A single-center surgical experience of 122 patients with single and multiple hepatocellular adenomas

Hepatocellular Adenoma: A Life-Threatening Presentation of a Rare Liver Tumor - Case Report and Literature Review

Hepatocellular adenoma is a rare benign liver tumor that occurs predominantly in young women who use exogenous estrogens. We describe a case of a 40-year-old woman on birth control pill who presented with acute right hypochondrial pain and signs of hemodynamical instability triggered by a large bleeding tumor in the right liver lobe. Arterial embolization was performed with cessation of bleeding. To determine etiology, magnetic resonance imaging was conducted with findings suggestive of a hepatocellular adenoma. The tumor was surgically resected, and histologic examination made the definite diagnosis of an inflammatory hepatocellular adenoma. This is a noteworthy case of a rare but potentially fatal complication of liver tumors, whose diagnosis requires a high index of suspicion. Clinicians should consider this diagnosis in young women on oral contraceptive pills who present with severe unexplained abdominal pain and hemodynamical instability. This case aimed to raise awareness of this condition, while reviewing important aspects concerning the management of hepatocellular adenomas.

A Rare Case of a Spontaneously Ruptured Hepatocellular Adenoma in the Third Trimester of Pregnancy

This case report details the management of a 29-year-old primigravida who presented at 35 weeks of gestation with abdominal pain and vomiting. The patient exhibited tachycardia and fetal bradycardia, with laboratory findings indicating severe anemia and elevated liver enzymes. An emergency cesarean section was performed due to hemodynamic instability, during which a ruptured hepatocellular adenoma (HCA) was discovered, necessitating an atypical left hepatectomy. Despite successful maternal recovery, the neonate succumbed to multiple organ failure. Hepatocellular adenomas (HCA), also known as hepatic adenomas, are rare benign epithelial liver tumors that predominantly occur in women during their reproductive years and have been strongly associated with the intake of oral contraceptives. This case highlights the rare occurrence of HCA rupture during pregnancy, emphasizing the importance of prompt diagnosis and intervention to prevent life-threatening complications. Additionally, it underscores the need for careful monitoring and potential preemptive intervention in pregnant women with large HCAs due to the elevated risk of rupture.

ACG Clinical Guideline: Focal Liver Lesions

Focal liver lesions (FLLs) have become an increasingly common finding on abdominal imaging, especially asymptomatic and incidental liver lesions. Gastroenterologists and hepatologists often see these patients in consultation and make recommendations for management of multiple types of liver lesions, including hepatocellular adenoma, focal nodular hyperplasia, hemangioma, and hepatic cystic lesions including polycystic liver disease. Malignancy is important to consider in the differential diagnosis of FLLs, and healthcare providers must be familiar with the diagnosis and management of FLLs. This American College of Gastroenterology practice guideline uses the best evidence available to make diagnosis and management recommendations for the most common FLLs.

Sonic hedgehog hepatocellular adenoma: magnetic resonance imaging features and correlation with histology

OBJECTIVES

Sonic hedgehog hepatocellular adenoma (shHCA) is a new hepatocellular adenoma (HCA) subgroup characterized by high risk of hemorrhage. ShHCA account for below 10% of all HCA cases and are often associated with female gender, obesity, and non-alcoholic steatohepatitis. No specific MRI characteristics have been described to date. The objective of this study was to assess the value of using MRI to identify shHCA, and correlate MRI findings with histology.

METHODS

We retrospectively collected MRI scans of 29 patients with shHCA from our center and from different liver referral centers to include 35 lesions. Diagnosis of shHCA was assessed by immunohistochemical overexpression of argininosuccinate synthase 1 or prostaglandin D2 synthase, then confirmed by molecular analysis of sonic hedgehog pathway activation and/or by proteomic analysis.

RESULTS

In 46% (n = 16/35) of shHCA cases, we detected intralesional fluid-filled cavities defined on MR images as fluid-like foci markedly hyperintense on T2-weighted sequences, and hypointense on T1-weighted sequences, with or without delayed enhancement. Pathologically, these cavities were observed in 54% of cases as vacuoles filled with blood at different stages of degradation. Hemorrhage and/or necrosis were detected among 71% of cases by MRI analysis (n = 25/35) versus 82% pathologically. Seventeen percent of shHCA cases (n = 6/35) were completely homogeneous via MRI and pathological analysis. No MRI criteria was found in favor of focal nodular hyperplasia, HNF1A-mutated HCA, or typical inflammatory HCA.

CONCLUSION

We reveal the presence of intralesional fluid-filled cavities among 46% of our shHCA cases that represent a new MRI finding possibly helpful for shHCA diagnosis.

CLINICAL RELEVANCE STATEMENT

This multicenter study is the first clinical study about the radiological aspect of this new hepatocellular adenoma subgroup. This highlights a strong correlation between MRI and histological analysis, with a specific pattern emerging for diagnosis.

KEY POINTS

• Sonic hedgehog hepatocellular adenoma is a new hepatocellular adenoma subgroup associated with high risk of hemorrhage, but imaging features of this subgroup remain unknown. • Analysis of MR images and correlation with pathology revealed intralesional fluid-filled cavities and necrotic-hemorrhagic changes. • Intralesional fluid-filled cavities have not yet been described in other adenoma subtypes and represent a new MRI finding for sonic hedgehog hepatocellular adenoma.

Imaging features and management of focal liver lesions

Notably, the number of incidentally detected focal liver lesions (FLLs) has increased dramatically in recent years due to the increased use of radiological imaging. The diagnosis of FLLs can be made through a well-documented medical history, physical examination, laboratory tests, and appropriate imaging methods. Although benign FLLs are more common than malignant ones in adults, even in patients with primary malignancy, accurate diagnosis of incidental FLLs is of utmost clinical significance. In clinical practice, FLLs are frequently evaluated non-invasively using ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Although US is a cost-effective and widely used imaging method, its diagnostic specificity and sensitivity for FLL characterization are limited. FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI. MRI is a problem-solving method with high specificity and sensitivity, commonly used for the evaluation of FLLs that cannot be characterized by US or CT. Recent technical advancements in MRI, along with the use of hepatobiliary-specific MRI contrast agents, have significantly improved the success of FLL characterization and reduced unnecessary biopsies. The American College of Radiology (ACR) appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients. ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommendations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios. The American College of Gastroenterology (ACG) Clinical Guideline offers evidence-based recommendations for both the diagnosis and management of FLL. American Association for the Study of Liver Diseases (AASLD) Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma. In this article, FLLs are reviewed with a comprehensive analysis of ACR Appropriateness Criteria, ACG Clinical Guideline, AASLD Practice Guidance, and current medical literature from peer-reviewed journals. The article includes a discussion of imaging methods used for the assessment of FLL, current recommended imaging techniques, innovations in liver imaging, contrast agents, imaging features of common nonmetastatic benign and malignant FLL, as well as current management recommendations.

Surgical Management of a Giant Inflammatory Hepatocellular Adenoma in a Young Female

Hepatocellular adenomas are rare and benign primary neoplasms of phenotypically mature hepatocytes. Our understanding of this pathology has greatly improved due to advances in molecular and anatomic knowledge. This article provides an in-depth review of hepatic adenomas (HCA) while presenting the case of a 20-year-old patient with a giant inflammatory hepatocellular adenoma with an atypical presentation, in whom surgical intervention was performed via right hepatectomy. In the post-surgical course, the patient had an in-hospital stay of three days with no complications. During outpatient monitoring via laboratory tests and imaging at eight months, the patient did not present any trace of recurrence.

Hepatic adenoma: evolution of a more individualized treatment approach

BACKGROUND

Hepatic adenomas (HAs) are benign, solid liver lesions, which carry a risk of hemorrhage and malignant transformation. This review article highlights the advances in the diagnosis and management of HAs.

METHODS

A comprehensive review was performed using MEDLINE/PubMed and Web of Science databases with a search period ending on September 30, 2023. Using PubMed, the terms "hepatocellular," "hepatic," and "adenoma" were searched.

RESULTS

HA has been classified into at least 8 subtypes based on molecular pathology, each exhibiting unique histopathologic features, clinical considerations, and risk of malignant transformation. The most common subtype is inflammatory HA, followed by hepatocyte nuclear factor 1α-inactivated HA, β-catenin exon 3-mutated HA (βex3-HA), β-catenin exon 7- or 8-mutated HA, sonic hedgehog HA, and unclassified HA. Magnetic resonance imaging is the best imaging method for diagnosis and can distinguish among HA subtypes based on fat and telangiectasia pathologic characteristics. The risk of malignant transformation varies among molecular subtypes, ranging from <1% to approximately 50%. Up to 42% of HAs present with spontaneous intratumoral hemorrhage and peritoneal hemorrhage. In general, only 15% to 20% of patients require surgery. HA larger than 5 cm are more likely to be complicated by bleeding and malignant transformation, regardless of subtype, and should generally be resected. In particular, βex3-HA carries a high risk of malignant transformation and can be considered a true precancerous lesion.

CONCLUSION

The management of HAs is based on a multidisciplinary approach. Clinical decision-making should integrate information on gender, tumor size, and HA subtyping. In the future, patients with HA will benefit from novel medical therapies tailored to the individual molecular subtypes.

Progestins as a Contributing Factor to Hepatocellular Adenoma: A Case Series and Literature Review

STUDY OBJECTIVE

To explore the role of progestins as potential contributing factors for the development of hepatocellular adenoma (HA) METHODS: We describe 3 cases of adolescents and young adults who developed HA while on norethindrone (NET), as well as their management. In addition, we provide a comprehensive literature review on the association between progestins and HA.

RESULTS

Since 1983, 16 cases of HA in patients on progestins have been reported. Ten patients were on NET and 5 on a prodrug of NET (4 on norethindrone acetate [NETA] and 1 on lynestrenol). One individual had a norgestrel implant. Eight subsequently ceased all hormones: 4 experienced a size reduction, and 3 had complete resolution of their HA. Among our patients, 1 ceased NET and instead had a levonorgestrel intrauterine device inserted, and another swapped from NET to oral medroxyprogesterone acetate. Both experienced complete resolution of their HA. The third ceased NET and underwent a hysterectomy, with size reduction of her HA.

CONCLUSION

These cases and the literature review suggest an association between progestin exposure, in particular NET and its prodrugs, and the development of HA. The pathophysiology is unknown but may include peripheral conversion of NET and NETA to ethinyl estradiol or a specific action of 19-nortestosterone derivatives on hepatocytes, especially those with higher systemic doses compared with the levonorgestrel intrauterine device. There are no case reports relating to other forms of progestins, such as 17-hydroxyprogesterone, which may be important when considering alternative therapeutic options in females requiring effective menstrual management who have comorbidities.

Hepatic Precancerous Lesions and Early Hepatocellular Carcinoma

This review discusses the diagnostic challenges of diagnosing and treating precursor lesions of hepatocellular carcinoma (HCC) in both cirrhotic and non-cirrhotic livers. The distinction of high-grade dysplastic nodule (the primary precursor lesion in cirrhotic liver) from early HCC is emphasized based on morphologic, immunohistochemical, and genomic features. The risk factors associated with HCC in hepatocellular adenomas (precursor lesion in non-cirrhotic liver) are delineated, and the risk in different subtypes is discussed with emphasis on terminology, diagnosis, and genomic features.

Phospholipase A2 Group IIA Is Associated with Inflammatory Hepatocellular Adenoma

Although benign hepatocellular adenomas (HCA) are very rare, recent observations have shown their occurrence in patients with diabetes mellitus. Consequently, most of these cases are treated by resection due to concerns regarding their potential progression to hepatocarcinoma (HCC). This decision is largely driven by the limited number of studies on HCC subtyping and the lack of molecular and biological insights into the carcinogenic potential of benign tumors. This study aimed to comprehensively investigate the subtype classification of HCA and to compare and analyze gene expression profiling between HCA and HCC tissues. One fresh inflammatory HCA (I-HCA), three non-B non-C HCCs, two hepatitis B virus-HCCs, and one normal liver tissue sample were subjected to single-cell RNA sequencing (scRNA-seq). Comparative analysis of scRNA-seq among different tissues showed that phospholipase A2 group IIA (PLA2G2A) mRNA was specifically expressed in I-HCA, following RNA-seq analysis in formalin-fixed paraffin-embedded tissues from other HCAs. Immunohistochemistry using the PLA2G2A antibody in these tissues indicated that the positive reaction was mainly observed in hepatocytes of I-HCAs and stromal cells surrounding the tumor tissue in HCC were also stained. According to a clinical database, PLA2G2A expression in HCC does not correlate with poor prognosis. This finding may potentially help develop a new definition for I-HCA, resulting in a significant clinical contribution, but it requires validation with other fresh HCA samples.

Surgical indications for solid hepatic benign tumors: An updated literature review

Hepatic hemangioma, focal nodular hyperplasia, and hepatic adenoma are the most common benign solid liver tumors. However, their surgical indications have been the subject of debate. Minimally invasive liver resection reduces the cost of surgery and may lead to overtreatment of benign liver tumors. Recently, there has been a growing understanding of the etiology, pathogenesis, and natural history of these tumors. Great progress has also been made in imaging. The use of MRI and contrast agents has improved the accuracy of non-invasive diagnosis of these tumors, and especially in the identification of specific molecular subtypes of liver adenoma. These factors have resulted in alterations of surgical indications for these tumors. This article examines recent literature and it discusses the surgical indications for hepatic hemangioma, focal nodular hyperplasia, and hepatic adenoma while summarizing modifications in clinical management.

Sex differences in chronic liver disease and benign liver lesions

The epidemiology, natural history, and therapeutic responses of chronic liver diseases and liver lesions often vary by sex. In this review, we summarize available clinical and translational data on these aspects of the most common liver conditions encountered in clinical practice, including the potential contributions of sex hormones to the underlying pathophysiology of observed differences. We also highlight areas of notable knowledge gaps and discuss sex disparities in access to liver transplant and potential strategies to address these barriers. Given established sex differences in immune response, drug metabolism, and response to liver-related therapies, emerging clinical trials and epidemiological studies should prioritize dedicated analyses by sex to inform sex-specific approaches to liver-related care.

Hypermethylation of DNA Methylation Markers in Non-Cirrhotic Hepatocellular Carcinoma

Aberrant DNA methylation changes have been reported to be associated with carcinogenesis in cirrhotic HCC, but DNA methylation patterns for these non-cirrhotic HCC cases were not examined. Therefore, we sought to investigate DNA methylation changes on non-cirrhotic HCC using reported promising DNA methylation markers (DMMs), including HOXA1, CLEC11A, AK055957, and TSPYL5, on 146 liver tissues using quantitative methylation-specific PCR and methylated DNA sequencing. We observed a high frequency of aberrant methylation changes in the four DMMs through both techniques in non-cirrhotic HCC compared to cirrhosis, hepatitis, and benign lesions (p < 0.05), suggesting that hypermethylation of these DMMs is specific to non-cirrhotic HCC development. Also, the combination of the four DMMs exhibited 78% sensitivity at 80% specificity with an AUC of 0.85 in discriminating non-cirrhotic HCC from hepatitis and benign lesions. In addition, HOXA1 showed a higher aberrant methylation percentage in non-cirrhotic HCC compared to cirrhotic HCC (43.3% versus 13.3%, p = 0.039), which was confirmed using multivariate linear regression (p < 0.05). In summary, we identified aberrant hypermethylation changes in HOXA1, CLEC11A, AK055957, and TSPYL5 in non-cirrhotic HCC tissues compared to cirrhosis, hepatitis, and benign lesions, providing information that could be used as potentially detectable biomarkers for these unusual HCC cases in clinical practice.

Borderline Hepatocellular Adenomas: A Practical Diagnostic Approach Based on Pathologic and Molecular Features

Borderline hepatocellular adenomas (BL-HCA) are characterized by focal architectural/cytologic atypia and reticulin loss, features that are insufficient for a definitive diagnosis of hepatocellular carcinoma (HCC). The diagnosis and management of BL-HCA are challenging as their biological behavior, especially in terms of malignant potential, is still debated. We aimed to compare the clinicopathologic and molecular features of BL-HCA with those of typical HCA (T-HCA), HCA with malignant transformation (HCC on HCA), and HCC to assess the risk of malignancy. One hundred six liver resection specimens were retrospectively selected from 2 reference centers, including 39 BL-HCA, 42 T-HCA, 12 HCC on HCA, and 13 HCC specimens. Somatic mutations, including TERT promoter mutations associated with HCA malignant transformation and the gene expression levels of 96 genes, were investigated in 93 frozen samples. Additionally, TERT promoter mutations were investigated in 44 formalin-fixed, paraffin-embedded samples. The clinical features of patients with BL-HCA were similar to those of patients with T-HCA, patients being mainly women (69%) with a median age of 37 years. The median tumor size was 7.5 cm, 64% of patients had a single nodule, and no recurrence was observed. Compared with T-HCA, BL-HCA was significantly enriched in β-catenin-mutated HCA in exon 3 (41% vs 6%; P < .001). Unsupervised statistical analysis based on gene expression showed that BL-HCA overlapped with T-HCA and HCC on HCA, favoring a molecular continuum of the tumors. TERT promoter mutations were observed only in HCC on HCA (42%) and in HCC (38%). In conclusion, these results suggest that despite their worrisome morphologic features, the clinicopathologic and molecular features of BL-HCA are much closer to those of T-HCA than those of HCC on HCA or HCC. This strongly supports the usefulness of combining morphologic and molecular analyses in a practical diagnostic approach for guiding the management of BL-HCA.

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.

Clinicopathologic characterization of hepatocellular adenomas in men: a multicenter experience

Hepatocellular adenomas (HCAs) are benign liver neoplasms which most commonly present in women in their reproductive age. In men, they are rare and have a higher risk of malignant transformation to hepatocellular carcinoma (HCC). Here we present our multicenter experience with HCA in men in the United States. A total of 27 HCA cases were included, with a mean age of presentation of 37 years (range, 9-69 years) and a mean size of 6.8 cm (range, 0.9-18.5 cm). Based on the 2019 World Health Organization classification, the most common subtype identified was inflammatory HCA (IHCA; 10 cases, 37.0%) followed by unclassified HCA (UHCA; 7 cases, 25.9%), HNF1A-inactivated HCA (H-HCA; 6 cases, 22.2%), β-catenin-activated IHCA (b-IHCA; 3 cases, 11.1%), and β-catenin-activated HCA (b-HCA; 1 case, 3.7%). Six additional cases diagnosed as hepatocellular neoplasm of uncertain malignant potential (HUMP) were also included in the study. These cases presented in a mean age of 46 years (range, 17-64 years) and a size of 10.8 cm (range, 4.2-16.5 cm). We evaluated the significance of androgen receptor (AR) expression by immunohistochemistry (IHC); of the 16 cases with materials available, 8 were considered positive using the Allred score system (2 IHCA, 2 H-HCA, 1 UHCA, and 3 HUMP). Of the total cases, 12 were diagnosed on biopsies, for which follow-up information is available for 7, and none of them show evidence of malignant transformation. Of the 21 resection cases, a concomitant well-differentiated HCC within the same lesion was identified in 5 cases (23.8%), which were diagnosed as HCA (n = 4) or HUMP (n = 1). Overall, 15% of cases in our entire cohort of HCA and HUMP showed concomitant HCC, while none of the 7 biopsy cases showed any malignant transformation on follow-up (range, 22-160 months; mean, 61.8 months).

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.

Relief of symptoms and quality of life after conservative versus surgical treatment of benign liver tumors (CONSULT): a retrospective propensity score matched study

BACKGROUND

Surgery can be considered for selected patients with benign liver tumours (BLT). The aim of this study was to compare symptoms and quality of life (QoL) after conservative and surgical management of BLT.

METHODS

In this dual-site cross-sectional retrospective study, adult patients with BLT diagnosed between 2000 and 2019 completed EORTC QLQ-C30 questionnaires on current symptoms and symptoms at diagnosis. Summary scores (SumScores) and QoL scores at follow-up were compared between surgically and conservatively treated patients by matched t-tests. Propensity score matching attempted to reduce confounding. Higher scores indicate less symptoms and higher QoL.

RESULTS

Fifty surgically (22.6%) and 171 (77.4%) conservatively treated patients were included at median 95 (IQR:66-120) and 91 (IQR:52-129) months, respectively. Most surgically treated patients reported stable, improved or disappeared symptoms (87%) and would undergo surgery again (94%). After propensity score matching, surgical patients had higher SumScores (mean difference 9.2, 95%CI:1.0-17.4, p = 0.028) but not higher QoL scores (p = 0.331) at follow-up than conservatively treated counterparts (31 patients in both groups).

DISCUSSION

Patients who had undergone surgery often reported they would undergo surgery again. Moreover, they had less symptoms than conservatively managed patients while they were propensity score matched on relevant variables, including baseline symptoms.

Hepatocellular Adenomas: Molecular Basis and Multimodality Imaging Update

Hepatocellular adenomas (HCAs) are a family of liver tumors that are associated with variable prognoses. Since the initial description of these tumors, the classification of HCAs has expanded and now includes eight distinct genotypic subtypes based on molecular analysis findings. These genotypic subtypes have unique derangements in their cellular biologic makeup that determine their clinical course and may allow noninvasive identification of certain subtypes. Multiphasic MRI performed with hepatobiliary contrast agents remains the best method to noninvasively detect, characterize, and monitor HCAs. HCAs are generally hypointense during the hepatobiliary phase; the β-catenin-mutated exon 3 subtype and up to a third of inflammatory HCAs are the exception to this characterization. It is important to understand the appearances of HCAs beyond their depictions at MRI, as these tumors are typically identified with other imaging modalities first. The two most feared related complications are bleeding and malignant transformation to hepatocellular carcinoma, although the risk of these complications depends on tumor size, subtype, and clinical factors. Elective surgical resection is recommended for HCAs that are persistently larger than 5 cm, adenomas of any size in men, and all β-catenin-mutated exon 3 HCAs. Thermal ablation and transarterial embolization are potential alternatives to surgical resection. In the acute setting of a ruptured HCA, patients typically undergo transarterial embolization with or without delayed surgical resection. This update on HCAs includes a review of radiologic-pathologic correlations by subtype and imaging modality, related complications, and management recommendations. ^© RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

[Benign solid liver tumors]

Benign solid liver tumors are frequently discovered during routine sonographic examinations. As a rule, malignant tumors can be excluded using contrast medium-based sectional imaging; however, unclear cases can represent a diagnostic challenge. The category of solid benign liver tumors includes first and foremost hepatocellular adenoma (HCA), focal nodular hyperplasia (FNH) and hemangioma. Based on the most recent data, an overview of the current standards in the diagnostics and treatment is given.

Body weight changes and duration of estrogen exposure modulate the evolution of hepatocellular adenomas after contraception discontinuation

BACKGROUND AND AIMS

The natural history of hepatocellular adenomas (HCAs) remains to be better described, especially in nonresected patients. We aim to identify the predictive factors of HCA evolution after estrogen-based contraception discontinuation.

APPROACH AND RESULTS

We retrospectively included patients with a histological diagnosis of HCA from three centers. Clinical, radiological, and pathological data were collected to identify predictive factors of radiological evolution per Response Evaluation Criteria in Solid Tumors, version 1.1, and occurrence of complications (bleeding, malignant transformation). We built a score using variables that modulate estrogen levels: body mass index and duration of estrogen-based contraception. An external cohort was used to validate this score. 183 patients were included in the cohort, including 161 women (89%) using estrogen-based contraception for a median of 12 years. Thirty percent of patients had at least one HNF1A -inactivated HCA, 45.5% at least one inflammatory HCA, and 11% at least one HCA with activation of β-catenin (bHCA). Twenty-one symptomatic bleedings (11%) and eleven malignant transformations (6%) occurred. Ages < 37 years old ( p = 0.004) and HCA > 5 cm at imaging were independently associated with symptomatic bleeding ( p = 0.003), whereas a bHCA was associated with malignant transformation ( p < 0.001). After a median follow-up of 5 years, radiological regression was observed in 31%, stabilization in 47%, and progression in 22% of patients. Weight loss was associated with regression ( p < 0.0001) and weight gain with progression ( p = 0.02). The estrogen exposure score predicted radiological regression (odds ratio, 2.33; confidence interval 95%, 1.29-4.19; p = 0.005) with a linear relationship between the rate of estrogen exposure and the probability of regression. This result was confirmed in an external cohort of 72 female patients ( p = 0.003).

CONCLUSION

Weight variation is strongly associated with radiological evolution after oral contraception discontinuation. A score of estrogen exposure, easily assessable in clinical practice at diagnosis, predicts regression of HCA.

β-Catenin-activated inflammatory hepatocellular adenoma with pigmentation and atypical features: a case report

Hepatocellular adenomas are rare diseases, defined as benign liver neoplasms composed of cells with hepatocellular differentiation. Differential diagnosis of hepatocellular adenoma from other lesions, including focal nodular hyperplasia and hepatocellular carcinoma, is crucial to determine treatment strategy. We describe a case of β-catenin-activated inflammatory hepatocellular adenoma with malignant transformation. A 50-year-old man with a suspected liver tumor, based on abdominal ultrasonography findings, was referred to our hospital. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a liver tumor in S2 which was enhanced in the arterial phase to the delayed phase. Based on diagnostic imaging findings, hepatocellular adenoma or focal nodular hyperplasia was suspected. We considered the possibility of malignant potential because of the enlargement of the lesion. Thus, we performed a laparoscopic hepatectomy. Histological examination showed pigment deposition in the hepatocytes, which was determined to be lipofuscin. Mild nuclear swelling and atypia in the tumor area indicated nodular growth. Based on the histological and immunohistochemical findings, the diagnosis was ꞵ-catenin-activated inflammatory hepatocellular adenoma with atypical features. The imaging features of hepatocellular adenoma and focal nodular hyperplasia are similar, but if the tumor tends to grow, surgical treatment should be performed because of the possibility of malignant hepatocellular adenoma.

A nationwide assessment of hepatocellular adenoma resection: Indications and pathological discordance

Hepatocellular adenomas (HCAs) are benign liver tumors associated with bleeding or malignant transformation. Data on the indication for surgery are scarce. We analyzed indications and outcome of patients operated for HCAs < 50 mm compared to HCAs ≥ 50 mm. Changes in final postoperative diagnosis were assessed. We performed a retrospective study that included patients who underwent resection for (suspected) HCAs in the Netherlands from 2014 to 2019. Indication for resection was analyzed and stratified for small (<50 mm) and large (≥50 mm) tumors. Logistic regression analysis was performed on factors influencing change in tumor diagnosis. Out of 222 patients who underwent surgery, 44 (20%) patients had a tumor <50 mm. Median age was 46 (interquartile range [IQR], 33-56) years in patients with small tumors and 37 (IQR, 31-46) years in patients with large tumors ( p  = 0.016). Patients with small tumors were more frequently men (21% vs. 5%, p  = 0.002). Main indications for resection in patients with small tumors were suspicion of (pre)malignancy (55%), (previous) bleeding (14%), and male sex (11%). Patients with large tumors received operations because of tumor size >50 mm (52%), suspicion of (pre)malignancy (28%), and (previous) bleeding (5.1%). No difference was observed in HCA-subtype distribution between small and large tumors. Ninety-six (43%) patients had a postoperative change in diagnosis. Independent risk factors for change in diagnosis were tumor size <50 mm (adjusted odds ratio [aOR], 3.4; p  < 0.01), male sex (aOR, 3.7; p  = 0.03), and lack of hepatobiliary contrast-enhanced magnetic resonance imaging (CE-MRI) (aOR, 1.8; p  = 0.04). Resection for small (suspected) HCAs was mainly indicated by suspicion of (pre)malignancy, whereas for large (suspected) HCAs, tumor size was the most prevalent indication. Male sex, tumor size <50 mm, and lack of hepatobiliary CE-MRI were independent risk factors for postoperative change in tumor diagnosis.

Sex disparity and drug-induced liver injury

Drug-induced liver injury (DILI) is a potentially serious clinical condition that remains a major problem for patients, physicians and those involved in the development of new drugs. Population and hospital-based studies have reported incidences of DILI varying from 1.4 to 19.1/100.000. Overall, females have a 1.5- to 1.7-fold greater risk of developing adverse drug reactions and the female/male ratio increases after the age of 49 years, suggesting a clear susceptibility of DILI after menopause. Sex differences in pharmacokinetics and pharmacodynamic, sex-specific hormonal effects or interaction with signalling molecules that can influence drug efficacy and safety and differences in abnormal immune response following drug exposure are the main probable causes of the higher vulnerability observed among female patients. A novel phenotype of autoimmune-mediated DILI following the use of check-point inhibitors in oncology and haematology has been recently described. Finally, there have been increasing reports of DILI associated with use of herbal and dietary supplements that is more frequently reported in women.

Benign liver tumours: understanding molecular physiology to adapt clinical management

Improvements in understanding the pathophysiology of the different benign liver nodules have refined their nosological classification. New criteria have been identified using imaging, histology and molecular analyses for a precise diagnosis of these tumours. Improvement in the classification of liver tumours provides a more accurate prediction of disease progression and has modified patient management. Haemangioma and focal nodular hyperplasia, the most common benign liver tumours that develop in the absence of chronic liver disease, are usually easy to diagnose on imaging and do not require specific treatment. However, hepatocellular adenomas and cirrhotic macronodules can be difficult to discriminate from hepatocellular carcinoma. The molecular subtyping of hepatocellular adenomas in five major subgroups defined by HNF1A inactivation, β-catenin mutation in exon 3 or exon 7/8, and activation of inflammatory or Hedgehog pathways helps to identify the tumours at risk of malignant transformation or bleeding. New clinical, biological and molecular tools have gradually been included in diagnostic and treatment algorithms to classify benign liver tumours and improve patient management. This Review aims to explain the main pathogenic mechanisms of benign liver tumours and how this knowledge could influence clinical practice.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

First Robotic Hepatectomy With Middle Hepatic Vein Reconstruction Using ePTFE Graft for Hepatic Adenoma: A Case Report

Surgical resection remains the best choice for the treatment of liver tumors. Hepatectomy combined with artificial vascular reconstruction has been proven as an alternative to treating tumors involving the main hepatic veins. As the cutting-edge surgical technique, robotic liver surgery is a novel procedure expanding the field of minimally invasive approaches, especially in complex reconstruction. This study reports, for the first time, on a robotic hepatectomy with middle hepatic vein (MHV) reconstruction using an expanded polytetrafluoroethylene (ePTFE) graft for a patient with hepatic adenoma. The tumor, which was located in segment 8, was adjacent to the MHV. Robot-assisted resection of segment 4 and partial segment 8, and MHV reconstruction using a ePTFE graft were performed. During the post-operative examination and follow-up, the blood flow of the ePTFE graft was patent, and liver function recovered well. Thus, robotic hepatectomy with MHV reconstruction is a safe, minimally invasive, and precise surgery that may provide a novel approach for patients with liver tumors that are invading or adjacent to the main hepatic veins.

Stereotactic radiofrequency ablation as a valid first-line treatment option for hepatocellular adenomas

OBJECTIVES

This study aimed to assess the safety and efficacy of stereotactic radiofrequency ablation (SRFA) in patients with hepatocellular adenomas (HCA).

METHODS

Retrospective analyses of all patients referred for SRFA treatment at our institution between January 2010 and October 2020 revealed 14 patients (10 women; mean age 34.4 [range, 17-73 years]) with 38 HCAs treated through 18 ablation sessions. Ablations were considered successful if a safety margin >5 mm was achieved. Demographic, interventional, and outcome data were collected and analyzed. Primary and secondary technical efficacy rates were assessed based on follow-up images consisting of contrast-enhanced CT or MR scans.

RESULTS

The mean tumor size was 22 mm (range, 7-75 mm). Overall, 37/38 (97.4%) tumors were successfully ablated at the initial SRFA (primary efficacy rate of 97.4%). The median follow-up duration was 49.6 months. No deaths or adenoma-related complications (hemorrhage or malignant transformation) were observed. Disease-free survival rates at 1, 3, and 5 years from the date of the first SRFA were 100%, 85.8%, and 85.8%, respectively. Two patients developed new distant tumors retreated with consecutive re-ablation. No major complications occurred during any of the 18 ablation sessions.

CONCLUSIONS

Percutaneous thermal ablation is efficient in the treatment of HCAs and may thus be considered a valid first-line treatment option. In addition, SRFA allows for an effective, minimally invasive treatment of large and multiple hepatic tumors within one session.

Hepatic Adenomas in Patients 60 and Older Are Enriched for HNF1A Inactivation and Malignant Transformation

Hepatic adenomas occur most commonly in women between the ages of 20 and 40 years, but rarely they occur in older aged persons, including those 60 years of age or older. This group of adenomas, however, has not been systemically examined. Twenty-six hepatic adenomas in persons 60 years of age or older were studied, along with a control group of 50 hepatic adenomas in persons aged 30 to 39. Hepatic adenomas in persons 60 or more years of age were found in 21 women and 5 men, while the control group had 44 women and 6 men. Subtyping the adenomas in persons 60 years or older showed the following results: 18 HNF1A-inactivated adenomas (69%), 4 inflammatory adenomas (15%), and 4 unclassified adenomas (15%). In contrast, the control group showed a significantly different pattern (P=0.003), with a greater percentage of inflammatory adenomas (28, 56%), fewer HNF1A-inactivated adenomas (8, 16%), and more unclassified adenomas (14, 28%). Atypia and malignant transformation within the hepatic adenomas was studied next. Of the hepatic adenomas in persons age 60 or greater, 3 (12%) showed atypical histologic features, and 6 (23%) had a malignant transformation. In contrast, for hepatic adenomas in the control group, only 4 (8%) adenomas showed atypical histologic features, and 3 (6%) had undergone malignant transformation. In addition, the hepatic adenomas that were atypical or showed early malignant transformation were less likely to have beta-catenin activation in patients over 60 (2/9 cases) compared with those between 30 and 39 years (5/7 cases). Myxoid change and heavy lipofuscin deposition were also more common in adenomas in older aged persons. In conclusion, hepatic adenomas in persons 60 years of age or older are enriched for HNF1A-inactivated adenomas and have a higher frequency of malignant transformation. Malignant transformation, however, is less likely to develop through activation of the beta-catenin pathway.

High childhood serum triglyceride concentrations associate with hepatocellular adenoma development in patients with glycogen storage disease type Ia

Background & Aims

Glycogen storage disease type Ia (GSDIa) is an inborn error of carbohydrate metabolism caused by pathogenic variants in the glucose-6-phosphatase catalytic subunit 1 (G6PC1) gene and is associated with hepatocellular adenoma (HCA) formation. Data on risk factors for HCA occurrence in GSDIa are scarce. We investigated HCA development in relation to sex, G6PC1 genotype, and serum triglyceride concentration (TG).

Methods

An observational study of patients with genetically confirmed GSDIa ≥12 years was performed. Patients were categorised for sex; presence of 2, 1, or 0 predicted severe G6PC1 variant (PSV); and median TG during childhood (<12 years; stratified for above/below 5.65 mmol/L, i.e. 500 mg/dl).

Results

Fifty-three patients (23 females) were included, of which 26 patients developed HCA at a median (IQR) age of 21 (17–25) years. At the age of 25 years, 48% of females and 30% of males had developed HCA (log-rank p = 0.045). Two-thirds of patients with GSDIa carried 2 PSVs, 20% carried 1, and 13% carried none. Neither the number of PSVs nor any specific G6PC1 variants were associated with HCA occurrence. Childhood TG was 3.4 (3.0–4.2) mmol/L in males vs. 5.6 (4.0–7.9) mmol/L in females (p = 0.026). Childhood TG >5.65 mmol/L was associated with HCA development at younger age, compared with patients with childhood TG <5.65 mmol/L (18 vs. 33 years; log-rank p = 0.001). Cox regression analysis including TG, sex, and TG–sex interaction correction revealed childhood TG >5.65 mmol/L as an independent risk factor for HCA development (hazard ratio [HR] 6.0; 95% CI 1.2–29.8; p = 0.028).

Conclusions

In patients with GSDIa, high childhood TG was associated with an increased risk of HCA, and earlier onset of HCA development, independent of sex-associated hypertriglyceridaemia, and G6PC1 genotype.

Lay summary

Glycogen storage disease type Ia (GSDIa) is a rare, inherited metabolic disease that can be complicated by liver tumours (hepatocellular adenomas), which in turn may cause bleeding or progress to liver cancer. Risk factors associated with hepatocellular adenoma formation in patients with GSDIa are largely unknown. In our study, we found that high serum triglyceride concentrations during childhood, but not specific genetic variants, were associated with increased risk of hepatocellular adenoma diagnosis later in life.

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Glycogen storage disease Ia (GSDIa) is a metabolic disease caused by mutations in glucose-6-phosphatase catalytic subunit 1 (G6PC1).

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Patients with GSDIa often develop hepatocellular adenoma (HCA), with unclear risk factors.

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Metabolic control in GSDIa is commonly evaluated through serum triglyceride concentration (TG).

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Patients with GSDIa with high childhood TG had increased risk and earlier onset of HCA.

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Sex-associated hypertriglyceridaemia and G6PC1 genotype were not associated with HCA.

Differentiation of hepatocellular adenoma by subtype and hepatocellular carcinoma in non-cirrhotic liver by fractal analysis of perfusion MRI

Background

To investigate whether fractal analysis of perfusion differentiates hepatocellular adenoma (HCA) subtypes and hepatocellular carcinoma (HCC) in non-cirrhotic liver by quantifying perfusion chaos using four-dimensional dynamic contrast-enhanced magnetic resonance imaging (4D-DCE-MRI).

Results

A retrospective population of 63 patients (47 female) with histopathologically characterized HCA and HCC in non-cirrhotic livers was investigated. Our population consisted of 13 hepatocyte nuclear factor (HNF)-1α-inactivated (H-HCAs), 7 β-catenin-exon-3-mutated (b^ex3-HCAs), 27 inflammatory HCAs (I-HCAs), and 16 HCCs. Four-dimensional fractal analysis was applied to arterial, portal venous, and delayed phases of 4D-DCE-MRI and was performed in lesions as well as remote liver tissue. Diagnostic accuracy of fractal analysis was compared to qualitative MRI features alone and their combination using multi-class diagnostic accuracy testing including kappa-statistics and area under the receiver operating characteristic curve (AUC). Fractal analysis allowed quantification of perfusion chaos, which was significantly different between lesion subtypes (multi-class AUC = 0.90, p < 0.001), except between I-HCA and HCC. Qualitative MRI features alone did not allow reliable differentiation between HCA subtypes and HCC (κ = 0.35). However, combining qualitative MRI features and fractal analysis reliably predicted the histopathological diagnosis (κ = 0.89) and improved differentiation of high-risk lesions (i.e., HCCs, b^ex3-HCAs) and low-risk lesions (H-HCAs, I-HCAs) from sensitivity and specificity of 43% (95% confidence interval [CI] 23–66%) and 47% (CI 32–64%) for qualitative MRI features to 96% (CI 78–100%) and 68% (CI 51–81%), respectively, when adding fractal analysis.

Conclusions

Combining qualitative MRI features with fractal analysis allows identification of HCA subtypes and HCCs in patients with non-cirrhotic livers and improves differentiation of lesions with high and low risk for malignant transformation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01223-6.

A Scoping Review of the Classification, Diagnosis, and Management of Hepatic Adenomas

BACKGROUND

Hepatic adenomas (HA), or hepatocellular adenomas, are benign, solid liver lesions that develop in otherwise normal livers, often in the setting of increased estrogen levels. While considered a benign tumor, there is a risk for substantial complications such as hemorrhage and malignant transformation. We review the diagnosis, classification, and potential therapeutic management options for patients with HA.

METHODS

A scoping narrative review was conducted based on recent literature regarding classification, diagnosis, and management of HA.

RESULTS

While HAs are typically considered benign, complications such as hemorrhage and malignant transformation may occur in approximately 25% and 5% of patients, respectively. Recent advances in imaging and molecular profiling have allowed for the classification of HAs into subtypes allowing for patient risk stratification that helps guide management. Surgical resection should be considered in asymptomatic patients who are male, have an adenoma ≥5 cm in diameter, or have the β-catenin-activated subtype due to an increased risk of hemorrhage and/or malignant transformation.

CONCLUSION

Molecular profiling has aided in the stratification of patients relative to the risk of complications to predict better the potential behavior of HAs.

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.

Liver Transplantation for Hepatic Adenoma: A UNOS Database Analysis and Systematic Review of the Literature

BACKGROUND

Liver transplantation (LT) has been employed for hepatic adenoma (HA) on a case-oriented basis. We aimed to describe the characteristics, waitlist, and post-LT outcomes of patients requiring LT for HA.

METHODS

All patients listed or transplanted for HA in the United States were identified in the United Network for Organ Sharing (UNOS) database (1987-2020). A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement.

RESULTS

A total of 199 HA patients were listed for LT in UNOS and the crude waitlist mortality was 9.0%. A total of 142 HA patients underwent LT; 118 of these were among those listed with an indication of HA who underwent LT, and 24 were diagnosed incidentally. Most did not experience hepatocellular carcinoma transformation (89.4%). Over a median follow-up of 62.9 mo, death was reported in 18.3%. The 1-, 3-, and 5-y patient survival rates were 94.2%, 89.7%, and 86.3% in the UNOS cohort. The systematic review yielded 61 articles reporting on 99 nonoverlapping patients undergoing LT for HA and 2 articles reporting on multicenter studies. The most common LT indications were suspected malignancy (39.7%), unresectable HA (31.7%), and increasing size (27.0%), whereas 53.1% had glycogen storage disease. Over a median follow-up of 36.5 mo, death was reported in 6.0% (n=5/84). The 1-, 3-, and 5-y patient survival rates were all 95.0% in the systematic review.

CONCLUSIONS

LT for HA can lead to excellent long-term outcomes in well-selected patients. Prospective granular data are needed to develop more optimal selection criteria and further improve outcomes.

Non-invasive diagnosis and follow-up of benign liver tumours

Hepatocellular benign liver tumours are mainly developed on normal liver and include hepatic hemangioma, focal nodular hyperplasia and hepatocellular adenoma from the most frequent to the less frequent. The diagnosis of hepatic hemangioma and of simple hepatic biliary cysts can be performed using non-invasive criteria using liver ultrasonography or contrast enhanced MRI. Most of the time the diagnosis of focal nodular hyperplasia can be achieved using contrast-enhanced ultrasonography or contrast enhanced MRI with an additional value of hepatobiliary contrast-agent in this setting. Rarely, if a doubt persists, a tumour and non-tumour liver biopsy can be required in order to establish the diagnosis. As hepatic hemangioma, simple hepatic biliary cysts and focal nodular hyperplasia are not associated with complications, they don't require any treatments or follow-up. Hepatocellular adenomas are mainly diagnosed at histology on surgical samples or liver biopsy even if some radiological features are highly suggestive of several subtypes of hepatocellular adenomas. Finally, the management of hepatocellular adenomas should be guided according to the tumour size, gender but also to the molecular subtypes.

Hepatocellular Adenoma: What We Know, What We Do Not Know, and Why It Matters

In the last 2 decades there has been significant progress in research and diagnosis of hepatocellular adenoma (HCA), resulting in the establishment of a molecular and immunohistological HCA classification. This review aims to fine-tune the current expertise in order to enhance the histopathological diagnostic possibilities, by refining issues that are already known, addressing diagnostic difficulties and identifying still unknown aspects of HCA. We will discuss novel methods to identify HCA subtypes, in particular the sonic hedgehog HCAs and the interpretation of glutamine synthetase patterns for the recognition of beta-catenin mutated HCAs. The major complications of HCAs, bleeding and malignant transformation, will be considered, including the dilemmas of atypical and borderline lesions. Paragraphs on HCAs in different clinical and geographical settings, e.g. pregnancy, cirrhosis and non-western countries are included. The natural history of the different HCA subtypes in relation with age, sex and risk factors is a feature still insufficiently investigated. This is also true for the risks of clinical bleeding and malignant transformation in association with HCA subtypes. As HCA is a relatively rare tumor, a multicenter and multidisciplinary approach across geographical boundaries will be the appropriate method to establish prospective programs to identify, classify and manage HCAs, focusing on several aspects, e.g. etiology, underlying liver disease, complications, regression and growth. Updating what we know, identifying and addressing features that we do not know matters to warrant optimal patient 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.

Applying criteria for hepatocellular neoplasm of uncertain malignant potential reclassifies more than half of hepatocellular adenomas

OBJECTIVES

Hepatocellular adenoma (HCA) is a benign well-differentiated hepatocellular neoplasm that can be difficult to distinguish from well-differentiated hepatocellular carcinoma (HCC). The term "well-differentiated hepatocellular neoplasm of uncertain malignant potential" (HUMP) has been proposed for neoplasms resembling HCAs, but arising in atypical clinical situations (in females over 50 years old or under 15, in males, with anabolic steroid use, or in some congenital conditions), and/or with atypical pathological features (focal cytological/architectural atypia, β-catenin activation, or focal reticulin loss) insufficient for an unequivocal diagnosis of HCC.

METHODS

This study evaluated HUMP criteria on 42 previously diagnosed HCAs from 33 patients.

RESULTS

Twenty-six (62%) masses from 21 patients were classified as HUMPs. Eleven (42%) had focal cytological atypia, and two (8%) had focal architectural atypia. Four (15%) showed focal reticulin loss. Five (19%) showed evidence of β-catenin activation. Four (12%) HUMP patients were male.

CONCLUSIONS

In this series, HUMP did not correlate with an increased rate of synchronous or metachronous HCC compared to HCA. Clinical colleagues may not accept such a high rate of tumors placed in a category of "uncertain malignant potential". Additional study is warranted to refine criteria for designating well-differentiated hepatocellular neoplasms as of uncertain malignant potential.

Hepatocellular adenoma in men: A nationwide assessment of pathology and correlation with clinical course

BACKGROUND & AIMS

Hepatocellular adenomas (HCA) rarely occur in males, and if so, are frequently associated with malignant transformation. Guidelines are based on small numbers of patients and advise resection of HCA in male patients, irrespective of size or subtype. This nationwide retrospective cohort study is the largest series of HCA in men correlating (immuno)histopathological and molecular findings with the clinical course.

METHODS

Dutch male patients with available histological slides with a (differential) diagnosis of HCA between 2000 and 2017 were identified through the Dutch Pathology Registry (PALGA). Histopathology and immunohistochemistry according to international guidelines were revised by two expert hepatopathologists. Next generation sequencing (NGS) was performed to confirm hepatocellular carcinoma (HCC) and/or subtype HCA. Final pathological diagnosis was correlated with recurrence, metastasis and death.

RESULTS

A total of 66 patients from 26 centres fulfilling the inclusion criteria with a mean (±SD) age of 45.0 ± 21.6 years were included. The diagnosis was changed after expert revision and NGS in 33 of the 66 patients (50%). After a median follow-up of 9.6 years, tumour-related mortality of patients with accessible clinical data was 1/18 (5.6%) in HCA, 5/14 (35.7%) in uncertain HCA/HCC and 4/9 (44.4%) in the HCC groups (P = .031). Four B-catenin mutated HCA were identified using NGS, which were not yet identified by immunohistochemistry and expert revision.

CONCLUSIONS

Expert revision with relevant immunohistochemistry may help the challenging but prognostically relevant distinction between HCA and well-differentiated HCC in male patients. NGS may be more important to subtype HCA than indicated in present guidelines.

Chirurgie bei gutartigen soliden Lebertumoren

Diese Übersicht konzentriert sich auf die 3 häufigsten gutartigen Lebertumoren – hepatische Hämangiome, fokale noduläre Hyperplasien und hepatozelluläre Adenome – und bietet einen Überblick über die klinischen Präsentationen, das diagnostische Vorgehen, das konservative Management sowie die interventionelle und chirurgische Behandlung.

Liver transplantation for benign liver tumors

Benign liver tumors are common lesions that are usually asymptomatic and are often found incidentally due to recent advances in imaging techniques and their widespread use. Although most of these tumors can be managed conservatively or treated by surgical resection, liver transplantation (LT) is the only treatment option in selected patients. LT is usually indicated in patients that present with life-threatening complications, when the lesions are diffuse in the hepatic parenchyma or when malignant transformation cannot be ruled out. However, due to the significant postoperative morbidity of the procedure, scarcity of available donor liver grafts, and the benign course of the disease, the indications for LT are still not standardized. Hepatic adenoma and adenomatosis, hepatic hemangioma, and hepatic epithelioid hemangioendothelioma are among the most common benign liver tumors treated by LT. This article reviews the role of LT in patients with benign liver tumors. The indications for LT and long-term outcomes of LT are presented.

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.

Risk factors for malignant transformation of hepatocellular adenoma to hepatocellular carcinoma: protocol for systematic review and meta-analysis

INTRODUCTION

Hepatocellular adenomas (HCAs) are solid liver tumours that are usually found incidentally during routine medical check-ups. Multiple modifiable and non-modifiable factors constitute a risk for the malignant transformation of HCAs to hepatocellular carcinoma (HCC), which has emerged to be one of the fastest growing causes of cancer-related mortality globally. This study protocol for a planned systematic review and meta-analysis documents the methodological approach to identify risk factors and their risk estimates for the transformation from HCA to HCC.

METHODS AND ANALYSIS

Two independent reviewers will systematically search and extract data from studies in patients of all ages published between January 1970 and June 2021 on PubMed, MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Scopus Web of Science, Ovid, The Cochrane Hepatobiliary Group Controlled Trials Register and The Cochrane Central Register of Controlled Trials by using an a priori defined search strategy. Study quality will be rated with the National Institute of Health quality assessment tools. Disagreements will be resolved by consensus with a third independent reviewer. The primary outcome will be the odds ratio (OR) of developing HCC in patients with prediagnosed HCA depending on the exposure to risk factors. HCC diagnosis must be inferred based on imaging techniques or pathology. We will use R V.4.0.2 to conduct meta-analyses and generate pooled ORs based on random effects models. Results will be presented as forest plots. Cochran's Q and I² test will be performed to assess heterogeneity between included studies. Funnel plots and Egger's weighted regression will be used to evaluate publication bias.

ETHICS AND DISSEMINATION

No ethical approval is required as we will use and analyse data from previously published studies in which informed consent was obtained. The results will be disseminated in a peer-reviewed journal on completion.

PROSPERO REGISTRATION NUMBER

CRD42020206578.

Long-term outcomes following resection of hepatocellular adenomas with small foci of malignant transformation or malignant adenomas

BACKGROUND & AIMS

Malignant transformation of hepatocellular adenoma (MT-HCA) may occur in up to 5% of tumours. However, the prognostic value of this event remains poorly described. In this study, we aimed to analyse the long-term outcomes of patients undergoing liver resection (LR) for MT-HCA compared to those of patients resected for hepatocellular carcinoma (HCC) occurring on normal liver parenchyma (NP-HCC).

METHODS

This single-centre retrospective study included all patients who underwent LR for MT-HCA at Beaujon Hospital between 2001 and 2019. MT-HCAs were classified as small foci of malignant transformation HCA (SF-HCA) and as malignant HCA (M-HCA) in cases of predominant HCC foci. Recurrence-free survival (RFS) of MT-HCA was compared with that of NP-HCC after propensity score matching.

RESULTS

Forty patients (24 men, 16 women) underwent LR for MT-HCA, including 23 with SF-HCA and 17 with M-HCA. Of these cases, 16/40 (40%) had β-catenin mutations, 19/40 (47.5%) were inflammatory, 1 was HNF1α-mutated HCA and 4 (10%) were unclassified HCA. Microvascular invasion (12% vs. 0%, p = 0.091) and satellite nodules (25% vs. 4%, p = 0.028) were more frequently observed in M-HCA than in SF-HCA. After a median follow-up of 67 months, 10 (25%) patients with MT-HCA had tumour recurrence, including 9 with M-HCA and 1 with SF-HCA (p = 0.007). M-HCA was linked to significantly poorer 1-, 3-, 5- and 10-year RFS rates than SF-HCA (76%, 63%, 39%, 37% vs. 100%, 100%, 100%, 91%, p = 0.003). Multivariate analysis showed that SF-HCA was independently associated with improved RFS (hazard ratio 0.064; 95% CI 0.008-0.519; p = 0.01). After propensity score matching, NP-HCC was associated with significantly poorer 1-, 3-, 5- and 10-year RFS rates than MT-HCA (p = 0.01).

CONCLUSIONS

HCA with malignant transformation yields a better long-term prognosis than NP-HCC. Among MT-HCA, SF-HCA is associated with a better prognosis than M-HCA.

LAY SUMMARY

The prognostic relevance of malignant transformation of hepatocellular adenoma (HCA) remains unknown. Thus, the aim of our study was to compare the outcomes of patients undergoing liver resection for malignant transformation to those of patients undergoing liver resection for hepatocellular carcinoma (HCC). The main long-term risk after resection for carcinoma is recurrence. In this study, 10/40 patients with malignant transformation of HCA relapsed after resection and we identified age >55 years, presence of satellite nodes, and microvascular invasion as risk factors for long-term recurrence. Compared to patients with HCC, patients who underwent liver resection for HCA with malignant transformation had better long-term survival.

Behavior and complications of hepatocellular adenoma during pregnancy and puerperium: a retrospective study and systematic review

BACKGROUND

Hepatocellular adenomas (HCA) are benign liver tumors at risk of hemorrhage. The influence of pregnancy on HCA growth and potential bleeding remains unclear. This study investigates HCA-associated behavior and bleeding complications during or shortly after pregnancy.

METHODS

(I) Single center retrospective cohort study of HCA during and after pregnancy (II) Systematic literature review.

RESULTS

The retrospective study included 11 patients, of which 4 with HCA ≥5 cm. In only two patients HCA showed growth during pregnancy. In this local cohort, no HCA-related hemorrhages occurred during median follow-up of 34 months (interquartile range 19-58 months). The systematic review yielded 33 studies, totaling 90 patients with 99 pregnancies. Of 73 pregnancies without prior HCA-related intervention, 39 HCA remained stable (53.4%), 11 regressed (15.1%), and 23 (31.5%) progressed. Fifteen HCA-related hemorrhages occurred in HCA measuring 6.5-17.0 cm. Eight patients experienced bleeding during pregnancy, two during labor and five postpartum.

CONCLUSION

Although hemorrhage of HCA during or shortly after pregnancy is rare and only reported in HCA ≥6.5 cm, it can be fatal. Pregnancy in women with HCA, regardless of size, warrant a close surveillance strategy. Observational studies on behavior and management of HCA ≥5 cm during and immediately after pregnancy are needed.

Hepatocellular Adenoma Risk Factors of Hemorrhage: Size is not the only Concern! Single Center Retrospective Experience of 261 Patients

OBJECTIVE

Our aim was to determine independent risk factors of clinical bleeding of hepatocellular adenoma (HCA) in order to define a better management strategy.

SUMMARY BACKGROUND DATA

HCA is a rare benign liver tumor with severe complications: malignant transformation which is rare (5-8%) and more often, hemorrhage (20-27%). To date, only size > 5 cm and histological subtype (possibly sonic hedgehog) are associated with bleeding, but these criteria are not clearly established.

METHODS

We retrospectively collected data from a cohort of 268 patients with HCA managed in our tertiary center, from 1984 to 2020 and focused on clinical bleeding. Hemorrhage was considered as severe when it required intensive care and moderate when bleeding symptoms required a hospitalization. We included 261 patients, of which 130 (49.8%) had multiple HCAs or liver adenomatosis. All surgical specimen and liver biopsy were reviewed by an experienced liver pathologist and reclassified in the light of the current immunohistochemistry. Mean duration of follow-up was 93.3 months (range 1-363). We analyzed type, frequency, consequences of bleeding and risk factors among clinical data and HCA characteristics.

RESULTS

Eighty-three HCA (31.8%) were hemorrhagic. There were 4 pregnant women with one newborn death. One patient died before treatment. Surgery was performed in 78 (94.0%) patients. Mortality was nil and severe complications occurred in 11.5%. Multivariate analysis identified size (OR 1.02 [1.01-1.02], p < 0.001), shHCA (OR 21.02 [5.05-87.52], p < 0.001), b-catenin mutation on exon 7/8 (OR 6.47 [1.78-23.55], p = 0.0046), chronic alcohol consumption (OR 9.16 [2.47-34.01], p < 0.001) as independent risk factors of clinical bleeding.

CONCLUSIONS

This series, focused on the hemorrhagic risk of HCA, shows that size, but rather more molecular subtype is determinant in the natural history of HCA.