Adult hepatoblastoma: learning from children

Predicting response of hepatoblastoma primary lesions to neoadjuvant chemotherapy through contrast-enhanced computed tomography radiomics

OBJECTIVE

To investigate the clinical value of contrast-enhanced computed tomography (CECT) radiomics for predicting the response of primary lesions to neoadjuvant chemotherapy in hepatoblastoma.

METHODS

Clinical and CECT imaging data were retrospectively collected from 116 children with hepatoblastoma who received neoadjuvant chemotherapy. Tumor response was assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST). Subsequently, they were randomly stratified into a training cohort and a test cohort in a 7:3 ratio. The clinical model was constructed using univariate and multivariate logistic regression, while the radiomics model was developed based on selected radiomics features employing the support vector machine algorithm. The combined clinical-radiomics model incorporated both clinical and radiomics features.

RESULTS

The area under the curve (AUC) for the clinical, radiomics, and combined models was 0.704 (95% CI: 0.563-0.845), 0.830 (95% CI: 0.704-0.959), and 0.874 (95% CI: 0.768-0.981) in the training cohort, respectively. In the validation cohort, the combined model achieved the highest mean AUC of 0.830 (95% CI 0.616-0.999), with a sensitivity, specificity, accuracy, precision, and f1 score of 72.0%, 81.1%, 78.5%, 57.2%, and 63.5%, respectively.

CONCLUSION

CECT radiomics has the potential to predict primary lesion response to neoadjuvant chemotherapy in hepatoblastoma.

Blastomas of the digestive system in adults: A review

Blastomas, characterized by a mixture of mesenchymal, epithelial, and undifferentiated blastematous components, are rare malignant neoplasms originating from precursor blast cells. This review focuses on digestive system blastomas in adult patients, including gastroblastoma, hepatoblastoma, and pancreatoblastoma. Gastroblastoma is a biphasic, epitheliomesenchymal tumor, with only sixteen cases reported to date. In addition to the characteristic histology, metastasis-associated lung adenocarcinoma transcript 1 - glioma-associated oncogene homolog 1 gene fusion is typical, although recently novel ewing sarcoma breakpoint region 1 - c-terminal binding protein 1 and patched 1 - glioma-associated oncogene homolog 2 fusions have been described. Hepatoblastoma is exceptionally rare in adults and can show a variety of histologic patterns which may cause diagnostic difficulty. Pancreatoblastoma, primarily a pediatric tumor, displays acinar differentiation and squamoid nests with other lines of differentiation also present, especially neuroendocrine. Diagnostic approaches for these blastomas include a combination of imaging modalities, histopathological examination, and molecular profiling. The treatment generally involves surgical resection, which may be supplemented by chemotherapy or radiotherapy in some cases. Prognoses vary with gastroblastoma generally showing favorable outcomes post-surgery whereas hepatoblastoma and pancreatoblastoma often have poorer outcomes, particularly in the setting of metastases. This review highlights the complexity of diagnosing and managing these rare adult blastomas as well as the need for ongoing research to better understand their pathogenesis and improve treatment strategies.

miR-139-3p/Wnt5A Axis Inhibits Metastasis in Hepatoblastoma

In order to examine new potential treatment options for the treatment of hepatoblastoma (HB), we identified the differential expression of five-candidate tumor suppressor miRNAs in HB and explored possible regulatory mechanisms of target miRNA molecule. By using real-time quantitative polymerase chain reaction (qPCR), we examined the expression of miRNAs in HB tissues and cells. The effect of has-miR-139-3p mimics on the invasion and migration ability was assessed by transwell assay and scratch-wound assay in HepG2 cells. Subsequently, we analyzed the target genes of miR-139-3p and their enrichment signaling pathways through bioinformatics. qPCR, Western-blot and dual-luciferase assays were further used to assess whether has-miR-139-3p targets Wnt5A. The results showed that hsa-miR-139-3p was significantly decreased in HB cells. Upregulation of hsa-miR-139-3p inhibited the invasive and migratory ability of HepG2. Bioinformatics analysis showed that hsa-miR-139-3p may target Wnt5A to regulate the WNT pathway, which was further confirmed by Western-blot and dual-luciferase assays. Overexpression of Wnt5A can reverse the miR-139-3p mimic-induced declines in the expression of WNT pathway-related proteins and restore the invasion and migration of HepG2. These data indicated that the hsa-miR-139-3p/Wnt5A axis inhibited HB metastasis, suggesting that miR-139-3p and Wnt5A may be potential targets for the treatment of HB.

BEX1 supports the stemness of hepatoblastoma by facilitating Warburg effect in a PPARγ/PDK1 dependent manner

BACKGROUND

Hepatoblastoma (HB) is a highly aggressive paediatric malignancy that exhibits a high presence of cancer stem cells (CSCs), which related to tumour recurrence and chemotherapy resistance. Brain expressed X-linked protein 1 (BEX1) plays a pivotal role in ciliogenesis, axon regeneration and differentiation of neural stem cells. However, the role of BEX1 in metabolic and stemness programs in HB remains unclear.

METHODS

BEX1 expression in human and mouse HB was analyzed using gene expression profile data from NCBI GEO and immunohistochemical validation. Seahorse extracellular flux analyzer, ultra-high-performance liquid-chromatography mass spectrometry (LC-MS), flow cytometry, qRT-PCR, Western Blot, sphere formation assay, and diluted xenograft tumour formation assay were used to analyze metabolic and stemness features.

RESULTS

Our results indicated that overexpression of BEX1 significantly enhanced the Warburg effect in HB cells. Furthermore, glycolysis inhibition largely attenuated the effects of BEX1 on HB cell growth and self-renewal, suggesting that BEX1 promotes stemness maintenance of HB cells by regulating the Warburg effect. Mechanistically, BEX1 enhances Warburg effect through the downregulation of peroxisome proliferator-activated receptor-gamma (PPARγ). Furthermore, pyruvate dehydrogenase kinase isozyme 1 (PDK1) is required for PPARγ-induced inhibition of Warburg effect in HB. In addition, BEX1 supports the stemness of HB by enhancing Warburg effect in a PPARγ/PDK1 dependent manner.

CONCLUSIONS

HB patients with high BEX1 and PDK1 expression had a poor prognosis. BEX1 promotes the stemness maintenance of HB cells via modulating the Warburg effect, which depends on PPARγ/PDK1 axis. Pioglitazone could be used to target BEX1-mediated stemness properties in HB by upregulating PPARγ.

TRMT61B rs4563180 G>C variant reduces hepatoblastoma risk: a case-control study of seven medical centers

N1-methyladenosine (m1A) is an essential chemical modification of RNA. Dysregulation of RNA m1A modification and m1A-related regulators is detected in several adult tumors. Whether aberrant RNA m1A modification is involved in hepatoblast carcinogenesis has not been reported. tRNA methyltransferase 61B (TRMT61B) is responsible for mitochondrial RNA m1A modification. Some evidence has shown that genetic variants of TRMT61B might contribute to cancer susceptibility; however, its roles in hepatoblastoma are unknown. This study attempted to discover novel hepatoblastoma susceptibility loci. With the TaqMan method, we examined genotypes of the TRMT61B rs4563180 G>C polymorphism among germline DNA samples from 313 cases and 1446 controls. The association of the rs4563180 G>C polymorphism with hepatoblastoma risk was estimated based on odds ratios (ORs) and 95% confidence intervals (CIs). We found that the TRMT61B rs4563180 G>C polymorphism correlated significantly with a reduction in hepatoblastoma risk (GC vs. GG: adjusted OR=0.65, 95% CI=0.49-0.85, P=0.002; GC/CC vs. GG: adjusted OR=0.66, 95% CI=0.51-0.85, P=0.002). In stratified analysis, significant associations were detected in children younger than 17 months old, girls, and subgroups with stage I+II or III+IV tumors. False-positive report probability analysis validated that children with the GC or CC genotype, particularly in those <17 months of age, had a decreased risk of hepatoblastoma. The rs4563180 G>C polymorphism also correlated with expression of TRMT61B and the nearby gene PPP1CB. We identified a high-quality biomarker measuring hepatoblastoma susceptibility, which may contribute to future screening programs.

Adult hepatoblastoma: making the challenging distinction from hepatocellular carcinoma

Hepatoblastoma is an exceptionally rare malignancy in adults with just over 70 non-pediatric cases reported in literature. Recounted is a case of a 49-year-old female who presented with acute right upper quadrant abdominal pain, elevated serum alpha fetoprotein and a large liver mass on imaging. Hepatectomy was performed under clinical suspicion of hepatocellular carcinoma. Immunomorphologic characteristics of the tumor proved consistent with hepatoblastoma of mixed epithelial and mesenchymal type. Hepatocellular carcinoma remains to be the primary differential diagnosis for adult hepatoblastoma, however, distinguishing between these two neoplasms requires close histomorphologic assessment and immunohistochemical profiling as clinical, radiologic and gross pathologic findings typically overlap. Making this distinction is highly crucial in the timely initiation of surgical and chemotherapeutic interventions for this inherently aggressive and rapidly fatal disease.

Two Cases of Hepatoblastoma in Adults

Adult hepatoblastoma is a rare tumor whose etiology and mechanisms of development are still incompletely understood. Imaging and biological tests such as AFP and liver enzymes are non-specific. Histologically, there are 2 histological variants: pure epithelial with 5 types (pure fetal, embryonal, small cell undifferentiated, cholangioblastic, and macrotrabecular), a mixed epithelial and a mesenchymal variant with or without a teratoid contingent. The main differential diagnosis concerns hepatocellular carcinoma. The treatment of hepatoblastoma in adults is not yet standardized and surgery remains the mainstay of treatment. In this report we aim to describe the clinical, pathological, and immunohistochemical features of this rare entity in adult patients and discuss the elements allowing its distinction from hepatocellular carcinoma (HCC).

METTL1 gene polymorphisms synergistically confer hepatoblastoma susceptibility

INTRODUCTION

Hepatoblastoma is a rare but devastating pediatric liver malignancy. Overexpressed methyltransferase-like 1 (METTL1) is a methyltransferase that catalyzes essential N7-methylguanosine (m7G) modification of eukaryotic mRNA. Accumulating evidence has revealed the oncogenic potential of METTL1. However, whether METTL1 gene polymorphisms confer susceptibility to hepatoblastoma has not been reported. This study aimed to identify causal relationships between genetic variants of this gene and susceptibility to hepatoblastoma.

MATERIALS AND METHODS

Using the TaqMan assay, we genotyped three METTL1 polymorphisms (rs2291617 G > T, rs10877013 T > C, rs10877012 T > G) in germline DNA samples from 1759 Chinese children of Han ethnicity (313 cases vs. 1446 controls).

RESULTS

None of these polymorphisms were associated with hepatoblastoma risk. However, combination analysis showed that children with 1 to 3 risk genotypes were associated with increased hepatoblastoma risk (adjusted odds ratio = 1.47, 95% confidence interval  1.07-2.02; P = 0.018). Stratified analyses revealed significant effects of combined polymorphisms mainly among young children (< 17 months of age), boys, and those with advanced hepatoblastoma.

CONCLUSION

We identified some potential functional METTL1 gene polymorphisms that work together to increase the risk of hepatoblastoma among Chinese Han children; single polymorphism showed only weak effects. These METTL1 polymorphisms may be promising biomarkers for screening high-risk individuals for hepatoblastoma. These findings are inspiring and deserve to be validated among individuals of different ethnicities.

Mitochondrial fragmentation is crucial for c-Myc-driven hepatoblastoma-like liver tumor

Hepatoblastoma is the most common liver cancer in children, and the aggressive subtype often has a poor prognosis and lacks effective targeted therapy. Although aggressive hepatoblastoma (HB) is often accompanied by abnormally high expression of the transcription factor c-Myc, the underlying mechanism remains unclear. In this study, we found that mitochondrial fragmentation was enhanced by c-Myc overexpression in human aggressive HB tissues and was associated with poor prognosis. Then, a mouse model resembling human HB was established via hydrodynamic injection of c-Myc plasmids. We observed that liver-specific knockout of the mitochondrial fusion molecule MFN1 or overexpression of mitochondrial fission molecule DRP1 promoted the occurrence of c-Myc-driven liver cancer. In contrast, when MFN1 was overexpressed in the liver, tumor formation was delayed. In vitro experiments showed that c-Myc transcriptionally upregulated the expression of DRP1 and decreased MFN1 expression through upregulation of miR-373-3p. Moreover, enhanced mitochondrial fragmentation significantly promoted aerobic glycolysis and the proliferation of HB cells by significantly increasing reactive oxygen species (ROS) production and activating the RAC-alpha serine/threonine-protein kinase (AKT)/mammalian target of rapamycin (mTOR) and nuclear factor κB (NF-κB) pathways. Taken together, our results indicate that c-Myc-mediated mitochondrial fragmentation promotes the malignant transformation and progression of HB by activating ROS-mediated multi-oncogenic signaling.

Crosstalk between circRNAs and the PI3K/AKT signaling pathway in cancer progression

Circular RNAs (circRNAs), covalently closed noncoding RNAs, are widely expressed in eukaryotes and viruses. They can function by regulating target gene expression, linear RNA transcription and protein generation. The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays key roles in many biological and cellular processes, such as cell proliferation, growth, invasion, migration, and angiogenesis. It also plays a pivotal role in cancer progression. Emerging data suggest that the circRNA/PI3K/AKT axis modulates the expression of cancer-associated genes and thus regulates tumor progression. Aberrant regulation of the expression of circRNAs in the circRNA/PI3K/AKT axis is significantly associated with clinicopathological characteristics and plays an important role in the regulation of biological functions. In this review, we summarized the expression and biological functions of PI3K-AKT-related circRNAs in vitro and in vivo and assessed their associations with clinicopathological characteristics. We also further discussed the important role of circRNAs in the diagnosis, prognostication, and treatment of cancers.

Adult Hepatocellular Carcinoma Coexisting with Extramedullary Hematopoiesis

Extramedullary hematopoiesis (EMH) in adults usually occurs in the liver, spleen, and lymph nodes when bone marrow hematopoiesis fails. EMH has also been recognized in benign or malignant hepatic tumors, such as hepatoblastoma, hepatocellular adenoma, and vascular tumors. However, it is rarely encountered in hepatocellular carcinoma (HCC) in elderly adults, and the molecular mechanism of EMH in hepatic tumors remains unclear. We present a case of a 74-year-old man without any hematopoietic disorders and hepatitis viral infection who underwent hepatic resection for HCC. Histological examination revealed a well-differentiated HCC with trilineage hematopoiesis in the tumor and non-neoplastic liver. The coexistence of HCC and EMH in adult patients with no hematopoietic disorders is very rare and must be distinguished from poorly differentiated or dedifferentiated HCC and hepatoblastoma.

Insights Into the Somatic Mutation Burden of Hepatoblastomas From Brazilian Patients

Hepatoblastoma is a very rare embryonal liver cancer supposed to arise from the impairment of hepatocyte differentiation during embryogenesis. In this study, we investigated by exome sequencing the burden of somatic mutations in a cohort of 10 hepatoblastomas, including a congenital case. Our data disclosed a low mutational background and pointed out to a novel set of candidate genes for hepatoblastoma biology, which were shown to impact gene expression levels. Only three recurrently mutated genes were detected: CTNNB1 and two novel candidates, CX3CL1 and CEP164. A relevant finding was the identification of a recurrent mutation (A235G) in two hepatoblastomas at the CX3CL1 gene; evaluation of RNA and protein expression revealed upregulation of CX3CL1 in tumors. The analysis was replicated in two independents cohorts, substantiating that an activation of the CX3CL1/CX3CR1 pathway occurs in hepatoblastomas. In inflammatory regions of hepatoblastomas, CX3CL1/CX3CR1 were not detected in the infiltrated lymphocytes, in which they should be expressed in normal conditions, whereas necrotic regions exhibited negative labeling in tumor cells, but strongly positive infiltrated lymphocytes. Altogether, these data suggested that CX3CL1/CX3CR1 upregulation may be a common feature of hepatoblastomas, potentially related to chemotherapy response and progression. In addition, three mutational signatures were identified in hepatoblastomas, two of them with predominance of either the COSMIC signatures 1 and 6, found in all cancer types, or the COSMIC signature 29, mostly related to tobacco chewing habit; a third novel mutational signature presented an unspecific pattern with an increase of C>A mutations. Overall, we present here novel candidate genes for hepatoblastoma, with evidence that CX3CL1/CX3CR1 chemokine signaling pathway is likely involved with progression, besides reporting specific mutational signatures.

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.

Role of HNF1β in the differential diagnosis of yolk sac tumor from other germ cell tumors

Identification of the yolk sac tumor (YST) component in germ cell tumors (GCT) may prove challenging, and highly sensitive and specific immunohistochemical markers are still lacking. Preliminary data from the literature suggest that HNF1β may represent a sensitive marker of YST. The specificity of HNF1β has not been addressed in GCT. A cohort of 49 YST specimens from 45 patients was designed, occurring either as pure tumors, or as a component of a mixed GCT. Immunohistochemistry was conducted on whole tumor sections using HNF1β. SALL4, OCT4, CD30, CDX2, Cytokeratin 19, Glypican 3, and GATA3 were used for classification of the GCT components. Patients were mostly male (39/45), aged 14 months to 49 years, with primary testicular tumors (37/39), or primary mediastinal pure YSTs (2/39). All 6 primary tumors occurring in females (6/45) were pure ovarian YSTs; age range was 4 to 72 years. HNF1β nuclear reactivity was seen in the YST component in all 49 tumors, with a moderate to strong nuclear pattern of staining. Embryonal carcinoma (EC, 0/32) and seminoma (0/6) were negative. Choriocarcinoma (6/6) showed faint focal cytoplasmic reactivity to HNF1β but no nuclear staining. In teratomas, only enteric-type glands showed nuclear reactivity to HNF1β (11/16). Therefore, HNF1β sensitivity in YST component identification was 100% and specificity was 80%. Thus, in our experience, HNF1β is a sensitive and reliable marker of the YST component in GCT, and allows distinction of YST from intricately admixed EC, especially in the diffuse embryoma pattern.

Two Cases of Hepatoblastoma in Young Adults

Adult hepatoblastoma (AHB) is a rare liver tumor with a poor prognosis in adolescents and adults. This contrasts with hepatoblastoma in children and is not fully understood. Here we describe two adolescents with AHB who were treated in our hospital. Adolescents are likely to receive less intensive chemotherapy protocols and are treated in hospitals with less experience in pediatric oncology, resulting in poor outcome. More research is necessary for optimal treatment of AHB in adolescents. Adolescents with AHB should be referred to hospitals experienced in pediatric oncology and receive intensive chemotherapy, followed by hemihepatectomy.

Hepatoblastoma of the adult with pericardial metastasis: A case report

•

Hepatoblastoma in the adult is a very rare tumor with a bad prognosis.

•

The diagnosis is always post surgery or post mortem (biopsy is not recomended).

•

Surgery is the only curative treatment.

•

Skills in vascular and thoracic surgery are useful for the treatment of this tumor.

Background

Hepatoblastoma is the most frequent liver tumor in children, but very rare in the adult and associated with an unfavorable prognosis. The diagnosis is always postoperative or post mortem and biopsy is not useful. Surgery is the only accepted treatment.

Case presentation

Our patient underwent surgery in the suspect of liver metastasis from a previous gastric cancer. Surgery consisted in left lobectomy with partial diaphragm resection and partial pericardiectomy for a pericardial lesion, found after the opening of the thorax. The diaphragm defect was corrected with a biological mesh.

Results

The histopathological examination indicated hepatoblastoma of the adult with pericardial metastases. The patient was asymptomatic and without recurrence after 21 months of follow up.

Conclusion

The hepatoblastoma of the adult is related to a poor prognosis with median survival time less than 5 months. Surgery is the only curative treatment, but in many cases tumor resection requires complex operations. Vascular and thoracic expertise could be useful in the management of hepatoblastoma.

Hepatoblastoma Associated with Trisomy 18

Very few reports exist in the literature regarding a possible association between trisomy 18 patients and the incidence of hepatoblastoma. Fewer reports exist on patients with multifocal hepatoblastoma. We reviewed our institutional database for the past 10 years and found three cases with this possible association to the tumor.

Upregulated genes at 2q24 gains as candidate oncogenes in hepatoblastomas

AIM

Cytogenetic data of hepatoblastomas, a rare embryonal tumor of the liver, mostly consist of descriptions of whole-chromosome aneuploidies and large chromosome alterations. High-resolution cytogenetics may provide clues to hepatoblastoma tumorigenesis and indicate markers with clinical significance.

PATIENTS & METHODS

We used array-CGH (180K) to screen for genomic imbalances in nine hepatoblastomas. Additionally, we investigated the expression pattern of selected genes exhibiting copy number changes.

RESULTS

Analysis showed mainly whole-chromosome or chromosome-arm aneuploidies, but some focal aberrations were also mapped. Expression analysis of 48 genes mapped at one 10 Mb amplification at 2q24 revealed upregulation of DAPL1, ERMN, GALNT5, SCN1A and SCN3A in the set of tumors compared with differentiated livers.

CONCLUSION

These genes appear as candidates for hepatoblastoma tumorigenesis.

α-Fetoprotein assay on dried blood spot for hepatoblastoma screening in children with overgrowth-cancer predisposition syndromes

BACKGROUND

Beckwith-Wiedemann syndrome (BWS) and hemihyperplasia (HH) are overgrowth conditions with predisposition to hepatoblastoma for which early diagnosis patients undergo cancer screening based on determination of the tumor marker α-fetoprotein (αFP). Repeated blood draws are a burden for patients with consequent compliance issues and poor adherence to surveillance protocol. We sought to analyze feasibility and reliability of αFP dosage using an analytical micromethod based on blood dried on filter paper (DBS).

METHODS

Overall 143 coupled αFP determinations on plasma and DBS collected simultaneously were performed, of which 31 were in patients with hepatoblastoma predisposition syndromes and 112 were in controls. The plasma αFP dosage method was adapted to DBS adsorbed on paper matrix for newborn screening.

RESULTS

There was strong correlation between plasmatic and DBS αFP (r2 = 0.999, P < 0.001). Cohen's k coefficient for correlation was 0.96 for diagnostic cut-off of 10 U/ml (P < 0.001), commonly employed in clinical practice. The measurements on plasma and DBS were highly overlapping and consistent.

CONCLUSION

The DBS method allowed to dose αFP reliably and consistently for the concentrations commonly employed in clinical settings for the screening of hepatoblastoma, opening new scenarios about conducting cancer screening in overgrowth syndromes.

C-KIT-positive undifferentiated tumor of the liver: A case report

With recent advances in cancer stem cell analysis, it has been postulated that the transformation of hepatic stem and progenitor cells underlies the development of certain liver cancers. Human C-KIT is a transmembrane type III receptor protein with intrinsic tyrosine kinase activity that has been proposed as a marker for human embryonic stem cells. In addition, human C-KIT functions in maintaining the undifferentiated state of stem cells, and has been identified as a marker for human hematopoietic and hepatic stem/progenitor cells. The present study identified an unusual case of a C-KIT-positive hepatic tumor with an undifferentiated stem cell phenotype distinct from existing descriptions of liver tumors. A 69-year-old male with Ampulla of Vater (AoV) cancer was admitted to the hospital for the treatment of a hepatic mass that was incidentally detected during evaluation of AoV cancer. Microscopically, the hepatic tumor was composed of solidly packed small, round and uniform undifferentiated cells, which resembled that of a small-blue-round-cell tumor. The immunophenotype of neoplastic cells (C-KIT⁺/EpCAM⁺/E-cadherin⁺/keratin 7⁻/keratin 19⁻/α-fetoprotein⁻/albumin⁻) supported primitive stem cell features with no hepatic or biliary phenotypes. Polymerase chain reaction and direct DNA sequencing revealed no C-KIT mutations. It is suggested that this tumor may have originated from transformed C-KIT⁺/EpCAM⁺/E-cadherin⁺ cells, which are more primitive and undifferentiated than bipotential hepatic progenitor cells.

Adult hepatoblastoma: A case report and literature review

INTRODUCTION

Adult hepatoblastoma is a rare malignant liver neoplasm. Surgery is the only cure, but recurrence is common even after complete resection. No therapeutic strategy has been established.

PRESENTATION OF CASE

A 22-year-old man presented with a rapidly expanding right hypochondrial mass. Pain preceded the appearance of the mass. No definitive diagnosis was established in the referring hospital. In addition, two attempts of embolization failed to reach the tumor due to its large size and vascular displacement. Clinical examination revealed a 26cm×23cm mass occupying the right hypochondrium and epigastrium as far as the right iliac fossa, compressing the stomach, spleen, kidneys and liver. The preoperative diagnosis was gastrointestinal stromal tumor because it appeared to originate from the stomach. During surgery, we found a mass arising from the liver, adhering to the omentum, stomach, and left hemidiaphragm, and infiltrating the pericardium. The tumor was completely resected off the inferior vena cava and pericardium. The histopathological diagnosis was a 30cm×30cm hepatoblastoma weighing 4kg. The postoperative treatment course went smoothly until day 10, when the patient developed complications like bilateral atrial thrombi and left ventricular hypokinesia and expired on day 16.

DISCUSSION

Due to the rarity of hepatoblastoma in adults and non-specific initial symptoms, hepatoblastoma is often overlooked as a diagnosis. Early detection may lead to improved prognosis and survival.

CONCLUSION

We report here the first case of adult hepatoblastoma in the Middle East and the largest such tumor ever reported in literature.

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.