Management of Hepatocellular Adenoma: Recent Advances

Hepatocellular adenomas with severe intra-abdominal bleeding, related to an underlying coagulation disorder: a case report

BACKGROUND

Hepatocellular adenoma is a rare benign liver tumor. Typically, hepatocellular adenomas are solitary and are found in young women who use estrogen-containing contraceptives. The occurrence of multiple hepatocellular adenoma has been linked to higher body mass index, and as the prevalence of overweight increases, multiple hepatocellular adenomas are seen more often. An hepatocellular adenoma does not always necessitate treatment, as they can regress under conservative strategies. In incidental cases, an adenoma presents owing to bleeding, which is mostly self-limiting. If it is not, embolization of hepatic involved vessels is indicated.

CASE PRESENTATION

In this case report, we discuss a 42-year old Caucasian woman with multiple hepatocellular bleeds, treated by multiple endovascular procedures. After the first embolization of an adenoma in the right liver lobe, a second bleed occurred in the left lobe, necessitating additional endovascular intervention. During admittance, treatment was complicated by pulmonary embolism and a pneumonia. During follow-up, our patient was diagnosed with antiphospholipid syndrome.

CONCLUSION

Hepatocellular adenoma is a rare diagnosis that requires centralized expertise. This particular case illustrates the complexity of treatment strategies for associated intra-abdominal bleeding and possible complications. Although liver adenoma is often an incidental finding, it can also result in significant morbidity. Centralization of treatment leads to expertise in managing complex treatment strategies.

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.

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.

Comparing Texture Analysis of Apparent Diffusion Coefficient MRI in Hepatocellular Adenoma and Hepatocellular Carcinoma

AIM

This study aimed to assess the effectiveness of using MRI-apparent diffusion coefficient (ADC) map-driven radiomics to differentiate between hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC) features.

MATERIALS AND METHODS

The study involved 55 patients with liver tumors (20 with HCA and 35 with HCC), featuring 106 lesions equally distributed between hepatic carcinoma and hepatic adenoma who underwent texture analysis on ADC map MR images. The analysis identified several imaging features that significantly differed between the HCA and HCC groups. Four classification models were compared for distinguishing HCA from HCC including linear support vector machine (linear-SVM), radial basis function SVM (RBF-SVM), random forest (RF), and k-nearest neighbor (KNN).

RESULTS

The k-nearest neighbor (KNN) classifier displayed the top accuracy (0.89) and specificity (0.90). Linear-SVM and KNN classifiers showcased the leading sensitivity (0.88) for both, with the KNN classifier achieving the highest precision (0.9). In comparison, the conventional interpretation had lower sensitivity (70.1%) and specificity (77.9%).

CONCLUSION

The study found that utilizing ADC maps for texture analysis in MR images is a viable method to differentiate HCA from HCC, yielding promising results in identified texture features.

Inflammatory Hepatocellular Adenoma Mimicking Focal Nodular Hyperplasia That Grew during Pregnancy and Changed Its Appearance on Magnetic Resonance Imaging after Delivery

We reported a notable case of inflammatory hepatocellular adenoma that grew during pregnancy, consequently changing its appearance on magnetic resonance imaging remarkably. A 5-months-pregnant 35-year-old woman presented with a 37-mm liver nodule that had been diagnosed as focal nodular hyperplasia 3 years earlier. She had never used oral contraceptives. After 2 months, the nodule grew to 57 mm. The patient delivered a full-term infant without complications. Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging performed after delivery revealed markedly different findings compared with the first images. A liver biopsy was performed, and the tumor was diagnosed as inflammatory hepatocellular adenoma.

Hepatocellular adenoma subtyping by qualitative MRI features and machine learning algorithm of integrated qualitative and quantitative features: a proof-of-concept study

AIM

To evaluate hepatocellular adenoma (HCA) subtyping using qualitative magnetic resonance imaging (MRI) features and feasibility of differentiating HCA subtypes using machine learning (ML) of qualitative and quantitative MRI features with histopathology as the reference standard.

MATERIALS AND METHODS

This retrospective study included 39 histopathologically subtyped HCAs (13 hepatocyte nuclear factor (HNF)-1-alpha mutated [HHCA], 11 inflammatory [IHCA], one beta-catenin-mutated [BHCA], and 14 unclassified [UHCA]) in 36 patients. HCA subtyping by two blinded radiologists using the proposed schema of qualitative MRI features and using the random forest algorithm was compared against histopathology. For quantitative features, 1,409 radiomic features were extracted after segmentation and reduced to 10 principle components. Support vector machine and logistic regression was applied to assess HCA subtyping.

RESULTS

Qualitative MRI features with proposed flow chart yielded diagnostic accuracies of 87%, 82%, and 74% for HHCA, IHCA, and UHCA respectively. The ML algorithm based on qualitative MRI features showed AUCs (area under the receiver operating characteristic curve [ROC] curve) of 0.846, 0.642, and 0.766 for diagnosing HHCA, IHCA, and UHCA, respectively. Quantitative radiomic features from portal venous and hepatic venous phase MRI demonstrated AUCs of 0.83 and 0.82, with a sensitivity of 72% and a specificity of 85% in predicting HHCA subtype.

CONCLUSIONS

The proposed schema of integrated qualitative MRI features with ML algorithm provided high accuracy for HCA subtyping while quantitative radiomic features provide value for diagnosis of HHCA. The key qualitative MRI features for differentiating HCA subtypes were concordant between the radiologists and the ML algorithm. These approaches appear promising to better inform clinical management for patients with 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.

Liver Transplantation for Treatment of Unresectable Spontaneous Ruptured Hepatocellular Adenoma: A Rare Indication

Hepatocellular Adenomas (HA) are rare benign tumors of the liver which occur predominantly in young women. Although benign, HA may have complications such as hemorrhage and malignant transformation. So, sometimes conservative management is not enough.

We report a case of a 26-year-old woman on oral contraceptives who presented with acute abdominal pain and signs of hemodynamic shock. She underwent transarterial embolization due to the presence of multiple HA with rupture and active hemorrhage. This minimally invasive treatment failed to control the disease. The patient presented a progressive increase in the size of the masses with signs of recent hemorrhage, and the HA became unresectable, so she underwent liver transplantation.

Liver transplantation is rarely indicated for the treatment of HA; however, in unresectable masses, it should be considered to prevent potential rupture with hemorrhage or malignant transformation.

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.

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

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

KETOgenic diet therapy in patients with HEPatocellular adenoma: study protocol of a matched interventional cohort study

INTRODUCTION

Hepatocellular adenoma (HCA) is an uncommon, solid and benign liver lesion, mainly occurring in women using oral contraceptives. Patients are advised to stop using oral contraceptives (OC) and, as overweight is frequently observed, dietary restrictions. Metabolic changes are assumed to play a role and it has been suggested that diet may help to reduce tumour size. A low-calorie ketogenic diet (LCKD) has been shown to induce weight loss and multiple metabolic changes, including the reduction of portal insulin concentrations, which downregulates hepatic growth hormone receptors. Weight reduction and an LCKD can potentially reduce the size of HCAs.

METHODS AND ANALYSIS

We designed a matched, interventional cohort study to determine the effect of an LCKD on the regression of HCA. The study population consists of female subjects with an HCA, 18-50 years of age, body mass index>25 kg/m², who are entering a surveillance period including cessation of OC. A historical control group will be matched. The intervention consists of an LCKD (approximately 35 g carbohydrate/1500 kcal/day) for 3 months, followed by a less strict LCKD for 3 months (approximately 60 g carbohydrate/1500 kcal/day). Main study endpoint is the diameter of the HCA after 6 months, as compared with the historic control group. Secondary endpoints include adherence, quality of life, change in physical activity, liver fat content, body weight, body composition and resting energy expenditure.

ETHICS AND DISSEMINATION

The medical ethical committee has approved the study protocol, patient information files and consent procedure and other study-related documents and procedures.

TRIAL REGISTRATION NUMBER

NL75014.078.20; Pre-results. https://www.trialregister.nl/trial/9092.

Hepatic Adenomatosis in a Young Asymptomatic but High-risk Patient: An Incidental Diagnosis with Potentially Severe Clinical Implications

Hepatic adenomatosis (HA) is a very rare condition and defined as the presence of 10 or more adenomas in an otherwise normal liver. HA has an incidence of 10–24% in patient with hepatic adenoma and it is more common in women. Most patients with HA are asymptomatic with a normal liver function test and half of cases are detected incidentally on imaging. Although HA is considered a benign disease, some patients may develop potentially fatal complications, such as hypovolaemic shock due to rupture of the liver lesion or malignant transformation to hepatocellular carcinoma.

We report the case of a 29-year-old woman who presented to the emergency room after a car accident. Whole-body computed tomography revealed multiple focal hepatic hypervascular lesions in the right lobe of the liver together with a fatty liver. Subsequent hepatic magnetic resonance imaging suggested the diagnosis of HA with a suspicion of focal nodular hyperplasia (FNH). The patient refused to undergo liver biopsy, so we instituted a 3-month surveillance program, which included clinical assessment, liver function tests, tumour marker assessment and blood tests as well as sonographic evaluation for follow-up of the liver lesions.

Life-Threatening Intraparenchymal Hemorrhage of Steroid-Induced Hepatic Adenomas in a Healthy Man

Hepatocellular adenomas are uncommon benign epithelial tumors of the liver that are associated with several risk factors such as anabolic androgens and oral contraceptive pills. They may present as incidental findings, with abdominal pain or hemorrhage. This case report details the presentation and management of a life-threatening hepatocellular adenomas hemorrhage in a seemingly healthy 28-year-old man. After initial conservative management, a clinical deterioration prompted urgent reevaluation and successful embolization of the liver through transarterial embolization. As oral contraceptive pills use and anabolic steroid abuse have become more prevalent in recent decades, we may begin to see more of these presentations.

Beta-catenin-activated hepatocellular adenoma in a male

Beta-catenin-activated hepatocellular adenoma is potentially malignant and warrants careful follow-up and surgical resection. Here, we report a 48-year-old man in whom a 55 mm single liver tumor was incidentally detected in the S1 segment. Contrast-enhanced computed tomography scans showed no enhancement in the early phase and a slight defection in the late phase. The tumor was enhanced hyperintensity in the hepatobiliary phase on Gd-ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging. The histologic features of ultrasound-guided fine-needle aspiration biopsy indicated hepatocellular adenoma, and the tumor was immunohistochemically positive for glutamine synthetase and β-catenin. Considering the risk of malignant transformation, he underwent laparoscopic-assisted partial liver resection. The resected tumor did not contain any malignant lesions. This case indicates that aspiration needle biopsy and immunohistochemistry were useful for histological diagnosis and treatment decisions based on the molecular definition of hepatocellular adenoma.

Pediatric Primary Hepatic Tumors: Diagnostic Considerations

The liver is the third most common site of abdominal tumors in children. This review article aims to summarize current evidence surrounding identification and diagnosis of primary hepatic tumors in the pediatric population based upon clinical presentation, epidemiology, and risk factors as well as classical imaging, histopathological, and molecular diagnostic findings. Readers will be able to recognize the features and distinguish between benign and malignant hepatic tumors within different age groups.

Bland Embolization of Benign Liver Tumors: Review of the Literature and a Single Center Experience

Transarterial embolization has shown promise as a safe, effective, and less invasive treatment modality for benign liver lesions (hemangioma, focal nodular hyperplasia (FNH), and hepatic adenoma (HA)) with fewer complications compared to surgical intervention. There is no consensus regarding the most appropriate embolization material(s) for the treatment of benign liver tumors. The purpose of this study was to review the current literature regarding the transarterial embolization of benign liver tumors and to share our single center experience. This was a non-blinded, retrospective, single-institution review of the bland embolization of benign liver tumors. Clinical data and imaging before and after embolization were used to evaluate lesion response to transarterial embolization. Twelve patients were included in the study. Five patients with six hemangiomas were treated. Pain was a presenting complaint in all five of these patients. The median change in tumor volume was −12.4% and ranged from −30.1% to +42.3%. One patient with two FNH lesions was treated, and both lesion volumes decreased by more than 50%. Six patients with 10 adenomas were treated. Pain was a presenting complaint in three patients, and five patients had a lesion >5 cm. The median change in tumor volume was −67.0% and ranged from −92.9% to +65.8%. Bland transarterial embolization of liver hemangiomas, FNH, and HA can be an effective and minimally invasive treatment modality to control the size and/or symptoms of these lesions. There is a variable response depending on tumor type and the embolization materials used.

Hepatocellular carcinoma in young morbid obese patients with non-alcoholic fatty liver disease

We report the two youngest cases of hepatocellular carcinoma (HCC) in non-alcoholic fatty liver disease (NAFLD) among our 119 NAFLD-HCC patients. A 36-year-old man was referred to our hospital due to a 5 cm in diameter liver tumor with elevation of α-fetoprotein and des-γ-carboxy prothrombin found at his annual health check. He had no symptoms other than 20 kg weight loss. He has been morbidly obese since he was a child. At the time of the diagnosis of NAFLD-HCC, blood chemistry showed FIB4-index 0.52, α-fetoprotein 11.1 ng/mL and des-γ-carboxy prothrombin 361 mAU/mL. He underwent curative operation. The non-cancerous lesion showed steatohepatitis with mild fibrosis. A 41-year-old man was diagnosed as having a huge liver tumor (15 cm in diameter) during medical examination for 10 kg weight loss. He had no clinical symptoms except weight loss. He has been morbidly obese since childhood. NAFLD was diagnosed at age 20. At the time of the HCC diagnosis, blood chemistry showed FIB4-index 1.42, α-fetoprotein 1974 ng/mL, and des-γ-carboxy prothrombin 82,602 mAU/mL. He underwent curative operation. We have to be aware that HCC can develop in young NAFLD patients without advanced fibrosis. Concerning tumor markers, elevation of des-γ-carboxy prothrombin was more sensitive than α-fetoprotein.

Benign Liver Tumors

Background

Due to the frequent use of medical imaging including ultrasonography, the incidence of benign liver tumors has increased. There is a large variety of different solid benign liver tumors, of which hemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) are the most frequent. Advanced imaging techniques allow precise diagnosis in most of the patients, which reduces the need for biopsies only to limited cases. Patients with benign liver tumors are mostly asymptomatic and do not need any kind of treatment. Symptoms can be abdominal pain and pressure effects on adjacent structures. The 2 most serious complications are bleeding and malignant transformation.

Summary

This review focuses on hepatic hemangioma (HH), FNH, and HCA, and provides an overview on clinical presentations, surgical and interventional treatment, as well as conservative management. Treatment options for HHs, if indicated, include liver resection, radiofrequency ablation, and transarterial catheter embolization, and should be carefully weighed against possible complications. FNH is the most frequent benign liver tumor without any risk of malignant transformation, and treatment should only be restricted to symptomatic patients. HCA is associated with the use of oral contraceptives or other steroid medications. Unlike other benign liver tumors, HCA may be complicated by malignant transformation. HCAs have been divided into 6 subtypes based on molecular and pathological features with different risk of complication.

Key Message

The vast majority of benign liver tumors remain asymptomatic, do not increase in size, and rarely need treatment. Biopsies are usually not needed as accurate diagnosis can be obtained using modern imaging techniques.

A systematic review on the complications and management of hepatic adenomas: a call for a new approach

Hepatic adenomas are benign hepatic lesions with heterogeneous characteristics. Awareness of complications, including haemorrhage and malignant transformation, has improved alongside a concurrent rise in their detection. Monitoring and management guidelines, however, remain inconsistent. This systematic review analyses the natural history of hepatic adenomas, and existing and novel risk factors associated with haemorrhage and malignant transformation. Results of this systematic review commonly identified male sex, and the beta-catenin histopathological hepatic adenoma subtype, as risk factors for malignant transformation, whilst those associated with haemorrhage included lesion size and number, exophytic nature, and recent hormone use. Overall, females demonstrated higher rates of haemorrhage, whilst males exhibited a higher risk of hepatocellular carcinoma development. This systematic review highlights that tumour size and subtype may not be as characteristically linked with complications as previously thought. We have additionally reported novel risk factors contributing to development of hepatic adenoma-related complications. We conclude by highlighting the risk of taking a conservative approach to seemingly low-risk lesions and suggest revised practice guidelines.

Multiple hepatocellular adenomas associated with long-term administration of androgenic steroids for aplastic anemia: A case report and literature review

INTRODUCTION

Anabolic steroids are widely administered to patients with aplastic anemia (AA) and are associated with numerous medical complications. To assist with future diagnoses, we report about a young boy with multiple hepatocellular adenomas (HAs) induced by long-term use of anabolic androgenic steroids (AAS) for AA and present a related literature review.

PATIENT CONCERN

A 15-year-old boy who was diagnosed with AA in 2011 had been treated with stanozolol (6 mg per day) and ciclosporin A (120-150 mg per day) for almost 4 years. He presented with epigastric pain and fever, and abdominal computed tomography showed a lesion of heterogenous density measuring 13.5 × 13.0 × 8.0 cm in the left hepatic lobe, which was initially misdiagnosed as a liver abscess.

DIAGNOSIS

The patient went into hemorrhagic shock twice after invasive manipulation that aimed at diagnosis and was finally diagnosed with HA using fine needle aspiration.

INTERVENTIONS

The patient discontinued AAS and only reserved ciclosporin A for AA treatment.

OUTCOMES

Follow-up abdominal computed tomography performed 4 years after AAS discontinuation showed obvious regression of the hepatic lesions.

CONCLUSION

It is of great importance for hematologists to completely understand that the long-term use of AAS may cause HA, which carries a great risk of hemorrhage and malignant transformation.

Extracapsular Hepatocellular Adenoma: A Diagnostic Dilemma

Hepatocellular adenoma (HCA) is a benign neoplasm of the hepatic parenchyma. The use of oral contraceptives (OCP) in women is the most well-established risk for the development of HCA. HCA commonly presents as an intracapsular mass of the liver but there are very few cases of extracapsular HCA. This is a case of a middle-aged female who presented to the emergency department with left shoulder pain and epigastric tenderness on physical exam. Subsequent imaging of the abdomen revealed a mass arising from the anterior wall of the stomach, with evidence of surrounding hemorrhage. The patient underwent exploratory laparotomy that revealed free blood in the peritoneum and a hemorrhagic mass arising from the stomach wall. The mass was successfully removed with no postoperative complications. Histopathological examination of the mass was consistent with an infarcted inflammatory HCA. This case illustrates this unusual presentation of a rare diagnosis.

Characteristics of atypical large well-differentiated hepatocellular carcinoma: a specific subtype of hepatocellular carcinoma?

BACKGROUND

Hepatocellular carcinoma (HCC) de-differentiation is thought to correlate with size, therefore well-differentiated HCC ≥3 cm are considered rare and not fully understood.

METHODS

Patients who underwent hepatectomy for HCC between 1998-2016 were retrospectively analyzed. Patient's characteristics and recurrence-free (RFS) and overall (OS) survival were compared between those with atypical- (well-differentiated-HCC ≥3 cm) and typical-HCC (moderate-to-poorly-differentiated HCC ≥3 cm).

RESULTS

Of 176 patients included in this study, 37 (21%) had atypical-HCC. Patients with atypical-HCC were less likely to be Asian ethnicity (3% vs. 17%, p = 0.062), have lower rate of viral infection (14% vs. 43%, p = 0.003), cirrhosis (8% vs. 27%, p = 0.015). The tumors were less likely to demonstrate vascular invasion (30% vs. 59%, p = 0.002), and were associated with a lower alpha-fetoprotein level (3.5 ng/ml vs. 33.2 ng/ml, p < 0.001). Patients with atypical-HCC had a longer RFS (5-y RFS: 58.3% vs. 35.7%, p = 0.016) and OS (5-y OS: 79.1% vs 53.3%, p = 0.029) as compared to those with typical-HCC following univariate analysis, however this did not appear following multivariate analysis.

CONCLUSION

Patients with atypical-HCC have different characteristic in terms of epidemiology, etiology, cirrhosis and vascular invasion as compared to typical-HCC. The etiology of atypical-HCC may be non-alcoholic fatty liver disease-related and/or malignant transformation of hepatocellular adenoma.

Current concepts in ablative procedures for primary benign liver lesions: a step forward to minimize the invasiveness of treatment when deemed necessary

With increased use of medical imaging, the incidental detection of benign solid liver tumors has become more frequent. Facing with benign disease, the indications for surgery are still object of discussion in light of the stable natural course of most lesions and obvious drawbacks of any surgical intervention; therefore, in most situations, a conservative approach is recommended, and surgery is mainly reserved for those cases with persistent or worsening symptoms, or who are at risk for complications as malignant transformation. The advent of ablative techniques has widened the range of treatment options available to these patients, presenting as a valid alternative to resection in terms of safety and efficacy in selected cases, particularly in patients who are considered poor surgical candidates and with smaller lesions. This review outlines the role of percutaneous ablative methods for benign solid liver tumors that are encountered in adults, providing a per histology analysis of the existing evidence. The up-to-date strategies for management of the most common benign solid tumors are recapitulated.

Management of patients with hepatocellular adenoma: a single-institution experience

BACKGROUND

Hepatocellular adenoma (HCA) is a rare benign liver tumour that may cause diagnostic and management dilemmas. This study describes the clinical and histopathological characteristics of patients who were treated for HCA in a tertiary referral hospital over a 17-year period.

METHODS

A retrospective review was performed of prospectively collected data of all patients treated for HCA within the Northern Upper GI Surgical unit between 2002 and 2018. Immunohistochemical β-catenin expression was evaluated.

RESULTS

Thirty-two patients had histological or radiologically confirmed HCA. Twenty-eight patients underwent 30 operations and four patients were treated conservatively. The median age of the operative group was 43 years (range 19-83) and most patients were female (95%). The median body mass index was 28.7 (range 20-51), and nine patients (33%) were obese. Seven patients (25%) had multifocal HCA. Evidence of prior bleed or rupture or a perceived risk of either a bleed or malignant change (i.e. tumours ≥50 mm) were the most common indications for resection. There were no perioperative mortalities. Nuclear expression of β-catenin by immunohistochemical staining was negative in all cases and there was no malignancy identified in any of the resected lesions. Two patients required transarterial embolization and two patients required a second liver resection for residual HCA.

CONCLUSION

HCA is a rare lesion predominantly affecting females. Haemorrhage is seen frequently on imaging studies, occasionally requiring urgent angioembolization and/or surgical intervention. Malignant transformation and immunohistochemical β-catenin expression are uncommon. HCA may be multifocal and residual tumours usually require ongoing surveillance and occasionally further intervention.

Case of resected multiple hepatocellular adenomas in a young man with severe obesity

BACKGROUND

Hepatocellular adenoma (HCA) is a rare liver tumor that has the potential for rupture and malignant transformation. Here, we report a case of multiple hepatocellular adenomas (HCAs) that were treated by surgical resection.

CASE PRESENTATION

An 18-year-old man was admitted to our hospital with proteinuria. His height was 176.5 cm, weight was 126 kg, and body mass index was 40 kg/m². A liver tumor was incidentally found on abdominal ultrasonography. Contrast-enhanced computed tomography and gadoxetic acid-enhanced magnetic resonance imaging revealed three hepatic tumors that were 68 mm, 16 mm, and 9 mm in segments 3/4, 8, and 1, respectively. A percutaneous needle biopsy of the largest tumor was performed, the diagnosis of unclassified type HCA was made, and laparoscopic partial liver resection was performed of all three. The postoperative course was uneventful, and the patient was discharged 12 days later. An immunohistochemical examination revealed positivity for serum amyloid A protein, no decrease in fatty acid-binding protein, and negativity for β-catenin, glutamine synthetase, and cytokeratin 7. Therefore, these tumors were diagnosed as inflammatory type HCAs.

CONCLUSIONS

We reported an extremely rare case of multiple resected HCAs in a young, obese Japanese man. Our findings suggest that HCA should be considered in the differential diagnosis of liver tumor in obese patients. Further studies that consider clinical and molecular risk factors are required to establish individualized treatment plans for HCA in obese patients.

Repeat surgery in HNF1alpha-inactivated adenomatosis

BACKGROUND AND AIMS

Stopping oral contraceptives following nodule detection usually prevents further hepatocellular growth (HCA); rare cases of growth have been reported after surgery. The aim of the study was to review our resected HCA cases and their outcomes and more specifically, growth.

METHODS

We retrieved all HCA cases that required a second intervention and HCA growth cases of none resected HCA after resection of one or several HCAs.

RESULTS

Out of the 210 resected classified HCA cases, a second resection was performed in 5 cases, 4 of which were in women with HNF1alpha-inactivated adenomatosis (H-adenomatosis) and had a favorable outcome. The fifth case was the occurrence of an inflammatory HCA, 3 years after resection of a previous one. Of the 65 resected HNF1-inactivated HCAs (H-HCAs), the nodules that remained continued to increase very slowly in 3 adenomatosis cases. After surgery, the liver became dysmorphic years later in one case, and the nodules grew but not significantly in another case. After the diagnosis of adenomatosis, progressive growth leads to surgery 12 years later in the last case.

CONCLUSION

These results confirm that, in rare H-adenomatosis, size of nodules may increase very slowly, probably in part through coalescence of micro H-HCAs and leading occasionally to a second resection.

Malignant transformation of hepatocellular adenoma in a young female patient after ovulation induction fertility treatment: A case report

BACKGROUND

Hepatocellular adenoma (HCA) is a rare benign liver tumor usually affecting young women with a history of prolonged use of hormonal contraception. Although the majority is asymptomatic, a low proportion may have significant complications such as bleeding or malignancy. Despite responding to the hormonal stimulus, the desire for pregnancy in patients with small HCA is not contraindicated. However, through this work we demonstrate that intensive hormonal therapies such as those used in the treatment of infertility can trigger serious complications

CASE SUMMARY

A 33-year-old female with a 10-year history of oral contraceptive use was diagnosed with a hepatic tumor as an incidental finding in an abdominal ultrasound. The patient showed no symptoms and physical examination was unremarkable. Laboratory functional tests were within normal limits and tests for serum tumor markers were negative. An abdominal magnetic resonance imaging (MRI) was performed, showing a 30 mm × 29 mm focal lesion in segment VI of the liver compatible with HCA or Focal Nodular Hyperplasia with atypical behavior. After a total of six years of follow-up, the patient underwent ovulation induction treatment for infertility. On a following MRI, a suspected malignancy was warned and hence, surgery was decided. The surgical specimen revealed malignant transformation of HCA towards trabecular hepatocarcinoma with dedifferentiated areas. There was non-evidence of tumor recurrence after three years of clinical and imaging follow-up.

CONCLUSION

HCAs can be malignant regardless its size and low-risk appearance on MRI when an ovultation induction therapy is indicated.

Bleeding Liver Masses: Imaging Features With Pathologic Correlation and Impact on Management

OBJECTIVE. The purposes of this article are to discuss a variety of liver masses that can present with hemorrhage, including their characteristic imaging features, and to propose a diagnostic approach. CONCLUSION. A broad spectrum of pathologic conditions can present as spontaneous hemorrhage within or surrounding the liver and may present acutely or as a chronic or incidental finding. Imaging characteristics and clinical history can often narrow the differential diagnosis and guide management.

Abdominal and pelvic imaging findings associated with sex hormone abnormalities

Hormones are substances that serve as chemical communication between cells. They are unique biological molecules that affect multiple organ systems and play a key role in maintaining homoeostasis. In this role, they are usually produced from a single organ and have defined target organs. However, hormones can affect non-target organs as well. As such, biochemical and hormonal abnormalities can be associated with anatomic changes in multiple target as well as non-target organs. Hormone-related changes may take the form of an organ parenchymal abnormality, benign neoplasm, or even malignancy. Given the multifocal action of hormones, the observed imaging findings may be remote from the site of production, and may actually be multi-organ in nature. Anatomic findings related to hormone level abnormalities and/or laboratory biomarker changes may be identified with imaging. The purpose of this image-rich review is to sensitize radiologists to imaging findings in the abdomen and pelvis that may occur in the context of hormone abnormalities, focusing primarily on sex hormones and their influence on these organs.

Current Approaches in the Management of Hepatic Adenomas

INTRODUCTION

Hepatic adenomas (HAs) are a benign and relatively rare type of liver neoplasms. We review the diagnosis, evaluation, and potential therapeutic management options for patients with HA.

METHODS

A comprehensive review of the English literature was performed utilizing MEDLINE/PubMed and Web of Science databases with end of search date the 30th April of 2018. In PubMed, the terms "hepatocellular," "hepatic," "liver," and "adenoma," "adenomatosis" were searched in the title and/or abstract.

RESULTS

Recent advances in molecular classification of HA have determined distinct subtypes with specific clinical, pathological, and imaging characteristics. In general, cessation of exogenous hormonal administration or weight loss may lead to HA regression. Surgical resection, either open or laparoscopic, should be considered in patients with symptoms and risk factors for hemorrhage or malignant transformation. These risk factors include tumor diameter greater than 5 cm, β-catenin activated subtype, and/or male gender. The management of acute hemorrhage should primarily aim at achieving hemodynamic stability via angioembolization followed by elective resection, whereas malignant transformation is treated according to oncologic resection principles. Although pregnancy is one of the known risk factors for tumor growth and associated complications, the presence of an HA per se should not be considered a contradiction to pregnancy.

CONCLUSION

Future genomic-based multicenter studies are required to provide a strong basis for formulating an evidence-based risk-adapted model that guides individualized management strategies for patients with HA.

Massive hepatic adenoma response to bland embolization: A case study

Hepatic adenomas are rare, benign liver masses of rising incidence in the United States. We present a report of a 22-year-old asymptomatic female with a massive (14.2 × 11.4 cm), centrally located hepatic adenoma. The unique presentation of the adenoma in close proximity to the hepatic vasculature meant the patient was not a candidate for surgical resection. An arterial embolization was used as an alternative approach to initial treatment. Arterial branches supplying the adenoma were identified via computed tomography and embolized with embospheres and coils. The treatment resulted in a large reduction in size and density of the adenoma identified at a 1-month follow-up. The case supports further use of arterial embolization as an initial treatment for large adenomas to improve the outcome of subsequent surgical approaches.

Regression of hepatocellular adenoma after bariatric surgery in severe obese patients

BACKGROUND & AIM

Obesity and metabolic syndrome are increasingly recognized as risk factors for hepatocellular adenomas (HCA). There is still sparse evidence whether weight loss or bariatric surgery could induce HCA regression in these patients. In this brief report we describe the effect of weight loss on HCA regression in severe obese patients that had undergone bariatric surgery in our centre.

METHODS

We performed an Electronic Patient Database search and included all patients who underwent bariatric surgery in our bariatric referral centre and had an ICD-10 code of benign neoplasm of liver in our centre from (2006-2017). All imaging studies of eligible patients were re-evaluated by the study radiologist. Primary outcome was change in maximal diameter of HCA.

RESULTS

Six of 11 eligible patients were excluded because their lesions were classified as probable focal nodular hyperplasia and two were lost to follow-up. Finally, three women with solitary (n = 1) or multiple HCA (n = 2) and a body mass index (BMI) ranging between 39 and 50 kg/m² were included. In two patients, HCA completely regressed in 1-2 years following bariatric surgery, after BMI reductions of 36%-48%. The third patient showed a reduction of >50% in diameter of the largest HCA in 2.5 years after bariatric surgery (31% BMI reduction), with complete resolution of smaller HCA.

CONCLUSIONS

Bariatric induced weight loss results in significant regression of HCA in severe obese women, which emphasizes the role of overweight in HCA pathophysiology.

Laparoscopic liver resection for hemorrhagic hepatocellular adenoma in a pregnant patient

INTRODUCTION

Hepatocellular adenoma (HCA) is a benign neoplasm of the liver, however, with a potential for life-threatening hemorrhage. The unpredictable course during pregnancy poses a clinical dilemma in the pregnant patient. Intra-peritoneal rupture may lead to life-threatening situations with adverse outcome for mother and unborn child. A pre-emptive strategy with adequate treatment before pregnancy is strongly advised. However, the strategy for treating symptomatic HCA during pregnancy remains challenging as experience is limited.

CASE PRESENTATION

A 31-year-old pregnant patient at the gestational age of 17 weeks presented with an acute episode of right upper abdomen pain. MR-imaging revealed a lesion of 9 cm located in segment III with stigmata of recent hemorrhage. At 18 weeks of gestation, she underwent a semi-elective laparoscopic left lateral sectionectomy.

RESULTS

Surgery and postoperative recovery were uneventful. Patient was discharged at POD +6. At 40 weeks of gestation, she went in spontaneous labor and delivered a healthy baby. Histological examination confirmed a HCA, inflammatory subtype, showing features of hemorrhage.

CONCLUSION

In the pregnant patient, HCA represents a significant diagnostic and therapeutic challenge. Anatomically favorable located lesions can be safely managed with laparoscopic liver resection. We suggest that laparoscopic liver resection should be considered as part of the currently available strategies for HCA during pregnancy.

A case of extensive hepatic adenomatosis in a renal transplant patient

Hepatic adenomatosis (HA) is a rare condition that is traditionally associated with oral contraceptive use, glycogen storage diseases or metabolic syndrome. Here we present a renal transplant recipient that was diagnosed with HA and has none of the traditional risk factors. We review the literature on diagnosing and managing HA.

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.

Long-term follow-up of hepatic adenoma and adenomatosis: analysis of size change on imaging with histopathological correlation

AIM

To analyse the change in size on follow-up of hepatic adenomas (HAs) and adenomatosis, and to investigate the relationship of imaging features with size change.

MATERIALS AND METHODS

The study included 44 patients (142 lesions) who underwent magnetic resonance imaging (MRI) or computed tomography (CT) for diagnosis and follow-up of HA. The imaging features and percentage change in maximum tumour dimension were observed over a follow-up duration of up to 139 months.

RESULTS

With an average follow-up of 43 months, 37% lesions decreased in size, 58% were stable, 4% increased; one lesion regressed completely. Adenomas were stratified into size groups (<3, 3-5, and ≥5 cm). Size change among the three groups was similar (p>0.05). Percent size change was different for lesions followed for ≤12 months (-7.2%) compared with lesions followed for 13-60 months (-20.5%), and those followed for ≥60 months (-23.5%; p<0.05); there was no difference between lesions followed for 13-60 months and ≥60 months (p=0.523). Baseline size and percent size change was similar between the hepatocyte nuclear factor 1α-inactivated HA (HA-H) and inflammatory HA (HA-I) subtype (p>0.05).

CONCLUSION

Most adenomas were either stable or regressed on follow-up. Size change was independent of baseline size. After an initial size decrease within 5 years, no further size reduction was noted on extended follow-up. The percent size change in the HA-H and HA-I subtype was similar.

HYPERVASCULAR LIVER LESIONS IN RADIOLOGICALLY NORMAL LIVER

Background:

The hypervascular liver lesions represent a diagnostic challenge.

Aim:

To identify risk factors for cancer in patients with non-hemangiomatous hypervascular hepatic lesions in radiologically normal liver.

Method:

This prospective study included patients with hypervascular liver lesions in radiologically normal liver. The diagnosis was made by biopsy or was presumed on the basis of radiologic stability in follow-up period of one year. Cirrhosis or patients with typical imaging characteristics of haemangioma were excluded.

Results:

Eighty-eight patients were included. The average age was 42.4. The lesions were unique and were between 2-5 cm in size in most cases. Liver biopsy was performed in approximately 1/3 of cases. The lesions were benign or most likely benign in 81.8%, while cancer was diagnosed in 12.5% of cases. Univariate analysis showed that age >45 years (p< 0.001), personal history of cancer (p=0.020), presence of >3 nodules (p=0.003) and elevated alkaline phosphatase (p=0.013) were significant risk factors for cancer.

Conclusion:

It is safe to observe hypervascular liver lesions in normal liver in patients up to 45 years, normal alanine aminotransaminase, up to three nodules and no personal history of cancer. Lesion biopsies are safe in patients with atypical lesions and define the treatment to be established for most of these patients.

Should we undertake surveillance for HCC in patients with NAFLD?

The pandemic of obesity and its related complications is rapidly changing the epidemiology of many types of cancer, including hepatocellular carcinoma (HCC). Non-alcoholic fatty liver disease (NAFLD) is becoming a major cause of HCC, with a steadily rising trend compared to viral or alcohol-induced chronic hepatitis. The much greater prevalence of the underlying liver disease in the general population and the chance of HCC occurrence in non-cirrhotic liver are the most worrisome aspects of HCC in NAFLD. Effective screening programmes are currently hampered by limited knowledge of the pathways of carcinogenesis and a lack of tools able to stratify the risk of HCC in the NAFLD population. Hence, poor surveillance has prevented the development of an adequate treatment for NAFLD-related HCC. Systemic and hepatic molecular mechanisms involved in hepatocarcinogenesis, as well as potential early markers of HCC are being extensively investigated. This review describes the current clinical impact of HCC in NAFLD and discusses the most important unmet needs for its effective management.

Fat-Containing Liver Lesions on Imaging: Detection and Differential Diagnosis

OBJECTIVE

The purpose of this article is to review how fat is detected on imaging and to discuss the differential diagnosis of fat-containing liver lesions.

CONCLUSION

Fat is a highly useful feature in characterizing liver lesions on imaging. Although a variety of liver lesions can show fat on cross-sectional imaging, the presence of fat usually indicates that the lesion is of hepatocellular origin. Less commonly, nonhepatocellular fatty lesions may be distinguished by ancillary clinical and imaging features.

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

The above article1 from Alimentary Pharmacology & Therapeutics, published online on 20 March 2017 in Wiley OnlineLibrary (www.onlinelibrary.wiley.com) has been retracted by agreement between the Authors, the Editor-in-Chief, R.E. Pounder, and John Wiley & Sons Ltd. The retraction has been agreed due to the inclusion of data accessible only during peer review for another journal.

Hepatic Adenomas in Adolescents and Young Women with Endometriosis Treated with Norethindrone Acetate

BACKGROUND

Endometriosis-ectopic implantation of endometrial-like tissue-affects 10% of female adolescents and adults. First-line treatment includes progesterone only (such as norethindrone acetate [NET-A]) or combined estrogen/progestin oral contraceptive pills. Estrogen-containing contraceptives confer increased risk of hepatic adenomas, whereas the association with NET-A is very rarely reported.

CASE

Three adolescents with stage I to II endometriosis managed with NET-A (up to 15 mg/d for 28-78 months) were diagnosed with hepatic adenomas at ages 17-22 years. They previously received estrogen-containing medications, which were stopped 24 months or longer before diagnosis of hepatic adenoma.

SUMMARY AND CONCLUSION

NET-A in a dose greater than 10 mg/d might be associated with increased risk for hepatic adenomas, likely due to peripheral conversion to ethinyl estradiol. Use of NET-A might not be advisable in patients with known hepatic adenomas.

Upregulated microRNA-429 inhibits the migration of HCC cells by targeting TRAF6 through the NF-κB pathway

Increasing evidence indicates that miR-429 is involved in tumor suppression in various human cancers. however, its role in hepatocellular carcinoma (HCC) remains unclear. In the present study, we found that miR-429 was significantly downregulated in HCC tissue samples and cell lines. Upregulation of miR-429 markedly suppressed proliferation and migration of HCC cells. Moreover, we identified TRAF6 as a direct target of miR-429. Downregulation of TRAF6 partially attenuated the oncogenic effect of anti‑miR-429 on HCC cells. Ectopic expression of miR-429 in HCC cells inhibited TCF-4 activity as well as nuclear accumulation of P65 and expression of the NF-κB targets c-Myc and phosphorylation of TAK1. In a nude xenograft model, miR-429 upregulation significantly decreased HCC growth. In conclusion, by targeting TRAF6, miR-429 is downregulated in HCC and inhibits HCC cell proliferation and motility. Our data suggest that miR-429 may serve as a potential anticancer target for the treatment of HCC.

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

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

Should fat in the radiofrequency ablation zone of hepatocellular adenomas raise suspicion for residual tumour?

OBJECTIVES

To assess the significance of fat in the radiofrequency ablation (RFA) zone of hepatocellular adenomas (HCA), and its association with tumoral fat and hepatic steatosis.

METHODS

The radiological archive was searched for patients with ablated HCAs and follow-up magnetic resonance imaging between January 2008 and June 2014. Age, sex, risk factors and duration of clinical and imaging follow-up were recorded. Pre-RFA imaging was assessed for tumour size, intra-tumoral fat and steatosis. Post-RFA imaging was reviewed for size, enhancement and intra-ablational fat. Intra-ablational fat was classified as peripheral, central or mixed; the association of these distributions with steatosis and tumoral fat was assessed using Fisher's exact test.

RESULTS

Sixteen patients with 26 ablated HCAs were included. Fat was present in 23/26 (88 %) ablation zones. Only 1/26 (4 %) showed serial enlargement and enhancement suggestive of residual disease; the enhancing area did not contain fat. All remaining ablations showed involution and/or diminishing fat content without suspicious enhancement (mean follow-up, 27 months; range, 2-84 months). The peripheral and mixed/central patterns of intra-ablational fat were associated with steatosis (P = 0.0005) and tumoral fat (P = 0.0003), respectively.

CONCLUSION

Fat in the ablation zone of HCAs is a common finding which, in isolation, does not indicate residual tumour.

KEY POINTS

• Fat in the RFA zone of HCAs is a common finding on MRI. • The distribution of fat is associated with hepatic steatosis and intra-tumoral fat. • In isolation, intra-ablational fat of treated HCAs does not indicate residual tumour.