Liver cell adenoma and liver cell adenomatosis

Androgen-Induced, β-Catenin-Activated Hepatocellular Adenomatosis with Spontaneous External Rupture

Androgens have long been recognized as oncogenic agents. They can induce both benign and malignant hepatocellular neoplasms, including hepatocellular adenoma (HCA) and hepatocellular carcinoma, though the underlying mechanisms remain unclear. Androgen-induced liver tumors are most often solitary and clinically silent. Herein, we reported an androgen-induced HCA complicated by spontaneous rupture. The patient was a 24-year-old male presenting with fatigue, diminished libido, radiology-diagnosed hepatocellular adenomatosis for 3 years, and sudden-onset, severe, sharp, constant abdominal pain for one day. He used Aveed (testosterone undecanoate injection) from age 17 and completely stopped one year before his presentation. A physical exam showed touch pain and voluntary guarding in the right upper quadrant of the abdomen. An abdominal CT angiogram demonstrated multiple probable HCAs, with active hemorrhage of the largest one (6.6 × 6.2 × 5.1 cm) accompanied by large-volume hemoperitoneum. After being stabilized by a massive transfusion protocol and interventional embolization, he underwent a percutaneous liver core biopsy. The biopsy specimen displayed atypical hepatocytes forming dense cords and pseudoglands. The lesional cells diffusely stained β-catenin in nuclei and glutamine synthetase in cytoplasm. Compared to normal hepatocytes from control tissue, the tumor cells were positive for nuclear AR (androgen receptor) expression but had no increased EZH2 (Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit) protein expression. The case indicated that androgen-induced hepatocellular neoplasms should be included in the differential diagnosis of acute abdomen.

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.

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.

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.

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.

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.

Case Report: Hepatic Adenomatosis in a Patient With Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a genetic disorder caused by the lack of expression of genes on the paternally inherited chromosome region 15q11.2-q13. It is a multisystem disorder that is characterized by severe hypotonia with poor suck and feeding difficulties in early infancy, followed in early childhood by excessive eating and gradual development of morbid obesity. The incidence of type 2 diabetes mellitus is high, particularly in obese patients. Non-alcoholic fatty liver disease has also been reported in some patients with PWS. Liver adenomatosis is a benign vascular lesion of the liver, defined by the presence of >10 adenomas, in the otherwise healthy liver parenchyma. We report the first case of a patient with PWS with severe obesity, type 2 diabetes mellitus, and non-alcoholic fatty liver who also developed liver adenomatosis, review the pediatric literature on liver adenomatosis, and discuss the potential underlying mechanisms.

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.

Value of discrepancy of the central scar-like structure between dynamic CT and gadoxetate disodium-enhanced MRI in differentiation of focal nodular hyperplasia and hepatocellular adenoma

PURPOSE

To identify the value of discrepancies in the central scar (CS)-like structure between dynamic CT and gadoxetate disodium-enhanced MRI for differentiating FNH from HCA.

METHODS

This retrospective study included 113 patients with pathologically-diagnosed FNH (n = 80) or HCA (n = 37). CS-like structures were evaluated on arterial phase (AP) CT and hepatobiliary phase (HBP) MRI. Presence of the CS-like structure, its discrepancy in visibility or size between AP CT and HBP MRI and between AP and HBP MRI, and features of non-scarred tumor portion were evaluated by two radiologists. Inter-observer agreement was evaluated by intraclass correlation coefficients (ICCs) and weighted kappa. Univariable and multivariable logistic regression and ROC analysis were performed to explore features differentiating FNH from HCA.

RESULTS

Inter-observer agreement was moderate-to-excellent (ICCs≥0.74, kappa≥0.65). On univariable analysis, presence of CS-like structures (P < 0.001), discrepancy of the CS-like structures between AP CT and HBP MRI (73.8 % in FNH; 16.2 % in HCA, P < 0.001) and between AP and HBP MRI (70.0 % in FNH; 16.2 % in HCA, P < 0.001), and the features of non-scarred tumor portion (P ≤ 0.011) were significantly different between FNH and HCA. On multivariable analysis, the discrepancy of CS-like structures between AP CT and HBP MRI, and the absence of low SI of the non-scarred tumor portion on HBP MRI, were suggestive of FNH (P = 0.036 and P < 0.001, respectively; area under the ROC curve, 0.96 [95 % CI, 0.93-0.99]).

CONCLUSION

Evaluation of discrepancy in the visibility or size of CS-like structures between dynamic CT and gadoxetate disodium-enhanced MRI may facilitate the differentiation of FNH from HCA.

HBP-enhancing hepatocellular adenomas and how to discriminate them from FNH in Gd-EOB MRI

BACKGROUND

Recent studies provide evidence that hepatocellular  adenomas  (HCAs) frequently take up gadoxetic acid (Gd-EOB) during the hepatobiliary phase (HBP). The purpose of our study was to investigate how to differentiate between Gd-EOB-enhancing HCAs and focal nodular hyperplasias (FNHs). We therefore retrospectively included 40 HCAs classified as HBP Gd-EOB-enhancing lesions from a sample of 100 histopathologically proven HCAs in 65 patients. These enhancing HCAs were matched retrospectively with 28 FNH lesions (standard of reference: surgical resection). Two readers (experienced abdominal radiologists blinded to clinical data) reviewed the images evaluating morphologic features and subjectively scoring Gd-EOB uptake (25-50%, 50-75% and 75-100%) for each lesion. Quantitative lesion-to-liver enhancement was measured in arterial, portal venous (PV), transitional and HBP. Additionally, multivariate regression analyses were performed.

RESULTS

Subjective scoring of intralesional Gd-EOB uptake showed the highest discriminatory accuracies (AUC: 0.848 (R#1); 0.920 (R#2)-p < 0.001) with significantly higher uptake scores assigned to FNHs (Cut-off: 75%-100%). Typical lobulation and presence of a central scar in FNH achieved an accuracy of 0.750 or higher in at least one reader (lobulation-AUC: 0.809 (R#1); 0.736 (R#2); central scar-AUC: 0.595 (R#1); 0.784 (R#2)). The multivariate regression emphasized the discriminatory power of the Gd-EOB scoring (p = 0.001/OR:22.15 (R#1) and p < 0.001/OR:99.12 (R#2). The lesion-to-liver ratio differed significantly between FNH and HCA in the PV phase and HBP (PV: 132.9 (FNH) and 110.2 (HCA), p = 0.048 and HBP: 110.3 (FNH) and 39.2 (HCA), p < 0.001)), while the difference was not significant in arterial and transitional contrast phases (p > 0.05).

CONCLUSION

Even in HBP-enhancing HCA, characterization of Gd-EOB uptake was found to provide the strongest discriminatory power in differentiating HCA from FNH. Furthermore, a lobulated appearance and a central scar are more frequently seen in FNH than in HCA.

Unclassified hepatocellular adenoma with beta-catenin mutation: a case report

Background

Hepatocellular adenoma (HCA) subtypes are considered as risk factors for malignant transformation; thus, an accurate diagnosis is important. We report a case of resected HCA previously diagnosed as unclassified HCA using immunohistochemistry, subsequently discovered to harbor a mutation in exon 3 of the beta (β)-catenin gene using deoxyribonucleic acid (DNA) sequencing.

Case presentation

The patient was a 26-year-old woman who was referred to our hospital because of a 150-mm tumor in the right lobe of the liver. Considering the possibility of malignancy, we performed right lobe hepatectomy. Based on the histopathological and immunohistochemical findings, the tumor was diagnosed as an unclassified HCA. Next, we performed sequencing of DNA isolated from the tumor and identified a mutation in exon 3 of β-catenin, suggesting that the tumor contained an activating mutation of the β-catenin gene.

Conclusion

β-Catenin mutations in HCA cannot be detected by immunohistochemistry alone, and molecular analysis is required to accurately diagnose and evaluate its prognosis.

Overview of spontaneous intraabdominal tumor hemorrhage: etiologies, imaging findings, and management

Hemorrhage is a potential complication of benign and malignant tumors and tumor-like conditions in the abdomen. Patients often have non-specific presentations, although they may present critically ill and hemodynamically unstable. Imaging plays an important role not only in the diagnosis of hemorrhage but also in the detection and characterization of an underlying mass. Ultrasound, computed tomography, and magnetic resonance imaging are utilized in evaluating these patients, with each having particular strengths and limitations. Spontaneous tumor hemorrhage is most commonly seen in hepatic and renal lesions, although it can arise from nearly every abdominal organ. In this article, we will review principles of tumor hemorrhage, illustrate common and uncommon imaging features, and highlight different options for management.

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.

Liver adenomatosis in patients with hepatocyte nuclear factor-1 alpha maturity onset diabetes of the young (HNF1A-MODY): Clinical, radiological and pathological characteristics in a French series

BACKGROUND

Liver adenomatosis (LA) is a rare disease resulting from biallelic inactivation of the hepatocyte nuclear factor-1 alpha (HNF1A) gene, which induces the proliferation of adenoma cells in liver parenchyma. Liver adenomatosis has only been documented in case reports from patients carrying a HNF1A germline mutation. We have evaluated the frequency of LA among a large cohort of patients with HNF1A-maturity onset diabetes of the young (MODY), previously termed "MODY3," and herein describe its clinical, radiological, and pathological characteristics.

METHODS

In all, 137 HNF1A-MODY subjects from 74 families were screened by liver ultrasonography in 13 centers, and 15 additional cases of LA were later included in the series. Liver adenomatosis was confirmed by liver computed tomography, magnetic resonance imaging (MRI), and/or histopathology.

RESULTS

Among 137 carriers of an HNF1A mutation, 9 patients (6.5%) from seven families were diagnosed with LA. Diabetes mellitus was present in 87.5% of patients with LA. In 25% of patients, LA was diagnosed due to intra-abdominal or intratumoral bleeding. Liver biochemistry was near normal in all patients. Liver imaging showed adenomas of various sizes and numbers. On MRI, most nodules had the radiological characteristics of steatotic adenomas. Histopathological confirmation of LA was available in 13 cases, and these adenomas were mostly steatotic. Surgery was initially performed in 37.5% of patients, and liver disease progression was observed in 30%. No disease progression was observed in 14 pregnancies.

CONCLUSIONS

The frequency of LA in a cohort of screened HNF1A-MODY patients and the high incidence of LA progression and/or hemorrhage warrants systematic screening for liver adenomatosis in HNF1A-MODY families.

A rare case of hepatocellular carcinoma arising from gadoxetate-retaining hepatic adenoma

Hepatocellular adenomas (HCAs) are benign lesions of the liver which can rarely undergo malignant transformation. We report a 26-year-old woman with no underlying liver disease found to have an incidental liver lesion on noncontrast CT during workup for gastric reflux. Follow up MRI revealed a 10 cm gadoxetate-retaining lesion within the right hepatic lobe with imaging features suggestive of HCA vs focal nodular hyperplasia . Within this lesion was a focus of arterial enhancement with venous washout suggestive of hepatocellular carcinoma (HCC) within HCA, later confirmed at surgical resection. Understanding the imaging characteristics of HCAs as well as their rare ability to undergo malignant transformation is useful in differentiating HCAs from focal nodular hyperplasia.

Hepatocellular Adenoma in a Patient with Ornithine Transcarbamylase Deficiency

Ornithine transcarbamylase (OTC) deficiency is an X-linked recessive disorder that leads to hyperammonemia and liver damage. Hepatocellular adenoma in OTC deficiency patients has not been previously described. Here we report the first such case to be described in the English language scientific literature.

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.

Safety and efficacy of transarterial embolization of hepatocellular adenomas

BACKGROUND

Hepatocellular adenoma (HCA) larger than 5 cm in diameter has an increased risk of haemorrhage and malignant transformation, and is considered an indication for resection. As an alternative to resection, transarterial embolization (TAE) may play a role in prevention of complications of HCA, but its safety and efficacy are largely unknown. The aim of this study was to assess outcomes and postembolization effects of selective TAE in the management of HCA.

METHODS

This retrospective, multicentre cohort study included patients aged at least 18 years, diagnosed with HCA and treated with TAE. Patient characteristics, 30-day complications, tumour size before and after TAE, symptoms before and after TAE, and need for secondary interventions were analysed.

RESULTS

Overall, 59 patients with a median age of 33.5 years were included from six centres; 57 of the 59 patients were women. Median tumour size at time of TAE was 76 mm. Six of 59 patients (10 per cent) had a major complication (cyst formation or sepsis), which could be resolved with minimal therapy, but prolonged hospital stay. Thirty-four patients (58 per cent) were symptomatic at presentation. There were no significant differences in symptoms before TAE and symptoms evaluated in the short term (within 3 months) after TAE (P = 0·134). First follow-up imaging was performed a median of 5·5 months after TAE and showed a reduction in size to a median of 48 mm (P < 0·001).

CONCLUSION

TAE is safe, can lead to adequate size reduction of HCA and, offers an alternative to resection in selected patients.

EASL Clinical Practice Guidelines: Drug-induced liver injury

Idiosyncratic (unpredictable) drug-induced liver injury is one of the most challenging liver disorders faced by hepatologists, because of the myriad of drugs used in clinical practice, available herbs and dietary supplements with hepatotoxic potential, the ability of the condition to present with a variety of clinical and pathological phenotypes and the current absence of specific biomarkers. This makes the diagnosis of drug-induced liver injury an uncertain process, requiring a high degree of awareness of the condition and the careful exclusion of alternative aetiologies of liver disease. Idiosyncratic hepatotoxicity can be severe, leading to a particularly serious variety of acute liver failure for which no effective therapy has yet been developed. These Clinical Practice Guidelines summarize the available evidence on risk factors, diagnosis, management and risk minimization strategies for drug-induced liver jury.

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.

Malignant degeneration of hepatic adenomas to hepatocellular carcinoma

Background Hepatic adenomas (HA) are rare, benign proliferations of hepatocytes with high glycogen and fat content that lack normal hepatic architecture. In general, the long-term incidence of malignant degeneration to HCC has not been well characterized. This case report discusses a 37 male with a 10-year history of weekly anabolic steroid abuse who presented with bilobar hepatic adenomas with subsequent malignant degeneration to hepatocellular carcinoma (HCC). Case Presentation Our patient is a 37 old male with a 10-year history of weekly anabolic steroid abuse who presented to his primary care physician (PCP) in July 2013 with intermittent right upper quadrant (RUQ) pain. He was subsequently referred to our cancer center after abdomen/pelvis computed tomography (CT A/P) with oral and intravenous (IV) contrast at an outside hospital revealed two large hepatic masses. The larger mass in segment 2 measured 6.5 x 9.1 cm, while the segment 6/7 mass measured 7.5 x 7.6 cm. Abdomen magnetic resonance imaging (MRI) with and without IV contrast performed at our institution on July 23, 2013 confirmed the presence of the two above noted masses, which were felt to be consistent with probable HA, although HCC could not be definitely ruled out. Of note, his carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) were within normal limits. Percutaneous, ultrasound-guided (US) biopsy of the left lobe mass was consistent with probable HA, although HCC could not be definitely ruled out. Conclusion We present the case of a 37-year-old male 10-year history of weekly anabolic steroid abuse who presented to us in 2013 with HA which had malignant degeneration to HCC while on surveillance over a 2-year period. This case report stresses the importance of having a high clinical suspicion for HA in patients with a history of anabolic steroid abuse and liver masses. Additionally, it reiterates that it can be difficult to differentiate HA from well-differentiated HCC on imaging and/or with a limited biopsy. Furthermore, it is important to keep in mind that the growth of a mass, especially off steroids is highly concerning for malignancy (and masses that fail to regress completely can harbor occult HCC).

Hemorrhage of hepatocellular adenoma: a complication that can be treated by conservative management without surgery

BACKGROUND

Hemorrhage is the main complication of hepatocellular adenoma (HCA). The aim of this study was to describe a single center's evolving management of patients with hemorrhagic HCA.

METHOD

Between 1990 and 2013, all patients with hemorrhagic HCA were included. During the study period, the management evolved from urgent surgery (period <2004) to arterial embolization with (period, 2004-2010) or without (period > 2010) delayed resection.

RESULTS

A total of 56 patients were identified. The median (range) size of HCA and the hematoma was 80 mm (35-160) and 50 mm (10-160). Patients were treated by urgent resection (group 1, n = 6), delayed resection with or without embolization (group 2, n = 43) and systematic embolization without surgery (group 3, n = 7). Embolization was performed in 0/6, 15/43 and 7/7 in groups 1, 2 and 3. Urgent resection was associated with higher morbidity (p < 0.001). Complete necrosis was observed in 0/6, 13/43 and 3/7 patients, and on histology it was associated with embolization (p = 0.001), a hematoma-tumor ratio > 60% (p = 0.046) and a cystic non-viable lesion before surgery (p < 0.001).

CONCLUSION

Hemodynamic stability can be achieved in patients presenting with hemorrhagic HCA by none surgical means. Subsequent surgery can be completely avoided with such an approach in up to 40% of patients.

Primary Liver Cancers-Part 1: Histopathology, Differential Diagnoses, and Risk Stratification

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the 2 most common primary malignant liver tumors, with hepatocellular and bile ductular differentiation, respectively. This article reviews the key histopathological findings of these 2 primary liver cancers and includes a review of the role of ancillary testing for differential diagnosis, risk stratification according to the American Joint Committee on Cancer (AJCC) staging recommendation, and a review of precancerous lesions. A literature review was conducted to identify articles with information relevant to precancerous precursors, current histopathological classification, ancillary testing, and risk stratification of primary malignant liver tumors. The histomorphology of normal liver, preinvasive precursors, primary malignancies, and morphological variants, and the utilization of ancillary tests for the pathological diagnosis are described. Dysplastic nodules are the preinvasive precursors of HCC, and intraductal papillary neoplasms of bile ducts and biliary intraepithelial neoplasia are the preinvasive precursors of CC. Benign liver nodules including focal nodular hyperplasia and adenomas are included in this review, since some forms of adenomas progress to HCC and often they have to be differentiated from well-differentiated HCC. A number of morphological variants of HCC have been described in the literature, and it is necessary to be aware of them in order to render the correct diagnosis. Risk stratification is still dependent on the AJCC staging system. The diagnosis of primary liver carcinomas is usually straightforward. Application of the appropriate ancillary studies aids in the differential diagnosis of difficult cases. The understanding of the carcinogenesis of these malignancies has improved with the standardization of the pathological classification of preinvasive precursors and studies of the molecular pathogenesis. Risk stratification still depends on pathological staging.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

Indications for liver surgery in benign tumours

Background

Management of benign liver tumours (BLT) is still object of discussion. Uncertainty still exists about patient selection, details of management, indications for surgical intervention and potential surgery-related complications. The up-to-date strategies for management of the most common benign solid tumours are recapitulated in this article. In addition, recommendations concerning practical issues are presented.

Methods

Available data from peer-reviewed publications associated with the major controversies concerning treatment strategies of solid BLT were selected through a PubMed literature search.

Results

Non-randomized controlled trials, retrospective series and case reports dominate the literature. Conservative management in BLT is associated with low overall morbidity and mortality when applied in an appropriate patient population. Surgical intervention is indicated solely in the presence of progressive symptoms and suspicion of a malignant change. Linking abdominal symptoms to BLT should be interpreted with caution. No evidence is recorded for malignant transformation in haemangiomas and focal nodular hyperplasia (FNH), while a subgroup of hepatocellular adenoma (HCA) is associated with malignancy. Follow-up controls of BLT at 3 and 6 months should be sufficient to prove the stability of the lesion and its benign nature, after which no long-term follow-up is required routinely. However, many questions regarding this topic remain without definitive answers in the literature.

Conclusion

Conservative management of solid BLT is a worldwide trend, but the available literature does not provide high-grade evidence for this strategy. Consequently, further prospective investigations on the unclear aspects are required. Hence, this article summarises practical highlights of therapeutic strategies.

Inflammatory hepatic adenomas: Characterization with hepatobiliary MRI contrast agents

PURPOSE

To characterize the MRI appearance of inflammatory hepatic adenomas using hepatobiliary contrast agents.

MATERIALS AND METHODS

MRI was performed using hepatobiliary contrast agents (3 with gadobenate dimeglumine and 24 with gadoxetic acid) in 27 patients with immunohistochemistry-confirmed diagnosis of inflammatory hepatic adenoma. The appearance of the lesions on T2 and diffusion-weighted images, pre-gadolinium T1-weighted images, dynamic post-gadolinium images, and hepatobiliary phase images was assessed.

RESULTS

Seven lesions (26%) showed predominant hyperenhancement on hepatobiliary phase images in comparison with adjacent hepatic parenchyma: 1 lesion showed diffuse, mildly heterogeneous hyperenhancement, and the remaining 6 lesions showed peripheral hyperenhancement and central hypoenhancement. Twenty lesions (74%) were predominantly hypoenhancing compared to adjacent liver on hepatobiliary phase images. Nine lesions showed a pattern of peripheral hyperenhancement and central hypoenhancement on hepatobiliary phase images; in 6 of these lesions a majority of the mass appeared hyperenhancing, while the remaining 3 lesions showed predominant hypoenhancement.

CONCLUSIONS

This investigation shows that a significant percentage of inflammatory hepatic adenomas appear isointense or hyperintense in comparison to adjacent normal liver on hepatobiliary phase images, and therefore this feature should not be used to distinguish hepatic adenomas from focal nodular hyperplasia without additional supporting evidence.

Role of selective intra-arterial embolization in benign liver tumors

OBJECTIVE

To present cases of symptomatic benign liver tumors diagnosed and treated with intra-arterial embolization before surgery.

MATERIAL AND METHODS

We present the cases of 7 patients diagnosed with symptomatic benign liver tumors that required treatment: 1 focal nodular hyperplasia, 2 giant cavernous hemangiomas, 1 hepatic adenomatosis, and 3 hepatic adenomas. Once the feeding arteries were identified, tumors were embolized with polyvinyl alcohol particles (500μm-700μm) and then the feeding artery was plugged with coils if there was an arterial pedicle to ensure the total vascular exclusion of the tumor. The surgical intervention took place 4 to 7 days after embolization.

RESULTS

All 7 patients were women (age range, 23-74 years); presurgical intra-arterial embolization was done in 6. In 1 patient with adenomatosis, embolization was done to control intraparenchymal hepatic hemorrhage. In the 6 patients who underwent surgery, the tumor was completely excised and no intraoperative bleeding events or postoperative complications occurred.

CONCLUSIONS

Provided there is a consensus among the multidisciplinary team, embolization is a useful option in the perioperative management of giant and/or symptomatic benign liver tumors.

18-Fluoro-deoxyglucose uptake in inflammatory hepatic adenoma: A case report

Positron emission tomography computed tomography (PET-CT) using 18-Fluoro-deoxyglucose (¹⁸FDG) is an imaging modality that reflects cellular glucose metabolism. Most cancers show an uptake of ¹⁸FDG and benign tumors do not usually behave in such a way. The authors report herein the case of a 38-year-old female patient with a past medical history of cervical intraepithelial neoplasia and pheochromocytoma, in whom a liver lesion had been detected with PET-CT. The tumor was laparoscopically resected and the diagnosis of inflammatory hepatic adenoma was confirmed. This is the first description of an inflammatory hepatic adenoma with an ¹⁸FDG up-take.

Short-term outcomes of laparoscopic vs. open liver resection for hepatocellular adenoma: a multicenter propensity score adjustment analysis by the AFC-HCA-2013 study group

BACKGROUND

Patients with hepatocellular adenomas are, in selected cases, candidates for liver resection, which can be approached via laparoscopy or laparotomy. The present study aimed to investigate the effects of the surgical approach on the postoperative morbidities of both minor and major liver resections.

METHODS

In this multi-institutional study, all patients who underwent open or laparoscopic hepatectomies for hepatocellular adenomas between 1989 and 2013 in 27 European centers were retrospectively reviewed. A multiple imputation model was constructed to manage missing variables. Comparisons of both the overall rate and the types of complications between open and laparoscopic hepatectomy were performed after propensity score adjustment (via the standardized mortality ratio weighting method) on the factors that influenced the choice of the surgical approach.

RESULTS

The laparoscopic approach was selected in 208 (38%) of the 533 included patients. There were 194 (93%) women. The median age was 38.9 years. After the application of multiple imputation, 208 patients who underwent laparoscopic operations were compared with 216 patients who underwent laparotomic operations. After adjustment, there were 20 (9.6%) major liver resections in the laparoscopy group and 17 (7.9%) in the open group. The conversion rate was 6.3%. The two surgical approaches exhibited similar postoperative morbidity rates and severities. Laparoscopic resection was associated with significantly less blood loss (93 vs. 196 ml, p < 0.001), a less frequent need for pedicle clamping (21 vs. 40%, p = 0.002), a reduced need for transfusion (8 vs. 24 red blood cells units, p < 0.001), and a shorter hospital stay (5 vs. 7 days, p < 0.001). The mortality was nil.

CONCLUSIONS

Laparoscopy can achieve short-term outcomes similar to those of open surgery for hepatocellular adenomas and has the additional benefits of a reduced blood loss, need for transfusion, and a shorter hospital stay.

Hepatocellular adenoma: when and how to treat? Update of current evidence

Hepatocellular adenoma (HCA) is a rare, benign liver tumor. Discovery of this tumor is usually as an incidental finding, correlated with the use of oral contraceptives, or pregnancy. Treatment options have focused on conservative management for the straightforward, smaller lesions (<5 cm), with resection preferred for larger lesions (>5 cm) that pose a greater risk of hemorrhage or malignant progression. In recent years, a new molecular subclassification of HCA has been proposed, associated with characteristic morphological features and loss or increased expression of immunohistochemical markers. This subclassification could possibly provide considerable benefits in terms of patient stratification, and the selection of treatment options. In this review we discuss the decision-making processes and associated risk analyses that should be made based on lesion size, and subtype. The usefulness of this subclassification system in terms of the procedures instigated as part of the diagnostic work-up of a suspected HCA will be outlined, and suitable treatment schemes proposed.

Progression of Hepatic Adenoma to Carcinoma in the Setting of Hepatoportal Sclerosis in HIV Patient: Case Report and Review of the Literature

We report a case of hepatic adenoma progression to carcinoma in the setting of hepatoportal sclerosis in an HIV+ patient and provide a review of the scarce literature regarding hepatoportal sclerosis in HIV patients. We describe the clinical presentation, diagnostic workup, and management. This is the first case report in the literature of progression of hepatic adenoma to carcinoma in hepatoportal sclerosis in an HIV patient. This case also highlights the broad differential diagnosis that should always be included in the study of any liver disease in this patient population, including the performance of invasive and aggressive tests to arrive at the final diagnosis.

Enhancements in hepatobiliary imaging: the spectrum of gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid usages in hepatobiliary magnetic resonance imaging

Gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a unique hepatocyte-specific contrast agent approved for clinical use in the United States in 2008. Gd-EOB-DTPA-enhanced MR has shown to improve detection and characterization of hepatic lesions. Gd-EOB-DTPA is now being routinely used in daily clinical practice worldwide. Therefore, it is important for radiologists to be familiar with the potential uses and pitfalls of Gd-EOB-DTPA, which extends beyond the assessment of focal hepatic lesions. The purpose of this article is to review the various usages of Gd-EOB-DTPA in hepatobiliary MR imaging.

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

Owing to the progress of imaging techniques, benign hepatocellular nodules are increasingly discovered in the clinical practice. This group of lesions mostly arises in the context of a putatively normal healthy liver and includes either pseudotumoral and tumoral nodules. Focal nodular hyperplasia and hepatocellular adenoma are prototypical examples of these two categories of nodules. In this review we aim to report the main pathological criteria of differential diagnosis between focal nodular hyperplasia and hepatocellular adenoma, which mainly rests upon morphological and phenotypical features. We also emphasize that for a correct diagnosis the clinical context such as sex, age, assumption of oral contraceptives, associated metabolic or vascular disturbances is of paramount importance. While focal nodular hyperplasia is a single entity epidemiologically more frequent than adenoma, the latter is representative of a more heterogeneous group which has been recently and extensively characterized from a clinical, morphological, phenotypical and molecular profile. The use of the liver biopsy in addition to imaging and the clinical context are important diagnostic tools of these lesions. In this review we will survey their systematic pathobiology and propose a diagnostic algorithm helpful to increase the diagnostic accuracy of not dedicated liver pathologists. The differential diagnosis between so-called typical and atypical adenoma and well differentiated hepatocellular carcinoma will also be discussed.

Prevalence of benign focal liver lesions: ultrasound investigation of 45,319 hospital patients

Purpose

The aim of the study was to determine the sonographic prevalence of benign focal liver lesions on the basis of a population of hospital patients.

Methods

The ultrasound results in a population of (n = 45,319) hospital patients over a period of 10 years were examined retrospectively and evaluated for the diagnosis of benign focal liver lesions [hepatic cysts, hepatic hemangioma, focal nodular hyperplasia (FNH), hepatic adenoma, and focal fatty sparing]. Results that were incomplete or ambiguous were excluded from this study.

Results

At least one of the lesions to be investigated was diagnosed in 15.1% (n = 6839) of the patients of the total population. The most commonly recorded lesion, with a total prevalence of 6.3% (n = 2839), was focal fatty sparing, followed by hepatic cysts with 5.8% (n = 2631). The prevalence of hepatic hemangioma was 3.3% (n = 1640), while that of FNH was 0.2% (n = 81) and that of hepatic adenoma was 0.04% (n = 19). An association between the occurrence of benign focal liver lesions and age was observed.

Conclusions

The calculated prevalence of benign focal liver lesions shows that on the fortuitous discovery of space-occupying lesions of the liver, first consideration should be given to focal fatty sparing, simple hepatic cysts and hemangiomas. The finding of a FNH or an adenoma is rarely a random discovery.

Hepatocellular adenoma: An update

Hepatocellular adenomas (HCA) are rare benign liver tumors. Recent technological advancements have helped in the early identification of such lesions. However, precise diagnosis of hepatocellular incidentalomas remains challenging. Studies at the molecular level have provided new insights into the genetics and pathophysiology of these lesions. These in turn have raised questions over their existing management modalities. However, the rarity of the tumor still restricts the quality of evidence available for current recommendations and guidelines. This article provides a comprehensive review on the etiology, molecular biology, patho-physiology, clinical manifestations, and complications associated with HCA. It also elaborates on the genetic advancements, existing diagnostic tools and current guidelines for management for such lesions.

Treatment of Hepatic Adenomatosis

Hepatic adenomatosis and hepatocellular adenomas share risk factors and the same pathophysiologic spectrum. The presence in the liver of 10 hepatocellular adenomas defines hepatic adenomatosis. The diagnosis may be established incidentally during a liver radiologic examination in the asymptomatic patient, or after associated right upper quadrant pain, hepatomegaly or liver test abnormalities. Upon the diagnosis of hepatic adenomatosis or either of its life-threatening complications - hemorrhage and progression to hepatocellular carcinoma - consideration should be given to potential medical, radiologic and surgical interventions including: observation (estrogens and androgens withdrawal), resection, transarterial embolization, radiofrequency ablation and liver transplantation. The management of patients with hepatic adenomatosis can be challenging. These patients should be ideally referred to centers with expertise in the management of liver diseases.

Management of hepatic adenomatosis

Hepatic adenomatosis (HeAs) is a rare clinical entity defined by the presence of 10 or more hepatic adenomas (HA) within the background of an otherwise normal liver parenchyma, in the absence of glycogen storage disease or anabolic steroid use. HA is a benign tumor associated with oral contraceptive use. Recent advances in pathogenesis and classification of HA have questioned the distinction between these two diseases. HA are currently classified into four different subtypes with genotypic and phenotypic correlation: HNF-1a inactivated HA, B-catenin activated HA, inflammatory HA, and undetermined subtype. The clinical presentation of HA depends on the lesion size and the subtype. MRI using hepatospecific contrast agents is helpful in diagnosing the most common subtypes. When diagnosis is uncertain, biopsy with immunohistochemistry is used to diagnose and classify the lesions. Management is governed by the molecular subtype and tumor size. Pregnancy is not routinely discouraged but management is individualized.

Malignant Transformation of Hepatic Adenoma in Glycogen Storage Disease Type-1a: Report of an Exceptional Case Diagnosed on Surveillance Imaging

Hepatocellular adenoma is a heterogeneous group of benign neoplasms arising from hepatocellular cells and can be subclassified into four major groups based on genotypic and phenotypic characteristics. These four subtypes are hepatocyte nuclear factor (HNF) 1α-inactivated, β-catenin–activated, inflammatory, and unclassified adenomas. Immunohistochemistry studies have demonstrated that since β-catenin–activated adenomas have a higher risk of malignant transformation, the identification of the subtype of adenoma remains crucial in patient management. However, malignant transformation of hepatic adenoma without β-catenin overexpression can be seen in 30–65% cases. We report a case of malignant transformation of hepatic adenoma without overexpression of β-catenin in a 31-year-old man with a known glycogen storage disease (GSD) Type-1a, which was diagnosed on surveillance magnetic resonance imaging (MRI). The MRI showed a mild interval increase in one lesion with relative stability of the other adenomas. The lesion was presumed to be suspicious for a hepatocellular carcinoma (HCC) and was confirmed on pathology.

Atypical Hepatocellular Neoplasm With Peliosis in Cirrhotic Liver Versus Hepatocellular Carcinoma: A Diagnostic Trap

Atypical hepatocellular neoplasm (AHN) is an adenoma-like hepatic tumor that even occurs in noncirrhotic liver of males (any age) or females ≥ 50 years old, or associates focal atypical features. In this article, 2 unusual cases diagnosed in elderly cirrhotic patients, unrelated to steroids, are presented. The first case was incidentally diagnosed in an 83-year-old female. During laparoscopic surgery for cholecystectomy, hemoperitoneum was installed and laparotomy was necessary to remove a 70-mm nodular encapsulated hepatic tumor that was microscopically composed by hepatocyte-like cells with clear cytoplasm, arranged in 1- to 2-cell-thick plates and intermingled with areas of peliosis, negative for alpha fetoprotein (αFP), p53, and keratin 7, with low Ki67 index and intact reticulin framework. The second case was incidentally diagnosed at ultrasound examination in a 66-year-old male. The surgical specimen was a 50-mm solid multinodular tumor that microscopically consisted of 3-cell-thick plates of hepatocyte-like cells with acinar, pseudoglandular, and trabecular architecture, intermingled with peliotic areas, without nuclear atypia and disintegrated reticulin framework. Both of the cases occurred in cirrhotic liver. The tumor cells were marked by AE1/AE3 keratin, displayed a Ki67 index < 5% and were negative for αFP, p53, and keratin 7. No recurrences or any other disorder occurred 6 months after surgery. In cirrhotic liver, adenomas with peliosis that do not satisfy all the diagnosis criteria synthesized in the article should be considered AHNs and differential diagnosis includes hepatocellular carcinoma but also focal nodular hyperplasia, regenerative nodules, and dysplastic nodules. This histological entity is not yet included in the WHO Classification list.

Focal Nodular Hyperplasia and Hepatocellular Adenoma: Accuracy of Gadoxetic Acid-enhanced MR Imaging--A Systematic Review

PURPOSE

To perform a systematic review to evaluate the diagnostic accuracy of hepatobiliary (HPB) phase gadoxetic acid-enhanced MR imaging of the liver in the diagnosis of focal nodular hyperplasia (FNH) versus hepatocellular adenoma (HCA) and to identify the rate of (a) reported HCAs that are iso- or hyperintense to liver and (b) reported FNHs that are hypointense to liver on HPB phase MR images.

MATERIALS AND METHODS

The institutional review board granted a waiver for this study type, and multiple databases were searched for studies in which researchers distinguished between FNH and HCA with gadoxetic acid-enhanced MR imaging. Studies to evaluate diagnostic accuracy were included; case reports and series were included to analyze the rate of iso- or hyperintense HCAs on HPB phase MR images. Risk of bias was assessed by using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Sensitivity and specificity were plotted with a forest plot; pooling was not performed because a small number of heterogeneous studies were included. Rate of iso- or hyperintense HCA on HPB phase gadoxetic acid-enhanced MR images was evaluated.

RESULTS

Six studies (309 patients; 164 with HCA, 233 with FNH) were included for diagnostic accuracy assessment. Twelve case series (129 patients; 81 with HCA, 70 with FNH) were included (studies with insufficient 2 × 2 table data for diagnostic accuracy assessment). Sensitivity was high (range, 0.91-1.00; lower margin of the 95% confidence interval: 0.77). Specificity was high (range, 0.87-1.00; lower margin of the 95% confidence interval: 0.54). Specificity was lowest among studies in which molecular subtyping of HCA was performed. Rate of iso-or hyperintensity of HCA on HPB phase MR images was variable (range, 0%-67%) and occurred more frequently in the inflammatory subtype. High risk of bias was identified in the domains of patient selection and reference standard.

CONCLUSION

The reported diagnostic accuracy of HPB phase gadoxetic acid-enhanced MR imaging in the diagnosis of HCA versus FNH is high; however, studies are few, heterogeneous, and at high risk for bias, indicating that diagnostic accuracy may be overestimated.

Hepatic adenomatosis: a rare but important liver disease with severe clinical implications

A 56-year-old white female presented to the emergency room (ER) with acute onset of right upper quadrant abdominal pain, nausea, and vomiting, and she was found to have a sudden drop in hemoglobin. Abdominal computed tomography (CT) with and without intravenous contrast revealed multiple bilobar focal hepatic hypervascular lesions, one of them demonstrating spontaneous rupture with active intraperitoneal bleeding. A moderate hemoperitoneum was present. The patient underwent exploratory laparotomy for right hepatic posterior segmentectomy (right posterior sectionectomy) and peritoneal lavage. The histopathology evaluation revealed multiple liver adenomas. Hepatic adenomatosis is a clinical entity characterized by 10 or more hepatic adenomas. It must be distinguished from isolated hepatic adenoma as it bears a much higher risk of complications, such as spontaneous rupture, hemorrhage and malignant transformation. Here we discuss the radiologic and histopathologic findings of the current case along with a review of the English language medical literature.

Multiple hepatocellular adenomas presenting in a male 8 years post-pancreaticoduodenectomy for islet cell tumor of the pancreas

We report the case of a 29-year-old male who presented with vague right upper quadrant pain, 8 years following a pancreaticoduodenectomy for a symptomatic pancreatic islet cell tumor. Subsequent imaging revealed multiple lesions in the right lobe of the liver. A diagnosis of metastatic disease could not be out ruled and hence a formal resection was performed. A formal retrospective review of case notes, preoperative imaging, operative notes, subsequent histology as well as a review of the current literature using the Medline, CINAHL, and EMBASE databases was performed. Histologic analysis showed these lesions to be hepatocellular adenomas. We highlight in this case the importance of preoperative imaging and workup, discuss hepatocellular adenomas in males and hypothesize as to the underlying pathophysiology in this particular case based on the available evidence.

Liver adenomatosis: a rare indication for living donor liver transplantation

Liver adenomatosis (LA) is a rare benign disease of the liver with unclear pathogenesis, which is characterized by multiple hepatic adenomas. The management of LA remains controversial. Herein we have reported a case of LA treated by living donor liver transplantation (LDLT). A 48-year-old woman developed multiple liver adenomas. In view of the sizes and localizations of the lesions, the patient underwent right hepatic resection and segment II nodulectomy. Thirty-four months later, she developed recurrence of multiple hepatic adenomas and 2 nodules were highly suspect for hepatocellular carcinoma. Re-resection was not indicated due to the whole liver being involved with adenomas. The patient underwent LDLT. At 45 months thereafter she is alive and disease-free. In conclusion, LDLT is indicated in cases of nonresectability; it may offer optimal results in view of the absence of portal hypertension and the elimination of waiting list time.

Gadoxetic acid enhanced MRI for differentiation of FNH and HCA: a single centre experience

OBJECTIVES

Evaluation of enhancement characteristics of histopathologically confirmed focal nodular hyperplasias (FNHs) and hepatocellular adenomas (HCAs) with gadoxetic acid-enhanced MRI.

METHODS

Sixty-eight patients with 115 histopathologically proven lesions (FNHs, n=44; HCAs, n=71) examined with gadoxetic acid-enhanced MRI were retrospectively enrolled (standard of reference: surgical resection, n=53 patients (lesions: FNHs, n=37; HCAs, n=53); biopsy, n=15 (lesions: FNHs, n=7; HCAs, n=18)). Two radiologists evaluated all MR images regarding morphological features as well as the vascular and hepatocyte-specific enhancement in consensus.

RESULTS

For the hepatobiliary phase, relative enhancement of the lesions and lesion to liver enhancement were significantly lower for HCAs (mean, 48.7 (±48.4)%and 49.4 (±33.9) %) compared to FNHs (159.3 (±92.5) %; and 151.7 (±79) %; accuracy of 89%and 90 %, respectively; P<0.001). Visual strong uptake of FNHs vs. hypointensity of HCAs in the hepatobiliary phase resulted in an accuracy of 92 %. This parameter was superior to all other morphological and dynamic vascular criteria alone and in combination (accuracy, 54–85 %).

CONCLUSIONS

For differentiation of FNHs and HCAs by means of MRI, gadoxetic acid uptake in the hepatobiliary phase was found to be superior to all other criteria alone and in combination.

KEY POINTS

EOB-MRI is well suited to differentiate FNHs and hepatocellular adenomas. For this purpose hepatobiliary phase is superior to unenhanced and dynamic imaging. Hepatobiliary phase (peripheral) hyper- or isointensity is typical for FNH. Hepatobiliary phase hypointensity is typical for hepatocellular adenomas. EOB-MRI helps to avoid misinterpretations of benign hepatocellular lesions.

Update on the new classification of hepatic adenomas: clinical, molecular, and pathologic characteristics

CONTEXT

Hepatic adenoma is an uncommon, benign, hepatic neoplasm that typically occurs in women of child-bearing age, often with a history of long-term use of oral contraceptive drugs. This is usually detected as an incidental mass lesion in a noncirrhotic liver during imaging studies. Pathologic evaluation by needle core biopsy remains the gold standard for diagnosis. Molecular studies have revealed that hepatic adenomas involve unique molecular pathways that are distinct from hepatocellular carcinoma. Based on these studies, a French collaborative group has recently proposed a molecular-pathologic classification for hepatic adenomas. In addition, advances in molecular studies have led to reclassification of the "telangiectatic variant of focal nodular hyperplasia" as "hepatic adenoma, inflammatory subtype."

OBJECTIVE

To review the proposed, new classification of hepatic adenoma and the changes in diagnostic workup in light of the above-mentioned developments.

DATA SOURCES

Review of published literature and illustrations from clinical case material.

CONCLUSIONS

Definitive diagnosis of liver mass lesion on needle core biopsies has a decisive role in clinical management. With the advent of the new classification of hepatic adenomas and its prognostic implications, it is vital for pathologists to be aware of the morphologic features seen in different subtypes and the available diagnostic tools, such as immunohistochemistry, to help identify the correct subtype.