIVKA-II antibody (MU-3). We examined the relationship between tissue PIVKA-II staining and serum PIVKA-II level, tumor histology and tumor size. PIVKA-II was mainly detected in the cytoplasm of the HCC cells. The positive rates of PIVKA-II were as follows: adenomatous hyperplasia (AH), 0% (0/9); well-differentiated HCC, 65% (15/23); moderately differentiated HCC, 85% (22/26); poorly differentiated HCC, 54% (7/13). The expression of tissue PIVKA-II staining in moderately differentiated HCC was significantly higher than in well- or poorly differentiated HCC, whereas the serum PIVKA-II level in poorly differentiated HCC was higher than well- or moderately differentiated HCC. There was no relationship between the expression of PIVKA-II in cancer tissues and serum levels of PIVKA-II. Immunohistochemical studies revealed that PIVKA-II was expressed even in small-sized or well-differentiated HCC cells, but expression was not detected in AH. It was concluded that PIVKA-II is a useful immunohistochemical marker, even in small-sized or well-differentiated HCC.     

Early stages of multistep hepatocarcinogenesis: adenomatous hyperplasia and early hepatocellular carcinoma.

From a series of 320 heptocellular carcinoma (HCC) cases treated surgically, we selected small nodular lesions that had not destroyed the preexisting liver structure grossly. After excluding metastases and large regenerative nodules, 58 lesions from 41 cases were chosen. All the lesions were hypercellular. Among them, 33 lesions showing histologic features of very well-differentiated HCC (Edmondson grade I), that is, small hepatocytes with little cellular atypia but with structural atypia, such as a thin trabecular structure of acinar formation in some areas, were classified as early HCC (eHCC). In seven eHCCs, areas of overt carcinoma, classified as Edmondson grade II, were found in the background of Edmondson grade I carcinoma. The remaining 25 lesions lacked structural atypia and were classified as adenomatous hyperplasia (AH). Among the AHs, 10 nodules with a very focal abnormal structure were subclassified as atypical adenomatous hyperplasia (AAH). There was a tendency for the size and cellularity of the atypical lesions to increase in order from AH to AAH to eHCC. All nodules larger than 1.5 cm were eHCC. A degree of cellularity more than twice that of a regenerative nodular was suggested to be an indicator of HCC. All small nodular lesions were associated with chronic liver disease. These histologic observations appear to explain the stepwise development of overt HCC from very well-differentiated eHCC, and of eHCC from AH probably through AAH, at least in cases of HCC associated with chronic liver disease.     

An autopsy case of metastatic foci of hepatocellular carcinoma in adenomatous hyperplasias of the liver.

Adenomatous hyperplasia of the liver is known as a preneoplastic or early developmental stage of hepatocellular carcinoma, in which overt malignant foci occasionally develop. We have recently experienced an autopsy case (a 70-year-old male) of liver cirrhosis with hepatocellular carcinoma and two nodules of adenomatous hyperplasia. The latter two nodules contained several microscopic foci of moderately differentiated hepatocellular carcinoma. There were a number of tumor microemboli in portal vein branches within areas of adenomatous hyperplasia in addition to areas surrounding cirrhotic liver, some of which grew into the parenchyma of adenomatous hyperplasia and cirrhotic regenerative nodules. These findings and the fact that adenomatous hyperplasia contained portal tracts including portal venous branches, suggest that malignant foci in adenomatous hyperplasia contained portal tracts including represent metastases from hepatocellular carcinoma in other parts of the liver via the intrahepatic portal venous system.     

Immunohistochemical detection of XIAP and p63 in adenomatous hyperplasia, atypical adenomatous hyperplasia, bronchioloalveolar carcinoma and well-differentiated adenocarcinoma.

The critical distinction of bronchioloalveolar carcinoma (BAC), well-differentiated adenocarcinoma (WDAC) of lung, adenomatous hyperplasia (AH) and atypical adenomatous hyperplasia (AAH), is based on morphological criteria alone, and is therefore potentially subjective. We examined expression of two markers, X-linked inhibitor of apoptosis protein (XIAP), the most potent of the inhibitor of apoptosis protein (IAP) family, and p63, a marker of bronchial reserve cells (BRC) and squamous cells, in these entities. H&E slides of 37 tissue blocks from 27 patients were reviewed and classified as AH (n=7), AAH (n=8), BAC (n=9) and WDAC (n=13). Immunostaining was performed on 4 mum sections with monoclonal anti-XIAP and monoclonal anti-p63. Granular or heterogeneous cytoplasmic staining for XIAP and nuclear staining for p63 were considered positive. Neither XIAP nor p63 were detected in normal lung alveolar cells. All seven AHs were negative for XIAP and negative or focally positive for p63. All eight AAHs were positive for XIAP and displayed p63 positivity in scattered cells. All BACs displayed XIAP positivity, which ranged from focal/weak to diffuse/strong. p63 was negative in seven and focally positive in two of nine BACs. Twelve of 13 WDACs showed XIAP positivity in a similar pattern to BAC; all were negative for p63. One aberrant case diagnosed on H & E as WDAC was negative for XIAP but strongly positive for p63. Significant XIAP expression appears to be useful for distinguishing AAH from AH. Commonality of XIAP staining in AAH, BAC and WDAC supports the possibility that AAH may be a pre-malignant lesion. The rarity of p63 expression confirms previous reports and supports a nonbronchial histogenesis of these entities. In contrast, diffuse p63 staining may facilitate the identification of rare cases that may have been misclassified as alveolar in origin based on morphology but may be of BRC origin.     

A histopathological analysis of five cases of adenomatous hyperplasia containing minute hepatocellular carcinoma.

We present five cases of adenomatous hyperplasia (AH) containing minute hepatocellular carcinoma (HCC) in cirrhotic liver. All the patients were Japanese, four males and one female, ranging in age from 60 to 80 years. Two of the specimens were obtained at surgery and the others at autopsy. The AH specimens ranged from 2.0 to 3.0 cm in diameter, and the maximum diameter of HCC foci in the AH was 2.0 cm. Histologically, apart from the HCC foci, the AH specimens showed intrinsic atypia, suggesting preneoplastic change. These features included an increase of both cellularity and the nucleo-cytoplasmic ratio, distortion of cord structure and pseudoacinar formation. All of the AH specimens contained typical portal triads. Details of diagnostic imaging were also obtained in four cases. The findings of the present study support the possibility that AH with intrinsic atypia is a preneoplastic lesion of HCC. The sequence of "adenomatous hyperplasia with intrinsic atypia-HCC foci" would thus represent part of the early phase of hepatocarcinogenesis in humans.     

Cytodifferentiation of atypical adenomatous hyperplasia and bronchioloalveolar lung carcinoma: immunohistochemical and ultrastructural studies

We used immunohistochemistry and electron microscopy to evaluate the differentiation of cells comprising atypical adenomatous hyperplasia (AAH; n = 26), early bronchioloalveolar lung carcinoma (BAC; n = 11), and overt BAC (n = 16), which are assumed to constitute a continuous spectrum of developmental steps of BAC. Surfactant apoprotein (SAP), a marker for type 2 alveolar cells, was expressed in cells from all the lesions of AAH, early BAC, and overt BAC. However, the proportion of SAP-positive cells decreased and their distribution became more heterogeneous with advancing lesion grade. Urine protein 1, which is identical to the Clara cell-specific 10 kDa protein, was expressed in 70% of overt BAC, whereas only 20% of early BAC showed weak reactivity and none of AAH lesions showed any reactivity at all. Ultrastructurally, type 2 alveolar cell differentiation was predominant among cells from AAH and early BAC. Our results suggest that precursor cells of BAC differentiate predominantly towards type 2 alveolar cells. Cells comprising overt BAC retain this differentiation phenotype, but to a reduced extent. In contrast, concomitantly with progression, cells with Clara cell differentiation emerge and their proportion increases. Such phenotypic changes may reflect metaplasia occurring in tumour cells during the development of BAC.     

Difference in the three-dimensional structure of the sinusoids between hepatocellular carcinoma and cirrhotic liver

The purpose of the present study was to estimate the difference in three-dimensional (3-D) structure of sinusoids between hepatocellular carcinoma (HCC) and cirrhotic liver, by the use of topology. Ten surgically resected lesions of HCC and 10 lesions of liver cirrhosis (LC) were used. Computer-alded reconstruction models of HCC sinusoids and LC sinusoids were developed from 20 4μm thick serial tissue sections from each specimen. A topologlcal invariant, called the first Bettl numberp., was used to estimate the complexity degree of the 3-D sinusoidal structure. The mean p, of the sinusoidal network in the examined tissue, 200X200X80 μm³ in size, was 46.5X33.0 In 10 HCC and 84.9 ±19.1 in 10 cirrhotic livers. There was a statistically significant difference between the two values (P<0.01), while there was no significant difference in the sinusoidal volume of the same size tissue between the HCC and the cirrhotic liver. It was found, therefore, that the sinusoidal network of HCC was more sparsely and coarsely knit in 3-D space than that of the cirrhotic liver.     

Early hepatocellular carcinoma macroscopically resembling adenomatous hyperplasia: Pathological resemblance to carcinoma-in-situ

The pathological features of 11 nodules of early hepatocellular carcinoma (EHCC) were studled. Their macroscopic features resembled those of adenomatous hyperplasia and differed from those of advanced hepatocellular carcinomas (AHCC). The EHCC extended along the hepatic lobular structure and lacked expansive growth. The endothelial cells in the dnusoids of EHCC did not react to Ulex europeeus aggiutinin 1 (UEA1) like adenomatous hyperplasla or other liver parenchyma, whereas the endothelial celis in the AHCC did react to UEA1. immunohistochemically, CD68-positlve Kupffer cells were noted in the alnusolds of EHCC, whereas in the AHCC Kupfter cails were not seen. Tumor emboli in the portal vein and intrahepatic metastases were not Identified In EHCC. which seemed to be carcinoma-in-situ or a microinvasive stage of hepatocareinogenesis.     

Fibrolamellár hepatocellular carcinoma. An immunohistochemical and ultrastructural study

Two cases of fibrolamellar carcinoma of the liver are reported in young female patients of 12 and 21 years of age. Small amounts of perinuclear alpha-fetoprotein were found, unrelated to hyaline globules, as well as alpha 1-antitrypsin in a periglobular fashion in isolated cells. Ferritin was present in a large number of cells. Ultrastructurally, the well differentiated nature of the neoplasm was substantiated by previously unreported findings such as intercellular lumina analogous to bile canaliculi and peroxisome-like bodies containing a central crystalloid. Filamentous material resembling Mallory's type of hyaline was also found. We conclude that both immunohistochemical and ultrastructural features reflect a high degree of differentiation.     

Immunohistochemistry and angiography in adenomatous hyperplasia and small hepatocellular carcinomas

The sinusoidal structure and blood supply of 38 liver nodules less than 2 cm In diameter were Investigated. There were 18 cases of adenomatous hyperplasia (AH) and 20 cases of hepatocetlular carcinoma (HCC). Growth pattern, encapsulation and vascularity were examined, and Immunohistochemistry performed for factor VIII related antigen (factor VIII), type IV collagen (collagen IV), lamlnln and CD68. There were significant differences between AH and small HCC, except for the expression of CD68. There were differences In tumor size, vasculartty and the components of the basement membrane between AH and small, well differentiated HCC. The cases of AH were supplied by the portal system and maintained the sinusoidal structure, but small well-differentiated HCC were supplied by a mixture of portal and arterial vessels. In spite of their small size, moderately and poorly differentiated HCC had capillary and were supplied by branches of the hepatic artery.     

C-cell hyperplasia and medullary thyroid carcinoma in the rat. An immunohistochemical and ultrastructural analysis.

Medullary thyroid carcinoma (MTC) is a distinctive neoplasm which is derived from the calcitonin-producing intrathyroidal C-cell system and which develops commonly in untreated rats of various strains. Thyroid glands of Long-Evans rats ranging in age from 3 months to 3 years showed a spectrum of C-cell proliferative abnormalities. As compared to 3-month-old control rats, thyroids from 9- to 12-month-old animals exhibited mild diffuse C-cell hyperplasia (CCH). Thyroids from animals ranging from 1 to 3 years of age exhibited progressively more severe C-cell abnormalities including severe diffuse CCH, nodular CCH, and/or MTC. In contrast to the normal basal serum calcitonin levels in controls and in animals with mild diffuse CCH, animals with severe diffuse CCH, nodular CCH, or MTC had elevated basal serum calcitonin values. Nodular CCH was characterized by the replacement and enlargement of individual follicles by C-cells. Larger foci of nodular CCH were characterized by similar changes in multiple adjacent follicles or by an irregular expansion of individual follicles. MTC was characterized by penetration of the follicular basal lamina by C-cells with extension into the adjacent thyroid stroma. In addition to the high incidence of thyroidal C-cell abnormalities, diffuse and/or nodular parathyroid hyperplasia was commonly found. There was no evidence of chronic renal failure in these animals, and the serum calcium levels were within normal limits. Although the stimulus for the initial C-cell proliferation remains unknown, the appearance of MTC is preceded by relatively prolonged phases of CCH. These findings are essentially identical with those noted in human familial MTC and indicate that the rat provides a useful model system for studying the regulation of C-cell proliferation during the processes of neoplastic development and progression.     

An unusual hepatocellular carcinoma: an ultrastructural and immunohistochemical study

This paper describes a 50-year-old woman with an unusual malignant tumour of the liver. Poorly differentiated liver cells, tubular structures and spindle cells in abundant intercellular ground substance characterized the tumour. Extremely high serum concentration of alpha-fetoprotein was present. The spindle cells showed strong immunoreactivity against this antigen and vimentin. Both the spindle and epithelial cells showed negative immunoreactivity against desmin, epithelial membrane antigen and keratin. Markers for low molecular cytokeratin (MAK-6, CAM 5.2) were demonstrated in both cell types. Ultrastructurally the neoplastic epithelial cells showed frequent intercellular spaces and well-formed brush borders suggestive of differentiation towards hepatocytes and bile duct epithelium. The immunohistological findings established the epithelial nature of the spindle cells thus distinguishing the tumour from hepatoblastoma.     

p53 immunoreactivity in hepatocellular adenoma, focal nodular hyperplasia, cirrhosis and hepatocellular carcinoma

The prolonged half-life of mutant p53 makes feasible its immunocytochemical detection. In order to assess the pathogenetic role of mutant p53 in regenerative and neoplastc liver disease we studied its immunohistochemical expression in cases of hepatic cirrhosis, hepatocellular carcinoma (HCC), cirrhosis with areas of HCC, hepatocellular adenoma and focal nodular hyperplasia. The study included needle and wedge biopsies of 50 cirrhotic livers, 59 HCCs (36 of them with associated cirrhosis), six adenomas and two focal nodular hyperplasias. Sixty-five HCC fineneedle cytology specimens were also included in the study. There was no immunohistochemical evidence of mutant p53 expression in any of the cases of cirrhotic liver (except for one instance associated with HCC) adenoma or focal nodular hyperplasia. In contrast p53 was detected in 8.5% of HCC cases in the biopsy series and 24% of HCC cases in the fine needle aspiration series. In addition, mutant p53 expression in HCC was positively correlated with tumour grade. According to grade, the distribution of p53 positive immunoreactivity among HCCs was as follows: Grade I-II, 0% of cases in the biopsy series and 9% in the fine needle aspirates; Grade III, 18% in the biopsy series and 55% in the fine needle aspirates; and Grade IV, 40% in the biopsy series. Therefore, mutant p53 expression does not seem to be associated with benign liver lesions but seems to correlate with the progression of HCC through various grades of increasing malignancy.     

Immunohistochemical and ultrastructural localization of epidermal growth factor receptor in human liver and hepatocellular carcinoma tissues

Expression of epidermal growth factor receptor (EGF-R) in human hepatocellular carcinoma (HCC), hepatoblastoma and non-cancerous liver tissues was investigated immunohistochemically in order to evaluate the possible role of EGF-R expression in neoplastic transformation of hepatocytes. Immunoreactive EGF-R molecules were identified on frozen sections by means of the avidin-biotin immunoperoxidase complex technique using a monoclonal antibody recognizing an epitope of the external domain of human EGF-R. Linear positive staining was present on the surface of carcinoma cells in one hepatoblastoma and in 9 of 11 HCCs. In addition, an enhanced level of surface EGF-R expression was observed on the tumor cells in 9 of 12 cases in comparison with that on hepatocytes in surrounding non-cancerous liver tissue, which in most cases showed chronic inflammation, hepatocyte injury or regeneration. No positive staining in the form of coalescent cytoplasmic granules was present in HCC or hepatoblastoma cells, nor in the cytoplasm of hepatocytes in normal or non-cancerous diseased liver tissue. Little or no reactivity was present on the surface membrane of hepatocytes in the normal liver tissues of 8 control cases. Furthermore, immunoelectron microscopy revealed the localization of this immunoreactive EGF-R molecule on the plasma membrane. Considering that the functional form of EGF-R could be localized on the plasma membrane, the enhanced expression of immunoreactive EGF-R on the tumor cell surface demonstrated here may suggest a possible role of EGF-R in the development or progression of human HCC as well as in hepatocyte regeneration.     

Lectin binding patterns in normal liver, chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma. An immunohistochemical and immunoelectron microscopic study.

We studied the binding patterns of 14 lectins in human normal and cirrhotic liver (LC) tissues and hepatocellular carcinomas (HCC) using the ABC method. Lectins were divided into 4 groups according to their binding patterns in normal tissues: (A) PHA, MPA, LcH, RCA-I, and WGA, which bound to hepatocytes and all three types of sinusoidal cells; (B) BPA, GS-I, PNA, and SBA, which bound to Kupffer cells and endothelia of interlobular arteries and veins and bile duct epithelia in the portal tract, but not to hepatocytes; (C) UEA-I, which bound only to endothelia of interlobular arteries and veins and bile duct epithelia in the portal tract; (D) LBA, Lotus, LPA, and SJA, which showed no binding. Thus group B lectins may be useful markers of Kupffer cells. Only electron microscopic examination revealed the precise binding sites of lectins in sinusoidal cells and hepatocytes. Hepatocyte cell surface polarities demonstrated by lectin binding in LC and HCC were different from those in the normal liver. The binding pattern of PHA to LC hepatocytes changed from a membranous to both a membranous and a cytoplasmic pattern, and that of LcH to HCC cells changed to dot-like staining in the cytoplasm. These changes of polarities in LC and HCC might be caused by changes in the distribution of lectin-binding carbohydrates or by the altered glycosylation of glycoconjugates.     

Cellular and matrix changes in drug abuser liver sinusoids: A semiquantitative and morphometric ultrastructural study

The aim of the present work was to analyse, at the ultrastructural level, the action of heroin of 150 centrilobular sinusoids from liver biopsies of five intravenous drug abusers, who presented clinical and biological manifestations of hepatic impairment. A comparative study of 90 sinusoids from liver biopsies of three control patients was performed. Electron microscopic observations showed a thickening of the sinusoidal wall related to endothelial cell hypertrophy and to fibrosis of the space of Disse. This was generally associated with basement-membrane-like material and hepatocyte microvilli flattening. In addicts, hepatic vascular pole changes were a constant finding, accompanied by interhepatocyte space disjunction and perisinusoidal collagenization. Morphometric assessment confirmed a significant increase of sinusoidal wall surface, endothelial cell body and processes and Ito cell process surface was significantly different between the patient groups. This cellular hypertrophy may represent hyperactivation of the sinusoidal cell functional capacity, triggering the fibrogenesis in the space of Disse. While this mechanical barrier might hinder the free exchange through the space of Disse, it may equally well protect the liver against heroin toxicity.     

Male breast carcinoma. An ultrastructural study.

A case of infiltrating ductal carcinoma of the male breast was studied by electron microscopy. The ultrastructure of the tumor is similar to that described in the female breast. Myofibroblasts are the preponderant cells in the stroma. Their significance and possible relation to hormonal stimuli are discussed.