Hepatic adenomatosis

Fatal rupture of hepatic adenomatosis: Autopsy case and review of the literature

Hepatic adenomatosis is a rare disease consisting of multiple adenomas in otherwise-normal liver parenchyma. Though the discovery of this entity goes back several years, its diagnosis is still challenging in terms of its definition and pathophysiology. Clinically, patients may be completely asymptomatic and the diagnosis is only made incidentally through imaging tests. The discovery could be made when complications occur such as intraperitoneal hemorrhage with hypovolemic shock due to the rupture of an adenoma. We report a fatal case of a ruptured adenoma in a case of hepatic adenomatosis discovered at autopsy. In order to achieve a better view of this disease, we conducted a literature review on this subject describing the pathogenesis, manifestations, and autopsy contribution to addressing this entity.

Large Hepatic Adenomas and Hepatic Adenomatosis: A Multicenter Study of Risk Factors, Interventions, and Complications

INTRODUCTION

Beyond oral contraceptives (OCs), metabolic factors have been suggested to increase the risk of hepatocellular adenoma (HCA). The impact of risks remains poorly defined, particularly among men and those with adenomatosis. Thus, we aimed to examine HCA clinical and outcome characteristics through a large multicenter cohort.

METHODS

HCA diagnosis was made based on a combination of clinical, radiologic, and histologic criteria. Patient and clinical data including follow-up imaging, complications, and interventions were collected between 2004 and 2018 from 3 large academic centers.

RESULTS

Among 187 patients (163 female and 24 male) with HCA, 75 had solitary HCA, 58 had multiple HCAs, and 54 had adenomatosis. Over a median follow-up of 3.3 years (quartile 1: 1.2, quartile 3: 8.8), 34 patients (18%) had radiologic interventions, 41 (21%) had surgical resections, 10 (5%) developed tumoral hemorrhage, and 1 had malignant transformation. OC and corticosteroid use were present in 70% and 16%, respectively. Obesity (51%), type 2 diabetes (24%), hypertension (42%), and hypertriglyceridemia (21%) were also common. Metabolic comorbidities were more common in patients with large HCAs and adenomatosis. Compared with women, men had less hepatic steatosis (4% vs 27%), smaller HCAs (2.3 cm vs 4.4 cm), and more corticosteroid use (38% vs 11%) ( P < 0.05 for all). With OC cessation, 69% had a decrease in size of HCA, but 25% eventually required advanced interventions.

DISCUSSION

In this large HCA cohort, obesity and metabolic comorbidities were important risk factors associated with large HCAs and adenomatosis. Long-term adverse outcomes were infrequent, 5% had tumor hemorrhage, and 1 patient exhibited malignant transformation.

Focal Nodular Hyperplasia and Hepatic Adenoma: Evaluation and Management

Focal nodular hyperplasia and hepatocellular adenoma are benign liver lesions that occur most frequently in women and may be found as incidental findings on imaging. hepatocellular adenomas may be infrequently associated with malignant progression or risk of rupture and as such, require surveillance or definitive treatments based on their size threshold. It is important clinically to differentiate these lesions, and utilizing imaging modalities such as contrast enhanced ultrasound or magnetic resonance imaging can be helpful in diagnosis. Further molecular subtyping of hepatocellular adenoma lesions may be beneficial to describe risk factors and potential future clinical complications.

Relevance of morphological features for hepatocellular adenoma classification in pathology practice

Background

Gene mutations correlated with histological and immunohistochemical phenotypes of hepatocellular adenoma were recently identified. Based on these findings, four adenoma subtypes were distinguished. We classify hepatocellular adenoma (HCA) into subtypes based on histologic and immunohistochemical findings and verify the contribution of histological features in pathology practice.

Methods

Thirty hepatocellular adenomas were classified in subtypes. Sinusoidal dilatation, ductular reaction, pseudoportal tracts, pseudoglands, steatosis, inflammatory infiltrate and cellular atypia were analyzed, as well as liver fatty acid binding protein, β catenin, serum amyloid A, glutamine synthetase, and C-reactive protein antibodies.

Results

Histologically, eleven adenomas were classified as HNF1A inactivated (HHCA), five were β-catenin-activated (bHCA) and fourteen were inflammatory adenoma (IHCA). Steatosis was found in all HHCA and was predominantly severe. Sinusoidal dilatation and inflammatory infiltrate were present in all IHCA. Ductular reaction, pseudoportal tracts and cellular atypia were observed in 71.4, 85.7 and 42.8%, respectively. Pseudoglands were present in 60% and cellular atypia in 80% of bHCA. According to immunohistochemistry, 11 were HHCA; 1 was bHCA; 17 were IHCA, among which 5 were β-catenin activated IHCA; and 1 was unclassified UHCA (UHCA). Superior concordance between the histological and immunohistochemical classifications was found for HHCA (К = 0.854) and IHCA (К = 0.657).

Conclusion

Approximately 90% of adenomas may be diagnosed by subgroup based only on morphological features. When aberrant β catenin nuclear staining is not found, glutamine synthetase positivity is useful for diagnosis, although supplementary molecular analysis may be necessary.

A Review of Benign Hepatic Tumors and Their Imaging Characteristics

This paper concisely reviews the benign hepatic tumors most commonly encountered by clinicians. It includes the epidemiology, pathology, and imaging characteristics of hepatic hemangiomas, focal nodular hyperplasia (FNH), and hepatic adenomas (HAs).

Primary Liver Cancers-Part 1: Histopathology, Differential Diagnoses, and Risk Stratification

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the 2 most common primary malignant liver tumors, with hepatocellular and bile ductular differentiation, respectively. This article reviews the key histopathological findings of these 2 primary liver cancers and includes a review of the role of ancillary testing for differential diagnosis, risk stratification according to the American Joint Committee on Cancer (AJCC) staging recommendation, and a review of precancerous lesions. A literature review was conducted to identify articles with information relevant to precancerous precursors, current histopathological classification, ancillary testing, and risk stratification of primary malignant liver tumors. The histomorphology of normal liver, preinvasive precursors, primary malignancies, and morphological variants, and the utilization of ancillary tests for the pathological diagnosis are described. Dysplastic nodules are the preinvasive precursors of HCC, and intraductal papillary neoplasms of bile ducts and biliary intraepithelial neoplasia are the preinvasive precursors of CC. Benign liver nodules including focal nodular hyperplasia and adenomas are included in this review, since some forms of adenomas progress to HCC and often they have to be differentiated from well-differentiated HCC. A number of morphological variants of HCC have been described in the literature, and it is necessary to be aware of them in order to render the correct diagnosis. Risk stratification is still dependent on the AJCC staging system. The diagnosis of primary liver carcinomas is usually straightforward. Application of the appropriate ancillary studies aids in the differential diagnosis of difficult cases. The understanding of the carcinogenesis of these malignancies has improved with the standardization of the pathological classification of preinvasive precursors and studies of the molecular pathogenesis. Risk stratification still depends on pathological staging.

Inflammatory hepatic adenomas: Characterization with hepatobiliary MRI contrast agents

PURPOSE

To characterize the MRI appearance of inflammatory hepatic adenomas using hepatobiliary contrast agents.

MATERIALS AND METHODS

MRI was performed using hepatobiliary contrast agents (3 with gadobenate dimeglumine and 24 with gadoxetic acid) in 27 patients with immunohistochemistry-confirmed diagnosis of inflammatory hepatic adenoma. The appearance of the lesions on T2 and diffusion-weighted images, pre-gadolinium T1-weighted images, dynamic post-gadolinium images, and hepatobiliary phase images was assessed.

RESULTS

Seven lesions (26%) showed predominant hyperenhancement on hepatobiliary phase images in comparison with adjacent hepatic parenchyma: 1 lesion showed diffuse, mildly heterogeneous hyperenhancement, and the remaining 6 lesions showed peripheral hyperenhancement and central hypoenhancement. Twenty lesions (74%) were predominantly hypoenhancing compared to adjacent liver on hepatobiliary phase images. Nine lesions showed a pattern of peripheral hyperenhancement and central hypoenhancement on hepatobiliary phase images; in 6 of these lesions a majority of the mass appeared hyperenhancing, while the remaining 3 lesions showed predominant hypoenhancement.

CONCLUSIONS

This investigation shows that a significant percentage of inflammatory hepatic adenomas appear isointense or hyperintense in comparison to adjacent normal liver on hepatobiliary phase images, and therefore this feature should not be used to distinguish hepatic adenomas from focal nodular hyperplasia without additional supporting evidence.

Case 235: Hepatic Adenomatosis Due to Inflammatory Adenomas

History An asymptomatic 33-year-old woman was referred to the Hepatology Department in 2013 for work-up of indeterminate multifocal liver masses. These lesions were discovered incidentally at multiphase contrast material-enhanced multidetector computed tomography (CT) performed in 2004 to investigate right lower quadrant pain. Imaging surveillance at sporadic intervals revealed slow progressive growth of the lesions over time; however, the number of lesions remained constant. There was no history of cancer, nor were there predisposing factors for chronic liver disease or cirrhosis. The patient had a history of menorrhagia, which was managed with oral contraceptive use for 20 years; this was stopped in 2013 after hysterectomy. The patient's γ-glutamyl transferase (77 U/L [1.28 μkat/L]; normal level, <55 U/L [<0.92 μkat/L]) and C-reactive protein (97.1 mg/L [924.8 nmol/L]; normal level, <8 mg/L [<76.2 nmol/L]]) levels were chronically elevated at serum testing. In 2013, 9 years after the initial CT examination, magnetic resonance (MR) imaging with gadoxetic acid (Primovist; Bayer Healthcare, Whippany, NJ) was performed. Finally, ultrasonography (US)-guided biopsy of one of the lesions (in segment 5/6) was performed a year after MR imaging.

Diagnosis and treatment of benign liver nodules: Brazilian Society of Hepatology (SBH) recommendations

Space-occupying lesions of the liver may be cystic or solid. Ultrasonography is an extremely useful method for initial screening, and suffices for diagnosis of simple hepatic cysts. Complex cysts and solid masses require computed tomography or magnetic resonance imaging for confirmation. Wide surgical excision is indicated in cystadenoma or cystadenocarcinoma. Clinical and epidemiological data are important, as nodules in noncirrhotic livers are more likely to be benign. Hemangiomas, the most common benign tumors, require no follow-up after diagnostic confirmation if they are small and asymptomatic. Patients with giant, symptomatic hemangiomas or compression of adjacent structures should be referred to hepatobiliary centers for potential surgery. The genetic heterogeneity of hepatocellular adenomas and their epidemiology and prognosis prompted classification of these tumors into four subtypes based on histology and immunohistochemistry. The major complications of hepatocellular adenomas are rupture with bleeding and malignant transformation. Rupture occurs in approximately 30% of cases. The main risk factors are tumors size >5 cm and inflammatory subtype. Hepatocellular adenomas may enlarge during pregnancy due to marked hormonal stimulation. As oral contraceptive pills and anabolic steroids have associated with hepatocellular adenomas growth, particularly of the hepatocyte nuclear factor-1alfa subtype, these drugs should be discontinued. Focal nodular hyperplasia is the second most common benign tumor of the liver. It is most frequent in women aged 20 to 60, and 70% to 90% of cases are asymptomatic. In the absence of a central scar and/or other hallmarks of Focal nodular hyperplasia, with uncertainty between this diagnosis and hepatocellular adenoma, liver-specific contrast agents are indicated.

PET-avid hepatocellular adenomas: incidental findings associated with HNF1-α mutated lesions

BACKGROUND

Hepatocellular adenoma (HCA) is the second most common benign liver neoplasm and occurs predominantly in women in their reproductive years. Positron emission tomography (PET) using [18F] fluorodeoxyglucose (FDG) is commonly used in cancer staging, surveillance and evaluation of treatment response. PET-avid HCA are rare and can be falsely interpreted as malignancies.

METHODS

A retrospective review of four institutions' database was performed to identify the PET-avid HCAs with clinico-pathological correlation.

RESULTS

Nine patients with histological proven PET-avid HCA was identified. Eight out of 9 patients were female with a median age at diagnosis of 44 years. All patients' tumors with available histological subtyping (8/8) were HNF1-α mutated and had no inflammatory changes; 6 out the 9 lesions had prominent (>50%) steatotic changes.

CONCLUSION

Hepatocellular adenomas, specifically the HNF1-α subtype, can cause false-positive PET findings when seeking to identify malignancy. Concomitantly, PET-CT may have the potential to identify the HCA histopathologic variant with the lowest malignant and hemorrhagic potential.

PET-avid hepatocellular adenomas: incidental findings associated with HNF1-α mutated lesions

BACKGROUND

Hepatocellular adenoma (HCA) is the second most common benign liver neoplasm and occurs predominantly in women in their reproductive years. Positron-emission tomography (PET) using [18F] fluorodeoxyglucose (FDG) is commonly used in cancer staging, surveillance and evaluation of the treatment response. PET-avid HCA is rare and can be falsely interpreted as malignancies.

METHODS

A retrospective review of four institutions' database was performed to identify the PET-avid HCAs with clinico-pathological correlation.

RESULTS

Nine patients with histological proven PET-avid HCA was identified. Eight out of nine patients were female with a median age at diagnosis of 44 years. All patients' tumours with available histological subtyping (8/8) were HNF1-α mutated and had no inflammatory changes; six out the nine lesions had prominent (>50%) steatotic changes.

CONCLUSION

Hepatocellular adenomas, specifically the HNF1-α subtype, can cause false-positive PET findings when seeking to identify malignancy. Concomitantly, PET-CT may have the potential to identify the HCA histopathological variant with the lowest malignant and haemorrhagic potential.

Treatment of Hepatic Adenomatosis

Hepatic adenomatosis and hepatocellular adenomas share risk factors and the same pathophysiologic spectrum. The presence in the liver of 10 hepatocellular adenomas defines hepatic adenomatosis. The diagnosis may be established incidentally during a liver radiologic examination in the asymptomatic patient, or after associated right upper quadrant pain, hepatomegaly or liver test abnormalities. Upon the diagnosis of hepatic adenomatosis or either of its life-threatening complications - hemorrhage and progression to hepatocellular carcinoma - consideration should be given to potential medical, radiologic and surgical interventions including: observation (estrogens and androgens withdrawal), resection, transarterial embolization, radiofrequency ablation and liver transplantation. The management of patients with hepatic adenomatosis can be challenging. These patients should be ideally referred to centers with expertise in the management of liver diseases.

Management of hepatic adenomatosis

Hepatic adenomatosis (HeAs) is a rare clinical entity defined by the presence of 10 or more hepatic adenomas (HA) within the background of an otherwise normal liver parenchyma, in the absence of glycogen storage disease or anabolic steroid use. HA is a benign tumor associated with oral contraceptive use. Recent advances in pathogenesis and classification of HA have questioned the distinction between these two diseases. HA are currently classified into four different subtypes with genotypic and phenotypic correlation: HNF-1a inactivated HA, B-catenin activated HA, inflammatory HA, and undetermined subtype. The clinical presentation of HA depends on the lesion size and the subtype. MRI using hepatospecific contrast agents is helpful in diagnosing the most common subtypes. When diagnosis is uncertain, biopsy with immunohistochemistry is used to diagnose and classify the lesions. Management is governed by the molecular subtype and tumor size. Pregnancy is not routinely discouraged but management is individualized.

Management of Hepatocellular Adenoma: Recent Advances

Hepatocellular adenoma (HCA) is a rare benign liver cell neoplasm that occurs more frequently in young women with a history of prolonged use of oral contraceptives. Surgical resection is considered because of the risk of hemorrhage in 25% and of malignant transformation in 5% of patients with HCA. HCA is a heterogeneous disease comprising 3 subtypes with distinct molecular and complication profiles. The inflammatory or telangiectatic subtype is at increased risk for hemorrhage, the β-catenin-activated subtype is at increased risk for malignant transformation, and the hepatocyte nuclear factor-1α-inactivated or steatotic subtype is at the least risk for complications. One-third of the patients with HCA have multiple tumors on imaging with no increased risk of complications. Magnetic resonance imaging is the modality of choice for the diagnosis and subtype characterization of HCA. Systematic resection of HCA is recommended in male patients owing to the higher incidence of malignant transformation, and surgical excision in women should be reserved for tumors 5 cm or larger associated with an increased risk of complications. Cessation of hormonal therapy and radiologic surveillance in women with HCA tumors smaller than 5 cm shows that the vast majority of HCA remain stable or undergo spontaneous regression. Percutaneous core needle biopsy is of limited value because the therapeutic strategy is based primarily on patient sex and tumor size. Transarterial embolization is the initial treatment for HCA complicated by hemorrhage. Pregnancy should not be discouraged in the presence of HCA, however, frequent sonographic surveillance is recommended.

Update on the new classification of hepatic adenomas: clinical, molecular, and pathologic characteristics

CONTEXT

Hepatic adenoma is an uncommon, benign, hepatic neoplasm that typically occurs in women of child-bearing age, often with a history of long-term use of oral contraceptive drugs. This is usually detected as an incidental mass lesion in a noncirrhotic liver during imaging studies. Pathologic evaluation by needle core biopsy remains the gold standard for diagnosis. Molecular studies have revealed that hepatic adenomas involve unique molecular pathways that are distinct from hepatocellular carcinoma. Based on these studies, a French collaborative group has recently proposed a molecular-pathologic classification for hepatic adenomas. In addition, advances in molecular studies have led to reclassification of the "telangiectatic variant of focal nodular hyperplasia" as "hepatic adenoma, inflammatory subtype."

OBJECTIVE

To review the proposed, new classification of hepatic adenoma and the changes in diagnostic workup in light of the above-mentioned developments.

DATA SOURCES

Review of published literature and illustrations from clinical case material.

CONCLUSIONS

Definitive diagnosis of liver mass lesion on needle core biopsies has a decisive role in clinical management. With the advent of the new classification of hepatic adenomas and its prognostic implications, it is vital for pathologists to be aware of the morphologic features seen in different subtypes and the available diagnostic tools, such as immunohistochemistry, to help identify the correct subtype.

[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.

Hepatic adenomatosis: spectrum of imaging findings

OBJECTIVE

This pictorial essay reviews the imaging appearance and differential diagnosis of hepatic adenomatosis.

CONCLUSION

In addition to such entities as multifocal hepatocellular carcinoma, metastases, and multiple focal nodular hyperplasia, hepatic adenomatosis should also be considered when confronted with multiple hypervascular liver lesions. Certain CT and MRI features can strongly suggest the diagnosis of adenomatosis.

Unusual uptake of 18FDG by a hepatic adenoma

Hepatic adenoma is a rare, benign tumor (with potential for malignant degeneration) and its diagnosis is difficult because its presentation is highly variable in medical imaging, particularly with MRI. In such cases, the use of a hepatic biopsy is usually recommended. (18)FDG-PET/CT provides a very significant predictive value for malignant hepatic lesions. In addition, the occurrence of an (18)FDG-avid benign tumor is a rare event. We hereby present the case of a patient with advanced breast cancer for whom an (18)FDG-PET/CT showed a focal hepatic uptake. A subsequent biopsy provided a diagnosis of a hepatic adenoma.

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.

Co-existence of hepatocellular adenoma and focal nodular hyperplasia in a young female

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HA) are both benign hepatocellular lesions, presenting mainly in women of childbearing age in non-cirrhotic, non-fibrotic livers. Simultaneous occurrence of these two lesions is extremely rare. We herein report a case of a young female without any predisposing risk factors who presented to our emergency department complaining of acute abdominal pain. Imaging studies revealed a 6 cm lesion in the right hepatic lobe and a 2.5 cm lesion in the left hepatic lobe, respectively. In view of the patient's symptoms and lack of a confirmed diagnosis based on imaging, we performed a bisegmentectomy V-VI and a wedge resection of the lesion in segment III by laparotomy. Postoperative course was uneventful and the patient was discharged on the fourth postoperative day. The pathology report demonstrated an HA in segments V-VI and FNH in segment III, respectively. Six months later, the patient remains asymptomatic with normal liver function tests, ultrasound and magnetic resonance imaging follow-up. To our best knowledge, this is the first case to describe simultaneous occurrence of HA and FNH without the presence of any known risk factors for these entities. The uncertainty in diagnosis and acuteness of presenting symptoms were established criteria for prompt surgical intervention.

Genetics and imaging of hepatocellular adenomas: 2011 update

Hepatocellular adenomas are benign liver neoplasms with specific but varied histopathologic findings and tumor biology. The results from recent studies of the pathologic and genetic basis of hepatocellular adenomas provide important insights into the pathogenesis and molecular changes, as well as the putative oncologic pathways used by diverse adenoma subtypes. On the basis of the genetic and pathologic features, hepatocellular adenomas are categorized into three distinct subtypes: (a) inflammatory hepatocellular adenomas, (b) hepatocyte nuclear factor 1 α-mutated hepatocellular adenomas, and (c) β-catenin-mutated hepatocellular adenomas. Different subtypes show variable clinical behavior, imaging findings, and natural history, and thus the options for treatment and surveillance may vary. Cross-sectional imaging plays an important role in the diagnosis, subtype characterization, identification of complications, and surveillance of hepatocellular adenomas. New schemas for genotype-phenotype classification of hepatic adenomas, as well as management triage of patients with specific subtypes of adenomas, are being proposed in an attempt to improve clinical outcomes.

Indicação e tratamento dos tumores benignos do fígado

INTRODUÇÃO: Os tumores hepáticos benignos ocorrem em 9% da população. A grande maioria dessas neoplasias é diagnosticada em pacientes assintomáticos durante a realização de exames de imagem de rotina. OBJETIVO: Apresentar os principais aspectos das indicações e tratamento dos tumores hepáticos benignos. MÉTODOS: Foi realizada revisão de literatura baseada em pesquisa no PubMed, Bireme e Scielo cruzando os descritores neoplasia hepática, hemangioma, adenoma e hiperplasia nodular focal. Foram selecionados, estudos de técnicas cirúrgicas e acrescentada a experiência dos autores. O hemangioma é o tumor hepático mais comum, sendo identificado entre 5% e 7% das necropsias. É mais comum nas mulheres entre as 3ª e 5ª décadas da vida e pode aumentar de tamanho na gravidez e com a administração de estrogênios. Apesar de não estabelecida, a sua causa está relacionada com os hormônios sexuais. As complicações incluem inflamação, coagulopatia, sangramento e compressão de estruturas vizinhas. Rotura espontânea é excepcional, com somente 35 casos descritos na literatura internacional. O adenoma e a hiperplasia nodular focal predominam no sexo feminino e na faixa etária de 20 a 40 anos. Enquanto o primeiro requer ressecção hepática pelo risco de sangramento e malignização, o segundo deve ter conduta expectante. CONCLUSÕES: Os tumores hepáticos benignos mais comuns são em ordem decrescente de frequência o hemangioma, hiperplasia nodular focal e o adenoma. A diferenciação entre tumores benignos e malignos é geralmente realizada com segurança com base nos dados clínicos e nos exames de imagem. O hemangioma e a hiperplasia nodular focal geralmente tem conduta expectante, enquanto que o adenoma requer ressecção pelo risco de hemorragia e de transformação em carcinoma.

Recent advances in cytogenetics and molecular biology of adult hepatocellular tumors: implications for imaging and management

Focal nodular hyperplasia (FNH), hepatocellular adenoma (HCA), and hepatocellular carcinoma (HCC) compose hepatocellular neoplasms that occur in adults. These tumors demonstrate characteristic epidemiologic and histopathologic features and clinical and imaging manifestations. HCAs are monoclonal neoplasms characterized by increased predilection to hemorrhage or rupture and occasional transformation to HCC. On the other hand, FNH is a polyclonal tumorlike lesion that occurs in response to increased perfusion and has an indolent clinical course. Up to 90% of HCCs occur in the setting of cirrhosis. Chronic viral hepatitis (hepatitis B and hepatitis C) infection and metabolic syndrome are major risk factors that can induce HCCs in nonfibrotic liver. Recent advances in pathology and genetics have led to better understanding of the histogenesis, natural history, and molecular events that determine specific oncologic pathways used by these neoplasms. HCAs are now believed to result from specific genetic mutations involving TCF1 (transcription factor 1 gene), IL6ST (interleukin 6 signal transducer gene), and CTNNB1 (β catenin-1 gene); FNHs are characterized by an "imbalance" of angiopoietin. While the β catenin signaling pathway is associated with well- and moderately differentiated HCCs, mutations involving p53 (tumor protein 53 gene), MMP14 (matrix metalloproteinase 14 gene), and RhoC (Ras homolog gene family, member C) are associated with larger tumor size, higher tumor grade with resultant shortened tumor-free survival, and poor prognosis. Fibrolamellar carcinoma (FLC), a unique HCC subtype, exhibits genomic homogeneity that partly explains its better overall prognosis. On the basis of recent study results involving cytogenetics and oncologic pathways of HCCs, novel drugs that act against molecular targets are being developed. Indeed, sorafenib (a multikinase inhibitor) is currently being used in the successful treatment of patients with advanced HCC. Characterization of genetic abnormalities and genotype-phenotype correlations in adult hepatocellular tumors provides better understanding of tumor pathology and biology, imaging findings, prognosis, and response to molecular therapeutics.

Surgicopathological classification of hepatic space-occupying lesions: A single-center experience with literature review

Accompanying rapid developments in hepatic surgery, the number of surgeries and identifications of histological types of primary hepatic space-occupying lesions (PHSOLs) have increased dramatically. This has led to many changes in the surgicopathological spectrum of PHSOLs, and has contributed to a theoretical basis for modern hepatic surgery and oncological pathology. Between 1982 and 2009 at the Eastern Hepatobiliary Surgery Hospital (EHBH) in Shanghai, 31 901 patients underwent surgery and were diagnosed as having a PHSOL. In this paper, we present an analysis of the PHSOL cases at the EHBH for this time period, along with results from a systematic literature review. We describe a surgicopathological spectrum comprising more than 100 types of PHSOLs that can be stratified into three types: tumor-like, benign, and malignant. We also stratified the PHSOLs into six subtypes derived from hepatocytes; cholangiocytes; vascular, lymphoid and hemopoietic tissues; muscular, fibrous and adipose tissues; neural and neuroendocrine tissues; and miscellaneous tissues. The present study provides a new classification system that can be used as a current reference for clinicians and pathologists to make correct diagnoses and differential diagnoses among various PHSOLs.

Hepatocellular adenomas: current update on genetics, taxonomy, and management

Hepatocellular adenomas (HCAs) are uncommon, benign hepatocellular neoplasms that commonly occur in young women. Recent advances in pathology and cytogenetics have thrown fresh light on the pathogenesis of HCAs leading to classification of HCAs into 3 distinct subtypes, each with a characteristic epidemiology, histopathology, oncogenesis, and imaging findings. The aim of the article was to provide a comprehensive review of contemporary taxonomy of HCAs, with an emphasis on cross-sectional imaging findings and management.

Malignant transformation of hepatocellular adenomas into hepatocellular carcinomas: a systematic review including more than 1600 adenoma cases

BACKGROUND

Malignant transformation of hepatocellular adenomas (HCAs) into hepatocellular carcinomas (HCCs) has been reported repeatedly and is considered to be one of the main reasons for surgical treatment. However, its actual risk is currently unknown.

OBJECTIVE

To provide an estimation of the frequency of malignant transformation of HCAs and to discuss its clinical implications.

METHODS

A systematic literature search was conducted using the following databases: The Cochrane Hepatobiliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, MEDLINE and EMBASE.

RESULTS

One hundred and fifty-seven relevant series and 17 case reports (a total of 1635 HCAs) were retrieved, reporting an overall frequency of malignant transformation of 4.2%. Only three cases (4.4%) of malignant alteration were reported in a tumour smaller than 5 cm in diameter.

DISCUSSION

Malignant transformation of HCAs into HCCs remains a rare phenomenon with a reported frequency of 4.2%. A better selection of exactly those patients presenting with an HCA with an amplified risk of malignant degeneration is advocated in order to reduce the number of liver resections and thus reducing the operative risk for these predominantly young patients. The Bordeaux adenoma tumour markers are a promising method of identifying these high-risk adenomas.