Molecular pathogenesis of focal nodular hyperplasia and hepatocellular adenoma

[Contrast-enhanced ultrasound (CEUS) for characterisation of focal liver lesions]

Due to the trend towards increased use of imaging and rising awareness among high-risk patients, gastroenterologists and hepatologists are more frequently confronted with patients with focal liver lesions. In the differentiation of these lesions, CT and MRI have increasingly found their way into primary diagnostic steps in everyday clinical practice. Contrast-enhanced sonography, on the other hand, is a very effective and cost-efficient method for assessing focal liver lesions. The success of the method is not only based on the visualisation of microvascularisation in real time. If sonography is performed by the treating physician, he can use the exact knowledge of history and clinical findings to specifically adapt the examination procedure and to interpret the sonographic findings with greater accuracy ("clinical sonography"). At the same time, the method enables the practitioner to combine diagnostics and management decisions in his or her own hands. To achieve excellent results with contrast-enhanced sonography-as with any other imaging method-it is necessary that the examiner is sufficiently qualified.This article systematically presents the sonographic characteristics of the most common liver lesions and clearly shows their contrast patterns using videos (available via QR code). The article illustrates that CEUS could-and from the authors' point of view, should-have an even greater significance in the future.

Patient with a novel syndrome with multiple benign hepatic lesions and extrahepatic neoplasms

Simultaneous occurrence of benign hepatic lesions of different types is a sporadic phenomenon. To the best of our knowledge, we report the first clinical case of a syndrome with simultaneous manifestations of three different entities of benign liver tumors (hepatocellular adenoma, focal nodular hyperplasia and hemangioma) with a novel mutation detected in the liver adenoma and in the presence of a number of further extrahepatic organ neoplasms. Furthermore, we describe for the first time the presence of liver epithelial cells of hepatocytic phenotype expressing cytokeratin 7 (CK7) at the border of the adenoma. These findings may be important for explaining pathogenesis of benign as well as malignant tumors based on genetic and histopathological features.

Superb Microvascular Imaging in Pediatric Focal Nodular Hyperplasia

OBJECTIVE

To investigate superb microvascular imaging (SMI), a novel Doppler ultrasound technique that can visualize low-velocity microvascular flow, for assessing pediatric focal nodular hyperplasia (FNH).

PATIENTS AND METHODS

Nine FNH lesions in 6 patients were enrolled. On SMI and color Doppler imaging (CDI), intralesional vascularity was assessed visually and categorized as typical spoke-wheel pattern (central vessel radiating from the center to the periphery), multifocal spoke-wheel pattern, and nonspecific pattern. We compared the vascular features of the lesions between SMI and CDI and evaluated vascular patterns according to lesion size.

RESULTS

In terms of vascularity pattern, the typical spoke-wheel pattern of FNH was noted more frequently on SMI (67%) than on CDI (11%; P < 0.05). In addition, a multifocal spoke-wheel pattern was noted in all remaining lesions (33%) on SMI. On the contrary, a nonspecific vascular pattern was detected in the majority (78%) of CDI. Regarding the lesion size and vascularity on SMI, the typical spoke-wheel pattern was seen more frequently in the small FNH group than in the large FNH group. The intralesional vascular signal was detected more frequently on SMI (100%) than on CDI (89%).

CONCLUSION

SMI is feasible in evaluating FNH in children and has a greater ability to demonstrate the spoke-wheel pattern than CDI.

Beta-Catenin-Mutated Hepatocellular Adenomas at Hepatobiliary Phase MRI: A Systematic Review and Meta-Analysis

BACKGROUND

Beta-catenin-mutated hepatocellular adenomas (β-HCAs) can appear iso- to hyperintense at the hepatobiliary phase (HBP) at magnetic resonance imaging (MRI). Given the relatively lower prevalence of β-HCAs, prior studies had limited power to show statistically significant differences in the HBP signal intensity between different subtypes.

PURPOSE

To assess the diagnostic performance of HBP MRI to discriminate β-HCA from other subtypes.

STUDY TYPE

Systemic review and meta-analysis.

POPULATION

Ten original studies were included, yielding 266 patients with 397 HCAs (9%, 36/397 β-HCAs and 91%, 361/397 non-β-HCAs).

FIELD STRENGTH/SEQUENCE

1.5 T and 3.0 T, HBP.

ASSESSMENT

PubMed, Web of Science, and Embase databases were searched from January 1, 2000, to August 31, 2023, for all articles reporting HBP signal intensity in patients with histopathologically proven HCA subtypes. QUADAS-2 was used to assess risk of bias and concerns regarding applicability.

STATISTICAL TESTS

Univariate random-effects model was used to calculate pooled estimates. Heterogeneity estimates were assessed with I2 heterogeneity index. Meta-regression (mixed-effect model) was used to test for differences in the prevalence of HBP signal between HCA groups. The threshold for statistical significance was set at P < 0.05.

RESULTS

HBP iso- to hyperintensity was associated with β-HCAs (pooled prevalence was 72.3% in β-HCAs and 6.3% in non-β-HCAs). Pooled sensitivity and specificity were 72.3% (95% confidence interval 54.1-85.3) and 93.7% (93.8-97.7), respectively. Specificity had substantial heterogeneity with I2 of 83% due to one study, but not for sensitivity (I2  = 0). After excluding this study, pooled sensitivity and specificity were 77.4% (59.6-88.8) and 94.1% (88.9-96.9), with no substantial heterogeneity. One study had high risk of bias for patient selection and two studies were rated unclear for two domains.

DATA CONCLUSION

Iso- to hyperintensity at HBP MRI may help to distinguish β-HCA subtype from other HCAs with high specificity. However, there was heterogeneity in the pooled estimates.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Primary Invasive Ductal Carcinoma of the Breast Occurring in a Patient With a History of Hepatocellular Carcinoma Developing From Focal Nodular Hyperplasia: A Case Report and Literature Review

The risk of developing another primary malignancy after an initial liver cancer diagnosis is rare, and the management of multiple primary cancers is not typically discussed. Focal nodular hyperplasia (FNH) is considered a benign tumor, but there have been cases reported that describe hepatocellular carcinoma (HCC) arising from or within FNH. Here, we report a woman in her 70s who had a longstanding history of FNH, later found to be HCC upon resection, who also developed invasive ductal carcinoma. She had no family history of cancer and no genetic testing results were available. Each of her cancers was managed independently, hepatectomy for HCC and neoadjuvant therapy followed by mastectomy for her breast carcinoma. This case demonstrates that the diagnosis of FNH based on radiographic imaging may necessitate a biopsy to confirm diagnosis for a symptomatic patient or those with lesions suspicious for malignancy. It also showcases the importance of close follow-up after a primary cancer diagnosis for the possibility of another primary malignancy emerging. Fresh tissue biopsy for new lesions could help determine primary malignancy or metastasis. Genetic sequencing may help identify driver mutations or genetic alterations that can be targeted.

Pedunculated Focal Nodular Hyperplasia: When in Doubt, Should We Cut It Out?

Focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor and can rarely present as an exophytic solitary mass attached to the liver by a stalk. Most FNH cases are usually detected as incidental findings during surgery, imaging or physical examination and have a high female predominance. However, the pedunculated forms of FNH are particularly rare and commonly associated with severe complications and diagnostic challenges. Hence, our study aims to provide a comprehensive summary of the available data on the pedunculated FNH cases among adults and children. Furthermore, we will highlight the role of different therapeutic options in treating this clinical entity. The use of imaging techniques is considered a significant addition to the diagnostic toolbox. Regarding the optimal treatment strategy, the main indications for surgery were the presence of symptoms, diagnostic uncertainty and increased risk of complications, based on the current literature. Herein, we also propose a management algorithm for patients with suspected FNH lesions. Therefore, a high index of suspicion and awareness of this pathology and its life-threatening complications, as an uncommon etiology of acute abdomen, is of utmost importance in order to achieve better clinical outcomes.

Evaluating Liver Biopsies with Well-Differentiated Hepatocellular Lesions

Needle core biopsies of liver lesions can be challenging, particularly in cases with limited material. The differential diagnosis for well-differentiated hepatocellular lesions includes focal nodular hyperplasia, hepatocellular adenoma, and well-differentiated hepatocellular carcinoma (HCC) in noncirrhotic liver, while dysplastic nodules and well-differentiated HCC are the primary considerations in cirrhotic liver. The first part of this review focuses on histochemical and immunohistochemical stains as well as molecular assays that are useful in the differential diagnosis. The second portion describes the features of hepatocellular adenoma subtypes and focuses on the differential diagnoses in commonly encountered clinicopathologic scenarios.

The Different MRI Features of Hepatocellular Adenoma and Hepatocellular Carcinoma

Background

Hepatocellular adenomas (HCAs) are benign tumours that may be broken down into three different molecular pathogenic categories: catenin activator, hepatic cell nuclear agent 1 (HNF- 1) that has been inactivated, and Inflammatory hepatic adenomas are a genetic and pathological subtype of hepatic adenoma.

Methodology

An analysis of 50 HCA cases was conducted to identify the magnetic resonance imaging characteristics that were specifically related to each HCA subtype IV. This method included 50 patients in total for the study, with 30 of them being new cases. Four cases involving medicine, pathology, surgery, and radiology were gathered and examined.

Results

As per these analyses for inactivated HNF-1, the sure predictive esteem about homogeneous indicator spillage on the compound shift pictures could have been as high as 100%, negative predictive quality could have been as high as 94.7%, affectability could have been as high as 86.7%, and specificity could have been as high as 100%. Enhancement of the solid blood vessels to support the ongoing and future stages of the portal vein change. It took a certain predictive quality of 88.5%, a negative predictive worth of about 84%, an affectability of about 85.2%, and more specificity of about 87.5% to diagnose incendiary HCA from the predominant signs seen for T2W successions linked with late constant upgrades.

Conclusions

Both HNF-1-mutated HCAs and incendiary HCAs need to be associated with specific magnetic resonance imaging phenotypes characterized independently as having diffused lipid repartition and sinusoidal expansion.

Suspected focal nodular hyperplasia in male adults: 10-year experience from a large liver centre

PURPOSE

Focal nodular hyperplasia (FNH) is commonly found in females of reproductive age. In males, the diagnosis is made more cautiously due to its lower incidence and higher incidence of hepatocellular carcinoma, which can have overlapping imaging features. Follow-up or biopsy is sometimes required. This retrospective study aims to assess management of suspected FNH in male adult patients at our institution over a 10-year period.

METHODS

Male adults (≥ 18 years) suspected of having FNH from January 2010-June 2020 were identified using a departmental radiology information system search. Data was collected from radiology reports and patient pathway manager.

RESULTS

Of 342 patients with suspected FNH, 62 were male (18.1%; F:M of 4.5:1). We only included patients investigated and followed up by MRI, total of 57 patients. Median age was 40 years (range 18-74 years). Background liver disease present in 21/57 (36.8%), majority with hepatic steatosis. Average number of lesions per patient 1.7. 22/57 (38.6%) had at least one MRI follow-up using liver-specific contrast with 7 lesions demonstrating variation in size (range growth: -3.27 mm/year to + 4 mm/year). In 7 cases, MRI was not definitive; 6 required biopsy and 1 resection. Only 2/7 demonstrated malignancy. Of the total 57 patients, 6 have deceased and none due to a misdiagnosed or mismanaged hepatic lesion.

CONCLUSION

FNH is relatively uncommon in males, however, our data suggests that lesions with typical MRI characteristics do not require follow-up and diagnosis can be made confidently, similar to females. Any atypical features should prompt a biopsy.

Subtyping of hepatocellular adenomas using Gd-EOB-DTPA: a qualitative and quantitative analysis

BACKGROUND

The goal of medical imaging is not only to identify the entity "hepatocellular adenoma," but to detect typical magnetic resonance (MR) patterns of the subtypes so that lesions with a higher malignant transformation rate could be differentiated from those that should just be controlled.

PURPOSE

To evaluate the differentiation between subtypes of hepatocellular adenomas using hepatobiliary specific contrast agent (Gd-EOB-DTPA) in MR imaging.

MATERIAL/METHODS

A total of 11 patients with 39 lesions with histologically proven hepatocellular adenomas were evaluated. Of the, 34 were inflammatory hepatocellular adenomas (IHCA) and 5 were HNF1α adenomas. No β-catenin-mutated adenoma was found. In all patients, a standard protocol considering the guidelines of the international consensus conference of Gd-EOB-DTPA was performed in a 1.5-T scanner. Besides a qualitative analysis of all sequences, we measured the quantitative signal intensity (SI) ratio in all examinations.

RESULTS

Qualitative analysis showed that best sequences for differentiation of HNF1α adenomas from IHCA were T1-weighted (T1W) precontrast (P = 0.03) and portalvenous phase (P < 0.0001) as well as arterial phase (P = 0.002). All adenomas were hypointense in hepatobiliary phase (15 min). The quantitative analyses of the SI ratio and of lesion-to-liver contrast (LLC) ratio show statistically significant differences in T1W precontrast (SI: P = 0.035; LLC: P = 0.049) and portalvenous phase (SI: P = 0.002; LLC: P = 0.002).

CONCLUSION

Subtyping of hepatocellular adenomas using Gd-EOB-DTPA is possible due to qualitative and quantitative analyses regarding T1W precontrast and portalvenous phase. In addition, the SI ratio and liver-to-lesion contrast ratio in the arterial phase gave additional qualitative information for differentiation.

Genetic Predisposition to Hepatocellular Carcinoma

Liver preneoplastic and neoplastic lesions of the genetically susceptible F344 and resistant BN rats cluster, respectively, with human HCC with better (HCCB) and poorer prognosis (HCCP); therefore, they represent a valid model to study the molecular alterations determining the genetic predisposition to HCC and the response to therapy. The ubiquitin-mediated proteolysis of ERK-inhibitor DUSP1, which characterizes HCC progression, favors the unrestrained ERK activity. DUSP1 represents a valuable prognostic marker, and ERK, CKS1, or SKP2 are potential therapeutic targets for human HCC. In DN (dysplastic nodule) and HCC of F344 rats and human HCCP, DUSP1 downregulation and ERK1/2 overexpression sustain SKP2-CKS1 activity through FOXM1, the expression of which is associated with a susceptible phenotype. SAM-methyl-transferase reactions and SAM/SAH ratio are regulated by GNMT. In addition, GNMT binds to CYP1A, PARP1, and NFKB and PREX2 gene promoters. MYBL2 upregulation deregulates cell cycle and induces the progression of premalignant and malignant liver. During HCC progression, the MYBL2 transcription factor positively correlates with cells proliferation and microvessel density, while it is negatively correlated to apoptosis. Hierarchical supervised analysis, regarding 6132 genes common to human and rat liver, showed a gene expression pattern common to normal liver of both strains and BN nodules, and a second pattern is observed in F344 nodules and HCC of both strains. Comparative genetics studies showed that DNs of BN rats cluster with human HCCB, while F344 DNs and HCCs cluster with HCCP.

A transcriptional regulatory network of HNF4α and HNF1α involved in human diseases and drug metabolism

HNF4α and HNF1α are core transcription factors involved in the development and progression of a variety of human diseases and drug metabolism. They play critical roles in maintaining the normal growth and function of multiple organs, mainly the liver, and in the metabolism of endogenous and exogenous substances. The twelve isoforms of HNF4α may exhibit different physiological functions, and HNF4α and HNF1α show varying or even opposing effects in different types of diseases, particularly cancer. Additionally, the regulation of CYP450, phase II drug-metabolizing enzymes, and drug transporters is affected by several factors. This article aims to review the role of HNF4α and HNF1α in human diseases and drug metabolism, including their structures and physiological functions, affected diseases, regulated drug metabolism genes, influencing factors, and related mechanisms. We also propose a transcriptional regulatory network of HNF4α and HNF1α that regulates the expression of target genes related to disease and drug metabolism.

An Extreme Case of Liver Adenomatosis: Are They All the Same?

Hepatocellular adenoma (HCA) is a rare and benign liver tumor that affects predominantly young and middle-aged women, especially between 30–40 years old. Liver adenomatosis (LA) is defined as the presence of 10 or more HCA. There are authors that report eight different subtypes of HCA, that correlates with clinical and histopathological features, being the inflammatory subtype the most common. We present a case of a 32-year-old Caucasian woman with a history of self-limited episodes of right abdominal pain and an abdominal ultrasound with multiple hypoechogenic liver nodules, suspected of metastasis. She was taking combined oral contraceptive for 6 years. Magnetic Resonance Imaging (MRI) disclosed around 40 nodules, suggestive of HCA. Liver biopsy confirmed HCA, inflammatory subtype. Oral contraceptive was stopped and control MRI 6 months later disclosed reduction of nodules’ dimensions. Management of patients with LA should be based on the size of the largest tumor, as clinical presentation and risk of bleeding or malignancy do not differ between patients with single or multiple HCAs. However, even with biopsy, there is a risk of missampling, raising concern about the real risk of bleeding and malignant potential in patients with different subtypes coexisting in the same liver.

Genomic analysis of focal nodular hyperplasia with associated hepatocellular carcinoma unveils its malignant potential: a case report

Background

Focal nodular hyperplasia (FNH) is typically considered a benign tumor of the liver without malignant potential. The co-occurrence of FNH and hepatocellular carcinoma (HCC) has been reported in rare cases. In this study we sought to investigate the clonal relationship between these lesions in a patient with FNH-HCC co-occurrence.

Methods

A 74-year-old female patient underwent liver tumor resection. The resected nodule was subjected to histologic analyses using hematoxylin and eosin stain and immunohistochemistry. DNA extracted from microdissected FNH and HCC regions was subjected to whole exome sequencing. Clonality analysis were performed using PyClone.

Results

Histologic analysis reveals that the nodule consists of an FNH and two adjoining HCC components with distinct histopathological features. Immunophenotypic characterization and genomic analyses suggest that the FNH is clonally related to the HCC components, and is composed of multiple clones at diagnosis, that are likely to have progressed to HCC through clonal selection and/or the acquisition of additional genetic events.

Conclusion

To the best of our knowledge, our work is the first study showing a clonal relationship between FNH and HCC. We show that FNH may possess the capability to undergo malignant transformation and to progress to HCC in very rare cases.

Senescence markers in focal nodular hyperplasia of the liver: pathogenic considerations on the basis of immunohistochemical results

Focal nodular hyperplasia (FNH) is a polyclonal tumour-like hepatic lesion characterised by parenchymal nodules, connective tissue septa without interlobular bile ducts, pronounced ductular reaction and inflammation. It may represent a response to local arterial hyperperfusion and hyperoxygenation resulting in oxidative stress. We aimed at obtaining closer insight into the pathogenesis of FNH with its characteristic morphologic features. Immunohistochemistry and immunofluorescence microscopy was performed on FNH specimens using antibodies against keratins (K) 7 and 19, neural cell adhesion molecule (NCAM), lamin B1, senescence markers (CDK inhibitor 1/p21^Cip1, CDK inhibitor /p16^Ink4a, senescence-associated (SA) β- galactosidase activity), proliferation markers (Ki-67, proliferating-cell nuclear antigen (PCNA)), and the abnormally phosphorylated histone γ-H2AX, indicating DNA double strand breaks; moreover SA β- galactosidase activity was determined histochemically. Ductular metaplasia of hepatocytes indicated by K7 expression in the absence of K19 plays a major role in the development of ductular reaction in FNH. Moreover, the expression of senescence markers (p21^Cip1, p16^Ink4a, γ-H2AX, SA β-galactosidase activity) in hepatocytes and cholangiocytes suggests that stress-induced cellular senescence contributes to fibrosis and inflammation via production of components of the senescence-associated secretory phenotype. Expression of proliferation markers (Ki-67, PCNA) was not enhanced in hepatocytes and biliary cells. Senescence and ductular metaplasia of hepatocytes may thus be involved in inflammation, fibrosis and apoptosis resistance. Hence, fibrosis, inflammation and reduced apoptotic cell death, rather than proliferation (hyperplasia) may be responsible for increased tissue mass and tumour-like appearance of FNH.

A case of focal nodular hyperplasia with hepatic failure treated with liver transplantation

Focal nodular hyperplasia (FNH) is a benign nodular lesion, but because of its feature of portal tract vessel abnormality, it may induce portal hypertension. A 27-year-old woman was admitted with a fever. A large nodule with satellite lesions was found in the liver and cotton wool-like feature of arteries were detected on angiography. Technetium galactosyl serum albumin scintigraphy and diagnostic laparoscopy showed that the tumor site was functional, while the surrounding area was a non-functional fibrotic area. A biopsy specimen indicated that the nodular lesion was an FNH-like lesion. She experienced several instances of variceal rupture and suffered liver failure, receiving liver transplantation. The excised liver showed a centrally scarred area in the nodule, indicating that the diagnosis was FNH. We herein report this case as a rare case of FNH that progressed to liver failure.

Liver tumors in children with chronic liver diseases

Liver tumors are rare in children, but the incidence may increase in some circumstances and particularly in chronic liver diseases. Most liver tumors consequent to chronic liver diseases are malignant hepatocellular carcinoma. Other liver tumors include hepatoblastoma, focal nodular hyperplasia, adenoma, pseudotumor, and nodular regenerative hyperplasia. Screening of suspected cases is beneficial. Imaging and surrogate markers of alpha-fetoprotein are used initially as noninvasive tools for surveillance. However, liver biopsy for histopathology evaluation might be necessary for patients with inconclusive findings. Once the malignant liver tumor is detected in children with cirrhosis, liver transplantation is currently considered the preferred option and achieves favorable outcomes. Based on the current evidence, this review focuses on liver tumors with underlying chronic liver disease, their epidemiology, pathogenesis, early recognition, and effective management.

Focal nodular hyperplasia associated with a giant hepatocellular adenoma: A case report and review of literature

BACKGROUND

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are well-known benign liver lesions. Surgical treatment is usually chosen for symptomatic patients, lesions more than 5 cm, and uncertainty of diagnosis.

CASE SUMMARY

We described the case of a large liver composite tumor in an asymptomatic 34-year-old female under oral contraceptive for 17-years. The imaging work-out described two components in this liver tumor; measuring 6 cm × 6 cm and 14 cm × 12 cm × 6 cm. The multidisciplinary team suggested surgery for this young woman with an unclear HCA diagnosis. She underwent a laparoscopic left liver lobectomy, with an uneventful postoperative course. Final pathological examination confirmed FNH associated with a large HCA. This manuscript aimed to make a literature review of the current management in this particular situation of large simultaneous benign liver tumors.

CONCLUSION

The simultaneous presence of benign composite liver tumors is rare. This case highlights the management in a multidisciplinary team setting.

Novel Strategy for Diagnosis of Focal Nodular Hyperplasia Using Gadolinium Ethoxybenzyl Diethylenetriaminepentaacetic Acid: Enhanced Magnetic Resonance Imaging and Magnetic Resonance Elastography

Focal nodular hyperplasia (FNH) is the second most frequent benign liver tumor, and it is a fiber-rich stiff lesion. Typically, FNH can be diagnosed by imaging without biopsy. However, liver biopsy and diagnostic resection may be required to differentiate atypical FNH from other liver tumors, such as hepatocellular adenoma (HCA). Therefore, improved noninvasive diagnostic methods are needed. We experienced 2 cases where combination of magnetic resonance elastography (MRE) and gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) helped diagnose FNH. A 36-year-old woman and 17-year-old boy with liver tumors measuring 40 mm in diameter each showed hypointense nodule centers, indicating a central scar, surrounded by hyperintense signals during the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI. To rule out HCA, we performed MRE and liver biopsy. On MRE, the mean stiffness of the mass was 11.6 kPa (mean stiffness of the background liver was 1.7 kPa) and 11.1 kPa (mean stiffness of the background liver was 2.4 kPa) in the first and second patients, respectively. Histological examination of both specimens showed CK7-positive bile-ductular proliferations, abundant fibrous tissue, and few Ki-67-positive cells. Based on these results, we diagnosed these tumors as FNH. Combination of Gd-EOB-DTPA-enhanced MRI and MRE can evaluate the character and stiffness of lesion and help in the diagnosis of FNH.

Comparison Between SonoVue and Sonazoid Contrast-Enhanced Ultrasound in Characterization of Focal Nodular Hyperplasia Smaller Than 3 cm

OBJECTIVES

This study aimed to compare the diagnostic efficacy of contrast-enhanced ultrasound (CEUS), including SonoVue (SV; sulfur hexafluoride; Bracco SpA, Milan, Italy) and Sonazoid (SZ; perflubutane; GE Healthcare, Oslo, Norway), and explore the differences between them in the characterization of CEUS features in focal nodular hyperplasia (FNH) smaller than 3 cm.

METHODS

This retrospective study included 31 lesions smaller than 3 cm diagnosed as FNH by CEUS between April 2019 and November 2019. Nine patients underwent SZ CEUS examinations, and 22 patients underwent SV CEUS examinations; all of them were confirmed by pathologic examinations or 2 other kinds of CEUS methods. We compared the CEUS features between SZ and SV in different phases, including arterial, portal venous, delayed, and Kupffer (SZ) phases.

RESULTS

Twenty-eight lesions were eventually diagnosed as FNH; 3 were misdiagnosed as FNH by SV CEUS. The overall diagnostic accuracy of CEUS including SZ and SV was 90.3% (28 of 31). No significant difference was found (P > .05) for the positive predictive value. Likewise, no significant difference in depicting centrifugal filling (9 of 9 versus 19 of 19), spoke wheel artery (6 of 9 versus 8 of 19), or feeding artery (2 of 9 versus 10 of 19) features was found between the contrast agents; However, SZ was significantly better at depicting the presence of a central scar than SV (5 of 9 versus 3 of 19; P = .030). Misdiagnosed cases are discussed in detail.

CONCLUSIONS

Contrast-enhanced ultrasound enables an accurate diagnosis in FNH smaller than 3 cm. Sonazoid CEUS and SV CEUS were comparable in diagnosing small FNH, and both agents were highly capable of depicting the centrifugal filling dynamic process of FNH smaller than 3 cm. Sonazoid CEUS might be better than SV CEUS at depicting a central scar.

Significance of hepatocyte atypia in liver fine needle aspiration

Fine needle aspiration (FNA) of the liver is frequently the diagnostic procedure of choice for sampling hepatic lesions. One of the main diagnostic challenges in the interpretation of liver FNA is distinguishing dysplastic lesions and well-differentiated hepatocellular carcinoma (WD-HCC) from benign processes, as they share significant cytomorphologic overlap. Furthermore, the diagnosis of HCC often requires evaluation of stroma for invasion, which may not be present on cytology and small needle biopsy specimens. A reporting system for liver cytopathology has yet to be instituted. Without standardized and well-defined criteria for hepatocyte atypia, we recommend limiting the use of atypia in evaluation of liver FNA specimens to describe a diagnosis of exclusion, in which all known benign and neoplastic processes have been ruled out. The cytologic findings on the FNA of a liver nodule may be best reported as atypical hepatocytes in the absence of a core needle biopsy or cell block sufficient to render a definitive diagnosis of HCC.

Scoping review of clinical practice guidelines on the management of benign liver tumours

Objective

Benign liver tumours (BLT) are increasingly diagnosed as incidentalomas. Clinical implications and management vary across and within the different types of BLT. High-quality clinical practice guidelines are needed, because of the many nuances in tumour types, diagnostic modalities, and conservative and invasive management strategies. Yet, available observational evidence is subject to interpretation which may lead to practice variation. Therefore, we aimed to systematically search for available clinical practice guidelines on BLT, to critically appraise them, and to compare management recommendations.

Design

A scoping review was performed within MEDLINE, EMBASE, and Web of Science. All BLT guidelines published in peer-reviewed, and English language journals were eligible for inclusion. Clinical practice guidelines on BLT were analysed, compared, and critically appraised using the Appraisal of Guidelines, Research and Evaluation (AGREE II) checklist regarding hepatic haemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA). Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations (PRISMA) for scoping reviews were adhered to.

Results

The literature search yielded unique 367 papers, 348 were excluded after screening of title/abstract, and 16 after full-text screening. Three guidelines were included: the American College of Gastroenterology (ACG; 2014), Brazilian Society of Hepatology (SBH; 2015), and European Association for the Study of the Liver (EASL; 2016). There was no uniformity in the assessment methods for grading and gravity of recommendations between guidelines. Among observed differences were: (1) indications for biopsy in all three tumours; (2) advices on contraceptive pills and follow-up in FNH and HCA; (3) use of an individualised approach to HCA; (4) absence of recommendations for treatment of HCA in men; and (5) approaches to HCA subtype identification on magnetic resonance imaging.

Conclusion

Recognising differences in recommendations can assist in harmonisation of practice standards and identify unmet needs in research. This may ultimately contribute to improved global patient care.

Application of Immunohistochemistry in the Pathological Diagnosis of Liver Tumors

Although radiological diagnostics have been progressing, pathological diagnosis remains the most reliable method for diagnosing liver tumors. In some cases, definite pathological diagnosis cannot be obtained by histological evaluation alone, especially when the sample is a small biopsy; in such cases, immunohistochemical staining is very useful. Immunohistochemistry is the most frequently used technique for molecular pathological diagnosis due to its broad application, ease of performance and evaluation, and reasonable cost. The results occasionally reflect specific genetic mutations. The immunohistochemical markers of hepatocellular carcinoma include those of hepatocellular differentiation—such as hepatocyte paraffin 1 and arginase-1—and those of malignant hepatocytes—such as glypican-3, heat shock protein 70, and glutamine synthetase (GS). To classify the subtypes of hepatocellular adenoma, examination of several immunohistochemical markers, such as liver fatty acid-binding protein, GS, and serum amyloid A, is indispensable. Immunohistochemical staining for GS is also important for the diagnosis of focal nodular hyperplasia. The representative immunohistochemical markers of intrahepatic cholangiocarcinoma include cytokeratin (CK) 7 and CK19. In this article, we provide an overview of the application of immunohistochemistry in the pathological diagnosis of liver tumors referring to the association with genetic alterations. Furthermore, we aimed to explain the practical points in the differential diagnosis of liver tumors by immunohistochemical staining.

Gd-EOB-DTPA MRI for focal nodular hyperplasia-like lesions in pediatric cancer survivors

OBJECTIVES

To investigate the hepatobiliary enhancement patterns of gadoxetic acid (Gd-EOB-DTPA) MRI and the temporal evolution of focal nodular hyperplasia (FNH)-like lesions in pediatric cancer survivors.

METHODS

We retrospectively included pediatric cancer survivors who had new liver lesions detected during surveillance imaging and who were diagnosed with FNH-like lesions by Gd-EOB-DTPA MRI without the aid of a hepatobiliary phase. The hepatobiliary enhancement patterns of FNH-like lesions were categorized as homogeneous hyperintense/isointense, heterogeneous hyperintense, and ring-like enhancement. Temporal changes in the FNH-like lesions were evaluated by follow-up Gd-EOB-DTPA MRI. Statistical analyses included one-way analysis of variance and Spearman's rank correlation test.

RESULTS

A total of 132 radiologically diagnosed FNH-like lesions in 18 patients showed the three different hepatobiliary enhancement patterns: homogeneous hyperintense/isointense (n = 65, 49%), heterogeneous hyperintense (n = 24, 18%), and ring-like enhancement (n = 43, 33%). A weak positive correlation was found between the lesion size and the hepatobiliary enhancement pattern (p = 0.015). Follow-up MRI showed alterations in the size and number of 55 FNHs in 8 patients, including stable size (n = 15, 27%), increased size (n = 17, 31%), decreased size (n = 11, 20%), disappearance (n = 12, 22%), and 74 new lesions (5 patients, 63%).

CONCLUSIONS

FNH-like lesions in pediatric cancer survivors showed three different hepatobiliary enhancement patterns and various temporal changes. Recognition of the radiological characteristics of FNH-like lesions may avoid unnecessary invasive procedures and reduce patients/parents' anxiety.

KEY POINTS

• FNH-like lesions in pediatric cancer survivors showed three different hepatobiliary enhancement patterns. The most common was homogeneous hyperintense/isointense, followed by heterogeneous hyperintense, and ring-like enhancement. • FNH-like lesions in pediatric cancer survivors can show various temporal changes during follow-up.

State-of-the-art MR Imaging of Fat-containing Focal Lesions of the Liver

BACKGROUND

Fat can be identified in numerous liver lesions, and usually is not a specific finding. Distinguishing between different kinds of fatty deposits is an important part of differential diagnosis. Magnetic Resonance Imaging (MRI) is superior to other imaging techniques because it allows distinguishing intracellular from macroscopic fat.

DISCUSSION

Intracellular lipid may be found in focal hepatic steatosis, hepatic adenoma, hepatocellular carcinoma and, less commonly, in focal nodular hyperplasia as well as regenerative and dysplastic nodules. Macroscopic fat is seen in angiomyolipoma, lipoma, metastases from fatcontaining neoplasms, primary or metastatic liposarcoma, hydatid cyst, pseudolipoma of the Glisson capsule, pericaval fat collection, lipopeliosis, hepatic teratoma, focal hepatic extramedullary haematopoiesis and adrenal rest tumour.

CONCLUSION

Liver nodules should be characterised with regard to underlying liver condition, MRI characteristics and contrast enhancement pattern, including hepatobiliary phase. In many cases, identification of fatty content may help narrowing the differential diagnosis.

Case Report: Hepatic Adenoma in a Child With a Congenital Extrahepatic Portosystemic Shunt

Congenital extrahepatic portosystemic shunts (CEPS), previously also described as Abernethy malformations, are rare malformations in which the extrahepatic portal system directly communicates with the vena cava inferior, thereby bypassing the liver. A hypoplastic portal vein (PV) exists in most cases. CEPS have been associated with the development of liver nodules, ranging from mostly focal nodular hyperplasia (FNH) to hepatic adenoma (HA) and even hepatocellular carcinoma (HCC). Tumor development in CEPS may be due to changes in perfusion pressures, oxygen supply or endocrine imbalances. It is important to rule out CEPS in children with liver tumors, because resection could impede future shunt occlusion procedures, and benign masses may regress after shunt occlusion. Here, we review the case of a 9-years-old male with CEPS and hepatic nuclear Factor 1-alpha (HNF-1-alpha) inactivated HA to raise awareness of this condition and review histopathological changes in the liver of CEPS.

Natural history of liver adenomatosis: A long-term observational study

BACKGROUND & AIMS

Liver adenomatosis (LA) is characterized by the presence of at least 10 hepatocellular adenomas (HCAs), but the natural history of this rare liver disorder remains unclear. Thus, we aimed to reappraise the natural history and the risk of complications in a cohort of patients with at least 10 HCAs.

METHODS

We analyzed the natural history of 40 patients with LA, excluding glycogen storage disorders, in a monocentric cohort. Pathological examination was performed, with immunostaining and molecular biology carried out on surgical specimens or liver biopsies.

RESULTS

Forty patients (36 female) were included with a median follow-up of 10.6 (1.9-26.1) years. Six (15%) patients had familial LA, all with germline HNF1A mutations. Median age at diagnosis was 39 (9-55) years. Thirty-three (94%) women had a history of oral contraception, and 29 (81%) women had a pregnancy before LA diagnosis. Overall, thirty-seven (93%) patients underwent surgery at diagnosis. Classification of HCAs showed 46% of patients with HNF1A-mutated HCA, 31% with inflammatory HCA, 3% with sonic hedgehog HCA, 8% with unclassified HCA. Only 15% of the patients demonstrated a "mixed LA" with different HCA subtypes. Hepatic complications were identified in 7 patients: 1 patient (3%) died from recurrent hepatocellular carcinoma after liver transplantation; 6 (15%) had hemorrhages, of which 5 occurred at diagnosis, with 1 fatal case during pregnancy, and 2 occurred in male patients with familial LA. Four patients (10%) had repeated liver resections. Finally, 4 (10%) patients developed extrahepatic malignancies during follow-up.

CONCLUSIONS

The diversity in HCA subtypes, as well as the occurrence of bleeding and malignant transformation during long-term follow-up, underline the heterogeneous nature of LA, justifying close and specific management. In patients with germline HNF1A mutation, familial LA occurred equally frequently in males and females, with a higher rate of bleeding in male patients.

LAY SUMMARY

Liver adenomatosis is a rare disease characterized by the presence of 10 or more hepatocellular adenomas that may rarely be of genetic origin. Patients with liver adenomatosis have multiple adenomas of different subtypes, with a risk of bleeding and malignant transformation that justify a specific management and follow-up.

Liver disease secondary to congenital heart disease in children

Introduction: Hepatic fibrosis and hepatocellular carcinoma (HCC) can develop in children with congenital heart disease. Although hepatic fibrosis and HCC are prone to develop after the Fontan operation, they can also develop in patients suffering from congenital heart disease who have not undergone Fontan operation. Area covered: The history of cardiac hepatopathy including Fontan-associated liver disease is described. Patient characteristics, liver histology, imaging examinations and blood tests are reviewed to elucidate the mechanism of cardiac hepatopathy. In addition, a flowchart for the follow-up management of cardiac hepatopathy in children with congenital heart disease is proposed. Expert opinion: Congestion and low cardiac output are the main causes of cardiac hepatopathy. Advanced hepatic fibrosis is presumed to be associated with HCC. HCC can develop in both adolescents and young adults. Regardless of whether the Fontan operation is performed, children with a functional single ventricle and chronic heart failure should be regularly examined for cardiac hepatopathy. There is no single reliable laboratory parameter to accurately detect cardiac hepatopathy; hepatic fibrosis indices and elastography have shown inconsistent results for detection of this disease. Further studies using liver specimen-confirmed patients and standardization of evaluation protocols are required to clarify the pathogenesis of cardiac hepatopathy.

The effect of oral contraceptive pill cessation on hepatocellular adenoma diameter: A retrospective cohort study

BACKGROUND & AIMS

Hepatocellular adenomas (HCA) are rare, hormone-driven, benign liver tumours. HCA >50 mm are associated with haemorrhage and malignant transformation. Guidelines recommend cessation of oral contraceptive pills (OCP) for size reduction; however, it is currently unknown how HCA respond to cessation of OCP. We sought to investigate the effect of OCP cessation on HCA size.

METHODS

A retrospective cohort study was performed including HCA patients who stopped OCP intake within 6 months of imaging between 2005 and 2018. Biometrics and hormonal medication use were evaluated with self-designed questionnaires. Response of the largest HCA was evaluated according to Response Evaluation Criteria in Solid Tumours (RECISTv1.1). Cox regression was performed for analysis of factors influencing HCA regression.

RESULTS

Seventy-eight HCA patients were included, diagnosed at a median (interquartile range) age of 32 (26-41) years. Follow-up was 1.6 (0.4-2.9) years. HCA size at diagnosis ranged 10-167 mm. After a median time of 1.3 (0.6-2.6) years after OCP cessation, 37.2% of HCA showed ≥30% regression, 5.1% complete regression, 56.4% stability and 1.3% progression. No HCA-induced complications were observed during follow-up. Cox regression analysis demonstrated a significant association of HCA size with rate of regression; 50 ≤ HCA < 100 mm (HR 2.4, 95% CI 1.1-5.3; P < 0.05), HCA ≥ 100 mm (HR 8.3, 95% CI 3.3-21.6; P < 0.001).

CONCLUSIONS

Ninety-eight per cent of HCA remained stable or regressed after OCP cessation. A longer wait-and-see period was associated with a larger proportion of regressing HCA, without HCA-related complications during follow-up.

Ultrasound Imaging of Hepatocellular Adenoma Using the New Histology Classification

Hepatocellular adenoma is a rare benign liver tumor. Predisposing factors include hepatic storage diseases and some genetic conditions. A new histology-based classification has been proposed but to date, the corresponding ultrasound imaging features have not been reported. Here we review the new classification scheme and discuss the corresponding features on contrast-enhanced ultrasound imaging.

A practical diagnostic approach to hepatic masses

The differential diagnosis of hepatic mass lesions is broad and arriving at the right diagnosis can be challenging, especially on needle biopsies. The differential diagnosis of liver tumors in children is different from adults and is beyond the scope of this review. In adults, the approach varies depending on the age, gender, and presence of background liver disease. The lesions can be divided broadly into primary and metastatic (secondary), and the primary lesions can be further divided into those of hepatocellular origin and nonhepatocellular origin. The first category consists of benign and malignant lesions arising from hepatocytes, while the second category includes biliary, mesenchymal, hematopoietic, and vascular tumors. Discussion of nonepithelial neoplasms is beyond the scope of this review. The hepatocytic lesions comprise dysplastic nodules, focal nodular hyperplasia, hepatic adenoma, and hepatocellular carcinoma, and the differential diagnosis can be challenging requiring clinicopathological correlation and application of immunohistochemical (IHC) markers. Liver is a common site for metastasis, sometimes presenting with an unknown primary site, and proper workup is the key to arriving at the correct diagnosis. The correct diagnosis in this setting requires a systematic approach with attention to histologic features, imaging findings, clinical presentation, and judicious use of IHC markers. The list of antibodies that can be used for this purpose keeps on growing continually. It is important for pathologists to be up to date with the sensitivity and specificity of these markers and their diagnostic role and clinical implications. The purpose of this review is to outline the differential diagnosis of hepatic masses in adults and discuss an algorithmic approach to make a right diagnosis.

Growth of Focal Nodular Hyperplasia is Not a Reason for Surgical Intervention, but Patients Should be Referred to a Tertiary Referral Centre

Background

When a liver lesion diagnosed as focal nodular hyperplasia (FNH) increases in size, it may cause doubt about the initial diagnosis. In many cases, additional investigations will follow to exclude hepatocellular adenoma or malignancy. This retrospective cohort study addresses the implications of growth of FNH for clinical management.

Methods

We included patients diagnosed with FNH based on ≥2 imaging modalities between 2002 and 2015. Characteristics of patients with growing FNH with sequential imaging in a 6-month interval were compared to non-growing FNH.

Results

Growth was reported in 19/162 (12%) patients, ranging from 21 to 200%. Resection was performed in 4/19 growing FNHs; histological examination confirmed FNH in all patients. In all 15 conservatively treated patients, additional imaging confirmed FNH diagnosis. No adverse outcomes were reported. No differences were found in characteristics and presentation of patients with growing or non-growing FNH.

Conclusion

This study confirms that FNH may grow significantly without causing symptoms. A significant increase in size should not have any implications on clinical management if confident diagnosis by imaging has been established by a tertiary benign liver multidisciplinary team. Liver biopsy is only indicated in case of doubt after state-of-the-art imaging. Resection is deemed unnecessary if the diagnosis is confirmed by multiple imaging modalities in a tertiary referral centre.

Hepatocellular adenoma in a woman who was undergoing testosterone treatment for gender identity disorder

A 32-year-old Japanese woman was admitted to our hospital for the diagnosis and treatment of multiple liver tumors. She had been receiving 125 mg testosterone enanthate every 2 weeks following female-to-male gender identity disorder (GID) diagnosis at 20 years of age. Ultrasonography, computed tomography, and magnetic resonance imaging showed 11 hepatic nodular tumors with a maximum diameter of 28 mm. Liver tumors with hepatocellular adenoma (HCA) were diagnosed with needle biopsy. Segmentectomy of the left lateral lobe including two lesions, subsegmentectomy of S6 including two lesions, enucleation of each tumor in S5 and S7, and open surgical radiofrequency ablation for each tumor in S4 and S7 were performed. Immunohistochemical specimens showed that the tumor cells were diffusely and strongly positive for glutamine synthetase and that the nuclei were ectopically positive for β-catenin. Thus, the tumors were diagnosed as β-catenin-activated HCA (b-HCA). Transcatheter arterial chemoembolization plus subsequent radiofrequency ablation was performed for the 3 residual lesions in S4 and S8. Although testosterone enanthate was being continued for GID, no recurrence was observed until at least 22 months after the intensive treatments. HCA development in such patients receiving testosterone should be closely monitored using image inspection.

Hepatocyte Nuclear Factor 1α-Mutated Hepatocellular Adenomas: An Atypical Presentation

Hepatocellular adenomas (HCAs) are rare benign monoclonal hepatic tumors that commonly occur in females (3-4 per 100,000 women) due to the use of oral contraceptives, its primary risk factor. Recently, HCAs have been classified into 4 distinct subtypes according to genotypic and phenotypic characteristics and clinical features: inflammatory HCA (40-50%), which are hypervascular with marked peliosis and a tendency to bleed; hepatocyte nuclear factor 1α (HNF1A)-mutated HCA (H-HCA, 30-40%) that are diffusely steatotic and rarely undergo malignant transformation; β-catenin activated HCA (10-15%), which frequently undergo malignant transformation and may seem hepatocellular carcinoma on imaging; and unclassified HCA (10-25%). In this study, we report the case of a 23-year-old female oral contraceptive user with H-HCA. Usually, H-HCA is considered to be nonsevere in most cases and often requires outpatient follow-up. However, in this case, the injury had substantially increased in volume and evolved with a major bleeding frame, which was an unusual finding for this subtype of adenoma. The therapeutic used for this patient was a laparoscopic left hepatic segmentectomy. Thus, the choice of treatment to be performed in a patient with H-HCA can depend on the tumor size (>5 cm), the outcome of previous bleeding, and the risk of bleeding recurrence.

Steatohepatitis-like Changes in Focal Nodular Hyperplasia, A Finding to Distinguish From Steatohepatitic Variant of Hepatocellular Carcinoma

Steatohepatitis-like change has not been described in focal nodular hyperplasia (FNH). Steatohepatitis-like change in FNH may show overlapping features with steatohepatitic variant of hepatocellular carcinoma (HCC). This problem can be compounded if seen in FNH with widened cell plates or hepatocyte rosettes, other features that can also be seen in HCC. This study examined steatotic FNHs for the frequency of steatohepatitis-like change, especially in the setting of FNH with rosettes and/or widened cell plates. Thirty-three resection specimens of steatotic FNH from 3 institutions were evaluated for degree of steatosis, background liver steatosis, ductular reaction, and lymphocytic infiltrate, as well as presence of thick fibrous bands, thick-walled vessels, ballooned hepatocytes, Mallory-Denk bodies, dilated sinusoids, hepatocyte rosettes, and thick hepatic plates. Steatosis was distributed along fibrous septa as well as diffusely throughout the FNH. Steatohepatitis-like changes were focally present in 54% (18 cases). Thick plates>3 cells were focally found in 14 cases (42%); rosettes were common (70%). All cases showed at least 2 of the histologic features highly suggestive for the diagnosis of FNH such as thick bands of fibrosis, thick-walled vessels and/or ductular reaction and the typical map-like pattern of glutamine synthetase immunostaining. More than half of fatty FNH examined for this study had features of at least focal steatohepatitis-like changes. This finding should not be confused with steatohepatitic variant of HCC. Common typical features of FNH including thick-walled vessels, ductular reaction and thick fibrous bands are helpful for discrimination of FNH from HCC.

Diagnostic Value of Gadoxetic Acid-Enhanced MR Imaging to Distinguish HCA and Its Subtype from FNH: A Systematic Review

Objective: The purpose of this study was to systematically review the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI) for differentiation of hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH), as well as HCA classification by using the low signal intensity (SI) in the hepatobiliary phase (HBP). Methods: A systematic process was used to review all published data in MEDLINE database about Gd-EOB-DTPA-MRI applied to differentiation of HCA and FNH, and classification of HCA by using low SI in the HBP. The pooled sensitivity and specificity were calculated to assess the diagnostic value of low SI in the HBP. Results: A review of 45 articles identified 10 eligible studies with a total of 288 HCA lesions. The pooled proportion of low SI in the HBP of HCA were 91% (95% CI: 0.81-0.97). In specific, the subtypes of HCA were 75% (95% CI: 0.64-0.85) for I-HCA, 100% (95% CI: 0.95-1.00) for H-HCA, 92% (95% CI: 0.70-1.00) for U-HCA, and 59% (95% CI: 0.00-1.00) for b-HCA, respectively. The pooled specificity and sensitivity of low SI in the HBP for distinguishing FNH from HCA were 95% (95% CI: 0.92-0.98) and 92% (95% CI: 0.87-0.96), respectively. Conclusion: Low SI in the HBP of Gd-EOB-DTPA-MRI is associated with higher accuracy for distinguishing HCA from FNH. However, the diagnostic accuracy may be overvalued, especially for the diagnosis of subtypes of b-HCA and I-HCA. Therefore, the risk factors and conventional imaging findings should be take into account simultaneously.

Diagnostic Value of Gd-EOB-DTPA-MRI for Hepatocellular Adenoma: A Meta-Analysis

Objective: This study aimed to systematically review the gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI) findings of hepatocellular adenoma (HCA), especially focusing on the diagnostic value of low signal intensity (SI) in the hepatocyte-phase (HBP) for differentiating HCA from focal nodular hyperplasia (FNH).

Methods: A thorough literature search was conducted in PubMed, Excerpta Medica Database (EMBASE) and China National Knowledge Infrastructure databases (CNKI) to identify studies evaluating Gd-EOB-DTPA-MRI presentations of HCA. Published studies using pathological examinations as the gold standard were included. The pooled proportions of low SI in the HBP, arterial-phase, portal venous-phase (PVP) in HCA were calculated, as well as pooled proportions of bleeding, fatty degeneration, and central scar. Meta-analysis was used to evaluate the diagnostic value of low SI in the HBP for HCA.

Results: The search yielded 90 studies, with 8 assessing a total of 256 HCA cases included in this study, total of 229 lesions showed low signal in the HBP. Pooled proportions of low SI in the arterial-phase, PVP, and HBP were 2% (95% CI: 0.01-0.05), 39% (95% CI: 0.25-0.55), and 89% (95% CI: 0.80-0.94), respectively. Pooled proportions of bleeding, fatty degeneration, and central scar in HCA were 11% (95% CI: 0.03-0.19), 37% (95% CI: 0.27-0.49), and 10% (95% CI: 0.03-0.27), respectively. The meta-analysis revealed the following characteristics of low SI in the HBP for HCA diagnosis: 1) pooled sensitivity, 0.917 (95% CI: 0.86-0.96); 2) pooled specificity, 0.952 (95% CI: 0.91-0.98); 3) pooled positive likelihood ratio, 15.028 (95% CI: 7.10-31.82); 4) pooled negative likelihood ratio, 0.105 (95% CI: 0.07-0.17); 5) area under the ROC, 0.9802 (Q value of 0.9375), The sensitivity analysis showed that no single study was found to influence the overall pooled estimates significantly, which indicated the stability of the meta-analysis results were good.

Conclusions: Low SI on the HBP of Gd-EOB-DTPA-MRI was helpful for the diagnosis of HCA and differentiating from FNH, but it was overvalued, especially for some HCA pathological subtypes. Combining low SI in the HBP with routine MRI presentations and the risk factors of liver diseases could substantially improve its diagnosis value for HCA as well as differential diagnosis.

Typical and atypical benign liver lesions: A review

Focal liver lesions are routinely encountered by clinical radiologists and represent a wide spectrum of pathology. Majority of these lesions are likely to be benign in nature, especially in the absence of chronic liver disease or primary cancer. A radiologist must be aware of common and uncommon imaging features of benign lesions across the various imaging modalities. This review discusses pathognomonic imaging features of common benign focal liver lesions seen on ultrasound, computed tomography and magnetic resonance, and adds to existing knowledge with the recent updates to have emerged in this area.

Gender differences in liver disease and the drug-dose gender gap

Although gender-based medicine is a relatively recent concept, it is now emerging as an important field of research, supported by the finding that many diseases manifest differently in men and women and therefore, might require a different treatment. Sex-related differences regarding the epidemiology, progression and treatment strategies of certain liver diseases have long been known, but most of the epidemiological and clinical trials still report results only about one sex, with consequent different rate of response and adverse reactions to treatment between men and women in clinical practice. This review reports the data found in the literature concerning the gender-related differences for the most representative hepatic diseases.

Systematic review: benefits and harms of transarterial embolisation for treating hepatocellular adenoma

BACKGROUND

Transarterial embolisation (TAE) is a standard treatment for bleeding hepatocellular adenoma (HCA) and, occasionally, symptomatic HCA involving large tumours. Whether TAE is similarly safe and effective as an elective treatment for bleeding and nonbleeding HCA remains unclear.

AIM

To investigate the benefits and harms of TAE for bleeding and nonbleeding HCA.

METHODS

PubMed, Scopus, Embase and Cochrane Library databases were systematically searched for studies that examined post-TAE tumour reduction in patients with bleeding or nonbleeding HCA and that were published between January 2000 and January 2017.

RESULTS

Systematic review of 21 case series involving 1468 patients with HCA in the systematic review identified 140 (9.5%) patients with 189 lesions who received TAE. Of these 140 patients, 66.4% had bleeding HCA and 33.6% had nonbleeding HCA. Intended elective TAE was performed in 27.1% of patients (38.6% of HCA lesions). Adenomatosis was observed in 6.1% of patients, and the rate of β-catenin expression was 4.5%. No malignant transformation was observed among the 189 tumours during a median follow-up time of 40 months. The complete response rate among 70 patients was 10.6%, and the partial response rate was 71.7%. No mortality or severe adverse side effects were reported during the hospitalisation period.

CONCLUSIONS

The available evidence suggests that TAE can be considered safe for elective managment of HCA as well as for management of bleeding HCA. Elective TAE can be regarded as a reasonable alternative to surgery. High-quality prospective studies with long-term follow-up are needed to corroborate and strengthen available evidence.

Benign Hepatocellular Nodules: Hepatobiliary Phase of Gadoxetic Acid-enhanced MR Imaging Based on Molecular Background

Gadoxetic acid is a contrast agent for magnetic resonance (MR) imaging with hepatocyte-specific properties and is becoming increasingly important in detection and characterization of hepatocellular carcinoma and benign hepatocellular nodules, including focal nodular hyperplasia (FNH), nodular regenerative hyperplasia (NRH), hepatocellular adenoma (HCA), and dysplastic nodule. In these hepatocellular nodules, a positive correlation between the grade of membranous uptake transporter organic anion-transporting polypeptide (OATP) 1B3 expression and signal intensity in the hepatobiliary (HB) phase has been verified. In addition, it has been clarified that OATP1B3 expression is regulated by activation of β-catenin and/or hepatocyte nuclear factor 4α. On the other hand, recent studies have also revealed some of the background molecular mechanisms of benign hepatocellular nodules. FNH commonly shows iso- or hyperintensity in the HB phase with equal or stronger OATP1B3 expression, with map-like distribution of glutamine synthetase (a target of Wnt/β-catenin signaling) and OATP1B3 expression. NRH shows doughnut-like enhancement with hypointensity in the central portion in the HB phase with OATP1B3 expression. The majority of HCAs show hypointensity in the HB phase, but β-catenin-activated HCA exclusively demonstrates iso- or hyperintensity with increased expression of nuclear β-catenin, glutamine synthetase, and OATP1B3. Dysplastic nodule commonly shows iso- or hyperintensity in the HB phase with similar to increased OATP1B3 expression, but one-third of high-grade dysplastic nodules can be demonstrated as a hypointense nodule with decreased OATP1B3 expression. Knowledge of these background molecular mechanisms of gadoxetic acid-enhanced MR imaging is important not only for precise imaging diagnosis but also understanding of the pathogenesis of benign hepatocellular nodules. ^©RSNA, 2016.

Malignant transformation of hepatocellular adenoma with bone marrow metaplasia arising in glycogen storage disease type I: A case report

Malignant transformation of hepatocellular adenoma (HA) is relatively rare and has been reported to be associated with dysregulation of the β-catenin pathway. The presence of bone marrow metaplasia in HA is an uncommon histological characteristic. The current report presents the case of a 46-year-old woman with glycogen storage disease type I (von Gierke's disease) who underwent resection of hepatocellular carcinoma (HCC) arising in a HA with associated bone marrow metaplasia producing three series of hematopoietic cells. The serum level of proteins induced by des-gamma-carboxy prothrombin (DCP) gradually increased as the tumors grew; following hepatic resection, DCP levels returned to normal. Nuclear accumulation of β-catenin was shown in HCC by immunohistochemistry; however, no mutation was detected in exon 3 of β-catenin. To the best of our knowledge, this is the first report of HA with absolute bone marrow metaplasia producing three series of hematopoietic cells. This occurrence suggests that elevated DCP may be an indicator of malignant transformation of HA.

Focal nodular hyperplasia: our experience of 53 Japanese cases

PURPOSE

Contrast-enhanced ultrasound (CEUS) is a very sensitive diagnostic tool in characterizing liver tumors. It is especially useful in the diagnosis of focal nodular hyperplasia (FNH) of the liver. According to the previous reports, FNH is common in young women, and it is usually diagnosed by MRI. The majority of the previous reports come from European countries, and a very few studies of large series designed to describe the clinical features in Japanese patients have been reported. The aim of this study was to (a) describe the clinical features in 53 patients (59 lesions) diagnosed with CEUS and (b) compare the data with those from the previous reports.

METHODS

The medical data from 53 patients diagnosed on the basis of typical CEUS findings at our institution and affiliated hospitals were reviewed, and their clinical data were analyzed.

RESULTS

(1) The medical data from 53 cases showed a slight male predilection, with 30 male cases (57 %) and 23 female cases (43 %), although the occurrence in both sexes was equal. FNH cases were distributed throughout all generations in both sexes, mostly concentrated in the age of 30-60 years old, and metabolic cases were more common in men than in women (4 vs 0). (2) The lesions were small (mean: 23 mm) and distributed throughout the whole liver. (3) Lesion size was not influenced by age in either sex. (4) A rapid draining to the hepatic vein was recognized in five out of 59 lesions (8 %).

CONCLUSIONS

Our data indicate that FNH occurs slightly more frequently in men than in women in Japan. It occurs also at any age in both sexes, but the mean lesion size was smaller in our series than in the previous reports. Metabolic disease was seen only in male FNH patients. A direct communication between the FNH lesion and the hepatic vein is diagnostically worth noting.

Evaluation of the characteristics of hepatic focal nodular hyperplasia: correlation between dynamic contrast-enhanced multislice computed tomography and pathological findings

Objective

To evaluate the characteristics of enhancement of focal nodular hyperplasia (FNH) of the liver by analyzing the dynamic contrast-enhanced multislice computed tomography (MSCT) features and correlating them with pathological findings.

Patients and methods

Nine males and 16 females with pathologically confirmed FNH and complete preoperative contrast-enhanced MSCT data were recruited for this study. The imaging features of FNH on the pre- and postcontrast MSCT were analyzed by two experienced radiologists by consensus.

Results

Pathology showed central scars and abnormal blood vessels in 17 and 21 of 25 lesions, respectively, while MSCT with multiphase enhancement showed central scars in eight of the 17 lesions (47.1%) and abnormal arteries or draining veins in 13 of the 21 lesions (61.9%). Furthermore, abnormal draining veins in five lesions were found to be diagnostic, which is another important finding.

Conclusion

Multiphase scanning can provide the panorama of FNH lesions and reveal their enhancement patterns and pathological characteristics. Abnormal blood vessels within or around the lesion are demonstrated more often than central scar, and both should be observed for FNH diagnosis.

Hepatocellular Neoplasms Arising in Association With Androgen Use

Correlation between androgen use and hepatocellular neoplasia is well established. However, there are no detailed studies of the histopathology and immunohistochemical/molecular profile of these tumors. We studied 9 patients with androgen-associated hepatocellular neoplasms. In addition to histology, immunostains for liver fatty acid-binding protein, β-catenin, glutamine synthetase, C-reactive protein, and serum amyloid A were utilized for tumor subtyping. Molecular testing using Solid Tumor Targeted Cancer Panel was performed on 3 cases. The neoplasms were predominantly seen in male individuals (7/9). Two patients (22%) had multifocal lesions. All lesions had architectural and 4/9 had cytologic atypia. Cholestasis was present in 6/9 cases. Reticulin was focally disrupted in 5/9 cases. Given the clinical setting, all lesions were classified as well-differentiated hepatocellular neoplasms of uncertain malignant potential. In cases with follow-up (6/9 cases, 67%), there were no recurrences or metastases. On the basis of the immunoprofile, 7 (78%) cases were β-catenin activated (including 1 hepatic adenoma with concurrent hepatocyte nuclear factor 1α inactivation) and 2 (22%) had inflammatory phenotype. Somatic mutations in CTNNB1 were detected in all 3 tested cases (all β-catenin activated by immunostain), all involving exon-3. Our data indicate that androgen-associated hepatocellular neoplasms most often develop in male individuals and always show some degree of atypia and/or focal reticulin disruption. Most are β-catenin activated, often harboring CTNNB1 exon-3 mutations, and a minority is inflammatory type. Although β-catenin and inflammatory pathways likely play a role in pathogenesis, the heterogenous molecular profile suggests there are other (yet to be characterized) primary oncogenic mechanisms in this unique tumor type.