Focal Nodular Hyperplasia in the Pediatric Population: A Multicenter Experience.

BACKGROUND: Focal nodular hyperplasia (FNH) is a benign liver lesion classically presenting in young females. In children, FNH is rare and its detailed clinicopathologic characteristics remain largely unknown. Furthermore, there are no studies comparing pediatric FNH features to those presenting in adults. METHODS: In this study, we analyzed a total of 47 FNH cases in pediatric patients (age range: 23 days to 18 years) from 3 centers and compared them to a cohort of 31 FNH cases in adult patients (age range: 20-64 years). RESULTS: Of the pediatric cases, 13 cases (28%) had a history of a prior malignancy of which 4 were treated with chemoradiation and stem cell transplantation (SCT), 5 with chemoradiation alone and 3 with chemotherapy and SCT. In the pediatric cases 41 (87%) had a central scar and 46 (98%) had fibrous septa. Both pediatric and adult FNH were more common in female patients. Cases in pediatric patients were also significantly associated with larger size (P = .047), absence of dystrophic vessels (P = .001), absence of sinusoidal dilatation (P = .029), pseudoacini formation (P = .013), and steatosis (P = .029). CONCLUSION: In our experience although most cases of pediatric FNH show the classic histologic features seen in adults, some significant differences exist, and awareness of these findings could aid in the evaluation of these rare cases.

[Benign solid liver tumors]. / Benigne solide Lebertumoren.

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.

Outcomes of transarterial embolization for large symptomatic focal nodular hyperplasia in 17 pediatric patients.

BACKGROUND: To evaluate the safety and the long-term outcomes of transarterial embolization (TAE) with lipiodol-bleomycin emulsion (LBE) plus N-Butyl cyanoacrylate (NBCA) in the treatment of children with large symptomatic focal nodular hyperplasia (FNH). METHODS: This is a retrospective case serial study. Children (aged <18 years) with FNH were treated. Indications for TAE were patients who were presenting with FNH related abdominal pain and the maximum diameter of FNH is more than 7 cm, and who were not candidates for surgical treatment. Technical success, adverse events, symptoms relief rate, and changes in the lesion size after TAE were evaluated. RESULTS: Between January 2003 and February 2018, 17 pediatric patients were included. Technical success was achieved in all patients. Mean follow-up was 67.5 months. All patients had complete resolution of abdominal symptom. The mean largest diameter of the lesions decreased from 10.5 cm to 1.9 cm (P < 0.01). The mean volume reduction rate was 96.9%. The complete resolution of the FNH was observed in 16 patients. No further therapy was needed for all patients. CONCLUSIONS: TAE with LBE plus NBCA appears to be a safe and effective treatment in pediatric patients with large symptomatic FNH. It could be considered as the first-line treatment for symptomatic large FNH.

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, ß-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.

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.

Management of benign liver tumors.

Benign liver tumors in children are far less frequent than their malignant counterparts. Recently, there have been advances of diagnostic procedures and novel treatments with improved classification as a result. While malignant pediatric liver tumors have been comprehensively addressed by multicenter international tumor trials, benign tumors have more usually relied upon individualised workup and treatment. Due to the rarity and heterogeneity of these different entities, large studies are lacking. In this article the authors highlight the spectrum of benign liver tumors with special focus on specific clinical features, pathology, and treatment.

Focal Nodular Hyperplasia and Hepatic Adenoma: Evaluation and Management.

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

Management of focal nodular hyperplasia of the liver: Experience of 50 pediatric patients in a tertiary center.

BACKGROUND: Focal nodular hyperplasia (FNH) is a rare benign hepatic lesion in children. No management guidelines for pediatric population exist because of limited evidence. OBJECTIVE: To review the experience of a large tertiary liver center, providing additional clinical data to help formulate management guidelines for FNH in the pediatric population. METHODS: We analyzed data of children <18 years diagnosed with FNH from 1996 to 2018 at our hospital, detailing management and long-term clinical outcome. RESULTS: 50 patients were identified. The median age was 10 years old (range 0.75-15.5 years old). The mean diameter of FNH was 5.9 cm (±3.1 cm). 10 patients had multiple lesions. First-line management: watchful waiting with serial checks (n = 37), surgery (n = 13). Of the watchful waiting patients, 10 required eventual second-line surgery. After a median follow-up of 4.7 years (range 0.5-20 years), 46 patients were asymptomatic, with no significant difference in clinical outcome (p = 0.962) between the two first-line management approaches. Lesions demonstrated growth in 13 cases: 5 of these required second-line surgery. In these patients, there was no significant difference in clinical outcome (p = 0.188) compared to nonoperative patients. Considering all surgically treated patients, there was no significant difference between first-line and second-line surgery for clinical outcome (p = 0.846), hospital stay (p = 0.410), complications (p = 0.510) and severe complications (p = 0.385). CONCLUSIONS: Our data support the hypothesis that watchful waiting is a safe initial approach to pediatric FNH management in patients with no major symptoms or complications. Surgery should be reserved for patients with diagnostic doubt, persistent symptoms and/or biological or significant anatomical abnormalities. FNH growth alone should not be considered as an indication for surgery. TYPE OF STUDY: Therapeutic study. LEVEL OF EVIDENCE: Level III.

[Management of benign liver tumors]. / Management benigner Lebertumoren.

Benign liver tumors form a heterogeneous group. The most frequent forms include simple cysts, hemangiomas, focal nodular hyperplasia and hepatocellular adenomas. They are often incidentally detected during routine sonography. The diagnosis of a liver tumor not uncommonly causes anxiety and insecurity in those affected, which is why a rapid and reliable diagnostic procedure should be carried out. Because some tumors, particularly hepatocellular adenomas, are of prognostic relevance due to the potential risk of malignant transformation, a correct classification should always be strived for. The type and extent of diagnostic clarification depend on the clinical and patient-related risk factors. This article describes the most important benign space-occupying lesions. The etiology, clinical manifestations and diagnostics as well as possible necessary treatment measures are presented.

[Benign liver tumours - current diagnostics and therapeutic modalities]. / A jóindulatú májdaganatok korszerû diagnosztikája és kezelési elvei.

The most common benign liver tumours are haemangiomas, focal nodular hyperplasia and hepatocellular adenoma. We perform a review of the literature and show the current diagnostic and therapeutic modalities based on the EASL Clinical Practice Guideline. With the widespread use of ultrasound, the detection of liver lesions is increased. They are usually found in women of childbearing age with atypical abdominal pain or incidentally. Contrast-enhanced US, CT or MRI are usually necessary for differential diagnosis. In atypical appearance or in malignancy suspect cases biopsy could be performed. For symptomatic patients conservative therapy can be sufficient. In haemorrhagic cases transarterial embolisation can be useful, also for tumour size decreasing before surgery. In patients with persisting symptoms, with vessel or soft tissue compression effect or in malignancy suspect cases definitive surgical treatment is advised. In men with hepatocellular adenoma primary resection is appropriate because of the higher risk for malignant transformation. As alternative treatment options radiofrequency ablation, irradiation, chemotherapy, monoclonal antibody therapy or liver transplantation are published.

Managing Focal Nodular Hyperplasia of the Liver: Surgery or Minimally-invasive Approaches? A Review of the Preferable Treatment Options.

BACKGROUND/AIM: Focal nodular hyperplasia (FNH) is the second most common benign tumor of the liver. As of 2017, many clinical, radiological and surgical features have been largely documented. On the other hand, little is still known about the correlation of FNH with hepatocellular carcinoma, nor the preferable modality of treatment. Our aim was to elucidate the latter topic. MATERIALS AND METHODS: We investigated the pertinent literature available as of 2017 through four popular search engines (PubMed, Science Direct, Scopus and Google Scholar). Four main approaches were selected: conservative treatment, surgery, radiofrequency ablation (RFA) and transarterial embolization (TAE). RESULTS: We found most works to be on conservative and surgical approaches. On the contrary, only one article has been published for RFA to date. Seventeen articles dealt with TAE. CONCLUSION: TAE currently represents the most cogent and successful alternative to surgery.

Transarterial embolization with bleomycin for symptomatic hepatic focal nodular hyperplasia.

PURPOSE: We aimed to evaluate the therapeutic effect and safety of transarterial embolization using bleomycin-iodinated oil and polyvinyl alcohol particles for the treatment of symptomatic hepatic focal nodular hyperplasia (FNH). METHODS: This retrospective study included 23 consecutive patients with symptomatic hepatic FNH, who underwent embolization using bleomycin-iodinated oil and polyvinyl alcohol particles between January 2005 and December 2012. Patients were followed-up with radiologic and clinical evaluation. Therapeutic effects including changes in lesion size and symptomatic improvement were evaluated after the procedure. RESULTS: Embolization was performed for 27 lesions in 23 patients. Follow-up period ranged from three months to 89 months. The mean lesion diameters decreased significantly from 5.0±2.4 cm to 3.2±1.5 cm at 3-9 months after embolization (P < 0.001). Five lesions had complete resolution in the follow-up period. The clinical symptoms were significantly relieved in all patients. Contrast-enhanced scans at follow-up showed complete lack of residual arterial blood supply in the majority of lesions. Local recurrence was found in one treated lesion at the 54-month follow-up. There were no major complications associated with the procedure. CONCLUSION: Transarterial embolization using bleomycin-iodinated oil and polyvinyl alcohol particles for hepatic FNH is a safe and effective alternative treatment with good long-term symptomatic control and reduction in lesion size after embolization.

Molecular patterns of diffuse and nodular parathyroid hyperplasia in long-term hemodialysis.

Secondary hyperparathyroidism is a well-known complication of end-stage renal disease (ESRD). Both nodular and diffuse parathyroid hyperplasia occur in ESRD patients. However, their distinct molecular mechanisms remain poorly understood. Parathyroid tissue obtained from ESRD patients who had undergone parathyroidectomy was used for Illumina transcriptome screening and subsequently for discriminatory gene analysis, pathway mapping, and gene annotation enrichment analysis. Results were further validated using quantitative RT-PCR on the independent larger cohort. Microarray screening proved homogeneity of gene transcripts in hemodialysis patients compared with the transplant cohort and primary hyperparathyroidism; therefore, further experiments were performed in hemodialysis patients only. Enrichment analysis conducted on 485 differentially expressed genes between nodular and diffuse parathyroid hyperplasia revealed highly significant differences in Gene Ontology terms and the Kyoto Encyclopedia of Genes and Genomes database in ribosome structure (P = 3.70 × 10-18). Next, quantitative RT-PCR validation of the top differently expressed genes from microarray analysis proved higher expression of RAN guanine nucleotide release factor (RANGRF; P < 0.001), calcyclin-binding protein (CACYBP; P < 0.05), and exocyst complex component 8 (EXOC8; P < 0.05) and lower expression of peptidylprolyl cis/trans-isomerase and NIMA-interacting 1 (PIN1; P < 0.01) mRNA in nodular hyperplasia. Multivariate analysis revealed higher RANGRF and lower PIN1 expression along with parathyroid weight to be associated with nodular hyperplasia. In conclusion, our study suggests the RANGRF transcript, which controls RNA metabolism, to be likely involved in pathways associated with the switch to nodular parathyroid growth. This transcript, along with PIN1 transcript, which influences parathyroid hormone secretion, may represent new therapeutical targets to cure secondary hyperparathyroidism.

Incidentally Detected Focal Liver Lesions - A Common Clinical Management Dilemma Revisited.

BACKGROUND: Detection of asymptomatic focal liver lesions (FLL) is increasing because of a widespread use of modern radiologic imaging. Most of these lesions are benign, though malignancy often has to be ruled out, which is posing a diagnostic challenge. AIM: To critically evaluate our treatment strategy in the context of recently published American College of Gastroenterology (ACG) guidelines. PATIENTS AND METHODS: The medical records of patients who underwent surgery for asymptomatic, incidentally detected FLL from 2005-2012 were reviewed. Primary end-points were the congruence of suspected diagnosis and final pathology, as well as the identification of predictors of malignancy. A systematic review was undertaken to help define a standardized management. RESULTS: Eighty patients, 37 male and 43 female with a mean age of 57 years (range=16-83) were included, harboring 39 (49%) malignant and 41 (51%) benign, asymptomatic hepatic lesions. Hepatocellular carcinoma (HCC) (n=24) represented most of malignant FLL, followed by cholangiocellular carcinoma (CCC) (n=10), whereas focal nodular hyperplasia (FNH) (n=19) and liver hemangioma (n=7) were the predominant benign entities. Fifty-one patients (64%) had a correct preoperative diagnosis, while patients with FNH were most commonly misdiagnosed (53%). We identified age (p<0.001) and male sex (p=0.013) as risk factors for malignancy in an asymptomatic FLL. CONCLUSION: Despite recent technical advances of the modern radiology setting a correct preoperative diagnosis in an asymptomatic FLL remains challenging. Male gender and old age seem to correlate with malignancy. In the absence of biomarkers and evidence-based guidelines, a multidisciplinary approach in an experienced tertiary referral center is recommended for an optimized individual management.

[Benign liver tumours - diagnosis and management]. / Diagnostik og behandling af benigne levertumorer.

Due to the expanding use of diagnostic imaging, an increasing number of liver tumours are discovered. Benign tumours are very common; they rarely cause symptoms and often they do not require any treatment. However, because of differences in the natural history including risk of complications and malignant transformation exact diagnosis is important. Dedicated radiological examinations serve as important diagnostic tools reducing the need for biopsy. In this review we provide an update on the diagnosis and treatment of benign liver tumours adding to existing recommendations on hepatocellular carcinomas and adenomas.

Multidetector computed tomography angiography in the management of transarterial embolization of primary and secondary liver malignancy.

BACKGROUND: Endovascular management is the mainstay of therapy for most patients with primary and secondary liver tumors. Radiologist should understand the anatomy of the hepatic vasculature and tumor feeding vessels to ensure successful conduction of the embolization procedure. The aim of this study was to evaluate the accuracy of multidetector computed tomographic angiography (MDCTA) for the evaluation of hepatic arterial anatomy and tumor feeding vessels prior to embolization procedure. METHODS: This study included 42 patients. They were 30 with hepatocellular carcinoma, 6 with colorectal cancer metastases, 3 with intrahepatic cholangiocellular carcinoma, 2 with giant focal nodular hyperplasia and 1 with gallbladder tumor. The findings of MDCTA were compared with the DSA findings, which served as the standard of reference. Sensitivity and specificity of the MDCTA were calculated. RESULTS: MDCTA showed 100% coincidence with the DSA and 100% accuracy in the evaluation of gross hepatic arterial anatomy and its variations. 61 out of the 64 feeders were correctly identified with the MDCTA. False positives and false negatives were 3 each. Accordingly sensitivity and specificity were 95.31%, 97.95% respectively. CONCLUSIONS: MDCT angiography permits accurate assessment of the hepatic vascular anatomy. Although some pathways of tumor irrigation may not be well visible on the computed tomography. These require detailed reevaluation of suspected tumor feeders during embolization procedure.

Clinical Features of Focal Nodular Hyperplasia of the Liver in Children.

BACKGROUND: Focal nodular hyperplasia (FNH) is a benign hepatic lesion that is rare in children. The aim of the present study was to review the clinical features of children with FNH and our institution's experience in the management of this rare disease. METHODS: A review of the medical records of children diagnosed as having FNH between 1999 and 2013 at West China Hospital of Sichuan University was undertaken. RESULTS: Seventy-nine patients with FNH were identified: 68 patients without a history of malignancy and 11 patients with a history of malignancy. Thirty-seven (46.8%) patients were symptomatic at presentation. Patients with a history of malignancy had smaller FNH lesions and were less likely to have a central scar in FNH than do patients without a history of malignancy. Forty-seven patients underwent liver resection because of concern for malignancy, symptoms, and/or large lesions. Three patients were treated by embolization because of compression of the adjacent organs. There was no operative death or severe postoperative complications. Fourteen patients underwent liver biopsy to rule out malignant masses. The remaining 15 patients were managed expectantly with imaging surveillance. On follow-up, 2 patients for whom observation was initially recommended eventually required resection because of a mass effect. CONCLUSIONS: The clinical features of pediatric FNH are variable and can be nonspecific. Our data emphasize the therapeutic approach that active management is indicated in symptomatic or progressive FNH and in children with diagnostic difficulties, whereas observation management is recommended in asymptomatic children with a definitive diagnosis.

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

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

RESUMO As lesões que ocupam espaço no fígado podem ser císticas ou sólidas. A ultrassonografia é extremamente útil como rastreamento inicial, bastando como método diagnósticos em casos de cistos simples. Em cistos complexos e em nódulos sólidos é necessária a complementação diagnóstica com tomografia computadorizada ou ressonância magnética. Em casos de cistadenoma ou cistadenocarcinoma, a ampla retirada cirúrgica está indicada. Dados clínico-epidemiológicos são importantes, já que nódulos em fígados não-cirróticos têm maiores probabilidades de serem benignos. Para os hemangiomas, tumores benignos mais frequentes, após a confirmação diagnóstica não existe necessidade de acompanhamento sistemático quando os nódulos são pequenos e assintomáticos. Hemangiomas gigantes sintomáticos ou comprimindo órgãos vizinhos devem ser encaminhados a centros de referência para avaliação de intervenção cirúrgica. A heterogeneidade genética nos adenomas hepatocelulares bem como características epidemiológicas e prognósticas motivou sua classificação em quatro subtipos, com base em achados histológicos e de imunohistoquímica. As principais complicações que ocorrem com o adenomas hepatocelulares são ruptura com hemorragia e transformação carcinomatosa. A primeira ocorre em cerca de 30% dos casos e o principal fator de risco para esta complicação são tumores maiores do que 5 cm, do subtipo hiperplasia nodular focal 1A, esses medicamentos devem ser suspensos. A hiperplasia nodular focal é o segundo tumor benigno mais frequente, mais comum nas mulheres entre 20 e 60 anos, sendo assintomáticos em 70% a 90% dos casos. Na ausência de lesão cicatricial central e/ou outros sinais sugestivos de hiperplasi nodular focal, havendo dúvida diagnóstica com adenoma hepatocelular, o uso de contraste hepatespecíficos está indicado.

Transarterial embolisation of a large focal nodular hyperplasia, using microspheres, in a paediatric patient.

Benign liver tumours are uncommon in children, haemangiomas being the most frequent. Focal nodular hyperplasia (FNH) represents about 2% of paediatric liver tumours. In children, as in adults, a conservative approach is generally recommended. However, large lesions (greater than 5 cm) are more frequent in the paediatric age group, and in these cases, as well as in growing lesions, surgical removal may be advised. Transarterial embolisation (TAE) has been a successful alternative option described in older patients, especially in cases where surgical removal is not possible. This minimally invasive procedure may also become an option in the paediatric group. The authors report the case of a boy with a large FNH treated with TAE using microspheres.

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

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