Hepatic tumors in children

Accuracy of contrast-enhanced CT in liver neoplasms in children under 2 years age

BACKGROUND

Multiple differentials exist for pediatric liver tumors under 2 years. Accurate imaging diagnosis may obviate the need for tissue sampling in most cases.

OBJECTIVE

To evaluate the imaging features and diagnostic accuracy of computed tomography (CT) in liver tumors in children under 2 years.

METHODS

Eighty-eight children under 2 years with treatment naive liver neoplasms and baseline contrast-enhanced CT were included in this institutional review board approved retrospective study. Two blinded onco-radiologists assessed these tumors in consensus. Findings assessed included enhancement pattern, lobulated appearance, cystic change, calcifications, central scar-like appearance, and metastases. The radiologists classified the lesion as hepatoblastoma, infantile hemangioma, mesenchymal hamartoma, rhabdoid tumor, or indeterminate, first based purely on imaging and then after alpha-fetoprotein (AFP) correlation. Multivariate analysis and methods of comparing means and frequencies were used for statistical analysis wherever applicable. Diagnostic accuracy, sensitivity, and positive predictive values were analyzed.

RESULTS

The mean age of the sample was 11.4 months (95% CI, 10.9-11.8) with 50/88 (57%) boys. The study included 72 hepatoblastomas, 6 hemangiomas, 4 mesenchymal hamartomas, and 6 rhabdoid tumors. Presence of calcifications, multilobular pattern of arterial enhancement, lobulated morphology, and central scar-like appearance was significantly associated with hepatoblastomas (P-value < 0.05). Fourteen out of eighty-eight lesions were called indeterminate based on imaging alone; six lesions remained indeterminate after AFP correlation. Pure radiology-based diagnostic accuracy was 81.8% (95% CI, 72.2-89.2%), which increased to 92.1% (95% CI, 84.3-96.7%) (P-value > 0.05) after AFP correlation, with one hepatoblastoma misdiagnosed as a rhabdoid tumor. If indeterminate lesions were excluded for biopsy, the accuracy would be 98.8% (95% CI, 93.4-99.9%).

CONCLUSION

CT had high accuracy for diagnosing liver neoplasms in the under 2-year age population after AFP correlation. Certain imaging features were significantly associated with the diagnosis of hepatoblastoma. A policy of biopsying only indeterminate lesions after CT and AFP correlation would avoid sampling in the majority of patients.

Hepatoblastoma Relapse-Findings from the German HB99 Trial and the German Liver Tumor Registry

Survival rates for HB patients have improved; however, outcomes for patients who relapse remain poor. A retrospective review of information gathered for the HB99 study and the German Liver Tumor Registry identified 25 relapse patients (6.9%, 25/362). The median time from initial diagnosis to first relapse was 13 months (range: 5-66 months). Two patients relapsed >36 months after initial diagnosis. A total of 68% (17/25) of relapses were metastatic, 24% local, and 8% combined. 67% of local relapses were alive at the last follow-up, in contrast to 53% of metastatic and 0% of combined relapses. At the last follow-up, 73% (8/11) of patients with lung relapses were still alive (0/4 with peritoneal, 1/2 with CNS involvement). A total of 20% of the patients had AFP-negative relapses, 64% of the relapse patients achieved a second complete remission, 69% were still in complete second remission at the last follow-up (median FU of 66 months), and 83% (5/6) of irinotecan-naïve patients who received relapse treatment including irinotecan were in second complete remission at the last follow-up. The 3-year overall survival/event-free survival from relapse was 63%/48% respectively. There is a good chance that HB patients will achieve a second remission despite a first relapse. However, patients who suffer further relapses tend to have a poorer prognosis.

Review on Pediatric Malignant Focal Liver Lesions with Imaging Evaluation: Part I

Malignant focal liver lesions (FLLs) are commonly reported in adults but rarely seen in the pediatric population. Due to the rarity, the understanding of these diseases is still very limited. In children, most malignant FLLs are congenital. It is very important to choose appropriate imaging examination concerning various factors. This paper will outline common pediatric malignant FLLs, including hepatoblastoma, hepatocellular carcinoma, and cholangiocarcinoma and discuss them against the background of the latest knowledge on comparable/similar tumors in adults. Medical imaging features are of vital importance for the non-invasive diagnosis and follow-up of treatment of FLLs in pediatric patients. The use of CEUS in pediatric patients for characterizing those FLLs that remain indeterminate on conventional B mode ultrasounds may be an effective option in the future and has great potential to be integrated into imaging algorithms without the risk of exposure to ionizing radiation.

Utility of the pediatric liver contrast-enhanced ultrasound criteria in differentiating malignant and benign multifocal lesions

BACKGROUND

The pediatric liver contrast-enhanced ultrasound (CEUS) criteria were developed to improve the diagnostic performance of CEUS in differentiating pediatric benign and malignant liver lesions. However, the diagnostic performance of CEUS in the evaluation of multiple focal liver lesions in the pediatric population has not yet been fully evaluated.

OBJECTIVE

To evaluate the diagnostic performance of the pediatric liver CEUS criteria in differentiating benign and malignant multifocal liver lesions in children.

MATERIALS AND METHODS

From April 2017 to September 2022, the CEUS characteristics of multifocal liver lesions in patients < 18 years were analyzed. Lesions classified as CEUS-1, CEUS-2 or CEUS-3 were considered benign and lesions classified as CEUS-4 or CEUS-5 were considered malignant. The diagnostic performance of the pediatric liver CEUS criteria (i.e. sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV] and accuracy) was assessed.

RESULTS

After exclusion, 21 patients (median age, 36.0 months; range, 1.0-204 months; 7 boys) were included. There were significant differences in the serum alpha fetoprotein level (P= 0.039) and the presence of washout (P < 0.001) between children with malignant and benign lesions. The sensitivity, specificity, PPV, NPV and accuracy of the pediatric liver CEUS criteria were 100.0% (10/10), 90.9% (10/11), 90.9% (10/11), 100.0% (10/10) and 95.2% (20/21), respectively.

CONCLUSION

The pediatric liver CEUS criteria had excellent diagnostic performance in differentiating benign and malignant multifocal liver lesions in children.

Hepatic benign and malignant masses in children: a single UK tertiary centre experience

PURPOSE

The aim of this study was to review the incidence, spectrum and investigation of liver masses presenting to our tertiary liver unit.

METHODS

A retrospective single-centre cohort study of paediatric patients (age < 16 years) diagnosed with a liver mass who were investigated at a UK paediatric hepatobiliary tertiary referral centre. Data relating to the clinical findings at presentation, source of referral, diagnostic investigations and histopathology findings were recorded and analysed.

RESULTS

107 patients were identified between July 2012 and July 2019 (55 females). 69 (64%) patients had benign liver lesions, whereas the remaining 38 (36%) were found to have malignant masses. The liver lesions were most commonly detected incidentally (33%) with the second most common presentation being with palpable mass (29%). 82 (77%) patients were referred from other hospitals. All patients underwent USS, 74% MRI, 36% CT, 5% CEUS, 1% PET and 5% HIDA scan with 47% ultimately undergoing biopsy. 72% of patients had AFP measured. The most common benign liver masses were haemangioma 33 (48%), hepatic cyst 17 (25%) and FNH 12 (19%). Amongst the malignant lesions, 29 (76%) were hepatoblastoma and 3 (8%) were hepatocellular carcinoma.

CONCLUSIONS

This large review series demonstrates that just over 1/3 of patients presenting to a paediatric tertiary referral centre with a focal liver lesion had neoplastic liver lesions, despite the published literature commonly stating that 2/3 of paediatric liver masses are malignant.

Case report: Multimodal neoadjuvant and adjuvant chemotherapy for hepatic undifferentiated embryonal sarcoma in a young adult

Hepatic undifferentiated embryonal sarcoma of the liver (UESL) is a rare hepatic malignancy found more commonly in pediatric patients. It has been associated with poor outcomes in adults and the role and timing of systemic therapy is unclear. There have been very few case reports detailing combination neoadjuvant and adjuvant chemotherapy use for hepatic undifferentiated embryonal sarcoma in adults. In this report, a 22-year-old male admitted with right upper quadrant pain was diagnosed with a 20 x 10 x 10 cm well-circumscribed, highly vascularized hepatic mass in the entirety of the left lobe. Biopsy confirmed the diagnosis of UESL. PET/CT showed no evidence of metastatic disease, and he received four cycles of Doxorubicin and Ifosfamide with demonstrated reduction in size and decrease in PET avidity. He underwent left hepatectomy with periportal lymphadenectomy, cholecystectomy, and partial gastrectomy with negative margins and received adjuvant Doxorubicin, Ifosfamide and Mesna. At 48 months, the patient was alive without evidence of disease. We hereby emphasize the potential advantages of combination chemotherapy and surgical resection in the management of UESL in adults.

Undifferentiated embryonal sarcoma of liver arising within mesenchymal hamartoma in a child "case report"

Background

Primary pediatric liver tumors are scarce. Undifferentiated embryonal sarcoma of the liver (UESL) embraces nine to fifteen percent of the pediatric hepatic neoplasms. Mesenchymal hamartoma of the liver (MHL) is the second most prevalent benign pediatric hepatic neoplasm following infantile hemangioendothelioma.

Case presentation

A 6-year-old female child presented with vague diffuse abdominal pain and palpable right lumbar mass by clinical examination. The US showed a well-circumscribed large right hepatic complex multilocular cystic lesion with multiple internal septations and some turbid loculi. The constellation of CT and dynamic MRI findings raised the presence of atypical suspicious complex cystic hepatic mass lesion with hemorrhagic, calcific entities and internal soft tissue enhancement. The histopathological correlation proved UESL on the background of MHL.

Conclusions

A case of a pediatric hepatic complex cystic lesion, which had typical ultrasound features of MHL, however, CT and MRI had atypical suspicious criteria. Finally, our case is presented as UESL in the background of MHL based upon pathological diagnosis. The radiologists must be familiar with overlapped entities between MHL, UESL, and other differential diagnosis entities regarding pediatric hepatic neoplasms.

Incidental Liver Lesions in children: A practical and evidence-based approach

Incidental liver lesions are increasingly being discovered in the context of the increased use of ultrasound studies and the majority are benign. In children, although individually rare, the differential diagnosis is broad and therefore a systematic approach is of utmost importance to reduce the radiological and disease burden in children and their families. This review article collected current evidence and provides fundamental information for the clinician regarding specific differential diagnoses and unique imaging features of benign liver lesions in children. Ultimately, we propose a practical stepwise approach mainly involving clinical and radiological workup. Laboratory tests and histopathological examination may be necessary in the presence of red flags or in indeterminate lesions.

A large undifferentiated sarcoma of the liver in a 13-year-old girl treated with anatomical resection: a case report and review of the literature

Background

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare liver tumor accounting for 6–13% of primary liver tumors. Accurate preoperative diagnosis is difficult, with a rather high misdiagnosis rate. Herein, we reported a very large UESL treated with anatomical resection. Our case is amongst the largest pediatric UESLs in the literature.

Case presentation

Herein, we report a 13-year-old girl presenting with right upper quadrant abdominal pain, postprandial vomiting, and abdominal distention, in which radiographic imaging demonstrated a huge UESL (28 × 20 × 12 cm). The patient was treated with partial hepatectomy and the 5 kg tumor was removed. The patient was discharged in good condition, with no significant complaints in her follow-up.

Conclusions

Although different treatment strategies have been reported for UESL cases, anatomical resection is still the main treatment approach, especially for large tumors.

Liver tumors in children with chronic liver diseases

Liver tumors are rare in children, but the incidence may increase in some circumstances and particularly in chronic liver diseases. Most liver tumors consequent to chronic liver diseases are malignant hepatocellular carcinoma. Other liver tumors include hepatoblastoma, focal nodular hyperplasia, adenoma, pseudotumor, and nodular regenerative hyperplasia. Screening of suspected cases is beneficial. Imaging and surrogate markers of alpha-fetoprotein are used initially as noninvasive tools for surveillance. However, liver biopsy for histopathology evaluation might be necessary for patients with inconclusive findings. Once the malignant liver tumor is detected in children with cirrhosis, liver transplantation is currently considered the preferred option and achieves favorable outcomes. Based on the current evidence, this review focuses on liver tumors with underlying chronic liver disease, their epidemiology, pathogenesis, early recognition, and effective management.

Contrast-enhanced ultrasound is useful for the evaluation of focal liver lesions in children

Introduction

Contrast‐enhanced ultrasound (CEUS) is a widely used diagnostic method. In adults, it has been proven to be a useful alternative to CT and MRI for the characterisation of focal liver lesions (FLLs). However, since there is no official paediatric licensing for any ultrasound contrast agents in Europe, its use has been restricted.

Purpose

To retrospectively outline our experience with CEUS as a tool for the characterisation of FLLs in paediatric patients.

Methods

An eleven‐year retrospective single‐centre study. During this period, we identified 287 CEUS examinations performed on children, of these 36 were relevant first‐time examinations with the aim of characterising a focal liver lesion. Clinical and radiological data were collected from the hospital chart.

Results

The overall agreement between the CEUS diagnosis and the reference diagnosis for benign versus malignant differentiation was 75%. When analysing conclusive CEUS examinations only, the overall agreement was 96%. The specificity for correctly characterising a lesion as benign was 96%, and the negative predictive value was 100%. No side effects from CEUS were detected.

Conclusions

Our study reinforces that CEUS can be useful in the medical workup for the identification and classification of focal liver lesions in children.

Imaging for Staging of Pediatric Abdominal Tumors: An Update, From the AJR Special Series on Cancer Staging

The three most common pediatric solid tumors of the abdomen are neuroblastoma, Wilms tumor, and hepatoblastoma. These embryonal tumors most commonly present in the first decade of life. Each tumor has unique imaging findings, including locoregional presentation and patterns of distant spread. Neuroblastoma, Wilms tumor, and hepatoblastoma have unique staging systems that rely heavily on imaging and influence surgical and oncologic management. The staging systems include image-defined risk factors for neuroblastoma, the Children's Oncology Group staging system for Wilms tumor, and the pretreatment extent of tumor system (PRETEXT) for hepatoblastoma. It is important for radiologists to be aware of these staging systems to optimize image acquisition and interpretation. This article provides a practical and clinically oriented approach to the role of imaging in the staging of these common embryonal tumors of childhood. The selection among imaging modalities, key findings for determining tumor stage, and the role of imaging in posttreatment response evaluation and surveil-lance are discussed. Recent updates to the relevant staging systems are highlighted with attention to imaging findings of particular prognostic importance. The information presented will help radiologists tailor the imaging approach to the individual patient and guide optimal oncologic management.

Laparoscopic management of Rhabdomyosarcoma of common Bile duct, Case report

INTRODUCTION

Embryonal Rhabdomyosarcoma (ERMS) is a malignant soft tissue musculoskeletal tumor which constitutes about 0.06% of all malignancies affecting children. Biliary tract ERMS is still rare, though it is considered the most common cause of malignant obstructive jaundice in children.

CASE PRESENTATION

A report of a 2-year-old boy, who was presented with recurrent episodes of scleral icterus of three months duration, is added to the related literature. His labs went with obstructive jaundice and the radiological investigations were consistent with a diagnosis of choledochal cyst. The found mass was suspected to be an ERMS of common bile duct and turned out to be so by the histopathology. He was managed totally by laparoscope, both excision and hepaticojejunostomy reconstruction, which is an extremely uncommon entity.

CONCLUSION

Common Bile Duct Rhabdomyosarcoma is rare and diagnosis at this anatomical site is difficult. Our case highlights the feasibility of laparoscopic resection and hepaticojejunostomy reconstruction with very good results at 16-month follow up and parents' gratitude as well.

Hepatic mesenchymal hamartoma and undifferentiated embryonal sarcoma of the liver: a pathologic review

This review highlights two rare entities that are predominantly seen in children: hepatic mesenchymal hamartoma (HMH) and undifferentiated embryonal sarcoma of the liver (UESL). HMH is a benign lesion predominantly seen in the first 2 years of life, while UESL is malignant and usually identified in patients between 6 and 10 years of age. UESL may arise in the background of HMH, and the association has been supported by similar chromosomal aberrations (19q13.4). The diagnosis of both lesions is primarily based on histologic evaluation, as the clinical and radiological features are not always typical. The clinicopathologic characteristics, pathogenesis, differential diagnoses and treatment for both lesions are discussed.

Clinicopathological profile of hepatoblastoma: An experience from a tertiary care center in India

Background

Hepatoblastoma is the most common primary hepatic malignancy in the pediatric population. Advances in pathological evaluation, imaging, risk stratification, neo-adjuvant chemotherapy, and surgery including transplantation have improved survival of these children in the western countries. However, a successful outcome in developing countries such as India with limited resources poses great challenges to the clinician and the family. Histology plays a major role in determining the prognosis of these patients.

Methods

A retrospective study was done on 10 children diagnosed with hepatoblastoma between January 2010 and December 2015 in our institution. Clinical, laboratory, radiological, histopathological diagnoses, treatment, and outcome data were collected and analyzed.

Results

The median age of these children at diagnosis was 11 months, and only 1 child was premature at birth. Most children were presented with abdominal distension. One child had lung metastasis at presentation. Elevated alpha fetoprotein levels were present in 90% of the children. The histological types were fetal, embryonal, macrotrabecular, and mixed epithelial-mesenchymal types. SIOPEL risk stratification was done, which showed 40% of the children to be of high risk. Three children had PRETEXT 1, 2, and 4, respectively.

Conclusion

Our study is significant with respect to the information on PRETEXT staging, risk status, and histological favorability. In developing countries with limited resources and low-socioeconomic status, it is important to have a multidisciplinary team approach and tailor treatment to manage these patients effectively and improve the overall survival.

Case Report: Hepatic Adenoma in a Child With a Congenital Extrahepatic Portosystemic Shunt

Congenital extrahepatic portosystemic shunts (CEPS), previously also described as Abernethy malformations, are rare malformations in which the extrahepatic portal system directly communicates with the vena cava inferior, thereby bypassing the liver. A hypoplastic portal vein (PV) exists in most cases. CEPS have been associated with the development of liver nodules, ranging from mostly focal nodular hyperplasia (FNH) to hepatic adenoma (HA) and even hepatocellular carcinoma (HCC). Tumor development in CEPS may be due to changes in perfusion pressures, oxygen supply or endocrine imbalances. It is important to rule out CEPS in children with liver tumors, because resection could impede future shunt occlusion procedures, and benign masses may regress after shunt occlusion. Here, we review the case of a 9-years-old male with CEPS and hepatic nuclear Factor 1-alpha (HNF-1-alpha) inactivated HA to raise awareness of this condition and review histopathological changes in the liver of CEPS.

Right trisegmentectomy after portal vein embolization in a high-risk toddler with hepatoblastoma

Portal vein embolization (PVE) is a pre-operative treatment modality in adults undergoing hepatectomy with concerns of post-operative liver failure from insufficient future liver remnant (FLR). PVE induces growth in the FLR. The success of this technique is well described in adults, but not in young children with hepatoblastoma.

Co-existing infantile hepatic hemangioma and mesenchymal hamartoma in a neonate

Infantile hepatic hemangioma (IHH) and mesenchymal hamartoma (MH) form the first and second most common benign hepatic tumors in children. In this case report, we present a newborn child in whom a growing hepatic mass was discovered at the age of 7 days. She suffered also from anemia, respiratory and renal failure. No signs of heart disease or cutaneous lesions were detected. Alpha-fetoprotein was elevated for her age (3562.2 ng/ml). Imaging studies showed multifocal large cystic lesions associated with heterogeneous small solid lesions with arterial enhancement of the liver. Non-anatomical liver resection was performed initially and synchronous MH and IHH GLUT-1 positive were discovered in the pathological analysis. Segmental IV hepatic resection and later on selective cysts excision were done for persistent hepatic lesion despite medical treatment. After 14 months of beta-blockers treatment, clinical follow-up shows a healthy child with no residual cystic lesions.

Imaging features of rare mesenychmal liver tumours: beyond haemangiomas

Tumours arising from mesenchymal tissue components such as vascular, fibrous and adipose tissue can manifest in the liver. Although histopathology is often necessary for definitive diagnosis, many of these lesions exhibit characteristic imaging features. The radiologist plays an important role in suggesting the diagnosis, which can direct appropriate immunohistochemical staining at histology. The aim of this review is to present clinical and imaging findings of a spectrum of mesenchymal liver tumours such as haemangioma, epithelioid haemangioendothelioma, lipoma, PEComa, angiosarcoma, inflammatory myofibroblastic tumour, solitary fibrous tumour, leiomyoma, leiomyosarcoma, Kaposi sarcoma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, rhabdomyosarcoma and hepatic metastases. Knowledge of the characteristic features of these tumours will aid in guiding the radiologic diagnosis and appropriate patient management.

Multidisciplinary management of hepatoblastoma in children: Experience from a developing country

BACKGROUND

Advances in chemotherapy, liver resection techniques, and pediatric liver transplantation have vastly improved survival in children with hepatoblastoma (HB). These are best managed by a multidisciplinary team (MDT) in a setting where all treatment options are available. Until recently, this was difficult to achieve in India.

METHODS

All children (<16 years) with HB treated in a pediatric liver surgery and transplantation unit between January 2011 and July 2016 were reviewed. Data regarding the clinical presentation, preoperative management, surgical treatment, postoperative course, and outcomes were extracted from a prospectively managed database.

RESULTS

Thirty children were treated for HB during the study period. Nine children were PRETEXT 4, 7 were PRETEXT 3, 13 were PRETEXT 2, and 1 was PRETEXT 1 (where PRETEXT is pretreatment extension). All children received a neoadjuvant chemotherapy before surgery followed by an adjuvant chemotherapy. Nineteen children had complete resection, while six underwent primary living donor liver transplantation. There were six mortalities including five children who poorly responded to chemotherapy with progressive tumor extension. At a median follow-up of 30 months, two children who underwent resection and one child who underwent liver transplant had disease recurrence.

CONCLUSION

Improved outcomes can be achieved in children with HB even in countries with limited resources when they are managed by MDTs with expertise in pediatric oncology, liver resection, and liver transplantation.

Space Occupying Lesions in the Liver

Space occupying liver lesions usually present with abdominal pain or abnormal physical findings, such as a palpable abdominal mass or distention. Liver lesions identified in children include benign and malignant neoplasms, inflammatory masses, cysts and metastatic lesions. Two-thirds of liver lesions in children are malignant. Hepatoblastoma accounts for two-thirds of malignant liver tumors in children. Benign lesions of the liver in children include vascular lesions, hamartomas, adenomas, and focal nodular hyperplasia. Although benign and malignant liver masses share some clinical manifestations, however treatment and prognosis differ. Evaluation involves physical examination, imaging evaluation and laboratory investigations such as serological markers [alpha-fetoprotein (AFP)] for malignant liver lesions. Ultrasound is the initial imaging modality of choice because it can detect, characterize, and provide the extent of liver lesions. However, CT or MRI are often subsequently performed for further characterization, assessment of precise extent, and detection of associated metastatic disease in cases of malignant hepatic neoplasm. Serological markers (such as alpha fetoprotein) can be useful in narrowing the differential diagnosis when they are markedly elevated but a substantial number of patients unfortunately do not have high levels of these markers at the time of presentation or cautious interpretation is warranted as AFP level is frequently elevated in infants up to 6 mo of age and may be slightly elevated with benign tumors and with hepatic insult or regeneration. Therefore, a tissue diagnosis is often required to guide subsequent management. The histology and anatomy of a pediatric liver tumor guides the treatment and prognosis.

MRI of paediatric liver tumours: How we review and report

Liver tumours are fortunately rare in children. Benign tumours such as haemangiomas and cystic mesenchymal hamartomas are typically seen in infancy, often before 6 months of age. After that age, malignant hepatic tumours increase in frequency. The differentiation of a malignant from benign lesion on imaging can often negate the need for biopsy. Ultrasound is currently the main screening tool for suspected liver pathology, and is ideally suited for evaluation of hepatic lesions in children due to their generally small size. With increasing research, public awareness and parental anxiety regarding radiation dosage from CT imaging, MRI is now unquestionably the modality of choice for further characterisation of hepatic mass lesions.

Nevertheless the cost, length of imaging time and perceived complexity of a paediatric liver MR study can be intimidating to the general radiologist and referring clinician. This article outlines standard MR sequences utilised, reasons for their utilisation, types of mixed hepatocyte specific/extracellular contrast agents employed and imaging features that aid the interpretation of paediatric liver lesions. The two commonest paediatric liver malignancies, namely hepatoblastoma and hepatocellular carcinoma are described. Differentiation of primary hepatic malignancies with metastatic disease and mimickers of malignancy such as focal nodular hyperplasia (FNH) and hepatic adenomas are also featured in this review..

Imaging should aim to clarify the presence of a lesion, the likelihood of malignancy and potential for complete surgical resection. Reviewing and reporting the studies should address these issues in a systematic fashion whilst also commenting upon background liver parenchymal appearances. Clinical information and adequate patient preparation prior to MR imaging studies help enhance the diagnostic yield.

Mesenchymal Hamartoma of the Liver in Older Children: An Adult Variant or a Different Entity? Report of a Case With Review of the Literature

Mesenchymal hamartoma of the liver (MHL) is an uncommon benign hepatic tumor typically affecting children under 2 years of age. Only 5% of MHL occur after 5 years and are very rarely observed in adults. According to age, MHL may differ in their morphologic features. We report a case of an 11-year-old boy with MHL, resembling a malignant lesion from a clinical point of view, characterized by unusual histologic features: a prominent myxoid stroma, with a minimal ductular component, and absent cystic spaces. The present case and others reported in older children or adults demonstrate that these lesions may represent a potential diagnostic pitfall when occurring outside their classic clinical context especially because of their peculiar histologic findings. Moreover, it may be hypothesized that variation in morphology might be related to different evolutive stages of the cell of origin. To support this hypothesis, we therefore studied the presence of components of the Notch pathway inside and outside the lesion. Their absence inside the tumor and, in contrast, the expression of Notch2 and HES1 evident in overrepresented bile ducts present at the periphery might explain not only the lack of bile ducts, but also indicate a more adult phenotype compared with classic pediatric MHL, which show more bile ducts and liver trabeculae embedded in the mesenchymal matrix.

Undifferentiated Embryonal Sarcoma of the Liver (UESL): A Single-Center Experience and Review of the Literature

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare and aggressive pediatric malignancy. The purpose of this study was to review the clinical, radiologic, and pathologic features and outcome of children with UESL at our institution, in the United Network of Organ Sharing database and to review the existing literature to define the state of the art for children with UESL. Six children were diagnosed with UESL at the Texas Children's Cancer Center between 1993 and 2014, 12 children underwent liver transplantation registered in the United Network of Organ Sharing database, and 198 children with UESL were described in 23 case series during 1978 to 2014. Patients were treated with multimodal treatment approaches including primary surgical resection, neoadjuvant and/or adjuvant chemotherapy, and liver transplantation resulting in overall survival reported between 20% and 100% with significant improvement over the recent years. We show that complete tumor removal remains the key element of treatment and our single-institutional experience and data in the published literature suggest that combination chemotherapy with ifosfamide and doxorubicin to facilitate complete surgical resection is an effective approach to cure children with UESL.

Thymosin β4 promotes hepatoblastoma metastasis via the induction of epithelial-mesenchymal transition

Hepatoblastoma (HB) is the most common malignant hepatic tumor in children and complete surgical resection offers the highest possibility for cure in this disease. Tumor metastasis is the principle obstacle to the development of efficient treatments for patients with HB. The present study aimed to measure the expression levels of thymosin β4 (Tβ4) in liver samples from patients with HB and to investigate the involvement of Tβ4 in HB metastasis. The expression of Tβ4 was significantly higher in liver samples from patients with metastatic HB and in the HepG2 metastatic HB cell line, compared with that in adjacent healthy liver samples and in the L02 healthy hepatic cell line. By contrast, the expression levels of epithelial-cadherin (E-cadherin) and cytosolic accumulation of β-catenin, the two most prominent markers involved in epithelial-mesenchymal transition (EMT), were reduced in liver specimens from patients with metastatic HB compared with that of healthy adjacent control tissue. HepG2 cells were transfected with small interfering-RNA in order to downregulate Tβ4 gene expression. This resulted in a reduced cell migratory capacity compared with control cells. Tβ4 gene expression knockdown significantly inhibited transforming growth factor β1-mediated-EMT in vitro by upregulating the expression of E-cadherin. The results of the present study suggested that Tβ4 may promote HB metastasis via the induction of EMT, and that Tβ4 may therefore be a target for the development of novel treatments for patients with HB.

Clinical efficacy and prognosis factors for advanced hepatoblastoma in children: a 6-year retrospective study

OBJECTIVE

This study aimed to investigate the effect of multimodality treatment of advanced paediatric hepatoblastoma (HB) and the factors affecting prognosis.

METHODS

A total of 35 children underwent multimodality treatments consisting of chemotherapy, surgery, interventional therapy, and autologous peripheral blood stem cell transplantation. The patients were followed up every month.

RESULTS

Serum AFP levels in 33 out of 35 patients in this study were significantly increased (P = 0.0002). According to the statistical scatter plot, the values of serum AFP on the 25th, 50th, and 75th percentages were 1,210, 1,210 and 28,318 ng/dl, respectively. Of the 35 cases, 21 were stage IV. 18 cases were treated with systemic chemotherapy before surgery, and 3 cases with locally interventional chemotherapy before surgery. Statistical analysis showed that the preferred interventional treatment affected prognosis, and that there was a statistically significant difference (P = 0.024). Some 33 patients completed the follow-up, of which 17 were in complete remission (CR), 5 were in partial remission (PR), 1 became disease progressive (DP) , and 10 died. The remission and overall survival rates were 66.7% (22/33) and 69.7% (23/33), respectively. Patients with the mixed HB phenotypes had worse prognoses than the epithelial phenotype (P < 0.001), and patients in stage IV had a lower survival rate than those in stage III (P < 0.001).

CONCLUSION

Multimodality treatment can effectively improve remission rate and prolong the survival of children with advanced HB. In addition, alpha-fetoprotein (AFP), a tumor marker of liver malignant tumors, HB pathological classification, and staging are highly useful in predicting prognosis.

Single-agent cisplatin treatment of children with high-risk hepatoblastoma

PURPOSE

The use of neoadjuvant chemotherapy has improved the survival of patients with hepatoblastoma (HB). However, an increased number of treatment complications and toxic deaths, particularly from heart failure, have been observed with doxorubicin treatment. We have applied cisplatin as a single agent to treat children with high-risk HB to improve event-free survival (EFS).

METHODS

Between 2007 and 2009, 14 patients with untreated high-risk HB were enrolled in this study. All the patients received a single-agent treatment of cisplatin. The initial cisplatin cycle was administered in a continuous intravenous 24-hour infusion of 80 mg/m/24 h. The primary outcome was the rate of complete resection. Secondary outcomes were EFS and overall survival (OS).

RESULTS

Eleven patients (78.6%) had an overall partial response. Two patients (14.3%) had stable disease. One patient experienced (7.1%) progression. Of the 4 patients who presented with lung metastases initially, 1 patient achieved complete response, 2 patients achieved partial response, and 1 patient experienced progression during preoperative chemotherapy. The complete resection rate was 78.6% (95% CI, 49%-95%). The Kaplan-Meier estimates of 2-year EFS and OS for the whole group were 64.3% (95% CI, 35%-87%) and 85.7% (95% CI, 57%-98%), respectively. The 2-year EFS and OS rates of patients who achieved complete resection were 81.8% (95% CI, 48%-98%) and 100% (95% CI, 62%-100%), respectively.

CONCLUSIONS

The single-agent cisplatin had less toxicity than cisplatin plus doxorubicin and achieved an equal rate of complete resection in high-risk HB compared with conventional multiagent chemotherapy.

Hepatocellular carcinoma and other hepatic malignancies: MR imaging

Magnetic resonance (MR) imaging surpasses all other imaging modalities in characterizing liver lesions by virtue of the exquisite tissue contrast, specificity for various tissue types, and extreme sensitivity to contrast enhancement. In addition to differentiating benign from malignant lesions, MR imaging generally discriminates between the various malignant liver lesions. Hepatocellular carcinoma constitutes most primary malignant liver lesions and usually arises in the setting of cirrhosis. Intrahepatic cholangiocarcinoma is a distant second and features distinctly different imaging features. Overall, metastases are the most common malignant liver lesions and arise from several primary neoplasms; most commonly gastrointestinal, lung, breast, and genitourinary.

Robotic-assisted surgery approach in a biliary rhabdomyosarcoma misdiagnosed as choledochal cyst

Rhabdomyosarcoma is a soft tissue malignant tumor affecting 1% of children from 0 to 14 years. Preoperative imaging may not always be diagnostic for hepatobiliary rhabdomyosarcoma and differential diagnosis with choledochal cyst (CC) could be difficult. We report a case of 2-years-old girl with a strange CC pattern of presentation. A grapelike lesion involving the choledochal and biliary ducts was easily and completely resected by robotic assisted surgery. Since no previous reports were available about oncologic safety of robotic approach, the porto-enterostomy was performed in open surgery. On histologic examination, the specimen revealed a botryoidembryonal rhabdomyosarcoma affecting both the common bile duct and the common hepatic duct. One year postoperatively the child is safe of tumor relapse. Robotic approach seems to be safe and advantageous to obtain a radical excision of the tumor at the porta hepatis, even in case of misdiagnosed malignant lesion mimicking a CC.

Towards an international pediatric liver tumor consensus classification: proceedings of the Los Angeles COG liver tumors symposium

Liver tumors are rare in children, and their diagnoses may be challenging particularly because of the lack of a current consensus classification system. Systematic central histopathological review of these tumors performed as part of the pediatric collaborative therapeutic protocols has allowed the identification of histologic subtypes with distinct clinical associations. As a result, histopathology has been incorporated within the Children's Oncology Group (COG) protocols, and only in the United States, as a risk-stratification parameter and for patient management. Therefore, the COG Liver Tumor Committee sponsored an International Pathology Symposium in March 2011 to discuss the histopathology and classification of pediatric liver tumors, and hepatoblastoma in particular, and work towards an International Pediatric Liver Tumors Consensus Classification that would be required for international collaborative projects. Twenty-two pathologists and experts in pediatric liver tumors, including those serving as central reviewers for the COG, European Société Internationale d'Oncologie Pédiatrique, Gesellschaft für Pädiatrische Onkologie und Hämatologie, and Japanese Study Group for Pediatric Liver Tumors protocols, as well as pediatric oncologists and surgeons specialized in this field, reviewed more than 50 pediatric liver tumor cases and discussed classic and newly reported entities, as well as criteria for their classification. This symposium represented the first collaborative step to develop a classification that may lead to a common treatment-stratification system incorporating tumor histopathology. A standardized, clinically meaningful classification will also be necessary to allow the integration of new biological parameters and to move towards clinical algorithms based on patient characteristics and tumor genetics, which should improve future patient management and outcome.

Imaging of multifocal hepatic lesions in pediatric patients

Imaging plays a vital role in detection and characterization of multifocal liver lesions in children. Numerous causes for these lesions exist, including benign and malignant neoplasms, infectious lesions, and congenital and inflammatory conditions. The imaging spectrum of multifocal liver lesions in children is presented with emphasis on key imaging features, differential diagnoses and helpful relevant clinical features.

Malignant liver tumors

Malignant tumors of the liver comprise a relatively small fraction of the total number of pediatric malignancies. However, these tumors can be a significant cause of morbidity and mortality, and there have been significant therapeutic gains during the past few decades through advances in systemic therapy and surgical treatment. Even in patients with advanced local disease, complete resection is now a possibility because of improvements in liver transplantation techniques. In this review, we will discuss the staging and treatment of common malignant tumors of the liver.

Undifferentiated sarcoma of the liver: a single institution experience using a uniform treatment approach

Undifferentiated (embryonal) sarcoma of the liver is a rare malignant tumor, most commonly seen in children aged 6 to 10 years. Previously believed to carry a poor prognosis, more recent reports indicate that treatment regimens combining surgical resection and adjuvant chemotherapy can yield long-term, disease-free survival. In this study, we review 5 pediatric patients with undifferentiated sarcoma of the liver treated with a uniform approach of resection followed by adjuvant chemotherapy and radiation when indicated. All 5 patients are disease free in their first remission at a median of 53 months.