Rare malignant liver tumors in children

Incidence of liver cancer in young adults according to the Global Burden of Disease database 2019

BACKGROUND AND AIMS

The worldwide burden of cancer is increasing in younger populations. However, the epidemiology of primary liver cancer remains understudied in young adults compared to other cancer forms.

APPROACH AND RESULTS

This study analyzed data from the Global Burden of Disease study between 2010 and 2019 to assess the age-standardized incidence, mortality, and disability-adjusted life years associated with primary liver cancer in the young (15-49 y), stratified by region, nation, sociodemographic index, and sex. The study found a global estimate of 78,299 primary liver cancer cases, 60,602 deaths, and 2.90 million disability-adjusted life years in the young population. The Western Pacific region exhibited the highest burden in 2019, showing the most significant increase compared to other regions between 2010 and 2019. More than half of the countries worldwide have undergone an increase in primary liver cancer incidence rates in young adults. Around 12.51% of deaths due to primary liver cancer occur in young individuals. Throughout the study period, there was a significant decline in primary liver cancer mortality due to most etiologies, except for metabolic dysfunction-associated steatotic liver disease-attributable primary liver cancer (annual percentage change + 0.87%, 95% CI: 0.70%-1.05%) and alcohol-attributable primary liver cancer (annual percentage change + 0.21%, 95% CI: 0.01%-0.42%). The limitations of the Global Burden of Disease database include reliance on the quality of primary data and possible underestimation of alcohol consumption.

CONCLUSIONS

Over the past decade, there has been a marked increase in the burden of primary liver cancer, especially that originating from steatotic liver disease. This trend calls for the development of urgent and comprehensive strategies to mitigate this rising burden globally.

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.

Diagnosis, Management, and Prognosis of Epithelioid Hemangioendothelioma of Maxillary Sinus: A Case Report

Epithelioid hemangioendothelioma (EHE) is a rare condition arising from endothelial cells of the blood vessels. This is a vascular tumor that may occur anywhere throughout the body. This tumor behaves on a spectrum as either a benign tumor or an aggressive sarcoma. The EHE tumor and its management depend on the location of the lesion and accessibility for surgical excision. This case is a rare example of a patient presenting with a maxillary aggressive EHE tumor. This lesion was incidentally found on head CT done for ruling out fractures of the mid-face with incidental findings of an asymptomatic destructive lytic lesion. The treatment of this tumor located in a vital region of the mid-face will be discussed.

Pediatric living donor liver transplantation for biliary embryonal rhabdomyosarcoma: a case report of a case showing disease-free survival over 2 years

Biliary rhabdomyosarcoma is a rare tumor, but it is still the most common tumor of the biliary tract in children. We report a case of a 6-year-old boy with biliary embryonal rhabdomyosarcoma and liver metastasis, which were treated with neoadjuvant and adjuvant chemotherapy combined with living donor liver transplantation (LDLT). Initial imaging studies showed a low-attenuation intraductal mass from the left hepatic duct to the intrapancreatic common bile duct with diffuse upstream dilatation of the intrahepatic duct and liver metastasis. Endoscopic biopsy revealed embryonal rhabdomyosarcoma. After tumor size reduction through neoadjuvant chemotherapy, LDLT was planned to remove the tumor completely. A left lateral section graft weighing 330 g was harvested from his 38-year-old mother and the graft-to-recipient weight ratio was 1.94%. Routine pediatric LDLT operation was performed with deep excavation of intrapancreatic distal bile duct. The explant liver showed minimal residual embryonal rhabdomyosarcoma with no lymph node metastasis. The patient recovered uneventfully from LDLT operation. Scheduled adjuvant chemotherapy was performed for 6 months. The patient is doing well without any evidence of tumor recurrence for 26 months after LDLT. In conclusion, liver transplantation could be an effective treatment for unresectable biliary rhabdomyosarcoma in children according to the location of tumor.

Primary Malignant Liver Tumors: eight-year experience in a Pediatric Hospital in Brazil. A cross-sectional study

INTRODUCTION

liver tumors are rare neoplasms in childhood (1-2%), and about 2/3 are malignant. Hepatoblastoma (HB) is the most frequent, followed by hepatocellular carcinoma (HCC). In both, the main treatment is surgical resection. Currently, chemotherapy and liver transplantation have improved outcomes.

OBJECTIVE

study of the epidemiological profile and evolution of liver cancer cases in a referral pediatric hospital.

METHODOLOGY

a retrospective survey of medical records of patients aged up to 18 years with a diagnosis of primary malignant hepatic neoplasm between 2012 and 2020, carried out in the largest exclusively pediatric hospital in Brazil.

RESULTS

a total of 13 patients with malignant liver tumors (HB 12, HCC 1) were treated. Of the HB cases, 66,7% were male, with a mean age of 2 years and the main alteration in the palpable abdominal mass. Tumors involved an average of 3 liver segments, more in the right lobe (54%). Only one patient was treated with surgery without neoadjuvant therapy, another one underwent transplantation like the first treatment, and another 2 required liver transplantation as a rescue. The middle follow-up time of patients with HB was 39 months and only 1 case died due to febrile neutropenia. The 5-year overall and disease-free survival was 91.7% and 81.5%, respectively.

CONCLUSION

Advanced staging at the time of diagnosis has always been a poor prognostic factor in patients with primary malignant liver tumors. However, the results and survival have improved with the advancement of chemotherapy, surgical technique, and liver transplantation.

Differentiating malignant and benign focal liver lesions in children using CEUS LI-RADS combined with serum alpha-fetoprotein

BACKGROUND

Contrast-enhanced ultrasound (CEUS) can be used to diagnose focal liver lesions (FLLs) in children. The America College of Radiology developed the CEUS liver imaging reporting and data system (LI-RADS) for standardizing CEUS diagnosis of FLLs in adult patients. Until now, no similar consensus or guidelines have existed for pediatric patients to improve imaging interpretation as adults.

AIM

To evaluate the performance of CEUS LI-RADS combined with alpha-fetoprotein (AFP) in differentiating benign and malignant FLLs in pediatric patients.

METHODS

Between January 2011 and January 2021, patients ≤ 18 years old who underwent CEUS for FLLs were retrospectively evaluated. The following criteria for diagnosing malignancy were proposed: Criterion I considered LR-4, LR-5, or LR-M lesions as malignancies; criterion II regarded LR-4, LR-5 or LR-M lesions with simultaneously elevated AFP (≥ 20 ng/mL) as malignancies; criterion III took LR-4 Lesions with elevated AFP or LR-5 or LR-M lesions as malignancies. The sensitivity, specificity, accuracy and area under the receiver operating characteristic curve (AUC) were calculated to determine the diagnostic value of the aforementioned criteria.

RESULTS

The study included 63 nodules in 60 patients (mean age, 11.0 ± 5.2 years; 26 male). There were no statistically significant differences between the specificity, accuracy, or AUC of criterion II and criterion III (95.1% vs 80.5%, 84.1% vs 87.3%, and 0.794 vs 0.902; all P > 0.017). Notably, criterion III showed a higher diagnostic sensitivity than criterion II (100% vs 63.6%; P < 0.017). However, both the specificity and accuracy of criterion I was inferior to those of criterion II and criterion III (all P < 0.017). For pediatric patients more than 5 years old, the performance of the three criteria was overall similar when patients were subcategorized by age when compared to all patients in aggregate.

CONCLUSION

CEUS LI-RADS combined with AFP may be a powerful diagnostic tool in pediatric patients. LR-4 with elevated AFP, LR-5 or LR-M lesions is highly suggestive of malignant tumors.

Surgical Outcome of Children with a Malignant Liver Tumour in The Netherlands: A Retrospective Consecutive Cohort Study

Introduction: Six to eight children are diagnosed with a malignant liver tumour yearly in the Netherlands. The majority of these tumours are hepatoblastoma (HB) and hepatocellular carcinoma (HCC), for which radical resection, often in combination with chemotherapy, is the only curative treatment option. We investigated the surgical outcome of children with a malignant liver tumour in a consecutive cohort in the Netherlands. Methods: In this nationwide, retrospective observational study, all patients (age < 18 years) diagnosed with a malignant liver tumour, who underwent partial liver resection or orthotopic liver transplantation (OLT) between January 2014 and April 2021, were included. Children with a malignant liver tumour who were not eligible for surgery were excluded from the analysis. Data regarding tumour characteristics, diagnostics, treatment, complications and survival were collected. Outcomes included major complications (Clavien−Dindo ≥ 3a) within 90 days and disease-free survival. The results of the HB group were compared to those of a historical HB cohort. Results: Twenty-six children were analysed, of whom fourteen (54%) with HB (median age 21.5 months), ten (38%) with HCC (median age 140 months) and one with sarcoma and a CNSET. Thirteen children with HB (93%) and three children with HCC (30%) received neoadjuvant chemotherapy. Partial hepatic resection was possible in 19 patients (12 HB, 6 HCC, and 1 sarcoma), whilst 7 children required OLT (2 HB, 4 HCC, and 1 CNSET). Radical resection (R0, margin ≥ 1.0 mm) was obtained in 24 out of 26 patients, with recurrence only in the patient with CNSET. The mean follow-up was 39.7 months (HB 40 months, HCC 40 months). Major complications occurred in 9 out of 26 patients (35% in all, 4 of 14, 29% for HB). There was no 30- or 90-day mortality, with disease-free survival after surgery of 100% for HB and 80% for HCC, respectively. Results showed a tendency towards a better outcome compared to the historic cohort, but numbers were too small to reach significance. Conclusion: Survival after surgical treatment for malignant liver tumours in the Netherlands is excellent. Severe surgical complications arise in one-third of patients, but most resolve without long-term sequelae and have no impact on long-term survival.

Neoplasias Malignas Primárias do Fígado: experiência de oito anos de um Hospital Pediátrico no Brasil. Estudo transversal

RESUMO Introdução: tumores hepáticos são neoplasias raras na infância (1-2%), sendo que cerca de 2/3 são malignos. O hepatoblastoma (HB) é o mais frequente, seguido do carcinoma hepatocelular (CHC). Em ambos, o principal tratamento é a ressecção cirúrgica completa. Atualmente, a quimioterapia e o transplante hepático têm melhorado os resultados. Objetivo: estudo do perfil epidemiológico e evolução dos casos de cânceres hepáticos em um hospital pediátrico de referência. Método: Levantamento retrospectivo de prontuários de pacientes até 18 anos com diagnóstico de neoplasia maligna primária hepática entre 2012 e 2020 realizado no maior hospital exclusivamente pediátrico do Brasil. Resultados: foram atendidos 13 pacientes com tumores malignos hepáticos (HB 12, CHC 1). Dos casos de HB, 66,7% eram do sexo masculino, com idade média de 2 anos e a principal alteração foi massa abdominal palpável. Os tumores envolviam em média 3 segmentos hepáticos, mais em lobo direito (54%). Um paciente foi tratado com cirurgia sem neoadjuvância, um foi submetido a transplante inicialmente e outros 2 necessitaram de transplante hepático como resgate. O tempo de seguimento dos pacientes com HB foi de 39 meses e apenas 1 caso foi a óbito por neutropenia febril. A sobrevida geral e livre de doença em 5 anos foi de 91,7% e 81,5% respectivamente. Conclusão: o estadiamento avançado no momento do diagnóstico sempre foi um fator de mau prognóstico em pacientes com tumores hepáticos malignos primários. Entretanto, os resultados e a sobrevida têm melhorado significativamente com o avanço da quimioterapia, da técnica cirúrgica e do transplante hepático.

Pediatric vascular tumors of the liver: Review from the pathologist’s point of view

Differential diagnosis of pediatric vascular liver tumors can be challenging due to inconsistent nomenclature, histologic overlap and the rarity of some entities. Here we give an up-to-date overview of the most important entities. We discuss the clinic, histology and pathophysiology of hepatic congenital and infantile heman gioma, hepatic epithelioid hemangioendothelioma and hepatic angiosarcoma.

CircSETD3 (Hsa_circ_0000567) Suppresses Hepatoblastoma Pathogenesis via Targeting the miR-423-3p/Bcl-2-Interacting Mediator of Cell Death Axis

Background: Up until now, the role of circSETD3 (Has_circ_0000567) in regulating cancer development has been reported in several tumors, but the role and regulatory mechanism of circSETD3 in hepatoblastoma (HB) remain unclear.

Methods: The qPCR and western blotting were used to determine the mRNA and protein levels in the present study. Stability of circular RNA was detected by RNA digested experiments. The gain-of-function and rescue experiments were used to explore the function and mechanism of circSETD3 in HB. Cell counting kit-8, colony formation, transwell assay, and xenograft mice model were used to detect effects and regulatory mechanism of circSETD3/miR-423-3p/Bim axis on cell aggressive phenotype in vitro and in vivo.

Results: Here, we identified that circSETD3 downregulated in both HB clinical tissues and cell lines, compared to that of normal tissues and cells. Further gain-of-function experiments validated that circSETD3 overexpression inhibited cell proliferation, viability, migration, epithelial-mesenchymal transition (EMT) and tumorigenesis, and induced cell apoptosis in HB cells. Next, we validated that miR-423-3p targeted both circSETD3 and 3′ untranslated region (3′UTR) of Bim, and circSETD3 positively regulated Bim in HB cells through sponging miR-423-3p in a competing endogenous RNA (ceRNA)-dependent manner. Furthermore, through conducting reversal experiments, we evidenced that the inhibiting effects of circSETD3 overexpression on HB development were abrogated by upregulating miR-423-3p and downregulating Bim.

Conclusion: Taken together, we evidenced that circSETD3 sponged miR-423-3p to upregulate Bim, resulting in the inhibition of HB development.

Imaging and clinical features of pediatric hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is rare in children and there is limited data on its imaging features.

OBJECTIVE

To describe imaging features of pediatric HCC and correlate them with clinical and laboratory findings.

MATERIALS AND METHODS

We retrospectively reviewed imaging in all pediatric HCC cases seen between January 2000 and January 2019. Imaging features defined in LI-RADS (Liver Imaging Reporting and Data System) and tumor extent by PRETEXT (pretreatment extent of disease) criteria were noted by two radiologists. Patient charts were reviewed to collect clinical features, alpha-fetoprotein (AFP) level and pathology findings.

RESULTS

Of the 15 children (7 boys, 8 girls; mean age: 11.8 years, age range: 6-17 years) included in the study, 12/15 had computed tomography, 9/15 had magnetic resonance imaging and 9/15 had ultrasound exams available for review. Pathological types of HCC included classic (11/15, 73%), fibrolamellar (3/15, 20%) and mixed cholangiocarcinoma-HCC (1/15, 7%). Eighty percent occurred de novo in normal liver and 67% showed elevated AFP levels. Arterial phase hyperenhancement was seen in 83% of cases, washout in 86%, capsule in 50% and tumor-in-vein in 33%. The mean tumor size was 9.8 cm and 40% were multifocal on imaging. Staging revealed PRETEXT II tumors in 47%, III in 20% and IV in 33%. There were no PRETEXT I tumors. The two most common PRETEXT annotation factors were portal vein and caudate lobe involvement in 71% and 43% of cases, respectively. Fibrolamellar HCC demonstrated central scar, normal AFP levels and normal background liver.

CONCLUSION

Pediatric HCC are large heterogeneous tumors, as reflected by high PRETEXT staging, and commonly include portal vein and caudate involvement. This affects resectability of these tumors at presentation. Central scar, normal AFP level and normal liver background may help differentiate fibrolamellar HCC from other types of HCC.

Epithelioid hemangioendothelioma, an ultra-rare cancer: a consensus paper from the community of experts

Epithelioid hemangioendothelioma (EHE) is an ultra-rare, translocated, vascular sarcoma. EHE clinical behavior is variable, ranging from that of a low-grade malignancy to that of a high-grade sarcoma and it is marked by a high propensity for systemic involvement. No active systemic agents are currently approved specifically for EHE, which is typically refractory to the antitumor drugs used in sarcomas. The degree of uncertainty in selecting the most appropriate therapy for EHE patients and the lack of guidelines on the clinical management of the disease make the adoption of new treatments inconsistent across the world, resulting in suboptimal outcomes for many EHE patients. To address the shortcoming, a global consensus meeting was organized in December 2020 under the umbrella of the European Society for Medical Oncology (ESMO) involving >80 experts from several disciplines from Europe, North America and Asia, together with a patient representative from the EHE Group, a global, disease-specific patient advocacy group, and Sarcoma Patient EuroNet (SPAEN). The meeting was aimed at defining, by consensus, evidence-based best practices for the optimal approach to primary and metastatic EHE. The consensus achieved during that meeting is the subject of the present publication.

•

This consensus paper provides key recommendations on the management of epithelioid hemangioendothelioma (EHE).

•

Recommendations followed a consensus meeting between experts and a representative of the EHE advocacy group and SPAEN.

•

Authorship includes a multidisciplinary group of experts from different institutions from Europe, North America and Asia.

[Imaging of hepatic tumors in children and adolescents]

BACKGROUND

Pediatric liver tumors are relatively rare, but thorough knowledge of their imaging features is still important.

OBJECTIVES

Frequency and imaging features of benign and malignant liver masses during childhood and adolescence.

MATERIALS AND METHODS

Discussion of relevant original articles, review manuscripts and expert recommendations concerning imaging of childhood liver tumors.

RESULTS

The most common malignant tumors of the liver are hepatoblastoma, which usually occur in younger children, as well as in some regions hepatocellular carcinoma. In contrast to most benign masses, such as focal nodular hyperplasia, simple cysts or fatty liver infiltrations, their imaging morphology is not very characteristic. Radiologically, sonography and magnetic resonance imaging (MRI) are used for assessment. Both methods benefit from intravenous contrast agent administration.

CONCLUSIONS

Childhood liver tumors show a broad spectrum of morphological manifestations. Some entities can be characterized using standard imaging, some require multimodal imaging or histological assessment. In addition to morphological imaging criteria, age and the medical history as well as laboratory data play an important role in establishing the correct diagnosis.

Primary malignant vascular tumors of the liver in children: Angiosarcoma and epithelioid hemangioendothelioma

Primary malignant vascular neoplasms of the liver, angiosarcoma and epithelioid hemangioendothelioma, are extremely rare entities in the pediatric population. International Society for the Study of Vascular Anomalies classification system is recommended for the pathologic diagnosis of hepatic vascular lesions in this age group. In this article, we highlight the clinicopathologic characteristics of hepatic angiosarcoma and epithelioid hemangioendothelioma in the pediatric population. Hepatic angiosarcoma in children shows a slight female predominance with an average age of 40 mo at diagnosis. The distinct histologic features include whorls of atypical spindled cells and eosinophilic globules, in addition to the general findings of angiosarcoma. Histologic diagnosis of pediatric hepatic angiosarcoma is not always straightforward, and the diagnostic challenges are discussed in the article. Hepatic epithelioid hemangioendothelioma also demonstrates a female predominance, but is more commonly identified in adolescents (median age at diagnosis: 12 years). Histologically, the lesion is characterized by epithelioid cells and occasional intracytoplasmic lumina with a background of fibromyxoid stroma. While WWTR1-CAMTA1 and YAP1-TFE3 fusions have been associated with epithelioid hemangioendothelioma, there are currently no known signature genetic alterations seen in pediatric hepatic angiosarcoma. Advancement in molecular pathology, particularly for pediatric hepatic angiosarcoma, is necessary for a better understanding of the disease biology, diagnosis, and development of targeted therapies.

Hepatocellular Malignant Neoplasm, Not Otherwise Specified: A New Name in Liver Tumors: A Brief Narrative Review of Published Cases

Background

Hepatocellular malignant neoplasm, not otherwise specified (HEM, NOS), is a rare liver tumor that is most commonly seen in adolescents. To the best of our knowledge, there has been no published review on this rare tumor in the English literature so far.

Summary

In this review, we will discuss all reported details, including demographic findings, clinical presentations, molecular histogenesis, imaging, gross pathology and histopathology, immunohistochemical findings, treatment modalities, and outcome, of the published cases of HEM, NOS, in the liver.

Key Message

Twenty-two cases of HEM, NOS, have been reported in the last 10 years in the English literature. This tumor produces a large liver mass and is characteristically seen in adolescents presenting with right upper quadrant pain. Histologically, HEM, NOS, is a nonbiliary hepatocytic tumor with a biphasic pattern, that is, a mixture of 2 components of hepatocellular carcinoma and hepatoblastoma (HBL). There is no characteristic immunohistochemical feature for this tumor. Imaging findings are also not specific. Treatment of this tumor needs extensive surgery or even liver transplantation. Most of the cases in the literature were treated with the primary diagnosis of HBL, so pathologists, onco-surgeons, and oncologists should get familiar with this tumor to provide better treatment options. More case series with more follow-ups are necessary for the definite determination of the outcome of this tumor as a unique entity.

Outcomes following liver transplantation in young infants: Data from the SPLIT registry

Liver transplantation (LT) in young patients is being performed with greater frequency. We hypothesized that objective analysis of pre-, intra-, and postoperative events would help understand contributors to successful outcomes and guide transplant decision processes. We queried SPLIT registry for pediatric transplants between 2011 and 2018. Outcomes were compared for age groups: 0-<3, 3-<6, 6-<12 months, and 1-<3 years (Groups A, B, C, D respectively) and by weight categories: <5, 5-10, >10 kg; 1033 patients were available for analysis. Cholestatic disease and fulminant failure were highest in group A and those <5 kg; and biliary atresia in group C (72.8%). Group A had significantly higher life support dependence (34.6%; P < .001), listing as United Network for Organ Sharing status 1a/1b (70.4%; P < .001), and shortest wait times (P < .001). The median (interquartile range) for international normalized ratio and bilirubin were highest in group A (3.0 [2.1-3.9] and 16.7 [6.8-29.7] mg/dL) and those <5 kg (2.6 [1.8-3.4] and 13.5 [3.0-28.4] mg/dL). A pediatric end -stage liver disease score ≥40, postoperative hospital stays, rejection, and nonanastomotic biliary strictures were highest in group A with lowest survival at 93.1%. Infants 0 to <3 months and those <5 kg need more intensive care with lower survival and higher complications. Importantly, potential LT before reaching status 1a/1b and aggressive postoperative management may positively influence their outcomes.

Diagnostic Performance of LI-RADS Version 2018 for Evaluation of Pediatric Hepatocellular Carcinoma

Background The Liver Imaging Reporting and Data System (LI-RADS) has standardized the evaluation of adult but not pediatric hepatocellular carcinoma (HCC). Purpose To evaluate the performance of LI-RADS version 2018 for diagnosis of pediatric HCC. Materials and Methods This multi-institution retrospective study evaluated all available dynamic CT and/or MRI scans of pediatric (≤18 years) HCC from five institutions between July 2009 and April 2019. The control group included an equal number of other enhancing hepatic lesions. Blinded to final diagnosis, three radiologists independently applied LI-RADS version 2018 criteria. The reference standard was pathologic examination or more than 1 year follow-up. Sensitivity and specificity of LI-RADS were computed using a dichotomous classification of LR-1, LR-2, or LR-3 versus LR-4, LR-5, LR-TIV (tumor in vein), or LR-M (probably or definitely malignant but not HCC-specific) for predicting hepatic malignancy in the entire cohort and in patients at risk for HCC. Results The cohort consisted of 116 children: 58 with HCC (mean age, 12 years ± 5; 31 girls) and 58 with other enhancing hepatic masses (mean age, 12 years ± 5; 42 girls). Frequencies of major criteria in classic HCC for the three readers were as follows: nonrim arterial phase hyperenhancement, 49%-62% (19-24 of 39 patients); nonperipheral "washout," 36%-59% (14-23 of 39 patients); and enhancing "capsule," 28%-38% (11-15 of 39 patients). For the full cohort, the sensitivity of LR-4, LR-5, LR-TIV, or LR-M for malignancy among the three readers ranged from 85% (95% CI: 76, 94) to 88% (95% CI: 80, 96); specificity of LR-1, LR-2, or LR-3 for benignity ranged from 54% (95% CI: 40, 68) to 70% (95% CI: 57, 83). In the at-risk subgroup, sensitivity ranged from 58% (95% CI: 36, 80) to 68% (95% CI: 48, 89); specificity ranged from 56% (95% CI: 37, 74) to 63% (95% CI: 45, 81). All lesions categorized as LR-TIV (n = 10-13) were HCCs. Conclusion Liver Imaging Reporting and Data System version 2018 had moderate sensitivity but low specificity for the diagnosis of pediatric hepatocellular carcinoma (HCC), which had low frequencies of the major criteria used for adult HCC diagnosis. © RSNA, 2021 See also the editorial by Paltiel in this issue.

Survival and prognostic factors for childhood malignant liver tumors: analysis of harmonized clinical data

BACKGROUND

Despite overall striking advances in survival of childhood liver tumors, outcomes remain poor for specific patient segments. We aimed to assess overall survival (OS) of this rare disease and evaluate the generalizability of prognostic variables included in international collaborative systems using, for the first time, harmonized clinical data from two geographically different cohorts (Greece and Moscow).

METHODS

Data for children (0-14 years) with liver tumors were retrieved from two Southern-Eastern European areas (Greece; 2001-2019 and Moscow; 2012-2019). Kaplan-Meier curves were constructed, and OS values were derived from Cox proportional models controlling for study variables.

RESULTS

A total of 171 newly diagnosed cases (54.4% males) were included. The OS_5-year exceeded 80% in patients <5 years, reaching 85% among 133 patients with hepatoblastoma (HBL). By contrast, children with other than HBL histology, especially hepatocellular carcinoma (HCC) had significantly worse prognosis (hazard ratio [HR] _HCC: 7.09, 95% confidence intervals [CI]: 2.56-19.65; HR _{other liver tumors}: 5.18; 95%CI: 2.15-12.49). The OS_5-year was poorer (40%-60%) in patients with extensive local, metastatic or relapsed disease. By contrast, a significantly lower risk of death was shown in case of microscopically margin-negative resection (HR: 0.06, 95%CI: 0.02-0.17) and liver transplantation (HR: 0.12, 95% CI: 0.02-0.63) compared to the non- operated group.

CONCLUSIONS

Outcomes of patients with liver tumors registered in two SEE areas were comparable to those reported by major collaborative trials. Ongoing clinical cancer registration could facilitate comparison of outcomes between different study groups in order to shape state of the art of treatment.

Liver Transplantation for Pediatric Liver Cancer

Unresectable hepatocellular carcinoma (HCC) was first removed successfully with total hepatectomy and liver transplantation (LT) in a child over five decades ago. Since then, children with unresectable liver cancer have benefitted greatly from LT and a confluence of several equally important endeavors. Regional and trans-continental collaborations have accelerated the development and standardization of chemotherapy regimens, which provide disease control to enable LT, and also serve as a test of unresectability. In the process, tumor histology, imaging protocols, and tumor staging have also matured to better assess response and LT candidacy. Significant trends include a steady increase in the incidence of and use of LT for hepatoblastoma, and a significant improvement in survival after LT for HCC with each decade. Although LT is curative for most unresectable primary liver sarcomas, such as embryonal sarcoma, the malignant rhabdoid tumor appears relapse-prone despite chemotherapy and LT. Pediatric liver tumors remain rare, and diagnostic uncertainty in some settings can potentially delay treatment or lead to the selection of less effective chemotherapy. We review the current knowledge relevant to diagnosis, LT candidacy, and post-transplant outcomes for these tumors, emphasizing recent observations made from large registries or larger series.