Hepatocellular adenoma management and phenotypic classification: the Bordeaux experience

[Multicentre study on hepatic adenomas]

INTRODUCTION

Hepatic adenomas (HA) are benign tumours which can present serious complications, and as such, in the past all were resected. It has now been shown that those smaller than 3 cm not expressing β-catenin only result in complications in exceptional cases and therefore the therapeutic strategy has been changed.

MATERIAL AND METHOD

Retrospective study in 14 HPB units.

INCLUSION CRITERIA

patients with resected and histologically confirmed HA.

STUDY PERIOD

1995-2011.

RESULTS

81 patients underwent surgery. Age: 39.5 years (range: 14-75). Sex: female (75%). Consumption of oestrogen in women: 33%. Size: 8.8 cm (range, 1-20 cm). Only 6 HA (7.4%) were smaller than 3 cm. The HA median was 1 (range: 1-12). Nine patients had adenomatosis (>10HA). A total of 51% of patients displayed symptoms, the most frequent (77%) being abdominal pain. Eight patients (10%) began with acute abdomen due to rupture and/or haemorrhage. A total of 67% of the preoperative diagnoses were correct. Surgery was scheduled for 90% of patients. The techniques employed were: major hepatectomy (22%), minor hepatectomy (77%) and one liver transplantation. A total of 20% were performed laparoscopically. The morbidity rate was 28%. There were no cases of mortality. Three patients had malignisation (3.7%). The follow-up period was 43 months (range 1-192). Two recurrences were detected and resected.

DISCUSSION

Patients with resected HA are normally women with large lesions and oestrogen consumption was lower than expected. Its correct preoperative diagnosis is acceptable (70%). The major hepatectomy rate is 25% and the laparoscopy rate is 20%. There was a low morbidity rate and no mortality.

P4 radiology of hepatobiliary diseases with gadoxetic acid-enhanced MRI as a biomarker

A recent paradigm shift in radiology has focused on the globalization of so-called P4 radiology. P4 radiology represents delivery of imaging results that are predictive, personalized, pre-emptive and participatory. The combination of the P4 approach and biomarkers is particularly pertinent to MRI, especially with technological advances such as diffusion-weighted imaging. The development of new liver-specific MRI contrast media, particularly gadoxetic acid, demonstrate specific pharmacokinetic properties, which provide combined morphologic and functional information in the same setting. The evaluation of hepatobiliary pathology beyond morphology gives rise to the possibilty of using gadoxetic acid-enhanced MRI as an imaging biomarker of hepatobiliary diseases. The integration of functional imaging with an understanding of complex disease mechanisms forms the basis for P4 radiology, which may ultimately lead to individualized, cost-effective, targeted therapy for patients. This will enable radiologists to determine the prognosis of the disease and estimate early response to treatment, with the participation of all the required medical disciplines.

Biochemical and functional analyses of gp130 mutants unveil JAK1 as a novel therapeutic target in human inflammatory hepatocellular adenoma

Inflammatory hepatocellular adenomas (IHCAs) are benign liver lesions that can be characterized histologically by the presence of an inflammatory infiltrate and at the molecular level by the overexpression of acute phase inflammatory response genes. Recurrent somatic mutations of the interleukin-6 (IL-6) signal transducer (IL6ST) locus, encoding the critical component of the IL-6 signal transduction machinery gp130, are present in 60% of IHCAs and in a subset (2%) of hepatocellular carcinoma (HCCs). By screening of 256 human hepatic adenoma specimens (the largest genetic analysis of IL6ST performed to date in this setting), we identified 24 distinct somatic IL6ST mutations among 66 mutant adenomas. The functional analysis of nine different gp130 mutants expressed in hepatic cancer cell lines consistently revealed the constitutive and IL-6-independent activation of the JAK/STAT signaling pathway. We further demonstrated that the signaling activity of mutant gp130 in IHCA remains responsive to suppressor of cytokine signaling 3 (SOCS3), a physiological gp130 inhibitor. Specifically, cells expressing a double mutant variant of gp130 with a disrupted SOCS3-binding site at residue 759 (Y186/Y759F) displayed a hyperactivation of signal transducer and activator of transcription 3 (STAT3) as compared with cells expressing the endogenous IHCA-associated Y186 gp130 mutant. Notably, we identified that constitutive signaling via gp130 in IHCA requires the Janus kinase family member JAK1, but not JAK2 or tyrosine kinase 2. In support of this notion, AG490, a tyrosine kinase inhibitor that selectively blocks JAK2, had no effect on gp130 activity. In stark contrast, we showed that ruxolitinib, a JAK1/JAK2-selective tyrosine kinase inhibitor used to treat patients with myelofibrosis, dramatically impaired JAK1-STAT signaling downstream of all IHCA-associated gp130 mutants. In conclusion, our findings provide a rationale for the use of JAK1 inhibitors for the treatment of HCAs expressing mutant gp130 as well as a subset of HCCs that bear similar mutations.

Solid liver masses: approach to management from the standpoint of a radiologist

Solid liver masses are being discovered at increasing rates due to the widespread use of medical imaging. Ultrasound, computed tomography, and magnetic resonance imaging play important and often complementary roles in detecting and diagnosing solid liver masses. Morphologic and enhancement characteristics as well as clinical history frequently allow a confident imaging diagnosis. Still, diagnosing liver masses with imaging alone remains a challenge, and masses that do not meet specific diagnostic criteria may require biopsy. Newly developed standardized terminology and imaging criteria have facilitated the imaging diagnosis of hepatocellular carcinoma (HCC) in patients with cirrhosis. Hepatobiliary-secreted MRI contrast agents have improved the ability to diagnose focal nodular hyperplasia and may also improve the detection and imaging diagnosis of HCC. These exciting new contrast agents are the subject of active investigation.

Successful treatment of multiple hepatocellular adenomas with percutaneous radiofrequency ablation

Hepatocellular adenoma (HCA) is one of the important complications of glycogen storage disease type Ia (GSD-Ia) because it can be transformed into hepatocellular carcinoma. Although surgical resection is a standard treatment of choice for solitary HCA, multiple HCAs in GSD-Ia patients present as therapeutic challenges for curative treatment. Therefore, treatment strategy according to malignant potential is important in management of HCAs in GSD-Ia. The authors present a case of histologically proven multiple HCAs without β-catenin mutations occurred in a GSD-Ia patient treated successfully with percutaneous radiofrequency ablation as a minimally invasive therapy.

Clinicopathological analysis of hepatocellular adenoma according to new bordeaux classification: report of eight korean cases

Background

Hepatocellular adenoma (HCA) is a rare benign tumor of the liver. A subtype classification of HCA (hepatocyte nuclear factor 1α [HNF1α]-mutated, β-catenin-mutated HCA, inflammatory HCA, and unclassified HCA) has recently been established based on a single institutional review of a HCA series by the Bordeaux group.

Methods

We used histologic and immunohistochemical parameters to classify and evaluate eight cases from our institution. We evaluated the new classification method and analyzed correlations between our results and those of other reports.

Results

Seven of our eight cases showed histologic and immunohistochemical results consistent with previous reports. However, one case showed overlapping histologic features, as previously described by the Bordeaux group. Four cases showed glutamine synthetase immunohistochemical staining inconsistent with their classification, indicating that glutamine synthetase staining may not be diagnostic for β-catenin-mutated HCA. HNF1α-mutated HCA may be indicated by the absence of liver fatty acid binding protein expression. Detection of amyloid A may indicate inflammatory HCA. HCA with no mutation in the HNF1α or β-catenin genes and no inflammatory protein expression is categorized as unclassified HCA.

Conclusions

Although the new classification is now generally accepted, validation through follow-up studies is necessary.

Living related liver transplantation in an adult patient with hepatocellular adenoma and carcinoma 13 years after bone marrow transplantation for Fanconi anemia: A case report

Fanconi anemia (FA) is an inherited bone marrow failure syndrome due to defective DNA inter-strand cross-link repair. Hematopoietic stem cell transplantation (HSCT) is curative for pancytopenia, but may not prevent the development of non-hematological malignancies. We describe a 26-year-old male patient with FA and Marfan syndrome who in 1994 underwent successful HSCT with bone marrow stem cells from his human leukocyte antigen (HLA)-identical sister. In 2006, three lesions in the liver were detected and resected. The three lesions all showed activation of the β-catenin pathway and were histologically characterized by a highly differentiated steatotic hepatocellular carcinoma (HCC) with remnants of the underlying adenoma from which it arose, a hepatocellular adenoma with foci of well-differentiated HCC, and a cholestatic adenoma. Risk factors for the emergence of HCC included FA itself, the use of androgens for a period of 3 years preceding HSCT and toxicity of the conditioning regimen. Because of the danger of developing additional HCC, liver transplantation was proposed, taking into consideration that immunosuppression would increase the risk of other malignancies. By using part of the liver of the sister, who already acted as bone marrow donor 13 years earlier, immunosuppression could be avoided. Liver transplantation was performed in 2007 without complication. Five years after liver transplantation the patient is doing well. This case is twofold special being the first case reporting FA co-occurring with Marfan syndrome and being the first reported case of FA treated for HCC by liver transplantation from a HLA-identical sibling donor without the use of immunosuppression.

Benign hepatocellular nodules: what have we learned using the patho-molecular classification

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors that develop most frequently in females and in non-cirrhotic livers. HCA are prone to bleed and to transform into hepatocellular carcinoma (HCC). Four major subgroups of HCA have been thus far identified: HNF1α mutated HCA, inflammatory HCA (IHCA), β-catenin mutated HCA (b-HCA and b-IHCA), based on mutations in specific oncogenes and tumor suppressors. B-HCA and b-IHCA are strongly associated with HCC transformation. Benign hepatocellular tumors can be classified using immunohistochemistry (LFABP, CRP, GS, b-catenin). Analysis of HCA phenotypes has led to the identification of patients at risk of HCC transformation and therefore improved the indications provided by invasive and non-invasive diagnostic techniques, such as biopsies and MRI. These recent advances have broadened the clinical scope of HCA in various conditions, such as their presence in males, in obese patients, in patients suffering from liver vascular disorders, genetic diseases. However, specific immunohistochemistry has shown limitations particularly for the identification of b-HCA, thereby, outlining the importance of molecular studies to improve the diagnosis/prognosis of HCA. If evaluation of prognosis and treatment has benefited from these advances, much more needs to be done to obtain guidelines for good clinical practice.

Hepatic adenoma mimicking a metastatic lesion on computed tomography-positron emission tomography scan

Positron emission tomography (PET) using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) is an imaging modality which reflects cellular glucose metabolism. Most malignant cells accumulate and trap ¹⁸F-FDG, allowing the visualisation of increased uptake. It is hence widely used to differentiate malignant from benign lesions. “False positive” findings of hepatic lesions have been described in certain instances such as hepatic abscesses, but are rare in cases involving hepatocellular adenomas. To our knowledge, there have been only 7 reports in the English literature documenting PET-avid hepatocellular adenomas; 6 of the 7 reports were published in the last 3 years with the first report by Patel et al. We report the case of a 44-year-old Chinese female patient with a history of cervical adenocarcinoma, referred for a hepatic lesion noted on a surveillance computed tomography (CT) scan. A subsequent CT-PET performed showed a hypermetabolic lesion (standardized uptake value 7.9) in segment IVb of the liver. After discussion at a multi-disciplinary hepato-pancreato-biliary conference, the consensus was that of a metastatic lesion from her previous cervical adenocarcinoma, and a resection of the hepatic lesion was performed. Histology revealed features consistent with a hepatocyte nuclear factor-1 α inactivated steatotic hepatocellular adenoma.

Imaging benign hepatocellular tumors: atypical forms and diagnostic traps

Management of patients with a benign hepatocellular tumor relies largely on imaging data; the diagnosis of focal nodular hyperplasia (FNH) must be made with certainty using MRI, because no other clinical or laboratory data can help diagnosis. It is also essential to identify adenomas to manage them appropriately. The radiological report in these situations is therefore of major importance. However, there are diagnostic traps. The aim of this paper is to present the keys to the diagnosis of benign lesions and to warn of the main diagnostic pitfalls.

Molecular and metabolic changes in human liver clear cell foci resemble the alterations occurring in rat hepatocarcinogenesis

BACKGROUND & AIMS

Activation of the AKT/mTOR and Ras/MAPK pathways and the lipogenic phenotype occurs in both a rat model of insulin-induced hepatocarcinogenesis and in human hepatocellular carcinoma (HCC). In the rat model, activation of these pathways is evident within the earliest morphologic detectable alterations, i.e., clear cell foci (CCF) of altered hepatocytes. CCF have also been described in the human liver, but molecular and metabolic alterations within these foci remain to be determined.

METHODS

A collection of human liver specimens was examined using electron microscopy, histology, enzyme- and immunohistochemistry, and molecular analysis. Human data were compared to rat preneoplastic CCF and HCC induced by N-nitrosomorpholine administration.

RESULTS

CCF occurred in ∼33% of extrafocal tissues of human non-cirrhotic livers. Electron microscopy showed massive glycogen storage within CCF, largely due to the reduced activity of the glycogenolytic enzyme glucose-6-phosphatase. Hepatocytes in CCF overexpressed the insulin receptor and glucose transporter proteins. AKT/mTOR and Ras/MAPK pathways as well as enzymes of glycolysis, de novo lipogenesis, beta-oxidation, and cholesterol synthesis were upregulated, both in human CCF, and in CCF and HCC of N-nitrosomorpholine-treated rats. The Ki-67 proliferation index was 2-fold higher in human CCF than in extrafocal tissue.

CONCLUSIONS

The high degree of similarity between human CCF and pre-neoplastic lesions from experimental models of hepatocarcinogenesis in terms of morphologic, molecular and metabolic features suggests a low-grade dysplastic nature of these lesions in human non-cirrhotic livers.

Diagnostic Approach to Hepatic Mass Lesions and Role of Immunohistochemistry

This review provides an overview of various hepatic mass lesions and a practical diagnostic approach, including most recent immunohistochemical stains used in clinical practice. A wide variety of benign and malignant lesions present as hepatic masses, and the differential diagnosis varies. In cirrhotic liver, the commonest malignant tumor is hepatocellular carcinoma (HCC), which needs to be differentiated from macroregenerative nodules, dysplastic nodules, and other tumors. The differential diagnosis of lesions in noncirrhotic liver in younger patients includes hepatic adenoma (HA), focal nodular hyperplasia (FNH), HCC, and other primary hepatic neoplasms and metastases. In older populations, metastases remain the most common mass lesions.

Hepatocellular Adenomas: WHO Classification and Immunohistochemical Workup

This review discusses the various subtypes of hepatocellular adenomas (HCAs), their diagnosis, and management. HCAs are benign tumors, mostly seen in young women in a normal background liver. Recent advances in understanding HCA pathogenesis and molecular alterations led to recognition of different subtypes, now included in the WHO classification. Complications include hemorrhage and rarely malignant transformation into hepatocellular carcinoma. Diagnosis and differentiation are challenging, requiring careful attention to clinical setting, histology, and immuostaining profile. Risk of complications varies depending on the HCA; hence, subtyping has clinical significance and is performed based on morphology and use of selected immunohistochemical markers.

[Immunophenotypic classification of 3 cases of hepatocellular adenoma. Differential diagnosis with focal nodular hyperplasia]

Interest in adenomas has been renewed by the discovery of the molecular changes in these tumors. The latest World Health Organization publication on gastrointestinal tract tumors (2010) includes four types of hepatic adenomas, which are well characterized immunohistochemically, genotypically and phenotypically. In these tumors, medical history and morphological behavior play an important role in determining the risk of malignancy, mainly in adenomas with a b-catenin mutation. The presence of steatosis, inflammation, vascular changes linked to response to L-FABP, serum amyloid A, and glutamyl synthetase help to classify these tumors into four groups: hepatocellular adenomas with the HNF1A mutation (H-HCA), those with the b-catenin mutation (b-HCA), inflammatory HCA (IHCA), and HCA without markers. The absence of glypican 3 expression, HSP 70 and perivenular mapping of glutamyl synthetase helps to distinguish these tumors from well differentiated hepatocellular carcinoma. We describe the clinical, morphological and immunophenotypic features of three patients diagnosed with hepatic adenomas in a 2-year period.

Hepatocellular benign tumors-from molecular classification to personalized clinical care

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors that develop most frequently in women without cirrhosis. Genomic approaches have identified signaling pathways related to these benign hepatocyte proliferations. FNH, a polyclonal lesion, is characterized by local vascular abnormalities and heterogeneous activation of Wnt/β-catenin and transforming growth factor β signaling. Four major subgroups of HCAs have been identified based on mutations in specific oncogenes and tumor suppressor genes. Each molecular subtype of HCA has been associated with specific pathways, providing new information about benign tumorigenesis. Key features include metabolic alterations (induced by defects in HNF1A), oncogene-induced inflammation (activation of JAK-STAT signaling in inflammatory adenomas), and an association between activation of Wnt/β-catenin signaling and progression of HCAs in hepatocellular carcinomas. Benign hepatocellular tumors can be classified using immunohistochemical analyses. Studies of genotypes and phenotypes of FNH and HCAs have led to the identification of risk factors and improved invasive and noninvasive diagnostic techniques, evaluation of prognosis, and treatment. We review the molecular pathways involved in benign hepatocyte proliferation and discuss how this basic knowledge has been progressively translated into personalized clinical care.

Focal Nodular Hyperplasia and Hepatocellular Adenoma around the World Viewed through the Scope of the Immunopathological Classification

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors. The risk of bleeding and malignant transformation of HCA are strong arguments to differentiate HCA from FNH. Despite great progress that has been made in the differential radiological diagnosis of the 2 types of nodules, liver biopsy is sometimes necessary to separate the 2 entities. Identification of HCA subtypes using immunohistochemical techniques, namely, HNF1A-inactivated HCA (35-40%), inflammatory HCA (IHCA), and beta-catenin-mutated inflammatory HCA (b-IHCA) (50-55%), beta-catenin-activated HCA (5-10%), and unclassified HCA (10%) has greatly improved the diagnostic accuracy of benign hepatocellular nodules. If HCA malignant transformation occurs in all HCA subgroups, the risk is by far the highest in the β -catenin-mutated subgroups (b-HCA, b-IHCA). In the coming decade the management of HCA will be more dependent on the identification of HCA subtypes, particularly for smaller nodules (<5 cm) in terms of imaging, follow-up, and resection.

SSAT/AHPBA joint symposium on evaluation and treatment of benign liver lesions

BACKGROUND

Benign liver lesions are common incidental radiologic findings.

METHODS

Experts convened in 2011 at a Society for Surgery of the Alimentary Tract/ Americas Hepato-Pancreato-Biliary Association joint symposium to discuss the evaluation and treatment of benign liver lesions.

RESULTS

Most benign liver lesions can be accurately diagnosed with high-quality imaging, including ultrasonography, multiphase computed tomography, and magnetic resonance imaging, particularly with hepatocyte-specific contrast agents. Percutaneous biopsy is reserved for lesions that cannot be characterized radiographically, and its accuracy is improved with immunophenotypic markers. Hepatic cysts are the most commonly diagnosed benign liver lesions; these must be distinguished from malignant cystic lesions, which are rare. Among the solid benign liver lesions, hemangiomas and focal nodular hyperplasia seldom require treatment. In contrast, hepatocellular adenomas are associated with a risk for complications. A new classification system for hepatocellular adenomas based on genetic and phenotypic features can help guide patient care. In patients who are symptomatic or at risk for complications, multidisciplinary evaluation and treatment based on clinicopathologic, radiographic, and molecular analysis is needed.

CONCLUSIONS

Most benign liver lesions can be accurately diagnosed radiographically and do not require treatment. Treatment is necessary for patients with symptoms or at risk for complications.

Liver transplantation for recurrent hepatic adenoma

Hepatic adenoma (HA) is a rare indication for liver transplantation (LTx). So far 20 cases of LTx for HA are reported in PubMed. In rare cases HA presents as multiple hepatic adenomas or recurrent adenoma after initial liver resection and in such cases LTx is the only potential cure and prevents the risk of bleeding or cancer transformation into hepatocellular carcinoma. We report the case of a 56 years old lady who underwent a left hepatectomy for giant adenoma in 2005 and resection of segment V-VI for recurrence of liver adenoma in 2007. She developed a second recurrence of HA with 3 new lesions in the right liver in 2008. The patient underwent LTx. After 3 years the patient is alive with no evidence of disease. LTx is indicated in patients with HA in which resection is not technically feasible.

Molecular characterization of hepatocellular adenomas developed in patients with glycogen storage disease type I

BACKGROUND & AIMS

Hepatocellular adenomas (HCA) are benign liver tumors mainly related to oral contraception and classified into 4 molecular subgroups: inflammatory (IHCA), HNF1A-inactivated (H-HCA), β-catenin-activated (bHCA) or unclassified (UHCA). Glycogen storage disease type I (GSD) is a rare hereditary metabolic disease that predisposes to HCA development. The aim of our study was to characterize the molecular profile of GSD-associated HCA.

METHODS

We characterized a series of 25 HCAs developed in 15 patients with GSD by gene expression and DNA sequence of HNF1A, CTNNB1, IL6ST, GNAS, and STAT3 genes. Moreover, we searched for glycolysis, gluconeogenesis, and fatty acid synthesis alterations in GSD non-tumor livers and compared our results to those observed in a series of sporadic H-HCA and various non-GSD liver samples.

RESULTS

GSD adenomas were classified as IHCA (52%) mutated for IL6ST or GNAS, bHCA (28%) or UHCA (20%). In contrast, no HNF1A inactivation was observed, showing a different molecular subtype distribution in GSD-associated HCA from that observed in sporadic HCA (p = 0.0008). In non-tumor GSD liver samples, we identified glycolysis and fatty acid synthesis activation with gluconeogenesis repression. Interestingly, this gene expression profile was similar to that observed in sporadic H-HCA.

CONCLUSIONS

Our study showed a particular molecular profile in GSD-related HCA characterized by a lack of HNF1A inactivation. This exclusion could be explained by similar metabolic defects observed with HNF1A inactivation and glucose-6-phosphatase deficiency. Inversely, the high frequency of β-catenin mutations could be related to the increased frequency of malignant transformation in hepatocellular carcinoma.

[Overview: liver tumors]

Since the introduction of abdominal ultrasound liver lesions have been increasingly detected. Being usually diagnosed by chance these lesions create psychological stress among patients because a potential malignant disease has to be taken into consideration. The increasing use of oral contraceptives with high estrogen doses starting in the 1980s led to a rising incidence of adenomas, whose natural history differed from those described in surgical and autoptic studies. This fact brought about a change towards a modern pathophysiologic and prognostic differentiation. Current histologic and molecular biological techniques are able to distinguish benign adenomas from those with malignant potential.

Molecular classification of hepatocellular adenomas

Hepatocellular adenomas (HCAs) are benign tumors developed in normal liver most frequently in women before menopause. HCAs lead to diagnostic pitfalls and several difficulties to assess the risk of malignant transformation in these young patients. Recent advances in basic knowledge have revealed a molecular classification related to risk factors, pathological features, and risk of transformation in hepatocellular carcinoma. Three major molecular pathways have been identified altered in specific HCA subgroups that are defined by either (1) inactivation of hepatocyte nuclear factor 1A (HNF1A) transcription factor, (2) activation of the WNT/β-catenin by CTNNB1 mutations, or (3) activation of the IL6/STAT3 pathway by somatic mutation of IL6ST, GNAS, or STAT3. Here, we will review the different molecular classes of HCA.

Histopathology of hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the most frequent primary liver malignancy, mostly occurring in the context of chronic liver diseases leading to cirrhosis. Epidemiological data demonstrate the increasing incidence of HCC worldwide, mainly related to viral hepatitis and metabolic syndrome. Pathological analysis recognizes several types of HCC according to macroscopic and microscopic features. A subset of HCC can develop on normal liver and usually corresponds to specific variants, including fibrolamellar carcinoma mostly encountered in young population. Prognosis of HCC remains poor, depending on delayed tumor diagnosis, the clinical status of the patient but also tumor behavior with a great propensity for angioinvasion.

Pathological Diagnosis of Hepatocellular Cellular Adenoma according to the Clinical Context

In Europe and North America, hepatocellular adenomas (HCA) occur, classically, in middle-aged woman taking oral contraceptives. Twenty percent of women, however, are not exposed to oral contraceptives; HCA can more rarely occur in men, children, and women over 65 years. HCA have been observed in many pathological conditions such as glycogenosis, familial adenomatous polyposis, MODY3, after male hormone administration, and in vascular diseases. Obesity is frequent particularly in inflammatory HCA. The background liver is often normal, but steatosis is a frequent finding particularly in inflammatory HCA. The diagnosis of HCA is more difficult when the background liver is fibrotic, notably in vascular diseases. HCA can be solitary, or multiple or in great number (adenomatosis). When nodules are multiple, they are usually of the same subtype. HNF1 α -inactivated HCA occur almost exclusively in woman. The most important point of the classification is the identification of β -catenin mutated HCA, a strong argument to identify patients at risk of malignant transformation. Some HCA already present criteria indicating malignant transformation. When the whole nodule is a hepatocellular carcinoma, it is extremely difficult to prove that it is the consequence of a former HCA. It is occasionally difficult to identify HCA remodeled by necrosis or hemorrhage.

Histological and immunohistochemical revision of hepatocellular adenomas: a learning experience

Light has been shed on the genotype/phenotype correlation in hepatocellular adenoma (HCA) recognizing HNF1 α -inactivated HCA (H-HCA), inflammatory HCA (IHCA), and β -catenin-activated HCA (b-HCA). We reviewed retrospectively our surgical HCA series to learn how to recognize the different subtypes histopathologically and how to interpret adequately their immunohistochemical staining. From January 1992 to January 2012, 37 patients underwent surgical resection for HCA in our institution. Nine had H-HCA (25%) characterized by steatosis and loss of L-FABP expression; 20 had IHCA (55.5%) showing CRP and/or SAA expression, sinusoidal dilatation, and variable inflammation; and 1 patient had both H-HCA and IHCA. In 5 patients (14%), b-HCA with GS and β -catenin nuclear positivity was diagnosed, two already with hepatocellular carcinoma. Two cases (5.5%) remained unclassified. One of the b-HCA showed also the H-HCA histological and immunohistochemical characteristics suggesting a subgroup of β -catenin-activated/HNF1 α -inactivated HCA, another b-HCA exhibited the IHCA histological and immunohistochemical characteristics suggesting a subgroup of β -catenin-activated/inflammatory HCA. Interestingly, three patients had underlying vascular abnormalities. Using the recently published criteria enabled us to classify histopathologically our retrospective HCA surgical series with accurate recognition of b-HCA for which we confirm the higher risk of malignant transformation. We also underlined the association between HCA and vascular abnormalities.

Benign hepatocellular tumors in children: focal nodular hyperplasia and hepatocellular adenoma

Benign liver tumors are very rare in children. Most focal nodular hyperplasia (FNH) remain sporadic, but predisposing factors exist, as follows: long-term cancer survivor (with an increasing incidence), portal deprivation in congenital or surgical portosystemic shunt. The aspect is atypical on imaging in two-thirds of cases. Biopsy of the tumor and the nontumoral liver is then required. Surgical resection will be discussed in the case of large tumors with or without symptoms. In the case of associated vascular disorder with portal deprivation, restoration of the portal flow will be discussed in the hope of seeing the involution of FNH. HepatoCellular Adenoma (HCA) is frequently associated with predisposing factors such as GSD type I and III, Fanconi anemia especially if androgen therapy is administered, CPSS, and SPSS. Adenomatosis has been reported in germline mutation of HNF1- α . Management will depend on the presence of a predisposing factor and may include metabolic control, androgen therapy withdrawn, or closure of the shunt when appropriate. Surgery is usually performed on large lesions. In the case of adenomatosis or multiple lesions, surgery will be adapted. Close followup is required in all cases.

Value and limits of routine histology alone or combined with glutamine synthetase immunostaining in the diagnosis of hepatocellular adenoma subtypes on surgical specimens

Immunohistochemistry is a valid method to classify hepatocellular adenoma (HCA). The aim was to test the performance of routine histology combined to glutamine synthetase (GS) staining to identify the 2 major HCA subtypes: HNF1 α inactivated (H-HCA) and inflammatory HCA (IHCA). 114 surgical cases, previously classified by immunohistochemistry, were analysed. Group A comprised 45 H-HCAs, 44 IHCAs, and 9 β -catenin-activated IHCAs (b-IHCA), and group B, 16 b-HCA and unclassified HCA (UHCA). Steatosis was the hallmark of H-HCA. IHCA and b-IHCA were mainly characterized by inflammation, thick arteries, and sinusoidal dilatation; b-IHCA could not be differentiated from IHCA by routine histology. Group B was identified by default. A control set (91 cases) was analyzed using routine and GS stainings (without knowing immunohistochemical results). Among the 45 H-HCAs and 27 IHCAs, 40 and 24 were correctly classified, respectively. Among the 10 b-IHCAs, 4 were identified as such using additional GS. Eight of the 9 HCAs that were neither H-HCA nor IHCA were correctly classified. Conclusion. Routine histology allows to diagnose >85% of the 2 major HCA subtypes. GS is essential to identify b-HCA. This study demonstrates that a "palliative" diagnostic approach can be proposed, when the panel of specific antibodies is not available.

MR Imaging of Hepatocellular Adenomas and Differential Diagnosis Dilemma

HEPATOCELLULAR ADENOMAS (HCAS) ARE CURRENTLY CATEGORIZED INTO DISTINCT GENETIC AND PATHOLOGIC SUBTYPES AS FOLLOWS: inflammatory hepatocellular adenoma, hepatocyte-nuclear-factor-1-alpha (HNF-1 α -mutated) hepatocellular adenoma, and β -catenin-mutated hepatocellular adenomas; the fourth, defined as unclassified subtype, encompasses HCAs without any genetic abnormalities. This classification has accepted management implications due to different risks of haemorrhage and malignant transformation of the four subtypes. Imaging guided biopsy and/or surgical resection very important in obtaining definitive characterization; nevertheless, MRI with intra-extravascular and hepatobiliary (dual phase) agents, is an important tool not only in differential subtypes definition but even in surveillance with early identification of complications and discovery of some signs of HCA malignant degeneration. Inflammation, abnormal rich vascularisation, peliotic areas, and abundant fatty infiltration are pathologic findings differently present in the HCA subtypes and they may be detected by multiparametric MRI approach. Lesion enlargement and heterogeneity of signal intensity and of contrast enhancement are signs to be considered in malignant transformation. The purpose of this paper is to present the state of the art of MRI in the diagnosis of HCA and subtype characterization, with particular regard to morphologic and functional information available with dual phase contrast agents, and to discuss differential diagnosis with the most common benign and malignant lesions mimicking HCAs.

A serum amyloid A-positive hepatocellular neoplasm arising in alcoholic cirrhosis: a previously unrecognized type of inflammatory hepatocellular tumor

Hepatocellular adenoma usually arises in the absence of significant fibrosis. Herein, we report seven patients with serum amyloid A-positive hepatocellular neoplasm, which shares features with inflammatory hepatocellular adenoma arising in alcoholic cirrhosis. Seven patients (two women and five men, age range 41-67 years) with hypervascular hepatocellular nodules associated with alcoholic cirrhosis were retrieved from our pathological files (1997-2011). The hepatocellular nodules were multiple (>3) in all patients and 17 nodules were histologically examined. We surveyed the immunoreactivity for serum amyloid A, glutamine synthetase, and glypican-3 in the hepatocellular nodules and control lesions, including 5 focal nodular hyperplasia, 18 dysplastic nodules, and 54 hepatocellular carcinomas in various background diseases. In all, 15 of 17 nodules showed strong and distinct immunoreactivity for serum amyloid A, sharing features with inflammatory hepatocellular adenoma. The serum amyloid A-positive hepatocellular neoplasms showed increased cellular density, inflammatory infiltrate, sinusoidal dilatation, and ductular reaction to various degrees. Although about a half of dysplastic nodules and hepatocellular carcinomas showed focal immunoreactivity for serum amyloid A, the extent of serum amyloid A expression was significantly higher in serum amyloid A-positive hepatocellular neoplasms, than in control nodules. The serum amyloid A-positive hepatocellular neoplasms did not show the overexpression of glutamine synthetase or immunoreactivity for glypican-3. In contrast, most hepatocellular carcinomas showed the overexpression of glutamine synthetase and immunoreactivity for glypican-3, irrespective of background diseases. In conclusion, this study highlights a characteristic group of hepatocellular neoplasms arising in alcoholic cirrhosis, which share features with inflammatory hepatocellular adenomas. These serum amyloid A-positive hepatocellular neoplasms may be a new type of inflammatory hepatocellular tumors in alcoholic patients.

Investigation and management of hepatic incidentalomas

With the widespread use of medical imaging has come the detection of incidental liver lesions that are, by and large, asymptomatic prior to their discovery. These lesions may become a source of anxiety and often require further investigation to reassure the patient of their usually benign nature. Use of contemporary hepatobiliary imaging and simple laboratory tests often allow a definite diagnosis to be made without resorting to exhaustive investigation or inappropriate surgery. The goal of this paper is to review the clinical features and imaging characteristics of common and important liver incidentalomas, their natural course, complications, and indications for surgical or other intervention.

Hepatocellular adenoma associated with familial adenomatous polyposis coli

Hepatocellular adenoma (HCA) is a benign liver tumor that most frequently occurs in young women using oral contraceptives. We report a rare case of HCA in a 29 years old female with familial adenomatous polyposis (FAP). The first proband was her sister, who underwent a total colectomy and was genetically diagnosed as FAP. A tumor, 3.0 cm in diameter, was detected in the right lobe of the liver during a screening study for FAP. A colonoscopy and gastroendoscopy revealed numerous adenomatous polyps without carcinoma. The patient underwent a total colectomy and ileo-anal anastomosis and hepatic posterior sectoriectomy. The pathological findings of the liver tumor were compatible with HCA. The resected specimen of the colon revealed multiple colonic adenomatous polyps. Examination of genetic alteration revealed a germ-line mutation of the adenomatous polyposis coli (APC) gene. Inactivation of the second APC allele was not found. Other genetic alterations in the hepatocyte nuclear factor 1 alpha and β-catenin gene, which are reported to be associated with HCA, were not detected. Although FAP is reported to be complicated with various neoplasias in extracolic organs, only six cases of HCA associated with FAP, including the present case, have been reported. Additional reports will establish the precise mechanisms of HCA development in FAP patients.

Hepatocellular adenomas associated with hepatic granulomas: experience in five cases

We present five cases in whom two rare entities were simultaneously found within the liver, i.e. hepatocellular adenomas (HCAs) and granulomas. Coexistence of both entities confuses diagnosis. Our aim is to disclose the association between HCA and hepatic granulomas. Five patients presented with HCA for which they underwent resection. During laparotomy or at pathological examination, granulomas were found in tumorous and non-tumorous tissue. No specific cause for the granulomas was found. Immunohistochemistry showed overexpression of C-reactive protein and serum amyloid A in 4/5 patients, classifying these lesions as inflammatory HCA. HCA and especially the inflammatory subtype may cause formation of granulomas in (peri-)tumorous tissue as a local response to persistent inflammation and/or the presence of a tumor. Both HCA and hepatic granulomas have also been associated with oral contraceptive use. In conclusion, HCAs associated with hepatic granulomas derive from a local response to (inflammatory) HCA or neoplasm, chronic use of oral contraceptives, or a combination of these factors.

Role of contrast-enhanced sonography in differentiation of subtypes of hepatocellular adenoma: correlation with MRI findings

OBJECTIVE

Hepatocellular adenomas (HCAs) are divided into three subtypes according to genotype and phenotype. The two main subgroups are hepatocyte nuclear factor 1α (HNF1α)-inactivated HCA and inflammatory HCA. Specific imaging features of these subgroups of adenoma have been delineated with MRI. The aim of this study was to document the contrast-enhanced sonographic (CEUS) features specific for adenoma subtypes and to correlate them with MRI findings.

MATERIALS AND METHODS

We retrospectively analyzed data on 38 patients with HCA confirmed at pathologic examination in all cases. All cases were classified with MRI.

RESULTS

HNF1α-inactivated HCA (n = 16) was found to have a homogeneous hyperechoic aspect at baseline gray-scale sonography, isovascularity or moderate hypervascularity with mixed filling in the arterial phase, and isoechogenicity in the portal and late portal venous phases. Homogeneous hyperechogenicity during B-mode sonography was the most specific pattern (sensitivity, 88%; specificity, 91%) and correlated with diffuse fat repartition observed on MR images obtained with chemical-shift sequences. In inflammatory HCA (n = 17) the association of arterial hypervascularity with centripetal filling, linear vascularities, peripheral rim of sustained enhancement, and central washout in the late venous phase was specific (sensitivity, 64%; specificity, 100%). Discrepancy between delayed washout during CEUS and sustained enhancement during MRI could be related to differences between gadolinium and microbubbles in diffusing in the interstitial spaces. In the five other HCA cases (four unclassified, one β-catenin activated) CEUS showed characteristics of benign hepatocellular tumors with no specific features.

CONCLUSION

HNF1α-inactivated HCA and inflammatory HCA had characteristic CEUS patterns. Delayed washout, an unusual finding in benign hepatic lesions, is of particular interest and was a characteristic of inflammatory HCA subtype.

How normal is the liver in which the inflammatory type hepatocellular adenoma develops?

The inflammatory type hepatocellular adenoma (IHCA) is a subtype of HCA which is a benign liver tumor, predominantly occurring in young women in an otherwise normal liver. IHCA contains either a mutation of gp130 or STAT3. Both mutations lead to a similar morphologic phenotype and to increased expression of C-reactive protein (CRP) and/or serum amyloid-A (SAA). IHCA comprised about 40% of all HCAs and is associated with obesity. We investigated the histomorphological and immunophenotypical changes of the nontumorous liver of 32 resected IHCA specimens. Similar types of changes are present in samples taken adjacent to tumor and distant ones. The lobular architecture is well preserved. Mild/moderate steatosis is found in a high frequency which is in accordance with the median BMI of 32 in our cases. Of note are the regular findings of sinusoidal dilatation, single arteries, and minute CRP foci which are all features of HCA. These distinct CRP foci are mostly found in cases of multiple IHCA which indicates that the remnant liver may also contain IHCA foci. These findings show that the nonlesional liver in IHCA does contain abnormalities, and this may have consequences for the followup, especially since it is known that obesity may stimulate malignant growth.

Hepatocellular adenoma subtypes: the impact of overweight and obesity

BACKGROUND

Hepatocellular adenomas (HCA) are rare benign tumours occurring mainly in women using oral contraceptives. With the appearance of a generation of new oral contraceptives, the number of HCA cases was anticipated to decrease, but in fact this was not observed in our practice. The influence of obesity was therefore suspected as a new co-factor.

AIMS

The aim of this study was to analyze the impact of overweight/obesity in our cohort of HCA patients classified according to their subtypes.

RESULTS

The number of HCA noticeably increased faster in the 2001-2011 period compared to the 1990-2000 period. This phenomenon concurred with an increasing number of patients overweight or obese. Females still represented the great majority of overweight/obese patients presenting HCA, however, overweight/obese male patients constituted a new entity in the inflammatory HCA and β-catenin activated- inflammatory HCA subgroups.

CONCLUSION

We propose that overweight/obesity may soon represent a major risk of malignant transformation of HCA, possibly via the IL-6 pathway.

Beta-catenin-activated hepatocellular adenoma showing hyperintensity on hepatobiliary-phase gadoxetic-enhanced magnetic resonance imaging and overexpression of OATP8

We report a male case of beta-catenin-activated hepatocellular adenoma (HCA) focusing on findings of gadoxetic-acid-enhanced magnetic resonance imaging (EOB-MRI) and discussing the molecular background and possible clinical significance. The patient was a 31-year-old man in whom computed tomography (CT) showed a large nodule of 14 cm in diameter in the right liver lobe. On dynamic contrast-enhanced CT, heterogeneous and slight to moderate enhancement was observed during the early phase, with washout in the late phase. Focal fat deposits and a scar-like portion in the lesion were also seen. Most of the lesion was slightly hyperintense compared with the background liver on the hepatobiliary phase of EOB-MRI. After operation, this patient was confirmed pathologically as having beta-catenin-activated HCA with a portion suggestive of malignant transformation. In addition, intense organic anion transporter polypeptide 8 expression was observed throughout the tumor by immunohistochemical staining.

Hepatocellular adenoma: evaluation with contrast-enhanced ultrasound and MRI and correlation with pathologic and phenotypic classification in 26 lesions

Purpose. To review the contrast-enhanced ultrasonographic (CEUS) and magnetic resonance (MR) imaging findings in 25 patients with 26 hepatocellular adenomas (HCAs) and to compare imaging features with histopathologic results from resected specimen considering the new immunophenotypical classification. Material and Methods. Two abdominal radiologists reviewed retrospectively CEUS cineloops and MR images in 26 HCA. All pathological specimens were reviewed and classified into four subgroups (steatotic or HNF 1α mutated, inflammatory, atypical or β-catenin mutated, and unspecified). Inflammatory infiltrates were scored, steatosis, and telangiectasia semiquantitatively evaluated. Results. CEUS and MRI features are well correlated: among the 16 inflammatory HCA, 7/16 presented typical imaging features: hypersignal T2, strong arterial enhancement with a centripetal filling, persistent on delayed phase. 6 HCA were classified as steatotic with typical imaging features: a drop out signal, slight arterial enhancement, vanishing on late phase. Four HCA were classified as atypical with an HCC developed in one. Five lesions displayed important steatosis (>50%) without belonging to the HNF1α group. Conclusion. In half cases, inflammatory HCA have specific imaging features well correlated with the amount of telangiectasia and inflammatory infiltrates. An HCA with important amount of steatosis noticed on chemical shift images does not always belong to the HNF1α group.

Case of telangiectatic/inflammatory hepatocellular adenoma arising in a patient with primary sclerosing cholangitis

Hepatocellular adenomas (HCA) have been recently identified as a heterogeneous group, differing based on genotypic as well as morphological characteristics. HCA are most frequently found in women on oral contraception. A type of HCA, inflammatory HCA, is also known as telangiectatic HCA and was previously referred to as telangiectatic focal nodular hyperplasia. We present the first case of HCA arising from the liver with primary sclerosing cholangitis (PSC). This case is a 30-year-old man with a past medical history of PSC, ulcerative colitis and diabetes mellitus. A routine ultrasonography for PSC detected the gradually enlarged intrahepatic mass. Liver biopsy could reveal the diagnosis of telangiectatic/ inflammatory HCA by morphological and immunohistochemical analyses. Partial hepatectomy was performed and the resected liver was pathologically diagnosed as the telangiectatic/inflammatory HCA arising in PSC. This is the first case report of such an association and here we review the current developments and published work of this rare tumor and the association with an activated inflammatory related tumorogenic pathway and PSC.

Hepatocellular adenoma: an excellent indication for laparoscopic liver resection

OBJECTIVES

Laparoscopic resection for benign liver disease has gained wide acceptance in recent years and hepatocellular adenoma (HA) seems to be an appropriate indication. This study aimed to discuss diagnosis and treatment strategies, and to assess the feasibility, safety and outcomes of pure laparoscopic liver resection (LLR) in a large series of patients with HA.

METHODS

Of 88 patients who underwent pure LLR, 31 were identified as having HA. Diagnosis was based on radiological evaluation and resections were performed for lesions measuring >5.0 cm.

RESULTS

The sample included 29 female and two male patients. Their mean age was 33.2 years. A total of 27 patients had a single lesion, one patient had two and one had four lesions. The two remaining patients had liver adenomatosis. Mean tumour size was 7.5 cm. Three right hepatectomies, 17 left lateral sectionectomies and 11 wedge resections or segmentectomies were performed. There was no need for blood transfusion or conversion to open surgery. Postoperative complications occurred in two patients. Mean hospital stay was 3.8 days.

CONCLUSIONS

Hepatocellular adenoma should be regarded as an excellent indication for pure LLR. Pure LLR is safe and feasible and should be considered the standard of care for the treatment of HA when performed by surgeons with experience in liver and laparoscopic surgery.

Systematic review of haemorrhage and rupture of hepatocellular adenomas

BACKGROUND

Although benign in itself, hepatocellular adenoma (HCA) can be complicated by hormone-induced growth, and subsequent haemorrhage and rupture. The exact risk of haemorrhage and rupture is not known. This systematic review of the literature was carried out with the aim of estimating the risk of haemorrhage and rupture in HCA.

METHODS

A systematic literature search of the PubMed and Embase databases was performed for all articles relevant to haemorrhage and/or rupture of HCA, published between 1969 and March 2011.

RESULTS

Twenty-eight articles met the selection criteria, containing a total of 1176 patients. Haemorrhage was reported with an overall frequency of 27·2 per cent among patients, and in 15·8 per cent of all HCA lesions. Rupture and intraperitoneal bleeding were reported in 17·5 per cent of patients. Bleeding was the first symptom in 68·5 per cent of patients with a bleeding HCA. Six of 13 articles reporting the size of HCA lesions in which bleeding occurred mentioned haemorrhage in HCAs smaller than 5 cm.

CONCLUSION

Haemorrhage and rupture are common in patients with HCA.

Hepatocellular adenoma in glycogen storage disorder type I: a clinicopathological and molecular study

AIMS

  Glycogen storage disease type I is a metabolic disorder resulting from deficiency of the glucose-6-phosphate complex. Long-term complications include the development of hepatocellular adenoma (HCA). In this retrospective study, our aim was to reclassify according to geno-phenotypic characteristics nodular lesions identified in hepatectomy specimens of such patients transplanted between 1998 and 2008 at our institution.

METHODS AND RESULTS

  Clinicopathological data of seven consecutive transplanted patients with glycogen storage disease type I were reviewed. Liver nodules were re-examined histologically and by immunohistochemistry. Molecular analysis was performed additionally in a case with specific features. Four patients had multiple tumours. We concluded that 26 of 38 nodules available for study had features of inflammatory hepatocellular adenomas, seven comprised adenomas not otherwise specified and five were found to be focal nodular hyperplasia.

CONCLUSIONS

  Further studies are needed to clarify the pathogenesis of hepatocellular adenomas in glycogen storage disease; in particular to determine whether they share abnormal metabolic pathways with inflammatory adenomas in the general population. Testing for acute phase proteins may be a helpful tool in the early detection of HCA in such patients. Finally, there is a need to further define their risk of malignant transformation, in relation to age and possible cofactors.