A macroregenerative nodule containing multiple foci of hepatocellular carcinoma in a noncirrhotic liver

Therapeutic potential of canine bone marrow stromal cells (BMSCs) in the carbon tetrachloride (CCl4) induced chronic liver dysfunction mouse model

Regenerative medicine using bone marrow cells is an attractive therapy for the cure of patients with severe liver disease. Here, we show the therapeutic potential of canine bone marrow stromal cells (BMSCs) in mouse models of CCl(4)-induced chronic liver dysfunction. We used two different models for xenotransplantation, nude mice and cyclosporine A (CSA) immunosuppressed mice. Serum parameters from a standard liver panel were not improved following transplantation. However, fibrotic liver lesions with severe inflammation were decreased in CCl(4)-treated CSA mice following BMSC transplantation. Effective migration of transplanted canine BMSCs was limited to persistently injured liver in CCl(4)-treated CSA mice, where they may be effective in resolving inflammatory fibrotic lesions. These results suggest that canine BMSCs are an effective cell source for liver regeneration.

Hepatitis C prevalence in patients with hepatocellular carcinoma without cirrhosis

BACKGROUND

Hepatocellular carcinoma (HCC) occurring in "noncirrhotic" hepatitis C virus (HCV)-infected patients has been reported; but the exact prevalence or incidence has not been described before.

METHODS

We conducted a systematic review of literature: Ovid was used to search the literature from January 1, 1990, to September 1, 2008. Articles containing "HCC" keywords (hepatocellular carcinoma, hepatoma, liver cancer) were combined with the word "cirrhosis" or "fibrosis" and with "absence" keywords [noncirrhotic, absence, without]. Two hundred articles were selected and screened according to predesigned exclusion and inclusion criteria.

RESULTS

Nineteen articles met the inclusion criteria. The estimated prevalence of noncirrhotic HCC ranged from 6.7% to 50.1%. The pooled prevalence estimates for HCV in noncirrhotic HCC ranged from 0% and 68.4% according to the geographic location. Reports from Japan had the highest estimated pooled prevalence of HCV (55.01%) followed by Italy (29.95%).

CONCLUSION

HCV can occur in patients with HCC without cirrhosis, but the true incidence and prevalence are very difficult to ascertain. Further studies are needed to define this group of patients.

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.

The expression of transforming growth factor-alpha in cirrhosis, dysplastic nodules, and hepatocellular carcinoma: an immunohistochemical study of 70 cases

The emergence of hepatocellular carcinoma (HCC) is thought to be a stepwise process, with high-grade dysplastic nodules (HGDN) representing premalignant lesions arising in a background of cirrhosis. Earlier studies have revealed altered expression of transforming growth factor-alpha (TGF-alpha) (a mitogen capable of inducing hepatocarcinogenesis in mice) in HCC and its surrounding parenchyma. DNA topoisomerase II-alpha (Topo II-alpha) is a nuclear protein targeted by several chemotherapeutic agents and is overexpressed in HCC. The expression of both TGF-alpha and Topo II-alpha in putative preneoplastic hepatocytic lesions, however, has not been extensively studied. We examined the patterns of TGF-alpha and Topo II-alpha expression in noncirrhotic liver, liver cirrhosis, low-grade dysplastic nodules (LGDN), HGDN, and HCC to define the possible relationships of these markers to tumor progression. Paraffin sections from formalin-fixed material were immunostained with antibodies against TGF-alpha, Topo II-alpha, and Ki-67. Forty-six HCC, 17 HGDN, and 12 low-grade dysplastic nodules were identified in 52 cirrhotic livers from explanted or resected specimens. Nuclear staining for Ki-67 and Topo II-alpha was significantly increased in the progression from cirrhosis, through HGDN, to HCC, whereas the scores for TGF-alpha in these lesions showed an inverse relationship. In comparison with 18 HCC arising in noncirrhotic livers, the expression of TGF-alpha is significantly stronger in cirrhotic liver than in noncirrhotic parenchyma and its expression is also stronger in HCC arising in cirrhosis than in HCC arising in noncirrhotic parenchyma. The increased expression of Topo II-alpha and Ki-67 from HGDN to HCC, when compared with cirrhosis, suggests that HGDN is a precursor lesion in hepatocarcinogenesis. The inverse relationship between these proliferative markers and TGF-alpha expression in these lesions and stronger expression of TGF-alpha in HCC arising in cirrhosis suggest that TGF-alpha may play an important role in the early events of liver carcinogenesis.

Diagnostic imaging of hepatocellular carcinoma in patients with cirrhosis before liver transplantation

1. The lack of whole-liver explant correlation has led to an overestimation of the sensitivity of imaging tests for the diagnosis of HCC in the radiological literature. 2. Ultrasound is insensitive for the diagnosis of HCC in the cirrhotic liver and should not be used for the detection of focal liver lesions in this setting. 3. Although magnetic resonance (MR) imaging is more sensitive than multidetector 3-phase computed tomography (CT) for the diagnosis of regenerative and dysplastic nodules it is probably no better than CT for detection of HCC and has a lower false-positive rate. 4. Approximately 10-30% of nodules measuring <2 cm seen only on the hepatic arterial phase at CT or MR imaging represent small HCC and vigilant surveillance imaging is required as interval growth is the best indicator of malignancy.

CT Evaluation of the Progression of Hypoattenuating Nodular Lesions in Virus-Related Chronic Liver Disease

OBJECTIVE

The purpose of this study was to clarify the natural outcomes of hypoattenuating nodular lesions in patients with virus-related chronic liver disease depicted on dynamic CT.

MATERIALS AND METHODS

Sixty lesions (mean size, 1.3 cm) exhibiting hypoattenuation or isoattenuation in the arterial and delayed phases of dynamic CT were retrospectively evaluated with additional CT (mean, six examinations) for a mean period of 838 days. The primary end point was emergence of hyperattenuating areas within hypoattenuating lesions, a phenomenon called attenuation conversion. Cumulative attenuation conversion rates suggesting rates of malignant transformation were calculated with the Kaplan-Meier method, and factors affecting attenuation conversion rate were analyzed with the Cox proportional hazard model.

RESULTS

Thirty-six (60%) of 60 hypoattenuating lesions developed to hyperattenuating lesions, 21 were unchanged, and three disappeared spontaneously. The 36 lesions that became hyperattenuating were divided into two subgroups according to lesion enhancement pattern: hyper-in-hypoattenuating (n = 25) and entirely hyperattenuating (n = 11). The cumulative attenuation conversion rates for the 60 hypoattenuating lesions were 15.8%, 44.3%, and 58.7% at 1, 2, and 3 years. The hyper-in-hypoattenuating lesions showed more rapid progression to entirely enhanced lesions. Positive results for hepatitis C viral antibody (p = 0.028) and initial lesion size (p = 0.007) showed a positive correlation with attenuation conversion rate.

CONCLUSION

Hypoattenuating hepatic nodular lesions in chronic liver disease depicted on dynamic CT have high malignant potential and should be followed with special attention to conversion from hypoattenuation to hyperattenuation to determine the optimal timing of treatment.

Concomitant hepatocellular adenoma and adenomatous hyperplasia in a patient without cirrhosis

AIM: Hepatocelluar adenoma (HCA) and adenomatous hyperplasia (AH) are rare benign tumors of the liver. HCA is usually found in women who use oral contraceptives. AH usually occurs in patients with liver cirrhosis. Both tumors have potential for malignant transformation.

METHODS: We described a male adult with chronic liver disease (CLD) who had been known to be a hepatitis B carrier (HBV) for years. He was found to have a space-occupying lesion with a suspicion of hepatocellular carcinoma (HCC) by abdominal ultrasonography. His α-fetoprotein (AFP) was normal. Angiographic findings were consistent with the diagnosis of HCC, he wished to avoid an operation, was treated with transcatheter hepatic arterial embolization.

RESULTS: He subsequently consented to surgery, and a right lobectomy was performed. The liver pathology disclosed HCA with nuclear dysplasia and post-embolization effects. In addition, there were multiple small foci of AH with nuclear dysplasia in the resected liver. Although he had some focal areas of cirrhosis-like change or post-embolization effect, the AH was associated only with normal liver tissue.

CONCLUSION: This case confirms that HCA and AH may resemble HCC on imaging studies, and that AH may occur in CLD in the absence of cirrhotic change.

Dysplastic nodules and hepatocarcinogenesis

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

Apoptosis and proliferation in hepatocarcinogenesis related to cirrhosis

BACKGROUND

Dysplastic nodules (DNs) recently have been identified as preneoplastic lesions of hepatocellular carcinoma (HCC). To test an alternative hypothesis regarding DN development, in which we have suggested that DNs develop as an infiltrating clonal expansion in advance of, or parallel to cirrhosis, the authors investigated the rates of apoptosis and proliferation in human hepatocarcinogenesis.

METHODS

The authors performed terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and proliferation cell nuclear antigen (PCNA) staining in 11 low-grade DNs, 8 high-grade DNs including 3 cases with HCC subnodules, 10 small HCCs, and 29 cases of surrounding cirrhotic nodules. Hepatocellular carcinoma subnodules were present in three cases of high DNs. They determined TUNEL-labeling indices (LIs) and PCNA-LIs as the percentage of positive hepatocyte nuclei per 500 randomly counted cells.

RESULTS

TUNEL-LIs (mean +/- standard deviation) were 0.8 +/- 0.82 in cirrhotic nodules, 1.0 +/- 0.98 in low-grade DNs, 3.0 +/- 4.33 in high-grade DNs, 8.7 +/- 7.71 in HCC subnodules of high-grade DNs, and 3.2 +/- 3.58 in small HCCs. The peak values of apoptotic activity were higher in high-grade DNs and HCCs than in low-grade DNs and cirrhotic nodules. Each case of low-grade DN showed a low to medium level of apoptotic activity when compared with those of the four surrounding cirrhotic nodules. The PCNA-LIs were 2.6 +/- 1.35 in cirrhotic nodules, 4.5 +/- 2.31 in low-grade DNs, 15.3 +/- 10.50 in high-grade DNs, 25.4 +/- 5.25 in HCC subnodules of high-grade DNs, and 34.9 +/- 15.70 in small HCCs. The peak values gradually increased, although only HCC showed significantly elevated proliferation activity. The differences of PCNA-LIs and TUNEL-LIs, measured in each case, were 1.7 +/- 1.89 in cirrhotic nodules, 3.6 +/- 2.43 in low-grade DNs, 7.9 +/- 5.69 in high-grade DNs, 16.2 +/- 2.87 in HCC subnodules of high-grade DNs, 28.2 +/- 13.97 in small HCCs. At all stages of hepatocarcinogenesis, the rates of cell proliferation were higher than apoptosis, allowing a preferential net gain of (pre)neoplastic cells, and it was significantly increased in small HCCs. In regenerative cirrhotic nodules, 14% (4 cases) showed higher rates of apoptosis than proliferation.

CONCLUSIONS

The regulation/dysregulation of apoptosis of (pre)neoplastic cells as well as of proliferation may play an important role in the process of hepatocarcinogenesis.

Prognostic factors and survival after hepatic resection for hepatocellular carcinoma without cirrhosis

BACKGROUND

Detailed follow-up of patients with chronic hepatitis has resulted in increased diagnosis of hepatocellular carcinoma (HCC) in patients without cirrhosis. Despite numerous studies on hepatic resection, the prognostic factors for intrahepatic recurrence and survival are not well known for patients with HCC without cirrhosis.

METHODS

Among 349 patients with HCC treated in the past 13 years, cirrhosis was absent in 126 patients (36 per cent). Curative hepatic resection was carried out in 100 (79 per cent) of these patients. Risk factors for intrahepatic recurrence and prognostic factors for survival were evaluated by univariate and multivariate analyses.

RESULTS

Postoperative morbidity and mortality rates were 22 and 3 per cent respectively. The 5- and 10-year disease-free and overall survival rates were 31 and 50 per cent, and 22 and 47 per cent respectively. Blood loss, surgical resection margin, intrahepatic metastasis, portal vein invasion and extent of hepatic resection were independently associated with overall survival. However, the only risk factors for intrahepatic recurrence were portal vein invasion and hepatitis C virus (HCV) infection. The former was related to early recurrence while the latter was related to later recurrence. The 5-year disease-free survival rate was 58 per cent in patients with hepatitis B virus infection while it was 6 per cent in patients with HCV infection (P < 0.001).

CONCLUSION

In the treatment of HCC without cirrhosis, major hepatectomy is advocated to prevent early recurrence. Liver transplantation may be required for patients with HCV infection.

Neoangiogenesis and sinusoidal "capillarization" in dysplastic nodules of the liver

The blood supply of hepatocellular carcinoma (HCC) is primarily arterial. Recent studies reported differences of vascular, especially arterial, supply among low- and high-grade dysplastic nodules and HCC. We assessed arterialization using monoclonal antibody specific for smooth muscle actin as well as simultaneous changes in sinusoidal capillarization in cirrhotic nodules, dysplastic nodules, and HCC. We immunohistochemically stained 56 cirrhotic nodules, 20 low-grade dysplastic nodules, 27 high-grade dysplastic nodules, and 20 HCCs for alpha smooth muscle actin (to identify unpaired arteries (i.e., arteries not accompanied by bile ducts) and CD34 (indicating sinusoidal capillarization). Distribution and number of unpaired arteries and distribution of sinusoidal capillarization were graded semiquantitatively. Unpaired arteries were rare in cirrhotic nodules, significantly more common in dysplastic nodules of both types (p < 0.00001), and most common in HCC. Sinusoidal capillarization was least common in cirrhotic nodules, significantly more common in dysplastic nodules (p < 0.0035), and most common in HCC. No topographic relationship between unpaired arteries and sinusoidal capillarization was identified. These findings showed that (1) distributions of sinusoidal capillarization and unpaired arteries in dysplastic nodules are intermediate between those in cirrhotic nodules and HCC, supporting dysplastic nodules as premalignant lesions; (2) unpaired arteries are histologically useful for distinguishing dysplastic nodules from large cirrhotic nodules; and (3) areas of sinusoidal capillarization within dysplastic nodules are unrelated to location of arterialization.

Cytological vs microhistological diagnosis of hepatocellular carcinoma: comparative accuracies in the same fine-needle biopsy specimen

There is still debate over the relative merits of cytology and histology in diagnosing hepatocellular carcinoma in cirrhotic livers. Previous comparisons of the diagnostic accuracies of these two methods may have been biased by sampling errors due to multiple punctures. We compared the diagnostic accuracies of cytology and microhistology using tissue and cells from the same point in liver nodules subsequently proved to be hepatocellular carcinoma. A single ultrasound-guided liver-nodule biopsy was obtained with a 20- to 21-G cutting needle from 131 cirrhotic patients. The solid portion of samples was used for microhistology; the remainder was subjected to smear cytology. The results of each type of examination were expressed as true positive, nonspecific malignancy, false negative, or inadequate for diagnosis. No false-positive diagnoses were made in 13 benign lesions. In 118 HCC nodules (particularly those <30 mm in diameter), cytology provided a significantly higher percentage of correct diagnoses (85.6%) that was only slightly inferior to that based on results of both studies (89.8%). The single-biopsy technique generally provides adequate tissue for histology and cytology specimens with a high cellularity. It reduces both the cost and the risks of fine-needle biopsy diagnosis of hepatocellular carcinoma.

Enzymatic cytochemistry, DNA ploidy and AgNOR quantitation in hepatocellular nodules of uncertain malignant potential in liver cirrhosis

Conventional histological examination of echo-guided biopsy specimens can be inconclusive in small nodular lesions in cirrhotic livers. We investigated the diagnostic potential of cytochemical analysis of dipeptidyl-peptidase IV (DPP IV), of image analysis of nuclear DNA content, and of interphase silver-stained nucleolar organizer regions (AgNORs) in 12 cases of small (13- to 29-mm in diameter) hepatic nodules visualized in cirrhotic patients by ultrasonography. All cases underwent an echo-guided liver biopsy at the time of detection and in none of them were histological signs of malignancy found. Characterization with the above-mentioned techniques was always done at the time of histological examination. These patients underwent a mean (+/- SD) follow-up of 27.0 (+/- 11.2) months after biopsy, with repeated ultrasound (US) examinations. In the seven patients with subsequent neoplastic growth, DPP IV score was altered in five of six; the fraction of mononucleated polyploid cells was altered in six of seven; and the AgNOR quantity exceeded the cutoff value of 4 microns2 in five of five cases. Among the five lesions whose US appearance remained unchanged during the follow-up, only one abnormality (AgNORs) was found in one case. The combined cytochemical analysis of DPP IV, nuclear DNA content, and quantitative evaluation of interphase AgNORs in biopsy samples may contribute to the differential diagnosis of hepatocellular nodules of uncertain type in the cirrhotic liver.

Low proliferative activity in macroregenerative nodules: evidence for an alternate hypothesis concerning human hepatocarcinogenesis

Macroregenerative nodules are commonly thought to be hyperplastic lesions, deriving both their large size and premalignant potential from an increased proliferative rate. We have previously suggested an alternate model of macroregenerative nodule development in which neither size nor premalignant potential of macroregenerative nodules would depend on increased proliferation. We tested this hypothesis by examining the proliferative activity in macroregenerative and surrounding cirrhotic nodules.

METHODS

Eighteen macroregenerative nodules, including five type I and 13 type II, were immunostained for proliferating cell nuclear antigen (PCNA). Type II macroregenerative nodules included ten with diffuse large (7) or small (3) liver cell dysplasia only and eight containing nodule-in-nodule lesions. Five nodule-in-nodule lesions met the histologic criteria for hepatocellular carcinoma. PCNA labeling indices (PCNA-LIs; percentage positive hepatocyte nuclei/500 randomly counted cells) were determined in macroregenerative nodules and the four largest adjacent cirrhotic nodules. Nodule-in-nodule lesions were assessed separately from the background macroregenerative nodule.

RESULTS

4/5 type I and 12/13 type II macroregenerative nodules (exclusive of NIN lesions) had PCNA-LIs lower than the mean of surrounding cirrhotic nodules. All nodule-in-nodule lesions, whether atypical or overtly malignant, had PCNA-LIs greater than any surrounding nodules. In conclusion, macroregenerative nodules have PCNA-LIs indistinguishable from, and often lower than, surrounding cirrhotic nodules. Increased proliferative activity only occurs with the development of atypia and transition to hepatocellular carcinoma.

CONCLUSION

Macroregenerative nodules derive neither their size nor their premalignant potential from on-going rapid proliferation, a finding consistent with our alternate hypothesis of macroregenerative nodule development.

Hepatic neoformations

The aim of the paper is an accurate histologic description and illustration of those liver lesions that are usually summarized under the heading of "hepatic tumors and related subjects". For in some cases it may be unclear or at least controversial, whether the individual lesion is indeed an autonomous neoplasia or a malformation, regeneration or hyperplasia, the indifferent master term of neoformation is introduced, based on the fact that all of them are characterized by a cellular multiplication. According to common definitory practice the survey distinguishes between mesenchymal (angiomatous and non angiomatous) and epithelial neoformations. Among the latter hepatocellular and cholangiocellular types are distinguished, the criterium for differentiation being a phenomenological one, which is by no means identical with a histogenetical statement. The definition of subgroups mostly adheres to current nomenclatory usage; only occasionally--in the group of endothelial tumors--a novel term is employed, in view of brevity and coordination with the overall system of neoformations.