Tumour surveillance in Beckwith-Wiedemann syndrome and hemihyperplasia: a critical review of the evidence and suggested guidelines for local practice

Hepatoblastoma in two siblings and familial adenomatous polyposis: causal nexus or coincidence?

Infantile and childhood hepatoblastoma (HB) occurs more frequently in children with hereditary predisposition to familial adenomatous polyposis (FAP) than in the general population. The occurrence of HB in two infant siblings is reported. The sister died of the disease. The brother survived the HB and was later diagnosed with familial adenomatous polyposis and advanced rectal cancer. He was found to carry a germline mutation of the APC gene. Presuming that the HB in the two siblings was the first manifestation of FAP we performed APC mutation analysis in DNA from archived tumour tissue of his sister and in blood samples of both parents. Surprisingly, the mutation was neither found in both parents, nor in the tissue samples of the sister. We outline the impact of this finding for genetic counselling and review the literature on FAP and HB.

Molecular findings in Beckwith-Wiedemann syndrome

Our understanding of Beckwith-Wiedemann syndrome (BWS) has recently been enhanced by advances in its molecular characterization. These advances have further delineated intricate (epi)genetic regulation of the imprinted gene cluster on chromosome 11p15.5 and the role of these genes in normal growth and development. Studies of the molecular changes associated with the BWS phenotype have been instrumental in elucidating critical molecular elements in this imprinted region. This review will provide updated information on the multiple new regulatory elements that have been recently found to contribute to in cis or in trans control of imprinted gene expression in the chromosome 11p15.5 region and the clinical expression of the BWS phenotype.

Bilateral pheochromocytomas, hemihyperplasia, and subtle somatic mosaicism: the importance of detecting low-level uniparental disomy

We report on a patient with early onset pediatric bilateral pheochromocytomas caused by mosaic chromosome 11p15 paternal uniparental isodisomy (UPD). Hemihyperplasia of the arm was diagnosed in a 4-month-old female and clinical methylation testing for 11p15 in the blood was normal, with a reported detection threshold for mosaicism of 20%. She was subsequently diagnosed at 18 months with bilateral pheochromocytomas. Single-nucleotide polymorphism (SNP) array analysis of pheochromocytoma tissue demonstrated mosaic deletions of 8p12pter, 21q21.1qter, 22q11.23qter; commonly seen in pheochromocytomas. In addition, mosaic 11p15.3pter homozygosity was noted. Molecular testing for other causes of pheochromocytomas was normal, suggesting that 11p15 homozygosity was the primary event. Subsequent SNP array analysis of skin fibroblasts from the hyperplastic side demonstrated 5% mosaic paternal UPD for 11p15. We have subsequently used SNP array analysis to identify four patients with subtle hemihyperplasia with low-level mosaic UPD that was not detected by methylation analysis. Given the increased sensitivity of SNP array analysis to detect UPD along with the increased incidence of tumorigenesis in these UPD patients, we suggest that it has high utility in the clinical work-up of hemihyperplasia. The present case also suggests that 11p15 paternal UPD may be an under-detected mechanism of sporadic pheochromocytoma in the pediatric population. Furthermore, a review of the literature suggests that patients with 11p15 paternal UPD may present after 8 years of age with pheochromocytoma and raises the possibility that ultrasound screening could be considered beyond 8 years of age in this subset of hemihyperplasia and Beckwith-Wiedemann syndrome patients.

Towards in silico oncology: adapting a four dimensional nephroblastoma treatment model to a clinical trial case based on multi-method sensitivity analysis

In the past decades a great progress in cancer research has been made although medical treatment is still widely based on empirically established protocols which have many limitations. Computational models address such limitations by providing insight into the complex biological mechanisms of tumor progression. A set of clinically-oriented, multiscale models of solid tumor dynamics has been developed by the In Silico Oncology Group (ISOG), Institute of Communication and Computer Systems (ICCS)-National Technical University of Athens (NTUA) to study cancer growth and response to treatment. Within this context using certain representative parameter values, tumor growth and response have been modeled under a cancer preoperative chemotherapy protocol in the framework of the SIOP 2001/GPOH clinical trial. A thorough cross-method sensitivity analysis of the model has been performed. Based on the sensitivity analysis results, a reasonable adaptation of the values of the model parameters to a real clinical case of bilateral nephroblastomatosis has been achieved. The analysis presented supports the potential of the model for the study and eventually the future design of personalized treatment schemes and/or schedules using the data obtained from in vitro experiments and clinical studies.

Incidence of abdominal tumors in syndromic and idiopathic hemihypertrophy/isolated hemihyperplasia

BACKGROUND

There is a reported increased risk of intra-abdominal tumors in children with both syndromic (SH) and isolated idiopathic hemihyperplasia (IH). Recommendations for tumor surveillance have been made, although there is no consensus for frequency and duration of screening. Our objective was to review the incidence of abdominal neoplasms in our pediatric population with SH and IH.

METHODS

We reviewed the diagnostic criteria, imaging findings, and any associated syndrome in all patients diagnosed with hemihypertrophy over a 10-year period.

RESULTS

One of 10 patients with SH, a child with Beckwith-Wiedemann syndrome, developed a hepatoblastoma resulting in a 10% tumor incidence in patients with SH. Three of the 250 (1.2%) children with IH developed an abdominal neoplasm. One was diagnosed with adrenal carcinoma and the other 2 with Wilms tumor.

CONCLUSIONS

We found an increased incidence of abdominal tumors in both SH and IH, however, our incidence of tumors with IH is lower than earlier reported studies. On the basis of this lower 1.2% incidence, the current literature on IH and available molecular genetic testing, it is reasonable to recommend referral of these patients to a clinical geneticist to identify subgroups with a higher risk for tumor development that are more likely to benefit from routine imaging surveillance.

LEVEL OF EVIDENCE

II-Retrospective study.

Primary malignant liver tumors in children

Liver tumors constitute only 1-4% of all solid tumors in children. Two-thirds of these are malignant. The primary malignant tumors are hepatoblastoma (HB), hepatocellular carcinoma (HCC), rhabdomyosarcoma (RMS), angiosarcoma, rhabdoid tumor, undifferentiated sarcoma and other rarer tumors. Of these HB is the commonest. The diagnosis of HB is based on the radiology, elevated levels of α-fetoprotein (αFP) and the histology/cytology. Staging is essential for risk categorization, risk adapted treatment and prognostication. The commonest staging and risk categorization system used today is PRETEXT system that is being used by nearly all multicentre trials (American, European, German, Japanese) in some way. Treatment of HB is multimodal with surgery and chemotherapy being the main modalities. Survival is not possible without complete surgical resection. Majority of tumors are unresectable at presentation but can be made resectable with chemotherapy, giving a resection rate of more than 85%. Cisplatin is the main stay of chemotherapy and is a part of all multidrug protocols. The 3-y overall survival (OS) today stands at 62%-70% but only 25% patients with metastasis get cured. Panhepatic tumors and those with local factors causing unresectability are now dealt with liver transplantation which has also given a survival rate of nearly 85%. The overall management of HB and HCC has evolved over the past 3 decades giving good long term survival rates for HB, though patients with HCC still do poorly. Successive therapeutic trials have focused attention on increasing the efficiency and reducing the toxicity and long term side effects of the treatment. Among the other uncommon tumors the rhabdoid tumor and angiosarcoma are chemoresistant and have a poor outcome while the undifferentiated sarcoma and rhabdomyosarcoma are now showing better response to the currently used chemotherapy combinations.

Beckwith-Wiedemann syndrome in sibs discordant for IC2 methylation

Genetically heterogeneous imprinting disorders include Beckwith-Wiedemann syndrome (BWS) and multiple maternal hypomethylation syndrome (MMHS). Using DNA sequencing, quantitative PCR, SNuPE, pyrosequencing, and hybridization to the Illumina GoldenGate Methylation Cancer Panel 1 array, we characterized the genomic DNA of two brothers with BWS who were discordant for loss of methylation at several differentially methylated regions (DMR), including imprinting center 2 (IC2) on chromosome band 11p15.5, which is often hypomethylated in BWS. In keeping with MMHS, the elder child had hypomethylation of SGCE and PLAGL1 as well as of IC2, whereas the younger brother demonstrated no loss of methylation at these DMRs. Although this discordance is consistent with the observation that 15-20% of individuals with BWS do not have detectable genetic or epigenetic alterations of 11p15.5, this is the first report of familial recurrence of BWS with discordance for chromosomal 11p15.5 alterations. We hypothesize that this apparent discordance arises either from mosaicism precluding identification of IC2 hypomethylation in blood or buccal mucosa DNA of the younger child, or from hypomethylation at a site not interrogated by our molecular studies.

A multidisciplinary approach to the treatment of oral manifestations associated with Beckwith-Wiedemann syndrome: a long-term case report

BACKGROUND

Beckwith-Wiedemann syndrome (BWS) is a congenital disorder that involves a somatic overgrowth during the patient's first years of life. Exomphalos, macroglossia and gigantism are the main clinical symptoms.

CASE DESCRIPTION

The authors describe a 15-year follow-up in a patient with BWS. They focus on a multidisciplinary approach to treating the patient's oral manifestations from age 9 months. The approach included an initial physiotherapy treatment, a partial glossectomy, a first phase of orthopedic treatment with a tongue crib and chin cap, and a second phase of orthodontic treatment with an edgewise appliance.

CLINICAL IMPLICATIONS

To obtain long-term positive and stable results, an appropriate treatment plan for patients with BWS and dentoskeletal alterations, including macroglossia, requires surgical tongue reduction when the patient is young, combined with physiotherapeutic phases and orthopedic and orthodontic treatment.

Association of adrenocortical carcinoma with familial cancer susceptibility syndromes

Our knowledge about inherited susceptibility to adrenocortical carcinoma (ACC) almost exclusively stems from experiences with familial cancer susceptibility syndromes, which are caused by single gene mutations (e.g. Li-Fraumeni syndrome (LFS)). Population-based studies are largely unavailable. ACC diagnosed during childhood is known to be commonly part of hereditary cancer syndromes. Childhood ACC is part of the classical tumor spectrum of LFS and Beckwith-Wiedemann syndrome (BWS). In adults ACC has been reported in patients with multiple endocrine neoplasia (MEN1), familial adenomatous polyposis coli (FAP) and neurofibromatosis type 1 (NF1). However, the evidence associating ACC with these syndromes is less well substantiated. Here, we will review the evidence for genetic predisposition in general and the association with known familial cancer susceptibility syndromes in particular. We will also review current recommendations regarding screening and surveillance of these patients as they apply to a specialized ACC or endocrine cancer clinic.

Surgical treatment of macroglossia in patients with Beckwith-Wiedemann syndrome: a 20-year experience and review of the literature

Macroglossia is observed in the majority of paediatric patients diagnosed with Beckwith-Wiedemann syndrome and surgical treatment may be indicated. A 20-year retrospective study was performed to evaluate all patients with Beckwith-Wiedemann syndrome who underwent tongue reduction surgery at the authors' institution. A literature review was performed. Surgical treatment was indicated and carried out in 23 patients with a yearly average varying from 0 to 3 subjects. The mean follow-up time was 7 years. Primary indications for surgical treatment of macroglossia included significant tongue protrusion in 30% (n=7), and a combination of clinical problems in 70% (n=16). In all cases, the procedure was performed by the same surgeon using an anterior, V-shaped, wedge resection technique. Two patients had direct postoperative complications. No recurrence of macroglossia was observed in this study. Reported clinical outcome during follow-up demonstrated a satisfactory resting tongue position in all patients. Review of the literature demonstrated variability in surgical indications and techniques, and postoperative outcome. The results of this study indicate that the anterior wedge resection is a simple, effective and safe technique in the surgical treatment of paediatric patients, diagnosed with Beckwith-Wiedemann syndrome, suffering from macroglossia.

Neonatal hepatoblastoma in a newborn with severe phenotype of Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome is an overgrowth disorder characterized by neonatal macrosomia, abdominal wall defects, macroglossia, renal anomalies, organomegaly, hypoglycemia, and cancer predisposition. Hepatoblastoma is the second most frequent tumor and periodic serum alpha-fetoprotein (αFP) dosage is the cornerstone of the tumor surveillance for its early detection. In this report, we describe the outstanding case of a Beckwith-Wiedemann syndrome (BWS) newborn with severe phenotype and paternal chromosome 11 uniparental disomy (UPD11) associated with a high tumor risk. Based on the clinical picture and previous reports, a close monitoring of αFP was commenced. The marker was normal immediately after birth, but rapidly raised in 20 days, leading to the diagnosis of an extremely aggressive hepatoblastoma. The latter was successfully treated with pre-surgical reductive chemotherapy, gross total mass resection, and subsequent chemotherapy. Based on this observation, the tumor surveillance routinely suggested every 3 months should be more intense and with closer time intervals in newborns with severe BWS phenotype. We suggest monitoring neonatal αFP every 20 days in such cases.

Imaging of cancer predisposition syndromes in children

The term cancer predisposition syndrome (CPS) encompasses a multitude of familial cancers in which a clear mode of inheritance can be established, although a specific gene defect has not been described in all cases. Advances in genetics and the development of new imaging techniques have led to better understanding and early detection of these syndromes and offer the potential for preclinical diagnosis of any associated tumors. As a result, imaging has become an essential component of the clinical approach to management of CPSs and the care of children suspected of having a CPS or with a confirmed diagnosis. Common CPSs in children include neurofibromatosis type 1, Beckwith-Wiedemann syndrome, multiple endocrine neoplasia, Li-Fraumeni syndrome, von Hippel-Lindau syndrome, and familial adenomatous polyposis. Radiologists should be familiar with these syndromes, their common associated tumors, the new imaging techniques that are available, and current screening and surveillance recommendations to optimize the assessment of affected children.

Liver neoplasia in children

Management of pediatric liver tumors has significantly improved over the last 2 decades. The management options for hepatocelluar carcinoma (HCC) are not well defined. In the pediatric context, the main clinical aims are to reduce chemotherapy toxicity (predominantly ototoxicity and nephrotoxicity) in children treated for hepatoblastoma and to investigate additional modes of treatment for HCC. An increasing number of children develop HCC in the background of chronic liver disease, and screening methods need to be better observed.

A review of the urologic manifestations of Beckwith-Wiedemann syndrome

OBJECTIVE

Beckwith-Wiedemann syndrome (BWS) is a constellation of congenital anomalies that classically presents with macroglossia, abdominal wall defects and gigantism. Although renal and adrenal pathology are the most commonly associated urologic findings of BWS, we report a case of a girl with BWS and symptomatic clitoromegaly, recurrent urinary tract infections and vesicoureteral reflux, followed by a review of the literature regarding urologic manifestations of BWS.

MATERIALS AND METHODS

A comprehensive review of the literature for renal and non-renal urologic manifestations of BWS was conducted using a computer-based (PubMed) search. The reported renal and non-renal urologic findings are summarized.

RESULTS

In addition to well-described renal manifestations, a variety of non-renal urologic findings have been reported in patients with BWS.

CONCLUSIONS

Healthcare providers should carefully evaluate both patients and their family members for urologic manifestations of BWS. Early diagnosis and thorough evaluation allows for potential improved management and prognosis of BWS urologic sequelae, including tumors, cryptorchidism and urinary tract abnormalities.

Exploiting clinical trial data drastically narrows the window of possible solutions to the problem of clinical adaptation of a multiscale cancer model

The development of computational models for simulating tumor growth and response to treatment has gained significant momentum during the last few decades. At the dawn of the era of personalized medicine, providing insight into complex mechanisms involved in cancer and contributing to patient-specific therapy optimization constitute particularly inspiring pursuits. The in silico oncology community is facing the great challenge of effectively translating simulation models into clinical practice, which presupposes a thorough sensitivity analysis, adaptation and validation process based on real clinical data. In this paper, the behavior of a clinically-oriented, multiscale model of solid tumor response to chemotherapy is investigated, using the paradigm of nephroblastoma response to preoperative chemotherapy in the context of the SIOP/GPOH clinical trial. A sorting of the model's parameters according to the magnitude of their effect on the output has unveiled the relative importance of the corresponding biological mechanisms; major impact on the result of therapy is credited to the oxygenation and nutrient availability status of the tumor and the balance between the symmetric and asymmetric modes of stem cell division. The effect of a number of parameter combinations on the extent of chemotherapy-induced tumor shrinkage and on the tumor's growth rate are discussed. A real clinical case of nephroblastoma has served as a proof of principle study case, demonstrating the basics of an ongoing clinical adaptation and validation process. By using clinical data in conjunction with plausible values of model parameters, an excellent fit of the model to the available medical data of the selected nephroblastoma case has been achieved, in terms of both volume reduction and histological constitution of the tumor. In this context, the exploitation of multiscale clinical data drastically narrows the window of possible solutions to the clinical adaptation problem.

Educational paper: screening in cancer predisposition syndromes: guidelines for the general pediatrician

Improvements in our understanding of the genetic basis of human disease and increased utilization of genetic testing have identified a variety of heritable disorders associated with the onset of benign or malignant neoplasms during childhood. In many cases, the optimal management of affected children is dependent upon the early detection and treatment of tumors. Surveillance strategies based on the natural history of these lesions are often complex, requiring clinical examinations and radiologic and laboratory studies that evolve over a patient's lifetime. A general pediatrician may be the first to suspect one of these disorders in a patient, or may be faced with questions regarding genetic testing, cancer risk, and cancer screening. The pediatrician may also coordinate and interpret the results of specific surveillance studies. In this review, we present the genetic etiology, presentation, natural history, and surveillance recommendations for four disparate hereditary tumor predisposing syndromes, including Beckwith-Wiedemann syndrome/idiopathic hemihyperplasia, von Hippel-Lindau disease, Li-Fraumeni syndrome, and rhabdoid tumor/schwannomatosis. These examples are meant to offer the clinician practical recommendations as well as a framework upon which to base the understanding and management of other conditions associated with an increased risk to develop tumors in childhood.

Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder characterized by overgrowth, tumor predisposition, and congenital malformations. Approximately 85% of reported BWS cases are sporadic, while the remaining 15% are familial. BWS is caused by epigenetic or genomic alterations which disrupt genes in one or both of the two imprinted domains on chromosome 11p15.5. In each domain, an imprinting center regulates the expression of imprinted genes in cis. Normally in domain 1, insulin-like growth factor 2 (IGF2) and the untranslated mRNA H19 are monoallelically expressed. In BWS, increased expression of IGF2 occurs via several mechanisms. In domain 2, CDKN1C, a growth repressor, and an untranslated RNA, KCNQ1OT1, are normally expressed monoallelically. In cases of BWS, several mechanisms result in reduced expression of CDKN1C. Recent reports of BWS cases have identified mutations outside the chromosome 11p15.5 critical region, thereby broadening the challenges in the diagnosis and genetic counseling of individuals and families with BWS.

Living donor liver transplantation for hepatoblastoma with Beckwith-Wiedemann syndrome

BWS is one of the most well-known somatic overgrowth syndromes, which is characterized by macroglossia, organomegaly, abdominal wall defects, and predisposition to embryonal tumors, such as Wilms' tumor, hepatoblastoma, and adrenocortical carcinoma. We report a case of BWS in a girl with unresectable hepatoblastoma, who received a planned LVDT following neo-adjuvant chemotherapy. This is the first case report of liver transplantation for patients with BWS. Tumor surveillance after transplantation would be necessary to detect possible recurrence of the original disease and development of other malignancies.

Addition of H19 'loss of methylation testing' for Beckwith-Wiedemann syndrome (BWS) increases the diagnostic yield

Beckwith-Wiedemann syndrome (BWS) is a clinical diagnosis; however, molecular confirmation via abnormal methylation of DMR2(LIT1) and/or DMR1(H19) has clinical utility due to epigenotype-tumor association. Despite the strong link between H19 hypermethylation and tumor risk, several diagnostic laboratories only test for hypomethylation of LIT1. We assessed the added diagnostic value of combined LIT1 and H19 testing in a large series of referred samples from 1298 patients, including 53 well-characterized patients from the St. Louis Children's Hospital BWS-Registry (validation samples) and 1245 consecutive nationwide referrals (practice samples). Methylation-sensitive enzymatic digestion with Southern hybridization assessed loss of normal imprinting. In the validation group, abnormal LIT1 hypomethylation was detected in 60% (32/52) of patients but LIT1/H19-combined testing was abnormal in 68% (36/53); sensitivity in the practice setting demonstrated 27% (342/1245) abnormal LIT1 and 32% (404/1245) abnormal LIT1/H19-combined. In addition, H19 methylation was abnormal in 7% of LIT1-normal patients. We observed absence of uniparental disomy (UPD) in 27% of combined LIT1/H19-abnormal samples, diagnostic of multilocus methylation abnormalities; in contrast to studies implicating that combined LIT1/H19 abnormalities are diagnostic of UPD. The overall low detection rate, even in validated patient samples and despite characterization of both loci and UPD status, emphasizes the importance of clinical diagnosis in BWS.

Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a model disorder for the study of imprinting, growth dysregulation, and tumorigenesis. Unique observations in this disorder point to an important embryonic developmental window relevant to the observations of increased monozygotic twinning and an increased rate of epigenetic errors after subfertility/assisted reproduction.

Recognition and management of the infant with Beckwith-Wiedemann Syndrome

Beckwith-Wiedemann Syndrome (BWS) is the most common overgrowth syndrome in infancy. The characteristic findings are macroglossia, abdominal wall defects, and macrosomia. Genetic studies in infants with BWS demonstrate 3 major subgroups of patients: familial, sporadic, or chromosomally abnormal. Recognition in the neonatal period is important because of the high incidence of childhood malignant tumors associated with BWS. This article provides an overview of the syndrome and discusses its etiology, physical findings, and diagnostic evaluation. Management and clinical implications including family support will also be discussed.

Experience with hemihyperplasia and Beckwith-Wiedemann syndrome surveillance protocol

Beckwith-Wiedemann syndrome (BWS) and isolated hemihyperplasia (IHH) are two well known overgrowth conditions that are associated with cancer predisposition. Multiple surveillance protocols have been proposed to detect the most commonly reported tumor types Wilms tumor and hepatoblastoma. We reviewed the history of our patients who were part of this monitoring protocol. Information from 63 cases was collected retrospectively while another 63 control samples for AFP measurement were obtained prospectively. Twenty-five (40%) patients had an ultrasound abnormality, the most frequent being nephromegaly/size discrepancy. Two patients had well documented cases of tumors/tumor precursor (2/63:3.2%) detected by ultrasound images. Three hundred thirty-six separate AFP values were available with values above 50,000 ng/ml seen in three patients older than 2 months, one with hepatoblastoma and two other with hemangiomas/hemangioendotheliomas. There was no clear difference in the range of AFP values between previously reported controls, our own normal population and affected patients. In conclusion, ultrasound surveillance detected renal and liver pathology including benign and malignant lesions. The known variability of AFP in normal neonates and patients with BWS makes interpretation difficult in early infancy. Very high AFP values did seem to be correlated with risk for identifiable liver lesions. Determination of the natural changes in AFP levels over time will allow more appropriate comparison.

Diagnostic criteria and tumor screening for individuals with isolated hemihyperplasia

Isolated hemihyperplasia, formerly termed isolated hemihypertrophy, is a congenital overgrowth disorder associated with an increased risk for embryonal tumors, mainly Wilms tumor and hepatoblastoma. This practice guideline will set forth the diagnostic criteria and tumor screening recommendations for children with isolated hemihyperplasia, based on the best information available. There is clinical overlap between isolated hemihyperplasia with Beckwith-Wiedemann syndrome. The majority of Beckwith-Wiedemann syndrome patients have a molecular abnormality involving the imprinted cluster of genes at 11p15.5. In contrast, the preponderance of isolated hemihyperplasia patients studied have no identified etiology. Tumors have developed in isolated hemihyperplasia patients with and without molecular abnormalities. For this reason, molecular diagnostics are not helpful in identifying the subset of isolated hemihyperplasia patients with tumor risk and all isolated hemihyperplasia patients should undergo tumor screening.

Liver tumors: pediatric population

Liver tumors in childhood are rare and are typically not detected clinically until they reach a large size and often spread within the organ or metastasize. This can make surgical resection problematic, and almost all of them require extirpation for cure. With very effective chemotherapy for hepatoblastoma and to some extent for sarcomas, many cancers can be shrunk to permit partial hepatectomy, but for most hepatocarcinomas, some of the other malignancies, and even some benign proliferations, their location at the hilum and multiplicity of masses in multiple lobes make transplantation the treatment of choice. Major advances in diagnostic imaging, especially enhanced computed tomography and magnetic resonance imaging, permit a preoperative choice of resection versus transplantation to be achieved in almost all instances, and for the remainder, intraoperative ultrasonography can further help to determine the most desirable approach. The outcome is very much better in the case of hepatoblastoma when transplantation is a primary modality rather than following unsuccessful attempts at resection. In this review, transplantation for liver tumors in children is considered from all aspects, including the importance of screening for tumors whenever possible to avoid the need for transplantation.

Focal nodular hyperplasia of the liver and elevated alpha fetoprotein level in an infant with isolated hemihyperplasia

A case of focal nodular hyperplasia of the liver in a 43-day-old baby girl with isolated hemihyperplasia and elevated serum alpha-fetoprotein is presented. The child referred to our hospital with bilateral renal masses detected by prenatal and postnatal ultrasonography. A mass lesion was detected in segment 6 of liver and was diagnosed as focal nodular hyperplasia. We present this case to emphasize the presence of focal nodular hyperplasia in a patient with isolated hemihypertrophy and elevated serum alpha-fetoprotein level.

[Risks factors for pediatric malignant liver tumors]

OBJECTIVE

Pediatric Hepatic Malignancies (PHMs) are the result of the interaction between constitutional and environmental risk factors (RFs). We review the evidence on the main RFs associated to PHMs.

METHOD

Systematic review of the literature published in the last 25 years on Medline, Embase, Cancerlit, Lilacs and SciElo using the following key words: "etiology/risk factor/epidemiology" and "malignant liver tumors/hepatic cancer" or "hepatoblastoma/hepatocarcionoma".

RESULTS

PHMs account for 1 % of all pediatric malignancies. The main types, hepatoblastoma (HB) and hepatocarcionma (HCC) make up 98-99 % of PHM. The main constitutional RFs are: a) Beckwith-Wiedemann (BW) syndrome; b) isolated hemihyperplasia syndrome (IHS); c) adenomatous polyps of the colon; d) hemochromatosis; e) Hereditary Tyrosinemia Type 1; f) a -1-antitrypsin deficiency; g) porphyrias; h) cirrhosis; i) nonalcoholic steatosis; and j) primary sclerosing cholangitis. The main environmental RFs are: a) hepatitis B virus (HBV) and C virus (HCV); b) B1 aflatoxin (B1AF); c) ionizing radiation; d) alcohol; e) hormonal treatments; f) occupational exposure to pesticides, solvents, vinyl chloride and metals; g) smoking; h) arsenic; i) prematury and very low birth weight; and j) trematodes.

CONCLUSIONS

The clinical, analytical and ultrasound screening facilitate the early diagnosis of HB in the previously mentioned genetic syndromes, particularly BW and IHS during the first years of life. HBV universal vaccination of newborns provides the biggest opportunity to prevent a substantial proportion of PHMs. Also systematic monitoring of HBV and HCV in blood, hemoderivates, donated organs and drug addicts, are very useful. Other effective measures are: the reduction/elimination of B(1)AF in food, zero alcohol intake during childhood and adolescence as well decreasing prenatal exposure to the tobacco, solvents, pesticides, vinyl chloride, metals, ionizing radiation and hormonal treatments.

Genetic testing and tumor surveillance for children with cancer predisposition syndromes

PURPOSE OF REVIEW

Genetic testing for the presence of germline mutations in cancer-predisposing genes can identify individuals at increased cancer risk. For these individuals, the institution of cancer surveillance measures is recommended with the aim of detecting cancers at early and hence more curable stages. While these principles are well established in adults, they are only entering the pediatric arena.

RECENT FINDINGS

The care of children with cancer-predisposing conditions remains a challenge for the practicing clinician. Here, we describe recent findings related to genetic testing and cancer surveillance in three conditions marked by the development of tumors during childhood, including retinoblastoma, Beckwith-Wiedemann syndrome/idiopathic hemihypertrophy and the Wilms' tumor-associated syndromes. We use these conditions to demonstrate how the integration of clinical genetic testing and cancer monitoring has favorably influenced the survival and quality of life for patients. Where possible, we provide evidence-based guidelines for patient management.

SUMMARY

Advances in the understanding of cancer predisposition and implementation of standardized cancer surveillance protocols have improved the outcome for certain patients. Future research focusing on enhancing the sensitivity of genetic testing and efficacy of surveillance for at-risk populations could further decrease the morbidity and mortality associated with these conditions.