Primary hepatic tumors of childhood

Amplification and overexpression of the IGF2 regulator PLAG1 in hepatoblastoma

There is evidence that 8q amplification is associated with poor prognosis in hepatoblastoma. A previous comparative genomic hybridization analysis identified a critical region in chromosomal bands 8q11.2-q13. Using restriction landmark genomic scanning in combination with a virtual genome scan, we showed that this region is delineated by sequences within contig NT_008183 of chromosomal subbands 8q11.22-q11.23. A real-time PCR-based genomic copy number assay of 20 hepatoblastomas revealed gain or amplification in this critical chromosomal region in eight tumors. The expression of four genes and expressed sequence tags (ESTs) within this newly defined region was assayed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) in four tumors with and six tumors without gain or amplification. The PLAG1 oncogene was found to be highly expressed in all but one tumor compared to normal liver tissue. Furthermore, quantitative RT-PCR revealed that the expression level of the developmentally regulated transcription factor PLAG1 was 3-12 times greater in hepatoblastoma tumors and cell lines compared to age-matched normal liver and comparable to the expression in fetal liver tissue. PLAG1 has been shown be a transcriptional activator of IGF2 in other tumor types. Using luciferase reporter assays, we demonstrated that PLAG1 transactivates transcription from the embryonic IGF2 promoter P3, also in hepatoblastoma cell lines. Thus, our results provide evidence that PLAG1 overexpression may be responsible for the frequently observed up-regulation of IGF2 in hepatoblastoma and therefore may be implicated in the molecular pathogenesis of this childhood neoplasia.

Total hepatectomy and liver transplant for hepatocellular adenomatosis and focal nodular hyperplasia

Extensive hepatocellular adenomatosis (HA) and focal nodular hyperplasia (FNH) represent a proliferation of hepatic cells that occurs most frequently in women. These lesions are uncommon in the pediatric age group, accounting for 2% of pediatric hepatic tumors, and are extremely rare in males. The etiology of HA and FNH has been correlated with the use of oral contraceptives. We report to the best of our knowledge the first series of patients treated with OLTx for HA and FNH (five cases). All these patients had lesions involving at least 90% of the hepatic parenchyma and all underwent major hepatic surgery before OLTx because of life threatening complications. One patient died in the immediate postoperative period following retransplantation for primary non-function of the first OLTx. Four out of five patients are currently alive from 4.1 to 9.6 years after OLTx. Our results justify the use of OLTx for symptomatic patients with HA and FNH who cannot be treated with conventional hepatic resections.

The Wnt signaling pathway in solid childhood tumors

The Wnt signaling pathway has long been known to direct growth and patterning during embryonic development. Recent evidence also implicates this pathway in the development of childhood tumors of the liver, the kidney, the brain, and the pancreas. Here, we review the current evidence on how constitutive activation of the Wnt signaling pathway may occur in hepato-, nephro-, medullo- and pancreatoblastomas. With particular emphasis the mutational activation of CTNNB1, an emerging major oncogene in solid childhood tumors, is discussed.

Calcificações hepáticas: freqüência e significado

OBJETIVO: Avaliar a freqüência e a origem de calcificações hepáticas identificadas na tomografia computadorizada (TC). MATERIAIS E MÉTODOS: Estudo retrospectivo de 1.362 exames consecutivos de TC do abdome, para determinar a freqüência de calcificações hepáticas. Foram revistos os prontuários clínicos, no sentido de estabelecer a origem das calcificações. RESULTADOS: Observaram-se calcificações intra-hepáticas em 3,6% (49/1.362) dos exames. Houve predominância no sexo feminino (57,2%) sobre o masculino (42,8%), e a idade dos pacientes variou de 18 a 92 anos (média: 59,4; mediana: 63,5). A maioria das calcificações (39/49; 79,5%) foi de origem residual e sem repercussão clínica, 14,4% (7/49) estavam associadas a metástases hepáticas e 6,1% (3/49) estavam associadas a lesões císticas. Foram observadas sete lesões metastáticas calcificadas, sendo cinco por neoplasia de cólon, uma por sarcoma e uma por teratoma maligno de ovário. Dessas metástases, duas apresentaram calcificações após tratamento quimioterápico. CONCLUSÃO: As calcificações hepáticas são de baixa prevalência em exames tomográficos (< 5%) e são mais freqüentemente de origem residual por processos infecciosos e inflamatórios pregressos.

Hemangioma of the liver in children: proliferating vascular tumor or congenital vascular malformation?

BACKGROUND

Hepatic vascular tumors (HVT) are the most common benign liver tumors present in infancy and childhood commonly associated with high output cardiac failure. Pediatric HVT usually are divided into infantile hemangioendothelioma (IHE), cavernous hemangioma (HC), and arteriovenous malformations (AVM). The aim of this study was to analyze clinical and histologic features of pediatric HVT in relation to treatment strategies.

PROCEDURE

During last 12 years, 17 children have been treated because of HVT. The diagnosis of HVT was established in all on the basis of clinical and imaging data. A retrospective analysis of clinical records and histopathology divided 17 into: Group 1, neonates; and Group 2, infants and older children.

RESULTS

Radiologic imaging revealed the vascular nature of the tumors in all patients. All nine from Group 1 were symptomatic from AVMs and seven were operated upon. Only one of eight children from Group 2 presented symptoms of AVM requiring surgery; four of five in this group had surgery because of the risk of malignancy. Within Group 1, a mixture of proliferating IHE with microscopic features of AVM was found in most. In three neonates with HVT immunologic and clinical features of cytomegalovirus (CMV) hepatitis were noted. In two Group 2 patients, pure HC was present and in another, the diagnosis of angiosarcoma was established after biopsy of a peritoneal metastasis.

CONCLUSIONS

HVT in children demonstrate internal morphologic heterogeneity and an age-related behavior of the disease. We also confirm the proliferative nature of all hemangioendotheliomas (HEs) in children. Further studies on the tumorigenesis of these lesions are needed.

Hepatoblastoma: assessment of criteria for histologic classification

BACKGROUND

Comparison of outcomes in different clinicopathologic studies of hepatoblastoma requires reproducible histologic classification. This review examines the diagnostic criteria employed by different pathologists for the classification of subtypes of hepatoblastoma and identifies specific problem areas.

PROCEDURE

A selected review of published literature is provided.

RESULTS

Published studies demonstrate that uniform criteria have not been applied in the classification of hepatoblastoma. These discrepancies hinder attempts to compare outcome data from different studies. Sampling error and potential treatment effects further complicate analysis of the published literature on the relationship between morphologic classification and outcome.

CONCLUSIONS

Standardized criteria are essential to allow reproducible histologic classification of hepatoblastoma. There is significant variation in diagnostic criteria used to define the major subtypes of hepatoblastoma in published studies. Additional potential problems are identified in sampling methods and treatment effects.

Adult type vs. Childhood hepatocellular carcinoma--are they the same or different lesions? Biology, natural history, prognosis, and treatment

BACKGROUND

Differences in the biology, natural history, and treatment results of hepatocellular carcinoma (HCC) in children and adults were sought based on the literature and experience resulting from SIOPEL 1 trial.

PROCEDURE

In the SIOPEL1 study, 40 children with HCC were registered from January 1990 to February 1994. Outcome was analyzed in 39. In most cases, disease was advanced at diagnosis: 31% had metastases and 39% had extrahepatic tumor extension and/or vascular invasion. More than 50% of patients had multifocal tumors; 39% of tumors were associated with hepatic cirrhosis. All, but two patients, received preoperative chemotherapy (PLADO--cisplatin and doxorubicin). Outcome, response to treatment, and prognostic factors were analyzed using the SAS statistical package.

RESULTS

Overall survival (OS) at 5 years is 28% and EFS is 17% at median follow-up of 75 months (49-90). Partial response to chemotherapy was observed in 18 of 37 cases evaluated (49%). Complete tumor resection was achieved in 14 of the 39 patients (36%). Twenty (51%) never became operable. Multifocality of the tumor, presence of metastases, and PRETEXT grouping adversely influenced OS. A large number of "de novo" HCC cases, fairly high response rate to preoperative chemotherapy (49%) and 54% survival after complete resection constitute a significant difference in comparison with adult HCC series.

CONCLUSIONS

Survival for pediatric HCC patients is below 30%. Radical tumor resection remains the only chance for survival. New multi-center prospective studies in children with HCC are required to better results and to allow further study of differences between adult and pediatric HCC should they exist.

Transitional liver cell tumors (TLCT) in older children and adolescents: a novel group of aggressive hepatic tumors expressing beta-catenin

BACKGROUND

We encountered on seven malignant hepatocellular tumors developing in older children and adolescents.

RESULTS

These tumors exhibit an unusual phenotype with respect to clinical presentation, histopathology, immunohistochemistry, and treatment response. As a working hypothesis, we suggest that these apparently novel, unusual, and aggressive tumors occurring in older children and adolescents may form a transition in the putative developmental pathway of hepatocarcinogenesis.

CONCLUSION

We therefore propose the term, transitional liver cell tumors (TLCT), to denote these lesions.

Hepatoblastoma with cholangioblastic features ('cholangioblastic hepatoblastoma') and other liver tumors with bimodal differentiation in young patients

In a subset of hepatoblastomas, differentiation of neoplastic cells can proceed along a pathway resulting in cholangiocyte-like cells. These cells either occur as single, immunohistochemically detectable elements, or form incomplete and complete duct-like profiles in continuation with embryonal, fetal or macrotrabecular hepatoblastoma components. As a working formulation it is proposed to employ the term, hepatoblastoma with cholangioblastic features (or 'cholangioblastic' hepatoblastoma), to denote such lesions. This bimodal differentiation presents itself in other rare tumors in the form of complex arrays of duct-like cells encircling nests of neoplastic hepatocyte lineage cells, in some way mimicking a ductal plate. A possible pathogenetic pathway is suggested, i.e., uni- or bipotential neoplastic progenitors switch into either of the two lineages.

Chemotherapy for suspected hepatoblastoma without efforts at surgical resection is a bad practice

BACKGROUND

US and European practices differ with respect to treating hepatoblastoma (HB). Should chemotherapy be given prior to resection in all cases, and even without biopsy confirmation (SIOPEL)?

PROCEDURE AND RESULTS

US data indicate that 40% of HBs are primarily resectable with no operative mortality and that those with pure fetal histology and low mitotic rate do not require toxic chemotherapy. They also suggest that those with a significant fraction of small undifferentiated cells do not respond to otherwise effective chemotherapy. Both US and European studies report a significant error rate in the clinical and imaging diagnosis of HB.

CONCLUSIONS

Although only 6.5% of confirmed HBs fall into categories that would be managed differently by US standards, there is no justification for denying those patients a more appropriate treatment nor should the 6-10% of cases that are misdiagnosed as HB be treated incorrectly.

Pediatric liver tumors and hepatic ontogenesis: common and distinctive pathways

Several types of pediatric liver tumors exhibit structural features apparently reflecting processes which normally occur during hepatic ontogenesis: some hepatoblastomas mimic distinct phases of hepatogenesis, including the formation of mesenchymal structures closely associated with immature epithelia, and there are tumors almost exclusively consisting of complex mesenchymal patterns. Current classifications of hepatoblastomas refer to the identification of more or less mature (differentiated) single or mixed components seen in histologic preparations. These do not, however, attempt to integrate ontogenic pathways, in contrast for example, to nephroblastoma and associated lesions, where such a view has proved to be highly fruitful. Based on the fact that an enormous amount of knowledge has recently been accumulated regarding hepatic ontogenesis, time may have come to look at these tumors with a new eye. In what follows, we aim at trying to analyze distinct features of pediatric hepatic tumors (except vascular tumors) within the background of ontogenesis. Some key steps of hepatogenesis and the regulatory factors involved may, in the future, deliver an armamentarium to search for novel molecular mechanisms involved in tumorigenic pathways.

Genetic alterations in hepatoblastoma and hepatocellular carcinoma: common and distinctive aspects

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are two different subtypes of primary tumors arising from liver parenchymal cells. These tumors differ by many histoclinical characteristics, and comparative analysis of genetic alterations in HB and HCC might provide some clues on the molecular oncogenic pathways leading to hepatocyte transformation. Recent outcomes have been provided by the assessment of global genetic changes in tumor cells, using conventional cytogenetic approaches, PCR-based microsatellite analysis and Comparative genomic Hybridization (CGH). Cytogenetic studies of HB, microsatellite analysis of HCC and recent CHG data have outlined common and distinctive characters between the two tumor types. HBs are characterized by a low number of chromosomal changes, consisting mainly of gains at chromosomes 1q, 2, 8q, 17q, and 20. By contrast, HCCs harbor multiple chromosomal abnormalities, predominantly losses, with increased chromosomal instability in tumors associated with hepatitis B virus infection. Common alterations in HB and HCC include gain of chromosomes 1q, 8q, and 17q, and loss of 4q. Another important common feature shared by the two tumor types is the frequent activation of Wnt/beta-catenin signaling by stabilizing mutations of beta-catenin. Immunohistochemical analysis of beta-catenin has demonstrated nuclear/cytoplasmic accumulation of the protein in most HBs and in more than one third of HCCs. Strikingly, beta-catenin mutations are associated with chromosomal stability in both tumor types. Together, these studies define different pathways in liver cell transformation, reflecting various developmental stages and multiple risk factors. A detailed understanding of the molecular hits underlying liver tumorigenesis, combined with clinicopathological parameters, will permit an accurate evaluation of major targets for prognostic and therapeutic intervention.

Hepatoblastoma: cytomorphologic characteristics in serious cavity fluids

BACKGROUND

Hepatoblastoma (HBL) represents the most common primary hepatic tumor in children. Although the cytologic features of this tumor have been amply elucidated on fine-needle aspiration, exfoliative cytomorphologic characteristics have not been reported. The authors reviewed the cytopathologic features of six serous cavity fluids (SCF) from four patients with histologically proven HBL.

METHODS

Five of the specimens evaluated were peritoneal fluids, and one specimen was pleural fluid from a patient with suspected pulmonary metastasis. Slides were prepared by cytocentrifugation and stained with Diff-Quik and Papanicolaou stains. The cytomorphologic features of each specimen were characterized, subclassified, and correlated histopathologically.

RESULTS

All specimens showed hypercellular smears in a relatively clean background. Mixed embryonal and fetal subtypes of HBL disclosed three-dimensional clusters of neoplastic cells that formed straight or branched cords and acinus-like structures. The cells were moderately pleomorphic and had high nuclear-to-cytoplasmic (N/C) ratios. Occasional cells had eccentrically placed nuclei and vacuolated cytoplasm. Numerous mitotic figures were present. Rare intranuclear inclusions were noted. The anaplastic (small cell) subtype of HBL showed tight clusters of small, round, primitive cells with hyperchromatic nuclei, high N/C ratios, and prominent nuclear molding. In addition, there were numerous single cells with naked nuclei, often in an Indian-file configuration. Bile pigment, osteoid, and other mesenchymal components were absent in all specimens.

CONCLUSIONS

The cytomorphologic features of HBL in SCF are quite characteristic. Although the differential diagnosis includes other childhood small, round, blue cell tumors and hepatocellular carcinoma, the above findings in the appropriate clinical-radiologic setting warrant a diagnosis of HBL.

Two case reports of childhood liver cell adenomas harboring beta-catenin abnormalities

The benign epithelial neoplasm liver cell adenoma is rare, especially in childhood. We report 2 such cases, 1 of which was associated with Prader-Willi syndrome. Differential diagnosis of the liver cell adenomas on the basis of histopathologic findings proved difficult and was based on the absence of cellular and nuclear atypia, mitotic activity, and invasive growth. In both cases, immunohistochemical staining demonstrated the nuclear accumulation of beta-catenin, and in 1 case, the tumor cells carried a mutation of the beta-catenin gene. Recently, disregulation of the Wnt/beta-catenin pathway, attributable to abnormalities of the beta-catenin gene, has been reported to be a major event in the development of hepatocellular carcinomas and hepatoblastomas. Our report may be the first to describe the beta-catenin abnormalities in childhood liver cell adenoma. These findings imply that abnormalities of beta-catenin can be an early initiating event in human liver tumorigenesis.

Pretreatment prognostic factors and treatment results in children with hepatoblastoma: a report from the German Cooperative Pediatric Liver Tumor Study HB 94

BACKGROUND

In the past 20 years, a dramatic improvement in the prognosis of patients with hepatoblastoma (HB) has been achieved by combining surgery with chemotherapy in several national and international trials. A worldwide, unsolved problem remains the treatment of patients with advanced or metastatic HB.

METHODS

The German Cooperative Pediatric Liver Tumor Study HB 94 was a prospective, multicenter, single-arm study. The study ran from January 1994 to December 1998. The protocol assessed the efficiency of chemotherapy consisting of cisplatin, ifosfamide, and doxorubicin (CDDP/IFO/DOXO) and/or etoposide and carboplatin (VP16/CARBO). The prognostic significance of the surgical strategy, pretreatment factors, and tumor characteristics for disease free survival (DFS) were analyzed.

RESULTS

Sixty-nine children with HB were treated in the HB 94 study. The median follow-up of survivors was 58 months (range, 32-93 months). Fifty-three of 69 patients (77%) remained alive, and 16 of 69 patients (23%) died. Long-term DFS was as follows: 26 of 27 patients had Stage I HB, 3 of 3 patients had Stage II HB, 19 of 25 patients had Stage III HB, and 5 of 14 patients had Stage IV. A complete resection of the primary tumor was achieved in 54 of 63 patients (86%). Six children (8%) had no surgical treatment. Twenty-two tumors were resected primarily, and 41 children underwent surgery after initial chemotherapy. Two children underwent liver transplantation. There was no perioperative death. Forty-eight children received primary chemotherapy with CDDP/IFO/DOXO. Forty-one of 48 children achieved partial remission after CDDP/IFO/DOXO. Eighteen children with advanced or recurrent HB underwent VP16/CARBO chemotherapy, with a response achieved by 12 children. The relevant pretreatment prognostic factors were growth pattern of the liver tumor (P = 0.0135), vascular tumor invasion (P = 0.0039), occurrence of distant metastases (P = 0.0001), initial alpha-fetoprotein level (P = 0.0034), and surgical radicality (P < 0.0001).

CONCLUSIONS

The current results underline the necessity of preoperative chemotherapy in all children with HB. Complete tumor resection is one of the main prognostic factors.

Hepatocellular carcinoma in children: results of the first prospective study of the International Society of Pediatric Oncology group

PURPOSE

To improve survival and reduce operative morbidity and mortality in children with primary epithelial liver tumors by using preoperative chemotherapy, as well as to collect information on the epidemiology, natural history, and prognostic factors.

PATIENTS AND METHODS

Forty children with hepatocellular carcinoma (HCC) were registered onto the Group for Epithelial Liver Tumors International Society of Pediatric Oncology's first study from January 1990 to February 1994. The outcome could be analyzed in 39 of those patients. Disease was often advanced at the time of diagnosis; metastases were identified in 31% of the children and extrahepatic tumor extension, vascular invasion, or both in 39%. Multifocal tumors were common (56%). Thirty-three percent of tumors were associated with hepatic cirrhosis. All but two patients received preoperative chemotherapy (cisplatin and doxorubicin).

RESULTS

Partial response was observed in 18 (49%) of 37 patients; there was no response or progression in the remainder. Complete tumor resection was achieved in 14 patients (36%). Twenty patients (51%) never became operable. Overall survival at 5 years was 28%, and event-free survival was 17%. Most deaths resulted from tumor progression (26 of 28). Presence of metastases and pretreatment extent of disease system grouping at diagnosis had an adverse influence on overall survival in multivariate analysis.

CONCLUSION

Survival for pediatric HCC patients is significantly inferior to that for children with hepatoblastoma. Complete tumor excision remains the only realistic chance of cure, although it is often prevented by advanced disease. The presence of metastases is the most potent predictor of poor prognosis. A prospective worldwide cooperation in the field of pediatric HCC should be encouraged to look for novel therapeutic concepts.

High-dose chemotherapy in children with metastatic hepatoblastoma

BACKGROUND

Despite the advent of effective chemotherapy,a poor prognosis has been reported for patients with metastatic hepatoblastoma. To improve this prognosis, we conducted high-dose chemotherapy with autologous bone marrow rescue in patients with metastatic hepatoblastoma.

METHODS AND RESULTS

Three patients were treated with high-dose chemotherapy. In patient 1, high-dose chemotherapy was given after the patient's first pulmonary relapse. Additional pulmonary metastases, which developed more than 6 months after high-dose chemotherapy, were treated by multiple thoracotomy without additional chemotherapy. Patient 2 presented additional pulmonary metastases soon after the end of the first thoracotomy and high-dose chemotherapy. Because of a decreased serum alpha-fetoprotein level after re-excision of the pulmonary metastases, a second round of high-dose chemotherapy was performed. In patient 3, multiple pulmonary metasteses responded to preoperative chemotherapy and disappeared according to the chest computed tomography. Intensive treatment with a high-dose chemotherapeutic regimen was performed at the end of postoperative chemotherapy. All three patients are alive and well, more than 6 years after receiving their diagnosis.

CONCLUSION

The role of high-dose chemotherapy in treatment of metastatic hepatoblastoma could not be clarified,because of the small number of patients. However, the better outcome of our patients indicates that multimodal therapy, including high-dose chemotherapy, may improve the outcome of the patients with metastatic hepatoblastoma.

Malignant liver tumors

Primary malignant liver tumors can arise from different components of the liver, such as hepatocytes, bile duct epithelium, neuroendocrine cells, and mesenchymal cells. A specific diagnosis frequently can be suggested from imaging studies, but biopsy remains the gold standard for definitive diagnosis of liver tumors. Clinical history of chronic liver disease, known risk factors, or other diseases are of great importance. Patient's age is also an important discriminating feature because several tumors such as hepatoblastoma, mesenchymal hamartoma, and infantile hemangioendothelioma, are found predominantly in pediatric populations, whereas cholangiocarcinoma and hepatocellular carcinoma are rare in pediatric populations.

Cytogenetic findings in two new cases of hepatoblastoma

We describe two cases of hepatoblastoma occurring in an 18-month-old boy and a 3-month-old girl. Cytogenetic analysis of the primary tumors revealed gain of 2q and 20 in both cases. In case 1, t(7;8;11) was seen as a secondary abnormality. Other chromosomal aberrations seen in case 2 were unbalanced t(1;1) and t(2;11), resulting in partial gains of 1q and 2q. These results support previous reports that gains of 2q and 20 and rearrangement of chromosome 1 are strongly associated with hepatoblastoma and may be essential for establishing this neoplasm. The 11q and 7q abnormalities may represent a pathway of genetic evolution associated with hepatoblastoma progression.

Distinct patterns of p27/KIP 1 gene expression in hepatoblastoma and prognostic implications with correlation before and after chemotherapy

Over the past 3 years, numerous studies have examined the diagnostic and prognostic significance of p27/Kip1 expression in various tumors. Almost all studies report decreased p27 expression in more aggressive tumors. Information about morphologic changes due to chemotherapy in hepatoblastoma (Hbs) is limited, and so is information about distinct patterns of p27 gene expression. Twenty-nine hepatoblastomas were evaluated for possible prognostic correlation between p27 expression in different histotypes of hepatoblastoma, changes during chemotherapy, and outcome. These observations should prompt prospective randomized studies designed to investigate the predictive role of p27 expression in different Hbs histotypes. Patients were treated according to the Children's Cancer Group and Pediatric Oncology Group protocols, which included initial surgery before chemotherapy wherever possible. Follow-up ranged from 1 to 133 months. The results show that primary well-differentiated fetal tumors without mitotic activity are strongly p27 positive. The embryonal pattern displays a variable p27 protein expression pattern, with focal positivity between completely negative zones; p27 is positive where the mitotic activity is low or absent and negative where the mitogenic activity is high. The vast majority of small undifferentiated cell components are p27 negative. p27 protein expression is downregulated after chemotherapy in the remaining fetal well-differentiated component of Hbs. Although this may imply selection of a more aggressive clone, all patients with this histology were cured in this series. Aggressiveness and ultimate prognosis for incompletely resected tumors after chemotherapy remain indeterminate.

Prognostic impact of molecular genetic alterations in hepatoblastoma

BACKGROUND

During recent years, we identified characteristic genetic alterations in sporadic hepatoblastoma (HB). These include loss of heterozygosity (LOH) at the chromosomal region 11p15.5, LOH on chromosome arms 1p and 1q, activating mutations in exon 3 of the beta-catenin gene, as well as overexpression of the c-met oncogene, which encodes the hepatocyte growth factor receptor. We now wanted to evaluate the prognostic relevance of these abnormalities concerning the outcome in a large group of patients.

PROCEDURE

All but 7 of 56 patients with HB were treated either with primary resection for small tumors, or neo-adjuvant chemotherapy with ifosfamide, cisplatin and doxorubicin (IPA) before delayed surgery in case of extended disease and additional adjuvant IPA therapy in all cases. Seven tumors were primarily resected and adjuvantly treated with different cytotoxic drugs. LOH 11p15.5, LOH 1p, and LOH 1q were detected in tumor tissue in comparison to normal liver and/or peripheral blood leukocytes by PCR based microsatellite analysis. Beta-catenin mutations were analysed with SSCP, deletion screening and direct sequencing. RT-PCR was used for identification of c-met mRNA overexpression. The results were correlated with the tumors' stage, histological type and epithelial differentiation, as well as with the patients' outcome.

RESULTS

Overall disease-free survival after median follow-up of 5 years was 43/56 patients (77%). LOH 11p15.5 was found in 15/56, LOH1p in 11/53, LOH1q in 7/53 and beta-catenin mutations in 25/55 HB. 13/23 HB had a c-met overexpression. LOH 11p15.5 and LOH 1p were significantly more often found in embryonal HB, while there was no correlation of other genetic alterations with histological type or differentiation. Furthermore, statistical analysis revealed no correlation of any of these disorders with initial tumor stage, nor with the patients' outcome.

CONCLUSION

None of the investigated molecular genetic alterations are suited to serve as a prognostic indicator in HB. Further investigations, especially genetic screening of tumor tissue may reveal prognostic markers for this neoplasm.

Chromosome rearrangement with no apparent gene mutation in familial adenomatous polyposis and hepatocellular neoplasia

We have identified a constitutional inversion in chromosome 5 associated with familial adenomatous polyposis in three generations of a Mexican family. Two of three siblings developed hepatic neoplasia in infancy. The gene truncation assay failed to demonstrate a truncated protein in the segment harboring the adenomatous polyposis coli (APC) genes. Polymerase chain reaction (PCR) amplification of APC gene coding exons and sequencing of PCR products did not reveal any significant mutation. The data suggest that in this family, the phenotype may be the result of a "position effect."

Small cell undifferentiated histology in hepatoblastoma may be unfavorable

BACKGROUND

Chemotherapy has improved the prognosis of hepatoblastoma demonstrably. It renders seemingly unresectable primary tumors amenable to surgery and can cure metastases. Some authors advocate preoperative chemotherapy for patients with tumors that are deemed resectable, relying solely on percutaneous biopsy or even on diagnostic imaging and elevated serum alpha-fetoprotein levels for diagnosis. However, certain cytologic features of hepatoblastoma appear to have important prognostic consequences. Well differentiated fetal hepatoblastomas that are confined to the liver and that have minimal mitotic activity may not require additional therapy if they are resected totally.

METHODS

In the current study 16 completely resected hepatoblastomas that exhibited partial or predominant small cell undifferentiated histology were identified retrospectively and correlated with patient outcome.

RESULTS

Ten of 16 patients with completely resected tumors exhibiting small cell undifferentiated histology developed a disease recurrence. Five of these recurrences were fatal.

CONCLUSIONS

Small cell undifferentiated histology may have an unfavorable effect on outcome in patients with completely resected hepatoblastoma. The focal distribution of small cell histology in the majority of these tumors suggests that treating hepatoblastoma based on limited preexcision biopsies may deprive some patients of appropriate therapy.

Successfully resected hepatoblastoma in a young adult with chronic hepatitis B: report of a case

Hepatoblastoma usually occurs in children, but a few cases have also been reported in adults. We report the unusual case of hepatoblastoma in an 18-year-old adult with chronic hepatitis B. He visited a local hospital with right upper abdominal pain. Abdominal ultrasound showed a large mass in the right lobe of his liver. He was referred to our hospital and admitted for further examination. At admission, liver function tests gave slightly elevated results (aspartate aminotransferase (AST) 103 IU/l, alanine aminotransferase (ALT) 63 IU/l). A test for hepatitis virus revealed that he was a hepatitis B surface antigen (HBsAg) carrier and had experienced seroconversion. His alpha-fetoprotein (AFP) was elevated to 1 548 000 IU/ml. Abdominal ultrasound showed a 109 x 96 x 80-mm mass with mosaic pattern in the right lobe of the liver and right portal vein thrombus. Abdominal computed tomography (CT) demonstrated a large low-density mass occupying the right lobe, with some high-density parts that showed calcification. From these results, we diagnosed hepatoblastoma in a young adult. A right lobectomy was performed. Pathological examination showed a highly differentiated hepatoblastoma. Adjuvant chemotherapy was performed with cisplatin and pirarubicin. The patient has been well and free of recurrence for 12 months, and his AFP level remains almost normal.

Current status of liver tumors in children

Most tumors of the liver in children are malignant. Benign tumors occur most often in infants, are usually vascular, and seldom require surgery. Hepatoblastoma and hepatocellular carcinoma are the most common malignant tumors. Hepatoblastoma affects younger children and hepatocellular carcinoma affects older children and adolescents. Treatment consists of surgical resection before or after chemotherapy, and long-term survival is impossible without resection. Survival rate exceeds 80% in children with hepatoblastoma. Children with hepatocellular carcinoma and other more unusual malignant tumors do not do as well. Current treatment plans are described for both benign and malignant tumors of the liver.

Biallelic inactivation of the APC gene is associated with hepatocellular carcinoma in familial adenomatous polyposis coli

BACKGROUND

Certain primary hepatic tumors have been associated with familial adenomatous polyposis (FAP), a condition caused by germline mutations of the adenomatous polyposis coli (APC) gene. However, a genetic association between FAP and hepatocellular carcinoma (HCC) has not been shown. This study tested the hypothesis that biallelic inactivation of the APC gene contributed to the development of HCC in a patient with FAP and a known germline mutation of the APC gene at codon 208, but no other risk factors for HCC.

METHODS

Total RNA and genomic DNA were isolated from the tumor, and in vitro synthesized protein assay and DNA sequencing analysis were used to screen for a somatic mutation in the APC gene.

RESULTS

A somatic one-base pair deletion at codon 568 was identified in the wild-type allele of the APC gene.

CONCLUSIONS

To the authors' knowledge, this study provides the first evidence that biallelic inactivation of the APC gene may contribute to the development of HCC in patients with FAP.

Infantile hemangioendothelioma of the liver in an adult

Hepatic infantile hemangioendothelioma (IHE) is a rare benign vascular tumor of the liver found mostly in infancy and early childhood. We describe herein a tumor of the liver, morphologically indistinguishable from IHE, that presented in an adult. The patient is a 56-year-old woman with a history of ductal carcinoma in situ of the left breast and a mass in the liver. The patient underwent resection of the tumor, and after 23 months of follow-up she is alive with no evidence of expansion of the liver tumor.

Surgical resection and chemotherapy improve survival rate for patients with hepatoblastoma

BACKGROUND

The authors reviewed retrospectively their experience in 30 children with hepatoblastoma (HB). Despite an increased trend in the incidence of HB during the last 2 decades, an encouraging cure rate has been achieved with complete resection of the tumor and chemotherapy before or after surgery with cisplatin plus doxorubicin (Adriamycin) or cisplatin plus vincristine plus 5-Fluorouracil.

RESULTS

There were 10 female and 20 male patients. For the period from 1963 to 1980 there were 8 patients, and for the period from 1981 to 1998 there were 22 patients. Their mean age at surgery was 16 months (range, 3.5 months to 5.5 years). Tumors were localized to the right lobe in 10 (42%), to the left lobe in 7 (29%), and in both lobes in 7 (29%) of the resected patients. Tumors were greater than 10 cm in size in 16 (67%) of these patients. Twenty-four patients (80%), underwent liver resection before or after chemotherapy. One patient (3%) with an unresectable tumor received chemotherapy and a liver transplant. In 5 patients (17%) the hepatic involvement was too extensive for resection. The types of resection performed were right lobectomy in 7, left lobectomy in 6, right trisegmentectomy in 8, left trisegmentectomy in 2, and middle hepatectomy in 1. The overall survival rate for 35 years of the study was 60% (18 of 30). With the association of surgery and chemotherapy (1981 through 1998) survival rate is 82% (14 of 17). Overall median follow-up in our study is 8 years (range, 2.5 to 24 years).

CONCLUSIONS

There has been a dramatic improvement in the results of treatment of hepatoblastoma. Formerly, only 25% to 30% of patients were cured, whereas today, with combination of chemotherapy and surgery, 75% to 80% may be cured.

Infantile hemangioendothelioma

Primary hepatic tumors are uncommon in children and account for only three per cent of the tumors in children. Infantile hemangioendothelioma is a rare benign hepatic tumor arising from mesenchymal tissue. Most of the cases present before six months. An unusual presentation and progression of infantile hemangioendothelioma is reported in a 19-month-old female child. The diagnosis was arrived at by radiological and histopathological examination. The patient underwent excision surgery, following which made an uneventful recovery. On follow-up at six months, patient was asymptomatic with no evidence of recurrence.

Hepatobiliary scintigraphic findings in obstructed intrahepatic choledochal cyst before and after surgery

The authors describe a 10-week-old boy who presented with symptoms of progressive obstructive jaundice and abdominal distension. Clinical examination revealed gross hepatomegaly. A preoperative Tc-99m mebrofenin hepatobiliary study showed a large photopenic area involving the entire right lobe of the liver that did not communicate with the biliary system. Ultrasonography revealed a huge cystic mass with a few intracystic septae involving nearly the entire liver parenchyma. Under ultrasound guidance, a pigtail catheter was inserted into the cyst and produced free drainage of bile-stained fluid. Subsequently, an obstructed choledochal cyst was diagnosed clinically, and a right hepatectomy followed by a Roux-en-Y loop implantation on the raw surface of the left lobe were performed. Serial postoperative Tc-99m mebrofenin hepatobiliary studies showed marked improvement in liver function and biliary drainage with significant regeneration of the liver parenchyma.

Comparative genomic hybridization detects multiple chromosomal amplifications and deletions in undifferentiated embryonal sarcoma of the liver

Undifferentiated embryonal sarcoma (UES) is the third most common hepatic malignancy in children. Previous reports have described a broad range of complex cytogenetic abnormalities in individual cases of hepatic UES. Herein we report the cytogenetic findings of six cases of hepatic UES at our institution analyzed by conventional cytogenetic methods and comparative genomic hybridization (CGH). The CGH demonstrated several chromosomal gains and deletions in each case, but there was no specific abnormality seen in every case. Patterns of chromosomal changes included gains of chromosome 1q (four cases), 5p (four cases), 6q (four cases), 8p (three cases), and 12q (three cases), and losses of chromosome 9p (two cases), 11p (two cases), and chromosome 14 (three cases). The three cases in which CGH showed gains in the 12q region were studied specifically for amplifications of MDM2 and CDK4, two genes that have been shown to be amplified in other soft tissue sarcomas. However, Southern analysis showed no amplification of MDM2 or CDK4 in these three cases. Further analysis will be needed to determine the critical events in the pathogenesis of these malignant pediatric liver tumors.

Liver transplantation for biliary atresia associated with malignant hepatic tumors

The authors report 3 cases of liver transplantations in children between 4 and 10 years of age, complicated with malignant hepatic tumors after biliary atresia. The preoperative abdominal computed tomography (CT) scans of all 3 cases showed hepatic masses. The serum alpha-fetoprotein levels were elevated highly in 2 cases. After living-related liver transplantation (LRLT), the pathologic findings of the masses in the resected livers showed hepatocellular carcinoma in 2 cases and hepatoblastoma in the other. All cases were associated with biliary cirrhosis. The stage of the liver tumor in the 3 cases using the TNM system was IVA (T4, N0, M0), II (T2, N0, M0) and IVA (T4, N0, M0). Chemotherapy was used in all cases after liver transplantation, and all patients survived with no recurrence. The results suggest that even though malignant liver tumors rarely are complicated with biliary atresia in childhood, one should be alert to the occurrence of hepatic malignancy and perform routine screening of alpha-fetoprotein levels, abdominal CT scans, and magnetic resonance imagings.

Trisomy 1q, 2, and 20 in a case of hepatoblastoma: possible significance of 2q35-q37 and 1q12-q21 rearrangements

Combined cytogenetic, chromosome painting, and spectral karyotyping (SKY) analyses in a case of hepatoblastoma revealed a karyotype of 49,XY,+Y,+der(2)t(2;3)(q35;q25),der(3)t(1;3)(q12; q25),+20. Trisomy 1q, 2, and 20 identified in the present case are consistent with the previously reported cytogenetic alterations in hepatoblastoma. The breakpoints at 1q12 and 2q35 identified in this case have also been reported previously as nonrandom changes. The frequent occurrence of these rearrangements in hepatoblastoma suggests that they may be of pathogenic significance.

Liver tumors

Liver tumors in children are rare, potentially complex, and encompass a broad spectrum of disease processes. Any age group may be affected, including the fetus. Most present with abdominal distension and/or a mass. Accurate preoperative diagnosis is usually possible using a combination of ultrasound scanning and cross-sectional imaging techniques (CT and/or MR), supplemented by liver biopsy and measurement of tumor markers. The most common benign tumors are hemangiomas, but mesenchymal hamartoma, focal nodular hyperplasia, and adenoma also are found. In Western countries, hepatoblastoma is the most common primary malignant liver tumor; disease-free survival is now possible in more than 80% of affected patients because of advances in combination chemotherapy, improved techniques of surgical resection, and the selective use of liver transplantation. In contrast, there has been less progress in the management of hepatocellular cancer, which still poses many therapeutic challenges.

Comparative genomic hybridization reveals population-based genetic alterations in hepatoblastomas

Hepatoblastoma is a malignant paediatric liver tumour. In order to approach the genetic background of this malignancy we have screened a panel of eighteen cases from Europe and Japan for chromosomal imbalances using comparative genomic hybridization (CGH). The most frequent losses included chromosomal regions 13q21-q22 (28%) and 9p22-pter (22%), while the most frequent gains occurred on 2q23-q24 (33%), 20q (28%) and 1q24-q25 (28%). A significant difference in CGH alterations between the tumours from patients of Caucasian and Japanese was revealed where loss of 13q was found only in the Japanese samples. In conclusion, the findings indicate several candidate regions for suppressor genes and oncogenes potentially involved in the hepatoblastomas of different ethnic origin.

p57(KIP2) is not mutated in hepatoblastoma but shows increased transcriptional activity in a comparative analysis of the three imprinted genes p57(KIP2), IGF2, and H19

Hepatoblastomas (HBs), representing malignant liver tumors of childhood, show frequent loss of heterozygosity (LOH) in the chromosomal region 11p15.5. This loss is of maternal origin suggesting the presence of a monoallelically expressed tumor suppressor gene in this region. p57(KIP2) (KIP2) located at 11p15.5 is predominantly expressed from the maternal allele and encodes a cyclin-dependent kinase inhibitor. We screened a series of 56 HB tumors and five HB cell lines for allelic loss (LOH) of the KIP2 locus by microsatellite analysis and KIP2 coding sequence mutations by single-strand conformation polymorphism analysis. Although LOH at the KIP2 locus occurred in 25% of the cases, no mutations were found. Analysis of KIP2 mRNA expression by competitive reverse transcriptase-polymerase chain reaction revealed up-regulation in nine of 12 HBs compared to matching liver samples. In contrast, mRNA levels of the putative suppressor gene H19 on 11p15.5 were decreased in 10 of 12 tumors, indicating that KIP2 and H19 are not co-regulated in HBs. IGF2 mRNA expression was increased in 11 of 12 HB samples. All HBs showed monoallelic KIP2 expression. However, the overexpression of KIP2 in HBs with maternal loss of 11p15.5 suggests a reactivation of the paternal allele in these cases. Overexpression of KIP2 in HBs argues against a role as a HB suppressor gene.

Characterization of genomic alterations in hepatoblastomas. A role for gains on chromosomes 8q and 20 as predictors of poor outcome

As data on the genomic alterations in hepatoblastoma (HB) are limited, 34 HB tumors and three HB cell lines were screened for DNA copy number changes by comparative genomic hybridization. The average number of chromosomal imbalances per tumor was 2.3 +/- 0.5 (mean +/- SEM) with gains sevenfold more frequent than losses. The most frequent gains of chromosomal material in HB tumors were on 2q (44%), 1q (41%), 2p (29%), 20 (24%), 22q (18%), 8q (15%), 8p and 12q (9% each), as well as 7q, 12p, and 17 (6% each) and the only recurrent loss was on 4q in 12% of cases. Highly amplified sequences were identified in four tumors and mapped to 2q24 in two cases, to 8q in two cases (once to 8q11.2-q13 and once to 8q11.2-q21.3) as well as to 10q24-q26 in one case. In one cell line, highly amplified DNA sequences were mapped to 7p and 8q. Comparison to previously published data on this series of HB revealed that the number of chromosomal imbalances was significantly higher in HB tumors with loss of heterozygosity on 11p (P = 0.03), whereas in five of 10 HB biopsies without chromosomal imbalances, beta-catenin gene mutations were found. HB patients were divided into a good (no evidence of disease) and a poor (died of disease) outcome group according to their clinical course after standard therapy. Two alterations were found to be significantly associated with poor outcome: gain on 8q (P = 0.007) and gain on 20 (P = 0.009). In summary, our analysis allowed the identification of gains on chromosomes 1q and 2 as hallmark DNA copy number changes in HB with 2q24 as a critical chromosomal band. Furthermore, this study provided evidence that gains on 8q and 20 play a role as markers of prognostic significance in HB.

Congenital primitive epithelial tumor of the liver showing focal rhabdoid features, placental involvement, and clinical features mimicking multifocal hemangioma or stage 4S neuroblastoma

We describe an unusual case of congenital primitive epithelial tumor of the liver with focal rhabdoid features. The present case is unique and informative in the following aspects: (1) a first case of congenital epithelial tumor of the liver with no hepatocytic differentiation but focal rhabdoid features, (2) clinical similarities to multicentric hemangioma or stage 4S neuroblastoma, (3) diagnosis obtained from histological examination of the placenta immediately after birth.

Activation of beta-catenin in epithelial and mesenchymal hepatoblastomas

Wnt/beta-catenin signaling is frequently activated in cancer cells by stabilizing mutations of beta-catenin or loss-of-function mutations of the APC tumor suppressor gene. We have analysed the role of beta-catenin in the pathogenesis of hepatoblastoma (HB), an embryonic liver tumor occurring mainly in children under 2 years of age. Sequence analysis of the beta-catenin NH2-terminal domain in 18 epithelial and mixed HBs revealed missense mutations in the GSK3beta phosphorylation motif or interstitial deletions in 12 tumors (67%). In the remaining cases, no truncating mutation of APC could be evidenced. Immunohistochemical analysis of beta-catenin in 11 HBs demonstrated nuclear/cytoplasmic accumulation of the protein in all tumors analysed, with predominant nuclear beta-catenin immunostaining in undifferentiated cells. Membranous beta-catenin localization was preserved only in fetal-type tumoral hepatocytes and was associated with E-cadherin expression. Moreover, we show that beta-catenin is aberrantly overexpressed in a large spectrum of tumor components, including hepatocyte-like cells at various differentiation stages and heterologous elements such as squamous, osteoid and chrondroid tissues, and in occasional other mesenchymally-derived cells. These data strongly suggest that activation of beta-catenin signaling is an obligatory step in HB pathogenesis, and raise the possibility that it interferes with developmental signals that specify different tissue types at early stages of hepatic differentiation.

Hepatocyte growth-factor-scatter factor can stimulate post-operative tumor-cell proliferation in childhood hepatoblastoma

Rapid growth of residual tumor after partial hepatectomy has been observed during the period of liver regeneration in children with malignant embryonal hepatoblastoma. The aim of this study was to elucidate the role of hepatocyte growth-factor-scatter factor (HGF-SF) in this phenomenon. Markedly increased serum levels of HGF-SF up to 15 ng/ml were found in 13/18 patients after liver resection and in 6/16 patients with regressive tumors after chemotherapy, in comparison with 15 patients with non-pre-treated hepatoblastoma and 20 healthy children of the same age group. In the tumors, epithelial tumor cells highly expressed the HGF-SF receptor c-met, as shown by immunohistochemistry and m-RNA RT-PCR. The hepatoblastoma cell lines HepT1, HepT3 and HUH6 reacted with significantly increased proliferation to rhHGF-SF in these concentrations (1-15 ng/ml). In the tumors, HGF-SF was found to be expressed in the stromal fibroblasts. In culture, hepatoblastoma cells (HepT3, HUH6) stimulated secretion of the factor by human fibroblasts, indicating the paracrine fashion of intratumoral HGF-SF production. Cultured hepatoblastoma cells ceased to proliferate at 20-50 ng/ml HGF-SF, and they underwent cell death at >/=100 ng/ml. In contrast, the hepatocellular-carcinoma cell line HepG2 decreased growth under HGF-SF in a dose-dependent manner. We conclude that post-operatively secreted and intratumorally produced HGF-SF can function as a growth factor for hepatoblastoma, while the same agent has a cytostatic effect in unphysiologically high concentrations.

Undifferentiated embryonal sarcoma of the liver: results of clinical management in one center

PURPOSE

This study was undertaken to review the authors' clinical experience with undifferentiated embryonal sarcoma of the liver (UES) in children, focusing on the clinical presentation and results of treatment.

METHODS

A retrospective analysis of all children who have undergone treatment for UES during the 15-year period from 1984 through 1998 was performed.

RESULTS

Seven patients (4 boys and 3 girls) ranging in age from 20 months to 12 years at the time of diagnosis were identified. All presented with large abdominal masses and normal liver function test results. All underwent complete tumor resection; trisegmentectomy was required in 4 of these cases. All patients received postoperative chemotherapy. Two patients suffered tumor recurrence at 12 and 29 months; both of these patients died of their disease. Another patient died of complications related to chemotherapy. The other 4 patients are alive with no evidence of disease after 19 to 150 months' follow-up.

CONCLUSIONS

Undifferentiated embryonal sarcoma of the liver presents as a large hepatic tumor. Operative resection is difficult, but combined with adjuvant chemotherapy offers the best hope for cure.