Benign hepatocellular nodules of healthy liver: focal nodular hyperplasia and hepatocellular adenoma

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.

Desmoplastic small round cell tumor of the liver: diagnosing a rare case on liver biopsy

Desmoplastic small round-cell tumors (DSRCT) frequently develop in the retroperitoneum, pelvis, omentum, and mesentery. Here, we present an unusual case of primary DSRCT in the liver. The patient was an 11-year-old boy with multiple solid masses in the liver parenchyma. The tumor in the needle biopsy had a histology revealing a small round cell morphology and desmoplasia. It shows the immunohistochemical features of DSRCT and documentation of EWSR1-WT1 fusion.A potential diagnostic pitfall is exerted when evaluating liver biopsy, in which DSRCT is a great mimicker and may be easily confused with more common liver malignancies of childhood, such as hepatoblastoma, calcifying nested stromal-epithelial tumor, undifferentiated embryonal sarcoma, and other small round cell tumors, as well as the fibrolamellar variant of hepatocellular carcinoma. This distinction is critical because an accurate therapeutic approach requires a correct diagnosis.

Hepatocellular Neoplasm of Uncertain Potential of Malignancy or Well-Differentiated Hepatocellular Carcinoma Arising within Hepatocellular Adenoma

Background. Hepatocellular adenoma (HCA) is an uncommon solid, solitary, benign liver lesion that develops in an otherwise normal-appearing liver. Hemorrhage and malignant transformation are the most important complications. Risk factors for malignant transformation include advanced age, male gender, use of anabolic steroids, metabolic syndrome, larger lesions, and beta-catenin activation subtype. The identification of higher risk adenomas enables the selection of patients most suitable for aggressive treatment and those who benefit with surveillance, minimizing the risks for these predominantly young patients. Case Presentation. We present the case of a 29-year-old woman with a history of oral contraceptive intake for 13 years, which was sent to evaluation in our Hepato-Bilio-Pancreatic and Splenic Unit because of a large nodular lesion in segment 5 of the liver, compatible with HCA, and was proposed to surgical resection. Histological and immunohistochemical investigation revealed an area with atypical characteristics, suggesting malignant transformation. Conclusions. HCAs share similar imaging characteristics and histopathological features with hepatocellular carcinomas; therefore, immunohistochemical and genetic studies assumes great importance to discriminate adenomas with malignant transformation. Beta-catenin, glutamine synthetase, glypican-3, and heat-shock protein 70 are promising markers to identify higher risk adenomas.

Variation in the management of benign liver tumors: A European survey and case vignette study

BACKGROUND

Management of focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA), is multidisciplinary and subject to practice variation. We aimed to evaluate variation in clinical management of FNH and HCA in Europe.

METHODS

We distributed an online survey (November 2021-March 2022) among 294 European experts. The survey included questions on local practice and included eight clinical vignettes. The clinical vignettes focused on FNH or HCA management in the setting of sex, lifestyle modification, and pregnancy.

RESULTS

The response rate was 32% and respondents included surgeons (38%), gastroenterologists/hepatologists (25%), radiologists (32%), and pathologists (1.6%) from ten European countries. We observed practice variation with regard to lifestyle modification and imaging follow-up in patients with FNH, and with regard to the management of HCA >5 cm before and during pregnancy. Finally, the management of HCA >5 cm after lifestyle modification deviated from EASL guideline recommendations.

CONCLUSION

Our survey illustrates variability in FNH and HCA management in Europe. Several areas were identified for future research and guideline recommendations, including FNH follow-up and the management of HCA >5 cm. We propose the organization of Delphi consensus meetings to prioritize areas of research and update current guidelines to optimize management for all patients with benign liver tumors.

Liver abnormalities in Turner’s syndrome – the importance of estrogen replacement

Turner syndrome is one of the most frequently reported sex chromosomal abnormalities, affecting approximately 40 in every 100 000 live female births. The underlying chromosomal alteration is the complete or partial loss of X chromosome or mosaicism. Because of primary ovarian insufficiency, the synthesis of estrogen hormones is compromised, and patients require hormone substitution. Apart from the phenotypical presentation (short stature, primary amenorrhea), the effects of ovarian insufficiency can affect diverse organ systems (such as cardiovascular, endocrine, and lymphatic systems). Hepatobiliary pathology can present on a broad spectrum: from mild asymptomatic hypertransaminasemia to marked architectural changes. Estrogen hormone replacement therapy in these patients can improve the perturbations of laboratory values and can attenuate the progression of hepatic structural changes. Moreover, providing sufficient estrogen replacement has numerous benefits for other conditions of the patients as well. Both the all-cause mortality and deaths from cardiovascular complications are greatly increased in Turner syndrome, and hormone replacement might contribute to the decreased incidence of these events. The diagnostics of Turner syndrome are outside the scope of our paper, and we briefly discuss the cardiovascular complications because many the liver involvement partially involves alterations of vascular origin. Though we sought to highlight the importance of proper hormone replacement therapy, we did not attempt to write a comprehensive recommendation for exact treatment protocols. We provided an overview of preferred therapeutic approaches, as the treatment should be tailored according to the individual patient’s needs.

Preneoplastic lesions in the liver: Molecular insights and relevance for clinical practice

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the most frequent primary liver cancers, accounting for approximately 80% and 15%, respectively. HCC carcinogenesis occurs mostly in cirrhosis and is a complex multi-step process, from precancerous lesions (low-grade and high-grade dysplastic nodules) to progressed HCC. During the different stages of liver carcinogenesis, there is an accumulation of pathological, genetic and epigenetic changes leading to initiation, malignant transformation and finally tumour progression. In contrast, a small subset of HCC occurs in normal liver from the transformation of hepatocellular adenoma (HCA), a benign hepatocellular tumour. The recent molecular classification enables to stratify HCAs according to their risk of complication, in particular malignant transformation, associated with mutations in exon 3 of the catenin beta 1 (CTNNB1) gene. Cholangiocarcinoma (CCA) derives from the multistep malignant transformation of preneoplastic lesions, like biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB), for which a pre-operative diagnosis remains difficult. Different genetic alterations are involved in BilIN and IPNB progression, leading to the development of tubular or intestinal adenocarcinoma. The aims of this review are to describe the main clinical and molecular features of preneoplastic lesions leading to the development of HCC and CCA, their implications in clinical practice and the perspectives for future research.

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.

Comparison of the Value of Color Doppler Ultrasound and Multislice Spiral CT in the Differential Diagnosis of Benign and Malignant Nodules in the Liver

Objective

This study aimed to explore the value of color Doppler ultrasound and multislice spiral CT (MSCT) in the differential diagnosis of benign and malignant nodules in the liver.

Methods

The clinical imaging data of 102 patients with nodular hepatocellular carcinoma (hepatocellular carcinoma group) and 50 patients with focal nodular hyperplasia (FNH) of the liver (FNH group) admitted to our hospital were collected, and their color Doppler ultrasound and MSCT imaging features were retrospectively analyzed to explore the value of their clinical application in the differential diagnosis of benign and malignant nodules in the liver.

Results

The sensitivity, accuracy, and negative predictive value of MSCT in the diagnosis of nodular liver cancer were 94.12%, 92.76%, and 88.24%, respectively, which were significantly higher than those of color Doppler ultrasound 79.41%, 84.21%, and 69.12%, and the difference was statistically significant (P < 0.05).

Conclusion

In conclusion, the value of MSCT in the differential diagnosis of benign and malignant liver nodules was significantly better than color Doppler ultrasound.

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.

Diagnosis and surgical treatment of a rare hepatic angiomyolipoma with internal hemorrhage

Although angiomyolipoma (AML) is commonly found in the kidney, its appearance in the liver is rare. The first hepatic AML was reported by Ishak in 1976. Since then, there have been various reports of AML. An AML is a tumour affecting adipocytes, muscle tissues, and blood vessels. Hepatic AML has been associated with tuberous sclerosis. Its spontaneous occurrence has also been noticed. It can have a varied presentation with some being asymptomatic, others presenting with a dull aching pain, while some with disastrous consequences due to rupture and torrential bleeding intra-abdominally. Herein, we present a case of a 47-year-old female with a large hepatic AML having an internal hemorrhage that caused changes in hepatic arteries. In our case, magnetic resonance imaging was unable to establish a diagnosis. Intraoperatively, AML caused dilatation and engorgement of vessels around the porta. Immediately post resection, vessel dilatation and engorgement were reduced on table. Another notable feature was that these changes caused no intra-operative or post-operative hemodynamic changes. We report a case of a huge hepatic AML with internal hemorrhage associated with perihepatic vascular changes having a successful surgical treatment.

Alpha‐fetoprotein and focal nodular hyperplasia: An unconventional couple

We report the case of a 36‐year‐old patient who was initially managed for gynecomastia. The first biological analyses showed a moderately elevated alpha‐fetoprotein (AFP) level. After an endocrine etiology was excluded, an abdominal computed tomography scan showed typical focal nodular hyperplasia (FNH) proven by biopsy and showing expression of AFP in FNH cells. After follow‐up for 24 months, the serum AFP and liver radiology remained unchanged. The association between an elevated AFP and FNH is rarely described in the medical literature.

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.

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.

CT-Based Radiomics Nomogram: A Potential Tool for Differentiating Hepatocellular Adenoma From Hepatocellular Carcinoma in the Noncirrhotic Liver

RATIONALE AND OBJECTIVES

To evaluate the value of a radiomics nomogram for preoperative differentiating hepatocellular adenoma (HCA) from hepatocellular carcinoma (HCC) in the noncirrhotic liver.

MATERIALS AND METHODS

One hundred and thirty-one patients with HCA (n = 46) and HCC (n = 85) were divided into a training set (n = 93) and a test set (n = 38). Clinical data and CT findings were analyzed. Radiomics features were extracted from the triphasic contrast CT images. A radiomics signature was constructed with the least absolute shrinkage and selection operator algorithm and a radiomics score was calculated. Combined with the radiomics score and independent clinical factors, a radiomics nomogram was developed by multivariate logistic regression analysis. The performance of the radiomics nomogram was assessed by calibration, discrimination and clinical usefulness.

RESULTS

Gender, age, and enhancement pattern were the independent clinical factors. Three thousand seven hundred and sixty-eight features were extracted and reduced to 7 features as the optimal discriminators to build the radiomics signature. The radiomics nomogram (area under the curve [AUC], 0.96; 95% confidence interval [CI], 0.93-0.99) and the clinical factors model (AUC, 0.93; 95%CI, 0.88-0.99) showed better discrimination capability (p = 0.001 and 0.047) than the radiomics signature (AUC, 0.83; 95%CI, 0.74-0.92) in the training set. In the test set, the radiomics nomogram (AUC, 0.94; 95%CI, 0.87-1.00) performed better (p = 0.013) than the radiomics signature (AUC, 0.75; 95%CI, 0.59-0.91). Decision curve analysis showed the radiomics nomogram outperformed the clinical factors model and the radiomics signature in terms of clinical usefulness.

CONCLUSION

The CT-based radiomics nomogram has the potential to accurately differentiate HCA from HCC in the noncirrhotic liver.

Hepatocellular adenomas: recent updates

Hepatocellular adenoma (HCA) is a heterogeneous entity, from both the histomorphological and molecular aspects, and the resultant subclassification has brought a strong translational impact for both pathologists and clinicians. In this review, we provide an overview of the recent updates on HCA from the pathologists’ perspective and discuss several practical issues and pitfalls that may be useful for diagnostic practice.

Appearance of Focal Nodular Hyperplasia after Chemotherapy in Two Patients during Follow-Up of Colon Carcinoma

Surgical liver resection is a treatment option in patients with resectable colorectal liver metastases. We present two cases of focal nodular hyperplasia (FNH) development after treatment with oxaliplatin during follow-up of colon carcinoma. The first case was a 40-year-old male patient who developed multiple liver lesions suspect for metastatic disease four years after he had undergone laparoscopic right-sided hemicolectomy and adjuvant chemotherapy (capecitabine and oxaliplatin). He underwent a metastasectomy of segments three and four and microwave ablation (MWA) of the lesion in segment one. Pathological analysis demonstrated FNH. The second patient was a 21-year-old woman who presented with multiple liver lesions during follow-up for colon carcinoma. She underwent a laparoscopic right-sided hemicolectomy and was adjuvantly treated with capecitabine and oxaliplatin three years ago. Magnetic resonance imaging (MRI) was performed, and the lesions showed no signs of metastatic disease but were classified as FNH. Therefore, the decision was made to follow up the patient. In conclusion, the development of benign liver lesions could occur during follow-up of colon carcinoma and might be caused by oxaliplatin-induced changes to the liver parenchyma. Hence, it is important to distinguish these from metastatic liver disease.

Is This Patient's Liver Mass Cancer?

Undiagnosed liver lesions are important findings that can affect the physical and mental well-being of patients. They are usually incidental findings identified while clinicians are performing other imaging tests. It is important for clinicians and patients to identify the causative factors for these lesions in order to further reduce risk, develop treatment plans, and produce better outcomes. Both men and women can develop liver lesions, which may require surgical intervention. Knowing the key risk factors for common lesions can help clinicians confidently diagnose patients without costly workup.

Panel of potential lncRNA biomarkers can distinguish various types of liver malignant and benign tumors

PURPOSE

Liver cancers are among the deadliest malignancies due to a limited efficacy of early diagnostics, the lack of appropriate biomarkers and insufficient discrimination of different types of tumors by classic and molecular methods. In this study, we searched for novel long non-coding RNA (lncRNA) as well as validated several known candidates suitable as probable biomarkers for primary liver tumors of various etiology.

METHODS

We described a novel lncRNA HELIS (aka "HEalthy LIver Specific") and estimated its expression by RT-qPCR in 82 paired tissue samples from patients with hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), combined HCC-CCA, pediatric hepatoblastoma (HBL) and non-malignant hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH). Additionally, we examined expression of cancer-associated lncRNAs HULC, MALAT1, UCA1, CYTOR, LINC01093 and H19, which were previously studied mainly in HCC.

RESULTS

We demonstrated that down-regulation of HELIS strongly correlates with carcinogenesis; whereas in tumors with non-hepatocyte origin (HBL, CCA) or in a number of poorly differentiated HCC, this lncRNA is not expressed. We showed that recently discovered LINC01093 is dramatically down-regulated in all malignant liver cancers; while in benign tumors LINC01093 expression is just twice decreased in comparison to adjacent samples.

CONCLUSION

Our study revealed that among all measured biomarkers only down-regulated HELIS and LINC01093, up-regulated CYTOR and dysregulated HULC are perspective for differential diagnostics of liver cancers; whereas others demonstrated discordant results and cannot be considered as potential universal biomarkers for this purpose.

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.

Patterns of enhancement in the hepatobiliary phase of gadoxetic acid-enhanced MRI

A variety of patterns of enhancement of liver lesions and liver parenchyma is observed in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI. It is becoming increasingly apparent that many lesions may exhibit HBP enhancement. Much of the literature regarding the role of gadoxetic acid-enhanced MRI in characterising liver lesions is dichotomous, focusing on whether lesions are enhancing or non-enhancing in the HBP, rather than examining the patterns of enhancement. We provide a pattern-based description of HBP enhancement of liver parenchyma and of liver lesions. The role of OATP1B3 transporters, hepatocyte function and lesion composition in influencing patterns of HBP hyperintensity are discussed.

Hepatic tumors: pitfall in diagnostic imaging

On computed tomography (CT) and magnetic resonance imaging (MRI), hepatocellular tumors are characterized based on typical imaging findings. However, hepatocellular adenoma, focal nodular hyperplasia, and hepatocellular carcinoma can show uncommon appearances at CT and MRI, which may lead to diagnostic challenges. When assessing focal hepatic lesions, radiologists need to be aware of these atypical imaging findings to avoid misdiagnoses that can alter the management plan. The purpose of this review is to illustrate a variety of pitfalls and atypical features of hepatocellular tumors that can lead to misinterpretations providing specific clues to the correct diagnoses. (www.actabiomedica.it)

Hepatobiliary MR contrast agents are useful to diagnose hepatocellular carcinoma in patients with Budd-Chiari syndrome

BACKGROUND & AIMS

Hepatobiliary phase (HBP) images can discriminate between benign and malignant liver lesions, but it is unclear if this approach can be used in patients with Budd-Chiari syndrome (BCS). Thus, we aimed to assess the diagnostic utility of HBP images in patients with BCS.

METHODS

This retrospective study included all patients admitted to our institution with a diagnosis of BCS and focal liver lesions on hepatobiliary contrast agent-enhanced MR imaging (HBCA-MRI) from 2000 to 2019. MR images were reviewed by 2 radiologists blinded to the diagnosis of the lesions. Patient and lesion characteristics were recorded, focusing on HBP imaging features.

RESULTS

Twenty-six patients (mean 35 ± 11 years old [13-65]; 21 women [81%] 35 ± 12 years old [13-65]; 5 men [19%] 36 ± 10 years old [19-44]) with 99 benign liver lesions and 12 hepatocellular carcinomas (HCCs) were analyzed. Patients with HCC were significantly older than those with benign lesions (mean 50 ± 10 vs. 33 ± 9 years old, p = 0.003), with higher alpha-fetoprotein (AFP) levels (3/4 [75%] vs. 1/22 [5%] with AFP >15 ng/ml, p <0.001). Homogeneous hypointense signals were identified on HBP in 14 lesions, including 12/12 (100%) HCCs, and 2/99 (2%) benign lesions (p <0.001). Most benign liver lesions showed either peripheral (n = 52/99 [53%]) or homogeneous hyperintensity (n = 23/99 [23%]) on HBP. Lesions with signal hypointensity on HBP in patients with AFP serum levels >15 ng/ml were all HCCs.

CONCLUSION

Most benign lesions showed homogeneous or peripheral hyperintensity on HBP images while all HCCs were homogeneously hypointense. HBP images are helpful to differentiate between benign lesions and HCCs and outperform other sequences. They should be systematically acquired for the characterization of focal lesions in patients with BCS.

LAY SUMMARY

Hepatobiliary phase imaging is an approach that has recently been shown to discriminate between benign and malignant lesions in the liver. However, it was not known whether this imaging approach could be used effectively in patients with Budd-Chiari syndrome. Herein, we have shown that hepatobiliary phase imaging appears to be useful for differentiating between benign and malignant liver lesions in patients with Budd-Chiari syndrome.

Multi-parameter ultrasound based on the logistic regression model in the differential diagnosis of hepatocellular adenoma and focal nodular hyperplasia

BACKGROUND

Focal nodular hyperplasia (FNH) has very low potential risk, and a tendency to spontaneously resolve. Hepatocellular adenoma (HCA) has a certain malignant tendency, and its prognosis is significantly different from FNH. Accurate identification of HCA and FNH is critical for clinical treatment.

AIM

To analyze the value of multi-parameter ultrasound index based on logistic regression for the differential diagnosis of HCA and FNH.

METHODS

Thirty-one patients with HCA were included in the HCA group. Fifty patients with FNH were included in the FNH group. The clinical data were collected and recorded in the two groups. Conventional ultrasound, shear wave elastography, and contrast-enhanced ultrasound were performed, and the lesion location, lesion echo, Young’s modulus (YM) value, YM ratio, and changes of time intense curve (TIC) were recorded. Multivariate logistic regression analysis was used to screen the indicators that can be used for the differential diagnosis of HCA and FNH. A ROC curve was established for the potential indicators to analyze the accuracy of the differential diagnosis of HCA and FNH. The value of the combined indicators for distinguishing HCA and FNH were explored.

RESULTS

Multivariate logistic regression analysis showed that lesion echo (P = 0.000), YM value (P = 0.000) and TIC decreasing slope (P = 0.000) were the potential indicators identifying HCA and FNH. In the ROC curve analysis, the accuracy of the YM value distinguishing HCA and FNH was the highest (AUC = 0.891), which was significantly higher than the AUC of the lesion echo and the TIC decreasing slope (P < 0.05). The accuracy of the combined diagnosis was the highest (AUC = 0.938), which was significantly higher than the AUC of the indicators diagnosing HCA individually (P < 0.05). This sensitivity was 91.23%, and the specificity was 83.33%.

CONCLUSION

The combination of lesion echo, YM value and TIC decreasing slope can accurately differentiate between HCA and FNH.

Down-regulation of cell membrane localized NTCP expression in proliferating hepatocytes prevents hepatitis B virus infection

Hepatocyte proliferation could result in the loss of covalently closed circular DNA (cccDNA) and the emergence of cccDNA-cleared nascent hepatocytes, which appear refractory to hepatitis B virus (HBV) reinfection with unknown mechanism(s). Sodium taurocholate cotransporting polypeptide (NTCP) is the functional receptor for HBV entry. In this study, down-regulation of cell membrane localized NTCP expression in proliferating hepatocytes was found to prevent HBV infection in HepG2-NTCP-tet cells and in liver-humanized mice. In patients, lower NTCP protein expression was correlated well with higher levels of hepatocyte proliferation and less HBsAg expression in HBV-related focal nodular hyperplasia (FNH) tissues. Clinically, significantly lower NTCP protein expression was correlated with more active hepatocyte proliferation in CHB patients with severe active necroinflammation and better antiviral treatment outcome. Mechanistically, the activation of cell cycle regulatory genes p53, S-phase kinase-associated protein 2 (SKP2) and cyclin D1 during cell proliferation, as well as proliferative and inflammatory cytokine Interleukin-6 (IL-6) could transcriptionally down-regulate NTCP expression. From these aspects, we conclude that within the milieu of hepatocyte proliferation, down-regulation of cell membrane localized NTCP expression level renders nascent hepatocytes resistant to HBV reinfection. This may accelerate virus clearance during immune-mediated cell death and compensatory proliferation of survival hepatocytes.

Challenging liver lesions in noncirrhotic patients: Report of three cases

We describe three cases of liver lesions, characterized by a discrepancy between presurgical imaging and histological features, in which the final histological diagnosis was quite different from what the surgeons expected. We present (1) a case of primary liver angiomyolipoma associated with focal nodular hyperplasia, (2) a case of perivascular epithelioid cell tumor, and (3) a case of liver splenosis associated with focal nodular hyperplasia. In all cases, a presurgical diagnosis of hepatocellular adenoma was made. Due to nonspecific clinical and radiological features, these rare liver lesions are often presurgically misdiagnosed, especially in young noncirrhotic patients. The association among different lesions represents one additional diagnostic challenge.

OATPB1/B3 and MRP3 expression in hepatocellular adenoma predicts Gd-EOB-DTPA uptake and correlates with risk of malignancy

BACKGROUND AND AIMS

Hepatobiliary phase (HBP) Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) has increased the accuracy in differentiating focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA). However, the ability of this technique to distinguish HCA subtypes remains controversial. The aim of this study was to investigate the expression of hepatocyte transporters (OATPB1/B3, MRP2, MRP3) in HCA subtypes, hence to understand their MRI signal intensity on HBP Gd-EOB-DTPA-enhanced MRI.

METHODS

By means of immunohistochemistry (IHC), we scored the expression of OATPB1/B3, MRP2 and MRP3, in resected specimens of FNH (n = 40), subtyped HCA (n = 58) and HCA with focal malignant transformation (HCA-HCC, n = 4). Results were validated on a supplementary set of FNH (n = 6), subtyped HCA (n = 17) and HCA-HCC (n = 1) with Gd-EOB-DTPA MR images.

RESULTS

All FNH showed a preserved expression of hepatocytes transporters. Beta-catenin-activated HCA (at highest risk of malignant transformation) and HCA-HCC were characterized by preserved/increased OATPB1/B3 expression (predictor of hyperintensity on HBP), as opposed to other HCA subtypes (P < 0.01) that mostly showed OATPB1/B3 absence (predictor of hypointensity on HBP). HCA-HCC showed an additional MRP3 overexpressed profile (P < 0.01). On HBP Gd-EOB-DTPA-enhanced MRI, FNH and HCA signal intensity reflected the profile predicted by their specific OATPB1/B3 tissue expression. The hyperintense vs hypointense HBP signal criterion was able to distinguish all higher risk HCA and HCA-HCC (100% accuracy).

CONCLUSIONS

OATPB1/B3 and MRP3 IHC and signal intensity on HBP Gd-EOB-DTPA-enhanced MRI can help to stratify HCA according to their risk of malignant transformation.

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.

MicroRNA Expression in Focal Nodular Hyperplasia in Comparison with Cirrhosis and Hepatocellular Carcinoma

The liver disease focal nodular hyperplasia (FNH) has several histological features that resemble hepatic cirrhosis. Since cirrhosis may develop further into hepatocellular carcinoma (HCC) contrary to FNH, the aim of the present study was to identify microRNAs (miRNA), which, by their altered expression levels, may be associated with the benign, tumor-like nature of FNH. Altogether 106 surgically removed formalin-fixed paraffin-embedded liver samples were selected, including 22 FNH, 45 cirrhosis, 24 HCC and 15 normal liver tissues. Etiology of the cases of cirrhosis and HCC includes hepatitis C and alcoholism and the HCC cases developed in cirrhotic livers. Relative expression levels of 14 miRNAs were determined using TaqMan MicroRNA Assays. In comparison to normal liver, the levels of miR-34a and miR-224 were elevated not only in FNH but also in cirrhosis and HCC, while the expression of miR-17-5p, miR-18a and miR-210 was decreased in FNH. Further, the levels of miR-21 and miR-222 were increased in cirrhosis and HCC but were decreased in FNH and the expression of miR-17-5p, miR-18a, miR-195 and miR-210 was decreased in FNH as compared with cirrhosis and/or HCC. In conclusion, the elevation of miR-34a and miR-224 may be associated with both benign and malignant proliferative processes, nevertheless the increased expression of oncomiRs miR-21 and miR-222 in cirrhosis and HCC but not in FNH may be related to malignant processes of the liver. The decreased levels of miR-18a, miR-195 and miR-210 may further differentiate FNH from cirrhosis, reflecting the different pathogenesis of these two entities contrary to some histologically similar features.

Changing role of histopathology in the diagnosis and management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and fatal cancer in the world. HCC frequently presents with advanced disease, has a high recurrence rate and limited treatment options, which leads to very poor prognosis. This warrants urgent improvement in the diagnosis and treatment. Liver biopsy plays very important role in the diagnosis and prognosis of HCC, but with technical advancements and progression in the field of imaging, clinical guidelines have restricted the role of biopsy to very limited situations. Biopsy also has its own problems of needle tract seeding of tumor, small risk of complications, technical and sampling errors along with interpretative errors. Despite this, tissue analysis is often required because imaging is not always specific, limited expertise and lack of advanced imaging in many centers and limitations of imaging in the diagnosis of small, mixed and other variant forms of HCC. In addition, biopsy confirmation is often required for clinical trials of new drugs and targeted therapies. Tissue biomarkers along with certain morphological features, phenotypes and immune-phenotypes that serve as important prognostic and outcome predictors and as decisive factors for therapy decisions, add to the continuing role of histopathology. Advancements in cancer biology and development of molecular classification of HCC with clinic pathological correlation, lead to discovery of HCC phenotypic surrogates of prognostic and therapeutically significant molecular signatures. Thus tissue characteristics and morphology based correlates of molecular subtypes provide invaluable information for management and prognosis. This review thus focuses on the importance of histopathology and resurgence of role of biopsy in the diagnosis, management and prognostication of HCC.

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.

Characterization of hepatocellular adenoma and carcinoma using microRNA profiling and targeted gene sequencing

Background

Hepatocellular adenomas (HCA) are benign liver tumors that may transform into hepatocellular carcinoma (HCC), but the molecular drivers of this transformation remain ill-defined. This study evaluates the molecular changes in HCA and HCC and in comparison to their adjacent non-neoplastic liver.

Methods

11 patients with HCA and 10 patients with HCC without underlying hepatitis or cirrhosis were included in this pilot study. Tumor and non-tumor liver tissues were selected for immunohistochemical staining, small RNA sequencing, and targeted gene sequencing. We compared microRNA expressions and mutations between HCA and HCC and non-neoplastic liver.

Results

HCA were classified as inflammatory (n = 6), steatotic (n = 4), or β-catenin activated (n = 1) subtypes. MicroRNA profile of all 3 HCA subtypes clustered between that of normal liver and HCC in principal component analysis. In both HCA and HCC, miR-200a, miR-429, and miR-490-3p were significantly downregulated compared to normal liver, whereas miR-452, miR-766, and miR-1180 were significantly upregulated. In addition, compared to HCA, HCC had significantly higher expression of members of the chromosome 19 miRNA cluster (C19MC), including miR-515-5p, miR-517a, miR-518b, and miR-520c-3p.

Conclusions

This study indicates that while there are significant differences in the molecular profile between HCA and HCC, several miRNAs are similarly deregulated in HCA and HCC compared to adjacent normal liver. These results may provide insights into the drivers of hepatocarcinogenesis and warrant further investigations.

Changes of Th1/Th2 cytokines in patients with primary hepatocellular carcinoma after ultrasound-guided ablation

Liver cancer is a malignancy of the digestive system and has a high morbidity and mortality rate. Local intervention has become a viable option in identifying liver treatment. The aim of the present study was to analyze the changes of Th1/Th2 cytokines in patients with primary hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) treatment. 26 patients with stage III-IV liver cancers and 25 healthy controls were selected to participate in the study. HCC patients were initiated with RFA treatment and the serum levels of alpha fetoprotein (AFP) and Th1/Th2 cytokines were valued. We found that with the level of AFP decreased, the levels of Th1 cytokines including interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were significantly increased after treatment with RFA (P<0.05). Meanwhile, the levels of Th2 cytokines consist of interleukin-4 (IL-4), IL-6 and IL-10 were decreased markedly on the contrary, and the differences were statistically significant (P<0.05). In conclusion, the levels of Th1/Th2 cytokines were correlated with the change of AFP in patients of HCC after treatment with RFA, which might be an important guiding significance for the prognosis of HCC.

Tissue Biomarkers in Hepatocellular Tumors: Which, When, and How

Few tissue markers are currently available to pathologists in the study of hepatocellular tumors. These markers should be used carefully taking into consideration not only morphology but also, and sometimes even more important, the clinical setting where the lesion to be diagnosed had developed. Glypican-3, heat shock protein 70, and glutamine synthetase (GS) are markers currently used, as a single panel, to discriminate the nature of a <2 cm hepatocellular lesion lacking radiological features of hepatocellular carcinoma (HCC) detected in a cirrhotic patient under surveillance. Their use, which can be improved by clathrin heavy chain, is mostly requested on liver biopsy. Hepatocyte paraffin 1, arginase-1, polyclonal carcinoembryonic antigen, CD10, and bile salt export pump are tissue markers used to confirm, at histology, the diagnosis of HCC made by imaging before enrollment for phase III studies on novel anti-HCC drugs. In this setting, pathologists are usually requested a conclusive diagnosis on a liver biopsy of a poorly differentiated, necrotic, enriched in stem-phenotype, carcinoma. Liver fatty acid-binding protein, serum amyloid A, C-reactive protein, prostaglandin D2 synthetase, GS, and β-catenin can be used either on biopsy or surgical specimen to classify hepatocellular adenoma into hepatocyte nuclear factor (HNF-1α) inactivated (steatotic), inflammatory, with dysregulation of sonic hedgehog and prostaglandin pathways, β-catenin mutated, and unclassified.

Hepatocellular adenoma: Classification, variants and clinical relevance

Hepatocellular adenomas are benign tumors with two major complications, bleeding and malignant transformation. The overall narrative of hepatocellular adenoma has evolved over time. Solitary or multiple hepatocellular developing in the normal liver of women of child bearing age exposed to oral contraceptives still represents the most frequent clinical context, however, new associations are being recognized. Hepatocellular adenoma is discovered on a background of liver diseases such as non-alcoholic steatohepatitis, vascular diseases, and alcoholic cirrhosis. Hepatocellular adenoma is also reported in men, young or older adults, and even in infants. On the morpho-molecular side, the great leap forward was the discovery that hepatocellular adenoma was not a single entity and that at least 3 different subtypes exist, with specific underlying gene mutations. These mutations affect the HNF1A gene, several genes leading to JAK/STAT3 pathway activation and the CTNNB1 gene. All of them are associated with more or less specific histopathological characteristics and can be recognized using immunohistochemistry either with specific antibodies or with surrogate markers. Liver pathologists and radiologists are the key actors in the identification of the different subtypes of hepatocellular adenoma by the recognition of their specific morphological features. The major impact of the classification of hepatocellular adenoma is to identify subjects who are at higher risk of malignant transformation. With the development of new molecular technologies, there is hope for a better understanding of the natural history of the different subtypes, and, particularly for their mechanisms of malignant transformation.