Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) System for Pediatric Patients with Hepatoblastoma: A Retrospective, Hospital-Based Cohort Study in South Korea.

PURPOSE: In 2017, the Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) system was introduced. We aimed to evaluate the accuracy of CHIC-HS System for the prediction of event-free survival (EFS) in Korean pediatric patients with hepatoblastoma. MATERIALS AND METHODS: This two-center retrospective study included consecutive Korean pediatric patients with histopathologically confirmed hepatoblastoma from March 1988 through September 2019. We compared EFS among four risk groups according to the CHIC-HS system. Discriminatory ability of CHIC-HS system was also evaluated using optimism-corrected C-statistics. Factors associated with EFS were explored using multivariable Cox regression analysis. RESULTS: We included 129 patients (mean age, 2.6±3.3 years; female:male, 63:66). The 5-year EFS rates in the very low, low, intermediate, and high-risk groups, according to the CHIC-HS system were 90.0%, 82.8%, 73.5%, and 51.3%, respectively. The CHIC-HS system aligned significantly well with EFS outcomes (p=0.004). The optimism-corrected C index of CHIC-HS was 0.644 (95% confidence interval [CI], 0.561 to 0.727). Age ≥ 8 (vs. age ≤ 2; hazard ratio [HR], 2.781; 95% CI, 1.187 to 6.512; p=0.018), PRE-Treatment EXTent of tumor (PRETEXT) stage IV (vs. PRETEXT I or II; HR, 2.774; 95% CI, 1.228 to 5.974; p=0.009), and presence of metastasis (HR, 2.886; 95% CI, 1.457 to 5.719; p=0.002), which are incorporated as the first three nodes in the CHIC-HS system, were independently associated with EFS. CONCLUSION: The CHIC-HS system aligned significantly well with EFS outcomes in Korean pediatric patients with hepatoblastoma. Age group, PRETEXT stage, and presence of metastasis were independently associated with EFS.

Panel of potential lncRNA biomarkers can distinguish various types of liver malignant and benign tumors.

PURPOSE: Liver cancers are among the deadliest malignancies due to a limited efficacy of early diagnostics, the lack of appropriate biomarkers and insufficient discrimination of different types of tumors by classic and molecular methods. In this study, we searched for novel long non-coding RNA (lncRNA) as well as validated several known candidates suitable as probable biomarkers for primary liver tumors of various etiology. METHODS: We described a novel lncRNA HELIS (aka "HEalthy LIver Specific") and estimated its expression by RT-qPCR in 82 paired tissue samples from patients with hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), combined HCC-CCA, pediatric hepatoblastoma (HBL) and non-malignant hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH). Additionally, we examined expression of cancer-associated lncRNAs HULC, MALAT1, UCA1, CYTOR, LINC01093 and H19, which were previously studied mainly in HCC. RESULTS: We demonstrated that down-regulation of HELIS strongly correlates with carcinogenesis; whereas in tumors with non-hepatocyte origin (HBL, CCA) or in a number of poorly differentiated HCC, this lncRNA is not expressed. We showed that recently discovered LINC01093 is dramatically down-regulated in all malignant liver cancers; while in benign tumors LINC01093 expression is just twice decreased in comparison to adjacent samples. CONCLUSION: Our study revealed that among all measured biomarkers only down-regulated HELIS and LINC01093, up-regulated CYTOR and dysregulated HULC are perspective for differential diagnostics of liver cancers; whereas others demonstrated discordant results and cannot be considered as potential universal biomarkers for this purpose.

Pediatric Liver Tumors: Updates in Classification.

Malignant primary liver tumors are rare in children. Yet a wide histologic spectrum is seen, particularly in hepatoblastoma, the most common malignant liver tumor in children. Furthermore, there can be significant morphologic overlap with hepatocellular carcinoma, the second most common pediatric liver malignancy, and tumors with hybrid features of hepatoblastoma and hepatocellular carcinoma are also reported (currently placed in the provisional category of malignant hepatocellular neoplasm, not otherwise specified). This review provides detailed morphologic descriptions and updates in the evolving clinical context of these tumors, and presents recent molecular advances that may further help in accurate classification of these tumors, which is critical in their management.

A combined clinical and biological risk classification improves prediction of outcome in hepatoblastoma patients.

AIM: Stratification of hepatoblastoma (HB) patients is based on clinical and imaging characteristics obtained at the time of diagnosis. We aim to integrate biomarkers into a tool that accurately predicts survival of HB patients. METHODS: We retrospectively analysed 174 HB patients for the presence of four biomarkers and explored their prognostic potential by correlating with overall survival (OS) and event-free survival (EFS). RESULTS: Mutations of CTNNB1, NFE2L2 and TERT were found in 135 (78%), 10 (6%) and 10 (6%) patients, respectively, and the adverse C2 subtype of the 16-gene signature in 63 (36%) patients. C2-patients had more frequent metastatic disease, higher alpha-fetoprotein levels, non-fetal histology and significantly worse 3-year OS (68% versus 95%) and EFS (63% versus 87%) than C1-patients. Patients carrying a NFE2L2 mutation had a significantly worse 3-year OS (57% versus 88%) than NFE2L2 wild-type patients and were more likely to have vessel invasive growth and non-fetal histology. TERT mutations were almost exclusively found in older patients, whereas CTNNB1 mutations showed no association with any clinical feature or outcome. In a multivariable analysis, the C2 subtype remained a significant predictor of poor outcome with hazard ratios of 6.202 and 3.611 for OS and EFS, respectively. When added to the Children's Hepatic tumors International Collaboration risk stratification, the presence of the C2 subtype identified a group of high-risk patients with a very poor outcome. CONCLUSION: We propose a new stratification system based on the combination of clinical factors and the 16-gene signature, which may facilitate a risk-adapted management of HB patients.

Clinicopathological profile of hepatoblastoma: An experience from a tertiary care center in India.

BACKGROUND: Hepatoblastoma is the most common primary hepatic malignancy in the pediatric population. Advances in pathological evaluation, imaging, risk stratification, neo-adjuvant chemotherapy, and surgery including transplantation have improved survival of these children in the western countries. However, a successful outcome in developing countries such as India with limited resources poses great challenges to the clinician and the family. Histology plays a major role in determining the prognosis of these patients. METHODS: A retrospective study was done on 10 children diagnosed with hepatoblastoma between January 2010 and December 2015 in our institution. Clinical, laboratory, radiological, histopathological diagnoses, treatment, and outcome data were collected and analyzed. RESULTS: The median age of these children at diagnosis was 11 months, and only 1 child was premature at birth. Most children were presented with abdominal distension. One child had lung metastasis at presentation. Elevated alpha fetoprotein levels were present in 90% of the children. The histological types were fetal, embryonal, macrotrabecular, and mixed epithelial-mesenchymal types. SIOPEL risk stratification was done, which showed 40% of the children to be of high risk. Three children had PRETEXT 1, 2, and 4, respectively. CONCLUSION: Our study is significant with respect to the information on PRETEXT staging, risk status, and histological favorability. In developing countries with limited resources and low-socioeconomic status, it is important to have a multidisciplinary team approach and tailor treatment to manage these patients effectively and improve the overall survival.

Fine-needle aspiration cytology and cell block in diagnosis and subtyping of hepatoblastoma.

Hepatoblastoma (HB) constitutes less than 1% of all pediatric malignancies and is the most common malignant tumor of liver in children. The fine-needle aspiration cytological (FNAC) diagnosis and sub-typing of this tumor is challenging, which is of critical importance from its treatment point of view. All cases with a clinicoradiological impression of "HB" during the study period of 1 year were subjected to ultrasound-guided (USG) FNAC and cell blocks were prepared in all cases. Detailed cytopathological examination was carried out based on the cytomorphological pattern and the cell blocks were used to correlate the findings and the final diagnoses were confirmed with the histopathological findings. Four cases were included during this study period. All were children, whose age ranged from 3 months to 10 years. All of them presented with mass per abdomen and increased serum alfa-feto protein (AFP) levels. On a detailed cytological examination, the clinical impression of HB was confirmed in all four cases with a subsequent histological correlation. Based on their distinct cytomorphological pattern, three of them were accurately sub-typed as"fetal type," wile the fourth was an "embryonal type of HB." All four cases had the evidence of extramedullary hematopoeisis. We conclude that a precise preoperative FNAC diagnosis with accurate sub-typing of HB is possible purely on cytomorphologic basis which has prognostic and therapeutic implications. Cell blocks are of great use for ancillary studies. Extramedullary hematopoiesis serves as an important "clue" in diagnosis.

New insights into diagnosis and therapeutic options for proliferative hepatoblastoma.

Surgery and cisplatin-based treatment of hepatoblastoma (HB) currently guarantee the survival of 70%-80% of patients. However, some important challenges remain in diagnosing high-risk tumors and identifying relevant targetable pathways offering new therapeutic avenues. Previously, two molecular subclasses of HB tumors have been described, C1 and C2, with C2 being the subgroup with the poorest prognosis, a more advanced tumor stage, and the worst overall survival rate. An associated 16-gene signature to discriminate the two tumoral subgroups was proposed, but it has not been transferred into clinical routine. To address these issues, we performed RNA sequencing of 25 tumors and matched normal liver samples from patients. The transcript profiling separated HB into three distinct subgroups named C1, C2A, and C2B, identifiable by a concise four-gene signature: hydroxysteroid 17-beta dehydrogenase 6, integrin alpha 6, topoisomerase 2-alpha, and vimentin, with topoisomerase 2-alpha being characteristic for the proliferative C2A tumors. Differential expression of these genes was confirmed by quantitative RT-PCR on an expanded cohort and by immunohistochemistry. We also revealed significant overexpression of genes involved in the Fanconi anemia (FA) pathway in the C2A subgroup. We then investigated the ability of several described FA inhibitors to block growth of HB cells in vitro and in vivo. We demonstrated that bortezomib, a Food and Drug Administration-approved proteasome inhibitor, strongly impairs the proliferation and survival of HB cell lines in vitro, blocks FA pathway-associated double-strand DNA repair, and significantly impedes HB growth in vivo. CONCLUSION: The highly proliferating C2A subtype is characterized by topoisomerase 2-alpha gene up-regulation and FA pathway activation, and the HB therapeutic arsenal could include bortezomib for the treatment of patients with the most aggressive tumors. (Hepatology 2018;68:89-102).

Fine needle aspiration in the diagnosis and classification of hepatoblastoma: Analysis of 21 New Cases.

BACKGROUND: Diagnosis of hepatoblastoma (HBL) is based on characteristic clinical and radiological presentation, young age and marked elevation of serum α-fetoprotein (aFP). Fine needle aspiration (FNA) technique is successfully used in the diagnosis of hepatoblastoma. To evaluate the value of FNA in the diagnosis and subtyping of HBL, we report our experience correlated to histological sections (core needle biopsy, CNB). METHODS: From 1991 to 2015, 21 cases from 20 patients were cytologically diagnosed as HBL. The patients were 15 males and 5 females, mean age being 3 years, and median age being 2 years and 4 months. Serum aFP levels ranged from negative to 1,285,000 ng/ml. We defined cytological criteria to diagnose fetal, embryonal, mesenchymal, and small cell undifferentiated components. RESULTS: The accurate cytological diagnosis of HBL was made in all cases; 8 cases exhibited a single component and 13 cases exhibited two or more components. Fetal and embryonal components were seen in 18 and 13 cases, respectively, and small cell undifferentiated component was seen in one case. Mesenchymal component was seen in 12 cases. Comparing cytology and histology, identical components were identified on both, FNA and CNB in 14 cases. When analyzing only the presence of epithelial components, 17 cases were concordant in both techniques. CONCLUSION: FNA allows to accurately diagnose HBL and recognize its histological subtypes. On the basis of high concordance between cytological and histological diagnosis, FNA is validated as an alternative diagnostic method to CNB. Diagn. Cytopathol. 2017;45:91-100. © 2016 Wiley Periodicals, Inc.

FNAC Aided Diagnosis and Categorization of Hepatoblastoma:: A Report of Three Cases.

Hepatoblastoma is the most common primary malignant hepatic tumour of infancy and early childhood. Histologically hepatoblastomas are categorized into pure epithelial and mixed epithelial-mesenchymal types and epithelial type is further subcategorized into pure fetal type, fetal and embryonal type, pure embryonal, and small cell types. This categorization has been shown to have prognostic and therapeutic implication. Fine needle aspiration cytology (FNAC) is useful in pre-operative diagnosis and categorization in most cases of hepatoblastomas. Periodic acid-Schiff (PAS) stain can be helpful to differentiate fetal subtype from embryonal subtype of hepatoblastoma. Here we describe three cases of hepatoblastomas diagnosed and categorized on cytology with subsequent confirmation on histological examination. Diagn. Cytopathol. 2017;45:77-82. © 2016 Wiley Periodicals, Inc.

Genomic analysis of hepatoblastoma identifies distinct molecular and prognostic subgroups.

Despite being the most common liver cancer in children, hepatoblastoma (HB) is a rare neoplasm. Consequently, few pretreatment tumors have been molecularly profiled, and there are no validated prognostic or therapeutic biomarkers for HB patients. We report on the first large-scale effort to profile pretreatment HBs at diagnosis. Our analysis of 88 clinically annotated HBs revealed three risk-stratifying molecular subtypes that are characterized by differential activation of hepatic progenitor cell markers and metabolic pathways: high-risk tumors were characterized by up-regulated nuclear factor, erythroid 2-like 2 activity; high lin-28 homolog B, high mobility group AT-hook 2, spalt-like transcription factor 4, and alpha-fetoprotein expression; and high coordinated expression of oncofetal proteins and stem-cell markers, while low-risk tumors had low lin-28 homolog B and lethal-7 expression and high hepatic nuclear factor 1 alpha activity. CONCLUSION: Analysis of immunohistochemical assays using antibodies targeting these genes in a prospective study of 35 HBs suggested that these candidate biomarkers have the potential to improve risk stratification and guide treatment decisions for HB patients at diagnosis; our results pave the way for clinical collaborative studies to validate candidate biomarkers and test their potential to improve outcome for HB patients. (Hepatology 2017;65:104-121).

Computer-assisted surgery planning in children with complex liver tumors identifies variability of the classical Couinaud classification.

BACKGROUND: In complex malignant pediatric liver tumors there is an ongoing discussion regarding surgical strategy; for example, primary organ transplantation versus extended resection in hepatoblastoma involving 3 or 4 sectors of the liver. We evaluated the possible role of computer-assisted surgery planning in children with complex hepatic tumors. METHODS: Between May 2004 and March 2016, 24 Children with complex liver tumors underwent standard multislice helical CT scan or MRI scan at our institution. Imaging data were processed using the software assistant LiverAnalyzer (Fraunhofer Institute for Medical Image Computing MEVIS, Bremen, Germany). Results were provided as Portable Document Format (PDF) with embedded interactive 3-dimensional surface mesh models. RESULTS: Median age of patients was 33months. Diagnoses were hepatoblastoma (n=14), sarcoma (n=3), benign parenchyma alteration (n=2), as well as hepatocellular carcinoma, rhabdoid tumor, focal nodular hyperplasia, hemangioendothelioma, or multiple hepatic metastases of a pancreas carcinoma (each n=1). Volumetry of liver segments identified remarkable variations and substantial aberrances from the Couinaud classification. Computer-assisted surgery planning was used to determine surgical strategies in 20/24 children; this was especially relevant in tumors affecting 3 or 4 liver sectors. Primary liver transplantation could be avoided in 12 of 14 hepaoblastoma patients who theoretically were candidates for this approach. CONCLUSIONS: Computer-assisted surgery planning substantially contributed to the decision for surgical strategies in children with complex hepatic tumors. This tool possibly allows determination of specific surgical procedures such as extended surgical resection instead of primary transplantation in certain conditions.

Pure fetal histology subtype was associated with better prognosis of children with hepatoblastoma: A Chinese population-based study.

BACKGROUND AND AIM: The aim of this study is to identify the association between histologic types and the prognosis of hepatoblastoma (HB) in a large Asian cohort of a single institution and to explore the interaction of histologic types with other independently risk factors in the process of affecting prognosis of HB. METHODS: We retrospectively reviewed 176 children with HB (82 female, 94 male) managed in our institution between May 1, 2001 and July 30, 2014. Prognostic factors were evaluated using Kaplan-Meier curves and Cox proportional hazards models. RESULTS: For the entire cohort of 176 patients, the overall median survival was 80.4 months(95% CI: 71.6-89.2 months), and the 5-year event-free survival and overall survival rates were 54.6 and 66.7%. Descriptive survival statistics and Kaplan-Meier curves suggested that alpha fetoprotein levels, tumor metastases, multifocality, histologic types, and Pre-Treatment Extent of Disease staging System stage had prognostic significance in this relatively selected cohort. Moreover, after eliminating the impact of the interaction of different classification methods of histologic types, pure fetal histologic (PFH) was an independent prognostic factor of HB (hazard ratio [HR]: 2.752, P = 0.021). Further stratification analysis showed that the impaction of other identified risk factors on the influence of PFH on the prognosis of HB patients was different. CONCLUSIONS: We have confirmed that the HB prognostic factors of HB and PFH was associated with better prognosis of children with HB based on an Asian population. PFH showed different significance in the process of affecting prognosis of HB with the interaction of other independent risk factors.

Towards an international pediatric liver tumor consensus classification: proceedings of the Los Angeles COG liver tumors symposium.

Liver tumors are rare in children, and their diagnoses may be challenging particularly because of the lack of a current consensus classification system. Systematic central histopathological review of these tumors performed as part of the pediatric collaborative therapeutic protocols has allowed the identification of histologic subtypes with distinct clinical associations. As a result, histopathology has been incorporated within the Children's Oncology Group (COG) protocols, and only in the United States, as a risk-stratification parameter and for patient management. Therefore, the COG Liver Tumor Committee sponsored an International Pathology Symposium in March 2011 to discuss the histopathology and classification of pediatric liver tumors, and hepatoblastoma in particular, and work towards an International Pediatric Liver Tumors Consensus Classification that would be required for international collaborative projects. Twenty-two pathologists and experts in pediatric liver tumors, including those serving as central reviewers for the COG, European Société Internationale d'Oncologie Pédiatrique, Gesellschaft für Pädiatrische Onkologie und Hämatologie, and Japanese Study Group for Pediatric Liver Tumors protocols, as well as pediatric oncologists and surgeons specialized in this field, reviewed more than 50 pediatric liver tumor cases and discussed classic and newly reported entities, as well as criteria for their classification. This symposium represented the first collaborative step to develop a classification that may lead to a common treatment-stratification system incorporating tumor histopathology. A standardized, clinically meaningful classification will also be necessary to allow the integration of new biological parameters and to move towards clinical algorithms based on patient characteristics and tumor genetics, which should improve future patient management and outcome.

Hepatoblastoma--an attempt of histological subtyping on fine-needle aspiration material.

Hepatoblastoma (HB) is classified into epithelial, mixed (epithelial/mesenchymal), and small-cell (anaplastic) type. Wnt/ß-catenin pathway plays a key role in hepatic development, regeneration, and tumorigenesis, and HB is known to present ß-catenin mutations (50-90%). The present study was undertaken to delineate the cytomorphologic features of HB and to evaluate the feasibility of subtyping of HB on fine-needle aspiration cytology (FNAC). The expression of ß-catenin in these tumors was also evaluated both of histopathologic sections and on the aspirated material. Thirty-three cases with fine-needle aspirates of HB were retrieved over a period of 12 years. Cytologic diagnosis was reviewed in the light of clinicoradiological data, response to therapy, and subsequent histopathology. Immunochemistry for ß-catenin was performed in 19 of 33 cases on histopathologic sections (n = 10)/cell blocks (n = 6)/cytosmears (n = 3). Based on the cytologic features, the cases were divided into fetal HB (n = 17), embryonal HB (n = 4), combined epithelial HB (n = 8), and mixed HB (n = 4). Four cases of histopathologically proven mixed HB were reported as pure epithelial HB on FNAC, as mesenchymal elements were not represented in the cytology smears. Cytoplasmic as well as nuclear staining for ß-catenin was noted in a total of 10 of 19 cases. FNAC can accurately categorize epithelial HB; however, in mixed type, the accuracy depends on number of areas sampled. Cell block can be of help to perform ancillary investigations especially ß-catenin for both diagnostic and therapeutic purposes.

Relationship of ß-catenin and postchemotherapy histopathologic changes with overall survival in patients with hepatoblastoma.

AIMS: Histopathologic spectrum and expression of ß-catenin were analyzed in patients with hepatoblastoma, diagnosed over a period of 14 years. These were correlated with the survival outcome. The morphologic features subsequent to chemotherapy were also analyzed. METHODS AND RESULTS: Histomorphologic features were studied on paraffin-embedded sections. There were 24 cases with 15 fetal, 4 embryonal, 4 macrotrabecular, and 1 of small cell subtype. Follow-up was available in 20 cases (mean = 16.8 mo). ß-catenin immunostaining performed by indirect immunoperoxidase method revealed 14 cases with nuclear and 10 cases with cytoplasmic positivity. Statistical analysis revealed no significant correlation between morphologic subtype and survival. Significant difference in survival was noted with respect to tumor stage, mitotic index, and ß-catenin staining pattern. Cases with nuclear expression had a mean survival of 71.54 ± 8.1 months in comparison with 14.71 ± 6.5 months in cases with cytoplasmic expression. Besides osteoid and cartilage formation, interesting postchemotherapy findings were the presence of tumoral maturation, hepatocellular carcinoma-like areas, peliotic-like foci, and "glomeruloid clusters." CONCLUSIONS: Nuclear ß-catenin expression is not a poor prognostic factor and this might be indicative of different genetic alterations in hepatoblastoma in the Indian subcontinent. There was no significant correlation between histologic subtype and osteoid differentiation with survival. The histopathologic changes observed were peliotic-like areas, tumoral maturation, hepatocellular carcinoma-like changes, and glomeruloid clusters besides the well-established features of osteoid differentiation after chemotherapy.

Current issues and controversies in the classification of pediatric hepatocellular tumors.

Systematic histopathologic examination of hepatoblastoma specimens from patients enrolled in therapeutic protocols has allowed the identification of clinically relevant histologic subtypes that are being incorporated into risk stratification systems. Genetic and molecular studies have documented recurrent chromosomal abnormalities and aberrant activation of developmental, and oncogenic signaling pathways in hepatoblastoma. Molecular profiling has also identified molecular subclasses and gene signatures that could be used to stratify hepatoblastoma patients. Future international collaboration is needed to develop consensus pathology classifications, and to progressively incorporate genetic and molecular biomarkers into therapeutic pediatric liver tumors protocols.

Hepatoblastoma: recent developments in research and treatment.

Hepatoblastoma is the most common liver tumor of early childhood. According to recent studies its incidence seems to be increasing in North America and Europe. Since new histological variants have been described recently the formerly clear-cut distinction of hepatoblastoma and hepatocellular carcinoma may not be valid anymore and a new histological classification will be inaugurated by an international working group. Recent research identified prognostically relevant gene signatures as well as potential molecular targets for therapy of hepatoblastoma. The multicentric study groups in the USA, Europe and Japan recommend cisplatin based chemotherapy for neoadjuvant and adjuvant treatment. However, their risk stratification systems and general treatment strategies differ substantially. Therefore the four groups agreed to pool their patients' data for an analysis of prognostic criteria which can be used for defining common risk groups. While 90% of standard risk and 65% of high risk hepatoblastomas can be cured, the still dismal outcome of multifocal disseminated and metastasising tumors warrants the investigation of new cytotoxic drugs and substances against specific molecular targets.

Hepatic tumours in childhood: an experience at the Children Hospital and Institute of Child Health, Lahore.

OBJECTIVES: In this report, we share our experience about the common types of childhood hepatic tumours during 10 years (2001-2010) and compare them with other studies. METHODS: During 10 years (2001-2010), all the hepatic tumours of childhood received at Pathology Department of the Children Hospital and Institute of Child Health, Lahore Pakistan are recorded. This includes both resected specimens and biopsies. All the slides were reviewed and the pathologic diagnosis was confirmed. RESULTS: We diagnosed 48 liver tumour cases in children (below 18 years of age). Among these tumours, 39 (81.25%) were malignant. Male to female ratio was 2:1. Hepatoblastoma was the most common liver tumour in this age group accounting for 69.23% of all malignant tumours (27 cases). The second most common primary tumour was hepatocellular carcinoma diagnosed in six patients (15.38%). Other malignant tumours were undifferentiated embryonal sarcoma and biliary rhabdomyosarcoma. Benign tumours included mesenchymal hamartoma, infantile haemangioendotheloima, hemangioma and benign cyst. There were also three metastatic tumours during these 10 years. In one case there was tumour necrosis only and as such no definitive diagnosis was rendered. CONCLUSION: The spectrum of hepatic tumours in children is different from that found in the older age group and most of them are malignant.

Small cell undifferentiated variant of hepatoblastoma: adverse clinical and molecular features similar to rhabdoid tumors.

BACKGROUND: Small cell undifferentiated (SCU) histology in patients with stage I hepatoblastoma (HB) predicts an increased risk of relapse. We sought to determine the significance of SCU histology in patients with unresectable HB. PROCEDURE: Patients enrolled on the pediatric Intergroup (INT0098) trial for HB and patients from the personal consultation files of two of the authors (MF, LG) were reviewed for cases with SCU histology. These patients were compared with SCU HB patients identified by literature review. RESULTS: Eleven patients were studied. All patients with reported AFP results exhibited normal or minimally increased serum AFP levels. None of the patients survived: 10 died of disease progression, and 1 died from treatment complications. Immunostaining revealed that tumors from six of six patients tested were INI1 negative. Cytogenetic and molecular abnormalities in one patient (and two patients from the literature review) were similar to those described in rhabdoid tumors. Comparison with patients from the literature review revealed similar results except that 4 of 29 patients survived without evidence of disease. CONCLUSIONS: SCU histology in HB patients is associated with an adverse outcome. These tumors appear to be biologically different from non-SCU HB. Evaluation of patient characteristics and outcomes for children with SCU HB and/or those with low AFP levels should be determined from large cooperative group studies. In the meantime, we suggest patients with unresectable HB containing SCU elements have careful cytogenetic, molecular, and immunohistochemical evaluation to ascertain rhabdoid features and receive treatment that differs from that provided for other HB patients.

Fine needle aspiration cytology of hepatoblastoma. Recognition of subtypes on cytomorphology.

OBJECTIVE: To delineate the cytomorphologic appearances of hepatoblastoma (HBL) in the largest series to date and to evaluate the feasibility of subtyping on fine needle aspiration cytology (FNAC). STUDY DESIGN: Papanicolaou- and May-Grünwald-Giemsa-stained smears of aspirates from 26 cases of HBL were analyzed by 2 observers. Histologic material, available in 15 cases, was correlated. A cytology grouping system was proposed on the basis of which all cases were classified. RESULTS: The ages of the patients ranged from 4 months to 9 years. Twenty-five cases were categorized as epithelial HBL, with epithelial fragments showing a trabecular arrangement and acinar formation in all, and extramedullary hemopoiesis in 20 cases. It was possible to differentiate fetal and embryonal areas on FNAC. Six cases showed only fetal elements (cytology group F), characterized by cells with abundant cytoplasm and a small, rounded nucleus resembling a normal fetal hepatocyte. The chromatin was finely granular, with a single, central nucleolus. Pleomorphism and mitoses were not seen, and the nuclear/cytoplasmic ratio was < or = 1/3. Fourteen cases showed, in addition to fetal elements, an embryonal component characterized by cells with scant cytoplasm, a pleomorphic nucleus, N/C ratio of > or = 3/1, coarsely granular chromatin and 2-4 angulated nucleoli. Mitoses were seen in these cells (1-4/1,000 cells). Of these 14 cases, 6 showed predominantly fetal and scant embryonal cells, while 8 cases showed fetal and embryonal components in equal amounts (cytology groups Fe and FE, respectively). Four cases showed predominantly embryonal cells (cytology group E). One case was unclassifiable (U). On histology, 8 of 14 cases were of mixed epithelial and mesenchymal type, but mesenchymal tissue was not seen on the corresponding cytology. The cytology grouping system correlated well with histology. One case was small cell undifferentiated HBL and resembled a round cell tumor without differentiation. Macrotrabecular arrangement was not seen on cytology but was seen on histology in 1 case. CONCLUSION: Epithelial HBL can be easily diagnosed in aspirates further classified into fetal and embryonal subtypes, which may be of prognostic relevance. The proposed cytology grouping system is effective in semiquantification of the observed subtypes.