Liver Tumors In Children Research Articles

Conversion of a neonatal hepatic hemangioma to focal nodular hyperplasia

Hepatic hemangioma and focal nodular hyperplasia are both frequently observed benign lesions of the liver. Whereas hepatic hemangioma is the most frequent benign liver tumor in children, focal nodular hyperplasia occurs predominantly in adult patients. Concomitance of both entities has been described in adults, suggesting a similar pathogenesis. We report on a 6-month-old child with a continuously shrinking hepatic hemangioma after interventional therapy and a growing hepatic mass 5 years later, which emerged as focal nodular hyperplasia at the site of the former hemangioma. Diagnostic and therapeutic strategies regarding this patient are discussed. The present case supports the theory that these two entities may share a similar pathomechanism.

Mesenchymal hamartoma of the liver

Mesenchymal hamartoma of the liver is the second most common benign liver tumor of childhood. Ultrasonography demonstrates a cystic lesion that may be very large. Computed tomographic scan will further establish the location and its relationship to vascular anatomy. Most will be amenable to gross total resection with clear margins. To illustrate the radiological and gross operative features, we present a 9-month–old male infant with a mesenchymal hamartoma with classic features.

Assessment of malignant liver tumors in children

Imaging plays a crucial role in the management of a child with a suspected liver tumor. There are various important differences between pediatric and adult practice, and in particular several liver tumor types that are almost never seen in adults are not uncommon in children. The radiologist makes important contributions to the diagnosis through non-invasive imaging and often biopsy. This paper describes imaging tips for the radiologist, including a discussion of the PRETEXT system for staging primary malignant tumors.

Germline APC Mutations Are Not Commonly Seen in Children With Sporadic Hepatoblastoma

Hepatoblastoma is the most common primary liver tumor in childhood and occurs more commonly in families with familial adenomatous polyposis. Germline mutations of the gene responsible for familial adenomatous polyposis--adenomatous polyposis coli (APC)--are described in patients with hepatoblastoma even without a family history. We investigated children presenting with apparently sporadic hepatoblastoma between 1991 and 2004. Blood samples were available from 29 children (18 boys) whose conditions were diagnosed at a median age of 22 months (range 6-119 months). No germline APC mutations were found, which does not support the need for routine screening in sporadic hepatoblastoma in the absence of a suggestive family history of colorectal cancer or suspicion of familial adenomatous polyposis.

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.

Liver transplantation for hepatoblastoma

From October 1993 to February 2007, 25 liver transplantations were performed for hepatoblastoma. Of these 25, 18 children received cadaveric grafts, and 7 received left lateral segments from living donors. Fifteen patients were at level IV in the pretreatment extent of disease staging system for hepatoblastoma (PRETEXT IV; 11 received cadaveric grafts and 4 underwent living related liver transplantation [LRLT]) and 10 were level III (PRETEXT III; 7 received cadaveric grafts and 3 underwent LRLT). Preoperative chemotherapy was given according to the risk stratification system for children with hepatoblastoma protocols of the International Childhood Liver Tumour Strategy Group of the International Society of Paediatric Oncology (SIOPEL): SIOPEL I in the first 3 patients, SIOPEL II in 6, SIOPEL III in 10, and SIOPEL IV in 3 patients. Patient and graft survival after cadaveric transplantation was 91%, 77.6%, and 77.6%, at 1, 5, and 10 years, respectively, with no retransplantations. Patient and graft survival for children undergoing LRLT was 100%, 83.3%, and 83.3%, at 1, 5, and 10 years, respectively. All surviving children but 1 remain disease-free, with a median follow up of 6.8 years (range, 0.9-14.9). There were 5 deaths at a median of 13 months post-transplantation, secondary to tumor recurrence (4) and respiratory failure (1). Liver transplantation is an established treatment for unresectable hepatoblastoma confined to the liver following chemotherapy. LRLT is a therapeutic option given that the outcome is similar to that of resection and cadaveric transplantation.

Primary perivascular epithelioid cell tumor of the liver not related to hepatic ligaments: hepatic PEComa as an emerging entity.

Primary perivascular epithelioid cell tumor (PEComa) of the liver is a very rare example of an emerging family of hepatic PEC tumors. Only few cases have been described so far. We report the case of a large but benign hepatic PEComa in a 53-year-old man without signs of tuberous sclerosis. In contrast to recently described PEC-derived liver tumors in children and young adults, this neoplasm was not related to the hepatic ligaments but had developed deeply within the liver substance. The neoplastic cells displayed the complete phenotype typical for PEComas, i.e. reactivity for several melanoma markers and for smooth muscle actin. The unique relationship of myoid tumor cells to the adventitia of blood vessels prompted us, in comparison with published findings obtained with angiomyolipomas, to comment on the possible origin of the still enigmatic perivascular epithelioid cells.

Malignant Liver Tumors in Children

Age at presentation is often the key to the differential diagnosis of a liver mass in children. Hepatoblastoma is the most common malignant liver tumor in infants and toddlers, whereas hepatocellular carcinoma is seen in older children and adolescents. Although symptoms are possible, these tumors most often present as an asymptomatic epigastric or right upper quadrant mass. Definitive diagnosis is made with percutaneous, laparoscopic or open biopsy, and biopsy is recommended in all patients unless radiographic imaging clearly demonstrates a benign hemangioma. The most common benign tumors are infantile hemangioma, focal nodular hyperplasia and mesenchymal hamartoma. Hepatoblastoma is often chemosensitive and, if resectable, may have a good prognosis. Conversely, hepatocellular carcinoma is often chemoresistant and is frequently diagnosed at an advanced stage making resection difficult. The pretreatment extent of disease is a stratification system developed by the Society of Pediatric Oncology Liver Tumor Study Group (SIOPEL) that is now used worldwide to stratify risk and predict surgical resectability. Treatment protocols recommended by Children's Oncology Group and SIOPEL are reviewed. Other malignant tumors discussed briefly include sarcomas (rhabdomyosarcoma, angiosarcoma and undifferentiated or embryonal sarcoma), rhabdoid tumors and metastatic disease.

Pediatric liver tumors – a pictorial review

Hepatic masses constitute about 5-6% of all intra-abdominal masses in children. The majority of liver tumors in children are malignant; these malignant liver tumors constitute the third most common intra-abdominal malignancy in the pediatric age group after Wilms' tumor and neuroblastoma. Only about one third of the liver tumors are benign. A differential diagnosis of liver tumors in children can be obtained based on the age of the child, clinical information (in particular AFP) and imaging characteristics. The purpose of this review is to report typical clinical and imaging characteristics of benign and malignant primary liver tumors in children.

Liver Tumors in Children

Malignant liver tumors account for slightly >1% of all pediatric malignancies, with roughly 150 new cases of liver tumors diagnosed in the U.S. annually. The embryonal tumor, hepatoblastoma, accounts for two thirds of malignant liver tumors in children. Other liver malignancies in children include hepatocellular carcinoma, sarcomas, germ cell tumors, and rhabdoid tumors. Benign tumors of the liver in children include vascular tumors, hamartomas, and adenomas. There is an apparent increase in the incidence of hepatoblastoma with perinatal exposures and decreased premature infant mortality as postulated causes for this increased risk. The known causes and associations of liver tumors in children as well as the approaches to diagnosis and treatment of children are discussed in this review article.

Hepatoblastoma: a single institutional experience of 18 cases

Hepatoblastomas are the most common liver tumours in children. However, they are rare as compared to other solid malignancies. Thus, there is a need to integrate data from surgical centers around the world to provide a clearer view on the outcomes of multidisciplinary management of these tumours. We set out to retrospectively review our experience of patients with surgically resected hepatoblastomas looking at primary and secondary outcomes. Children diagnosed with hepatoblastoma and managed surgically (along with chemotherapy) at a single institution between 1 January 2000 and 31 May 2007, were analyzed. Out of the 18 patients, there were 12 male and 6 female patients. The median age was 18 months (range 8-72). A palpable mass in abdomen was the presenting symptom in 88% patients. Sixteen patients (88.8%) underwent major liver resection. Sixteen patients (88.8%) received preoperative chemotherapy. Complete gross resection (stage I and II) was achieved in all 18 patients (100%). The mortality and morbidity rates were 0 and 11.2%, respectively. The 80-month disease-free survival was 67%. This series, the largest from India in terms of surgical resections for hepatoblastoma, reaffirms that major liver resection can be performed with minimal perioperative mortality and morbidity and that the use of chemotherapy has definitely helped in down staging tumours for liver resection.

Surgery of Liver Tumors in Children in the Last 15 Years

Aim of the study was to review our experience in the management of liver tumors in children over the last 15 years. A cohort of 78 children with liver tumors managed in our institution between 1991 and 2006 was retrospectively reviewed. There were 45 males and 33 females with a mean age of 32 +/- 41 months at diagnosis. Most tumors were malignant (n = 57); the most frequently occurring tumor was hepatoblastoma (n = 47), followed by hepatocarcinoma (n = 5), sarcoma (n = 4), and lymphoma (n = 1). Vascular tumors (n = 12) predominated among the benign tumors followed by mesenchymal hamartoma (n = 4), focal nodular hyperplasia (n = 3), adenoma (n = 1), and inflammatory pseudotumor (n = 1). We reviewed the epidemiologic features, clinical presentation, diagnosis, treatment and outcomes. We employed MRI and angio-CT for SIOPEL PRETEXT staging and selected the management accordingly for malignant tumors. We analyzed the long-term survival using Kaplan-Meier curves. Benign tumors had an excellent outcome with both medical or surgical management. Of the malignant tumors 4 were PRETEXT I and were treated by left lateral segmentectomy with 100 % survival; 20 were PRETEXT II (12 left and 8 right lobe) and were treated by lobectomy of the corresponding side, except for 1 case which required OLT (90 % survival); 9 children had PRETEXT III tumors requiring trisegmentectomy or extended lobectomies with OLT in 1 case (77.7 % survival). Fourteen children had PRETEXT IV tumors: 10 received OLT and 9 of them are still alive (64.2 % survival). Overall survival was 80.8 %, and actuarial survival at 6 years was 82.2 %. Other malignant tumors had variable results. Outcomes have improved much in the last years. Surgical removal is necessary in most cases. Transplantation is a very useful adjunct. Treatment of these tumors should be concentrated in centers with expertise.

Tumors of the liver in children

In this review we examine the diagnosis and treatment of pediatric liver tumors- both malignant and benign. The two most common malignant tumors are hepatoblastoma and hepatocellular carcinoma. Hepatoblastoma is seen in younger children, hepatocellular carcinoma in older children. Other malignant liver tumors are quite rare and include biliary rhabdomyosarcoma, angiosarcoma, rhabdoid tumor, and undifferentiated sarcoma. The commonly seen benign liver tumors in children are infantile hemangioma, mesenchymal hamartoma, and focal nodular hyperplasia. Rare benign tumors are hepatic adenoma, which is occasionally seen in teenage girls, and teratoma which is a very rare liver tumor in infants.

Bcl-2 Gene Silencing in Pediatric Epithelial Liver Tumors

Proteins of the Bcl-2 family prevent cells of various tumor types from undergoing apoptosis and thus contribute to their chemotherapy resistance. The phenotype of multidrug resistance is a major factor for poor treatment results of advanced epithelial liver tumors in children. The role of Bcl-2 proteins in these tumors is yet unclear. The purpose of this study was to analyze the influence of Bcl-2 on the chemotherapy resistance of hepatoblastoma (HB) and pediatric hepatocellular carcinoma (HCC). Bcl-2 expression was analyzed in the HB cell lines HUH6 and HepT1 as well as in the HCC cell line HepG2 before and after treatment with cisplatin, doxorubicin, taxol, and etoposid. Silencing of the Bcl-2 gene was performed via RNA interference using specific siRNA. Treatment efficiencies of cytotoxic agents were assessed against original and Bcl-2 siRNA transfected tumor cells. The mixed HB cell line HUH6 showed a relevant amount of Bcl-2 expression, which increased after chemotherapy. In these cells Bcl-2 appeared within the nuclei and the cytosol. Treatment with all cytotoxic agents was significantly improved through Bcl-2 siRNA (P < 0.001-0.0054) in this cell line. There was no effect of Bcl-2 siRNA in HepT1 and HepG2 cells. Bcl-2 seems to play a role in antiapoptotic mechanisms of some HB subtypes. Thus, this gene might serve as target for a gene-directed adjuvant therapy. Further studies seem necessary to clear the susceptibility of pediatric epithelial liver tumors toward the described approach.

Treatment of infantile choriocarcinoma of the liver

Primary choriocarcinoma of the liver is an extremely rare childhood malignancy frequently associated with clinical instability at initial presentation. It often mimics other benign and malignant childhood liver tumors. Prompt diagnosis and initiation of treatment are necessary to attain a successful outcome. We describe a critically ill infant with metastatic choriocarcinoma whose diagnosis was based on radiographic and tumor marker findings, without an initial biopsy, and her successful management with neo-adjuvant chemotherapy and delayed surgery. She is currently in continuous remission 24 months from diagnosis.

Oxidative stress induces p53‐dependent apoptosis in hepatoblastoma cell through its nuclear translocation

Hepatoblastoma (HBL) is the most common malignant liver tumor in children. Since tumor suppressor p53 is rarely mutated in HBL, it remains unknown whether p53 could contribute to the hepatocarcinogenesis. In the present study, we have found for the first time that, like neuroblastoma (NBL), wild-type p53 was abnormally accumulated in the cytoplasm of the human HBL-derived Huh6 cells. In accordance with this notion, immunohistochemical analysis demonstrated that p53 is largely expressed in cytoplasm of human primary HBLs. In response to the oxidative stress, Huh6 cells underwent apoptotic cell death in association with the nuclear translocation of p53 and the transactivation of its target gene implicated in apoptotic cell death. siRNA-mediated knockdown of the endogenous p53 conferred the resistance of Huh6 cells to oxidative stress. Intriguingly, histone deacetylase inhibitor (nicotinamide) treatment strongly inhibited the oxidative stress-induced nuclear translocation of p53 as well as the p53-dependent apoptosis in Huh6 cells. In contrast to the previous observations, the cytoplasmic anchor protein for p53 termed Parc had undetectable effect on the cytoplasmic retention of p53. Collectively, our present results suggest that the abnormal cytoplasmic localization of p53 might contribute at least in part to the development of HBL.

Liver Tumors in Children

Liver Tumors in Children

Outcome of Liver Resection for Liver Tumours in Children: An Institutional Review from a Developing Country

Availability of gadgets like Harmonic Scalpel allows liver resection to be performed with ease andminimal blood loss. The scenario is different in a developing country which lacks these modern gadgets. We present a review of our results of liver resection from a referral institute in a developing country. We reviewed children with liver resection done at our Institute from July 1999 - July 2006. Children with liver trauma and non operated tumour cases were excluded. Twenty one resections were carried out in 7 years, achieving a 68.4% disease free survival rate. The most common presenting complaint was abdominal mass (19 /21-90%). The majority (85%, 18/21) were found to be malignant on histopathological examination. Anatomical resections were performed in 16 (85%) children; 4 developed tumour recurrence, 3 with recurrence did not respond to second line chemotherapy and diedwhilewaiting for reoperation. One with recurrent liver tumour refused further treatment.Two (10%)were lost to followup. Liver resections can be safely performed in the absence of the modern gadgets, although presence of such gadgets would facilitate resection in terms of operating time and blood loss. Keywords : Liver resection, paediatric liver tumours, outcome African Journal of Paediatric Surgery Vol. 4 (1) 2007: pp. 3-6

P-217B Two cases of rare malignant liver tumor of childhood(Oncology, 44th Annual Meeting of Japanese Society of Pediatric Surgeons)

P-217B Two cases of rare malignant liver tumor of childhood(Oncology, 44th Annual Meeting of Japanese Society of Pediatric Surgeons)

2005 PRETEXT: a revised staging system for primary malignant liver tumours of childhood developed by the SIOPEL group

Over the last 15 years, various oncology groups throughout the world have used the PRETEXT system for staging malignant primary liver tumours of childhood. This paper, written by members of the radiology and surgery committees of the International Childhood Liver Tumor Strategy Group (SIOPEL), presents various clarifications and revisions to the original PRETEXT system.