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In the present study, we found that EZH1 depletion in MYCN-amplified neuroblastoma cells resulted in significant cell death as well as xenograft inhibition. EZH1 depletion decreased the level of H3K27me1; the interaction and protein stabilization of MYCN and EZH1 appear to play roles in epigenetic transcriptional regulation. Transcriptome analysis of EZH1-depleted cells resulted in downregulation of the cell cycle progression-related pathway. In particular, Gene Set Enrichment Analysis revealed downregulation of reactome E2F-mediated regulation of DNA replication along with key genes of this process, TYMS, POLA2, and CCNA1. TYMS and POLA2 were transcriptionally activated by MYCN and EZH1-related epigenetic modification. Treatment with the EZH1/2 inhibitor UNC1999 also induced cell death, decreased H3K27 methylation, and reduced the levels of TYMS in neuroblastoma cells. Previous reports indicated neuroblastoma cells are resistant to 5-fluorouracil (5-FU) and TYMS (encoding thymidylate synthetase) has been considered the primary site of action for folate analogues. Intriguingly, UNC1999 treatment significantly sensitized MYCN-amplified neuroblastoma cells to 5-FU treatment, suggesting that EZH inhibition could be an effective strategy for development of a new epigenetic treatment for neuroblastoma.

Purpose Hepatobiliary scintigraphy is a minimally invasive imaging method that evaluates bile flow dynamics. At our hospital, it has been performed for postoperative evaluation of patients with choledochal cysts (CC). This study evaluated the usefulness of biliary scintigraphy for predicting late complications in patients with CCs. Methods The study included pediatric patients with CC who underwent surgery at Chiba University Hospital from 1978 to 2020, followed by postoperative biliary scintigraphy and subsequent radiologic evaluation. The patients were divided into two groups according to the presence or absence of “biliary cholestasis” on biliary scintigraphy. Results The study included 108 patients, with a median age at surgery of 2 years and 11 months. The median follow-up period was 5203 days, with 11 hepatolithiasis cases and 8 cholangitis cases. No patients had cholangiocarcinoma. Twelve patients were considered to have “cholestasis” following biliary scintigraphy evaluation. There was no significant difference in the occurrence of hepatolithiasis between the cholestasis and non-cholestasis groups (p = 0.47), but cholangitis was significantly more common in the cholestasis group (p = 0.016). Conclusion Biliary cholestasis on postoperative hepatobiliary scintigraphy was a risk factor for cholangitis in patients with CCs. These particular patients should be monitored carefully.

Background Clinical trials have reported the efficacy of tropomyosin receptor kinase (TRK) inhibitors against neurotrophic receptor tyrosine kinase (NTRK) fusion gene-positive advanced solid tumors. The accumulated evidence of tumor-agnostic agent has made since TRK inhibitors were approved and used in clinical practice. Therefore, we have revised the ‘Japan Society of Clinical Oncology (JSCO)/Japanese Society of Medical Oncology (JSMO)-led clinical recommendations on the diagnosis and use of tropomyosin receptor kinase inhibitors in adult and pediatric patients with neurotrophic receptor tyrosine kinase fusion-positive advanced solid tumors, cooperated by the Japanese Society of Pediatric Hematology/Oncology (JSPHO)’. Methods Clinical questions regarding medical care were formulated for patients with NTRK fusion-positive advanced solid tumors. Relevant publications were searched by PubMed and Cochrane Database. Critical publications and conference reports were added manually. Systematic reviews were performed for each clinical question for the purpose of developing clinical recommendations. The committee members identified by JSCO, JSMO, and JSPHO voted to determine the level of each recommendation considering the strength of evidence, expected risks and benefits to patients, and other related factors. Thereafter, a peer review by experts nominated from JSCO, JSMO, and JSPHO, and the public comments among all societies' members was done. Results The current guideline describes 3 clinical questions and 14 recommendations for whom, when, and how NTRK fusion should be tested, and what is recommended for patients with NTRK fusion-positive advanced solid tumors. Conclusion The committee proposed 14 recommendations for performing NTRK testing properly to select patients who are likely to benefit from TRK inhibitors.

Small cell undifferentiated (SCU) histology and alpha-fetoprotein (AFP) levels below 100 ng/mL have been reported as poor prognostic factors in hepatoblastoma (HB); subsequent studies reported SMARCB1 mutations in some SCU HBs confirming the diagnosis of rhabdoid tumor. The Children’s Hepatic tumors International Collaboration (CHIC) database was queried for patients with HB who had AFP levels less than 100 ng/mL at diagnosis or were historically diagnosed as SCU HBs. Seventy-three of 1605 patients in the CHIC database were originally identified as SCU HB, HB with SCU component, or HB with low AFP levels. Upon retrospective review, they were re-classified as rhabdoid tumors (n = 11), HB with SCU component (n = 41), and HB with low AFP (n = 14). Seven were excluded for erroneously low AFP levels. Overall survival was 0% for patients with rhabdoid tumors, 76% for patients with HB with SCU component, and 64% for patients with HB with AFP less than 100 ng/mL. Patients with HB with SCU component or low AFP should be assessed for SMARCB1 mutations and, if confirmed, treated as rhabdoid tumors. When rhabdoid tumors are excluded, the presence of SCU component and low AFP at diagnosis were not associated with poor prognosis in patients diagnosed with HB.

Purpose Although the impairment of regulatory T-cells (Tregs) has been shown in the liver or portal area of biliary atresia (BA) the frequency and function of circulating Tregs in BA patients is poorly understood. We aimed to investigate the frequency and function of circulating Tregs in BA patients. Methods Peripheral blood mononuclear cells were collected from 25 BA patients and 24 controls. Treg frequency was measured by flow cytometry; function was determined by T-cell proliferation assay. We also assessed the association between Treg frequency/function and clinical parameters in BA cases. Results There was no significant difference between the two groups in both frequency (BA: 3.4%; control: 3.2%; p = 0.97) and function (BA: 22.0%; control: 7.5%; p = 0.23) of Tregs. We further focused on 13 preoperative BA patients and 14 age-matched controls. Neither Treg frequency nor function were significantly different (frequency: BA: 4.6%; control: 3.4%; p = 0.38, function: BA: 2.7%; control: 7.6%; p = 0.89). There was no association between Treg frequency/function and clinical parameters. Conclusion Neither the frequency nor function of circulating Tregs was affected in BA patients, suggesting the negative role of circulating Tregs in the pathogenesis of BA. Further investigation of local Treg profiles is warranted.

Two cases of pediatric lung cancer (in 23-month-old and 6-year-old boys) resulting from mother-to-infant transmission of uterine cervical tumors were incidentally detected during routine next-generation sequencing of paired samples of tumor and normal tissue. Spontaneous regression of some lesions in the first child and slow growth of the tumor mass in the second child suggested the existence of alloimmune responses against the transmitted tumors. Immune checkpoint inhibitor therapy with nivolumab led to a strong regression of all remaining tumors in the first child. (Funded by the Japan Agency for Medical Research and Development and others; TOP-GEAR UMIN Clinical Trials Registry number, UMIN000011141.).

Purpose The optimal timing of surgery for congenital diaphragmatic hernia (CDH) is controversial. We aimed to validate our protocol for the timing of CDH repair using the quantified patent ductus arteriosus (PDA) flow pattern. Methods This retrospective comparative study analyzed patients with a prenatal diagnosis of isolated CDH between 2007 and 2020. We defined the “LR ratio” as the percentage of velocity–time integral (VTI) of the left-to-right flow of PDA against overall VTI on echocardiography. Since 2010, we followed the decision criterion of performing surgery when LR ratio of > 50% has been achieved in the patients (protocol group). The protocol group (2010–2020) was compared with the historical control group (2007–2009). Results The average age at surgery was 104.1 ± 175.9 and 37.3 ± 30.6 h in the control and protocol groups, respectively (p = 0.11). Survival rate (88.9% vs. 95.0%, p = 0.53) and the rate of worsening of pulmonary hypertension within 24 h after surgery (22.2% vs. 10.0%, p = 0.57) were not different between the groups. The protocol group had a significantly shorter duration of tracheal intubation (26.9 ± 21.1 vs. 13.3 ± 9.5 days, p = 0.03). Conclusion Our decision criterion might have the advantage of facilitating early and safe surgery for patients with CDH.

Purpose Oncolytic viral therapy for neuroblastoma (NB) cells with Sindbis virus (SINV) is a promising strategy for treating high-risk NB. Here, we evaluated the possibility of using SINV structural proteins as therapeutic agents for NB since UV-inactivated SINV could induce cytopathogenic effects. Methods The cytotoxicity of UV-inactivated SINV toward human NB cell lines NB69, NGP, GOTO, NLF, SK-N-SH, SH-SY5Y, CHP134, NB-1, IMR32, and RT-BM-1 were analyzed. Apoptosis was confirmed by TUNEL assays. To determine the components of SINV responsible for the cytotoxicity of UV-inactivated SINV, expression vectors encoding the structural proteins, namely capsid, E2, and E1, were transfected in NB cells. Cytotoxicity was evaluated by MTT assays. Results UV-inactivated SINV elicited more significant cytotoxicity in NB69, NGP, and RT-BM-1 than in normal human fibroblasts. Results of the transfection experiments showed that all NB cell lines susceptible to UV-inactivated SINV were highly susceptible to the E1 protein, whereas fibroblasts transfected with vectors harboring capsid, E1, or E2 were not. Conclusions We demonstrated that the cytotoxicity of the UV-inactivated SINV is due to apoptosis induced by the E1 structural protein of SINV, which can be used selectively as a therapeutic agent for NB.

Rationale: Unresectable abdominal tumors cause various complications, and fistulizaton with intestine is a rare but serious complication. We report this condition in 2 cases. Patient Concerns: The first case was that of a 14-year-old male patient who had a desmoid tumor and the second case was that of a 17-year-old female patient with a recurrent malignant peripheral nerve sheath tumor. They were admitted with a giant chemoresistant tumor that was gradually growing and causing abdominal pain. Diagnoses: They were diagnosed with intertumor abscesses caused by fistulous communications with the intestine. Interventions: Both the patients underwent percutaneous drainage, and after being stabilized, they underwent surgery. Outcomes: The patient with desmoid tumor was continuing his daily routine without any problem. The patient with malignant peripheral nerve sheath tumor was able to consume food orally and discharged after the surgery. Lessons: In the treatment of abdominal intratumor abscesses caused by fistulous communications with intestine, it is necessary to consider the optimal treatment strategies based on the tumor location and patient prognosis.

Hepatoblastoma (HB) is the most common pediatric liver malignancy; however, hereditary predisposition and acquired molecular aberrations related to HB clinicopathological diversity are not well understood. Here, we perform an integrative genomic profiling of 163 pediatric liver tumors (154 HBs and nine hepatocellular carcinomas) based on the data acquired from a cohort study (JPLT-2). The total number of somatic mutations is precious low (0.52/Mb on exonic regions) but correlated with age at diagnosis. Telomerase reverse transcriptase (TERT) promoter mutations are prevalent in the tween HBs, selective in the transitional liver cell tumor (TLCT, > 8 years old). DNA methylation profiling reveals that classical HBs are characterized by the specific hypomethylated enhancers, which are enriched with binding sites for ASCL2, a regulatory transcription factor for definitive endoderm in Wnt-pathway. Prolonged upregulation of ASCL2, as well as fetal-liver-like methylation patterns of IGF2 promoters, suggests their “cell of origin” derived from the premature hepatoblast, similar to intestinal epithelial cells, which are highly proliferative. Systematic molecular profiling of HB is a promising approach for understanding the epigenetic drivers of hepatoblast carcinogenesis and deriving clues for risk stratification., While hepatoblastoma is the most common pediatric liver cancer, its molecular background has not been fully characterised. Here, the authors perform genomic and epigenomic profiling of 163 untreated pediatric liver tumours and suggest the upregulation of ASCL2 and methylation patterns of IGF2 promoters in driving hepatoblast carcinogenesis.

Background In Japan, allogeneic hematopoietic stem cell transplantation is widely performed for recurrent neuroblastomas. This retrospective study aimed to investigate the prognosis of recurrent neuroblastoma in Japan and explore the effectiveness of allogeneic hematopoietic stem cell transplantation. Methods Clinical characteristics and data on the treatment of patients with high-risk neuroblastoma who experienced first progression between 2003 and 2010 after attaining complete remission or partial remission were collected from hospitals participating in the Japanese Neuroblastoma Research Group. Results Data from 61 patients who fulfilled these criteria were collected. The median interval from disease onset to first progression was 19 months (range, 7–65 months), whereas the median observation time of the surviving patients was 18 months (range, 1–69 months). All patients were treated with chemotherapy, where 22 and 3 patients received allogeneic and autologous hematopoietic stem cell transplantation, respectively. Seven patients were alive in second complete remission, and 39 died, including two in complete remission. The 3-year progression-free survival and overall survival rates were 15.3% (SE: 6.1%) and 16.9% (SE: 6.5%), respectively. For patients with allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 28.3% (standard error, 12.0%) and 24.3% (standard error, 11.5%), respectively, and for patients without allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 6.0% (standard error 5.5%) and 12.0% (standard error 7.6%), respectively. The duration of initial remission (≥ 18 months) and implementation of allogeneic hematopoietic stem cell transplantation were independently predictive of progression-free survival (P = 0.002 and P = 0.017), whereas for overall survival, only allogeneic hematopoietic stem cell transplantation was predictive (P = 0.012). Conclusion Although allogeneic hematopoietic stem cell transplantation contributed to some improvement in prognosis, it was insufficient.

PURPOSEWe report here the outcomes and late effects of the Japanese Study Group for Pediatric Liver Tumors (JPLT)-2 protocol, on the basis of cisplatin-tetrahydropyranyl-adriamycin (CITA) with risk stratification according to the pretreatment extent of disease (PRETEXT) classification for hepatoblastoma (HB).PATIENTS AND METHODSFrom 1999 to 2012, 361 patients with untreated HB were enrolled. PRETEXT I/II patients were treated with up-front resection, followed by low-dose CITA (stratum 1) or received low-dose CITA, followed by surgery and postoperative chemotherapy (stratum 2). In the remaining patients, after 2 cycles of CITA, responders received the CITA regimen before resection (stratum 3), and nonresponders were switched to ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC; stratum 4). Intensified chemotherapeutic regimens with autologous hematopoietic stem-cell transplantation (SCT) after resection were an optional treatment for patients with refractory/metastatic disease.RESULTSThe 5-year event-free and overall survival rates of HB patients were 74.2% and 89.9%, respectively, for stratum 1, 84.8% and 90.8%%, respectively, for stratum 2, 71.6% and 85.9%%, respectively, for stratum 3, and 59.1% and 67.3%%, respectively, for stratum 4. The outcomes for CITA responders were significantly better than those for nonresponders, whose outcomes remained poor despite salvage therapy with a second-line ITEC regimen or SCT. The late effects, ototoxicity, cardiotoxicity, and delayed growth, occurred in 61, 18, and 47 patients, respectively. Thirteen secondary malignant neoplasms (SMNs), including 10 leukemia, occurred, correlating with higher exposure to pirarubicin and younger age at diagnosis.CONCLUSIONThe JPLT-2 protocol achieved up-front resectability in PRETEXT I/II patients with no annotation factors, and satisfactory survival in patients who were CITA responders in the remaining patients. However, outcomes for CITA nonresponders were unsatisfactory, despite therapy intensification with ITEC regimens and SCT. JPLT-2 had a relatively low incidence of cardiotoxicity but high rates of SMNs.

Background: Esophageal leiomyomatosis (EL) is a rare benign tumor defined as a diffuse form of marked hypertrophy in the muscular layer of the esophagus. Relapses have been reported as a result of misdiagnoses of other tumors or achalasia, followed by inappropriate surgical intervention. The endoscopic approach is preferred because of its lesser degree of invasiveness and better cosmesis; however, its effectiveness for treatment of EL is unclear because these tumors are bulkier and more extensive than those in other esophageal diseases. Case presentation: We treated an 11-year-old girl who had been experiencing progressive dysphagia, vomiting, and coughing during sleep since the age of 4 years and was correctly diagnosed with EL using computed tomography and endoscopic ultrasonography. She was successfully treated with total minimally invasive esophagectomy (MIE), combining thoracoscopy and laparoscopy, in the prone position, without any complications or recurrence of symptoms. To our knowledge, this is the first case report of MIE for EL. A review of 84 EL cases (including the present case) revealed a rate of accurate preoperative diagnosis of only 23.8%. Esophagectomy should be employed because the recurrence rate of the non-esophagectomy cases, involving myotomy and tumorectomy, was significantly higher than that of the esophagectomy cases (57.9% vs. 7.7%, p = 0.002). Among 11 relapse cases in the non-esophagectomy cases, esophagectomy was performed in eight. Among the four relapse cases in the esophagectomy group, additional esophagectomy was necessary in three because of insufficient resection of the tumors at the primary esophagectomy. Conclusions: Multimodal imaging contributes to accurate diagnosis and assessment of the extent of the tumors, thus leading to the selection of the appropriate surgical intervention, i.e., radical esophagectomy. Total MIE in the prone position provides excellent exposure of the operative fields; our experience suggests that total MIE is beneficial for EL, as it is for other esophageal tumors. Keywords: Esophageal leiomyomatosis, Minimally invasive esophagectomy, Prone position, Achalasia, Case report, Review of literature

Duodenal duplication cyst is not a common congenital anomaly and the pathophysiology may become very complicated if the cyst is situated at the ampulla of Vater. Here we report a very rare female case of duodenal duplication cyst at the ampulla of Vater, which caused acute pancreatitis due to massive protein plaques in the pancreatic duct. She had a past history of double duodenal atresia and underwent surgery as a neonate. The correct diagnosis could not be determined before the second operation at four years of age and the exact pathophysiology finally became apparent during the operation with a contrast medium study and duodenotomy. We discuss the complicated clinical features and diagnostic and treatment procedures before and during the operation.

The outcome of multimodal therapy for localized bladder rhabdomyosarcoma is quite good in terms of morbidity, and conservative surgery is generally recommended. However, in cases originating in the bladder neck, tumorectomy or partial cystectomy has adverse effects on bladder function. A 2-year-old girl underwent transurethral resection of a bladder tumor (TUR-BT), chemotherapy consisting of vincristine, actinomycin-D, and cyclophosphamide, and radiotherapy. She was in remission for 3 years when frequent urination became evident. Her bladder capacity and compliance were low; however, her urinary symptom was controlled using anticholinergic medication. Accordingly, TUR-BT could be an optional approach for bladder rhabdomyosarcoma. Keywords: Rhabdomyosarcoma, Transurethral resection, Conservative surgery

A rare pediatric case of pancreaticobiliary maljunction (PBM) with pancreas divisum is reported. The case showed extremely rare arrangement of the biliary tree and pancreatic duct; the common channel usually seen in PBM did not exist and the common bile duct was connected to the dorsal pancreatic duct via a dilated intermediary duct, in which a large protein plug had formed. The common bile duct was not dilated at all. All of these anomalies may have been caused by abnormal development of the ventral and dorsal pancreatic ducts at an early gestational age.We report a very rare pediatric case of pancreaticobiliary maljunction (PBM) complicated with pancreas divisum. In this case, the common bile duct showed a normal caliber and it was connected to the dorsal pancreatic duct through an intermediary dilated duct, which contained a protein plug that dammed up bile and pancreatic juice flow. This anomaly is very similar to type IIIc3 choledochal cyst, whose classification was addressed by Komi et al. (1), but it differed in the following point; in our case, the common bile duct did not connect to the duodenum through the ampulla of Vater (the common channel was absent) and bile was drained to the duodenum through Santorini duct. These quite rare anomalies might have been caused in the fetus by some kind of maldevelopment of the ventral and dorsal pancreatic ducts. Keywords: Pancreaticobiliary maljunction, Pancreas divisum, Pancreatitis

BACKGROUND Genetic hallmark of atypical teratoid/rhabdoid tumor (AT/RT) is loss-of-function variants or deletions in SMARCB1 gene on 22q11.2 chromosome, which is common to extracranial malignant rhabdoid tumors (MRT). Previous studies demonstrated that approximately one-thirds of AT/RT and extracranial MRT patients harbored germline SMARCB1 variants as the rhabdoid tumor predisposing syndrome. We studied herein intensive analysis of the SMARCB1 gene in AT/RT and extracranial MRT patients focusing on prevalence of germline genetic variants. PROCEDURE: In total, 16 patients were included. Both tumor-derived DNA and germline DNA were obtained from all patients. First, screening for SMARCB1 alterations in the tumor specimens was done by direct sequencing, ddPCR and SNP array analysis. Then, analysis of germline DNA samples focusing on the genomic abnormalities detected in the paired tumors in each case was performed. RESULTS In eight of 16 cases (50%), genomic alterations observed in the tumor-derived DNA were also detected in the germline DNA. It is worth noting that three patients had germline mosaicism. Two of three patients had mosaic deletion, including SMARCB1 region, and the average copy number of the deleted region in the SMARCB1 gene in the germline was 1.60 and 1.76. For another patient, the fraction of SMARCB1 variants in normal cells was as low as 1.7%. CONCLUSIONS Approximately half the MRT cases in this study had SMARCB1 germline alterations. Considering the presence of low-frequency mosaicisms which conventional methods might overlook, inherited germline variants in predisposition genes are more important than previously assumed for the pathogenesis of pediatric cancers.

Congenital high airway obstruction syndrome (CHAOS) is a rare congenital anomaly and the most common etiology is laryngeal atresia. Recently, an increasing number of cases have survived due to prenatal diagnosis and pre- and peri-natal care including ex-utero intrapartum treatment (EXIT). More than 100 cases of CHAOS have been reported, and about half of them were complicated with associated anomalies. Here we report a very rare case of prenatally diagnosed CHAOS (laryngeal atresia) complicated with esophageal atresia, tracheoesophageal fistula (TEF) and duodenal atresia, and the patient was saved by EXIT. This combination of anomalies resulted in a very confusing prenatal diagnosis with unique imaging feature of the fetus.

Pleuropulmonary blastoma (PPB) is a rare malignant mesenchymal tumor. It is classified into 3 subgroups, and PPB type 1 is known to be a cystic lesion with good prognosis. Here, we report a case of PPB type 1 seen in a 1-year-old girl whose pulmonary cystic lesion had been followed-up as a congenital pulmonary airway malformation since neonate. The cyst had been diagnosed as congenital pulmonary airway malformation before surgery but the final diagnosis was type 1 PPB. The tumor had a somatic mutation in exon 25 of the DICER 1 gene whereas no germline mutation was found.

Summary Background Comparative assessment of treatment results in paediatric hepatoblastoma trials has been hampered by small patient numbers and the use of multiple disparate staging systems by the four major trial groups. To address this challenge, we formed a global coalition, the Children's Hepatic tumors International Collaboration (CHIC), with the aim of creating a common approach to staging and risk stratification in this rare cancer. Methods The CHIC steering committee—consisting of leadership from the four major cooperative trial groups (the International Childhood Liver Tumours Strategy Group, Children's Oncology Group, the German Society for Paediatric Oncology and Haematology, and the Japanese Study Group for Paediatric Liver Tumours)—created a shared international database that includes comprehensive data from 1605 children treated in eight multicentre hepatoblastoma trials over 25 years. Diagnostic factors found to be most prognostic on initial analysis were PRETreatment EXTent of disease (PRETEXT) group; age younger than 3 years, 3–7 years, and 8 years or older; α fetoprotein (AFP) concentration of 100 ng/mL or lower and 101–1000 ng/mL; and the PRETEXT annotation factors metastatic disease (M), macrovascular involvement of all hepatic veins (V) or portal bifurcation (P), contiguous extrahepatic tumour (E), multifocal tumour (F), and spontaneous rupture (R). We defined five clinically relevant backbone groups on the basis of established prognostic factors: PRETEXT I/II, PRETEXT III, PRETEXT IV, metastatic disease, and AFP concentration of 100 ng/mL or lower at diagnosis. We then carried the additional factors into a hierarchical backwards elimination multivariable analysis and used the results to create a new international staging system. Results Within each backbone group, we identified constellations of factors that were most predictive of outcome in that group. The robustness of candidate models was then interrogated using the bootstrapping procedure. Using the clinically established PRETEXT groups I, II, III, and IV as our stems, we created risk stratification trees based on 5 year event-free survival and clinical applicability. We defined and adopted four risk groups: very low, low, intermediate, and high. Interpretation We have created a unified global approach to risk stratification in children with hepatoblastoma on the basis of rigorous statistical interrogation of what is, to the best of our knowledge, the largest dataset ever assembled for this rare paediatric tumour. This achievement provides the structural framework for further collaboration and prospective international cooperative study, such as the Paediatric Hepatic International Tumour Trial (PHITT). Funding European Network for Cancer Research in Children and Adolescents, funded through the Framework Program 7 of the European Commission (grant number 261474); Children's Oncology Group CureSearch grant contributed by the Hepatoblastoma Foundation; Practical Research for Innovative Cancer Control and Project Promoting Clinical Trials for Development of New Drugs and Medical Devices, Japan Agency for Medical Research; and Swiss Cancer Research grant.

We report here a male case of autonomous adenoma (AA) in the thyroid that was caused by a somatic heterozygous mutation in the thyroid-stimulating hormone receptor (TSHR) gene at codon 453, which encodes the second transmembrane domain of the protein. This activating mutation of TSHR induced an increase in cell proliferation that resulted in the development of a thyroid goiter. The patient showed symptoms of hyperthyroidism since perinatal age and developed a thyroid goiter at the age of 1 year. Technetium scan showed a hot spot in the right lobe and weak tracer uptake in the left lobe of the thyroid, which were typical findings in AA. He underwent right hemi-thyroidectomy at 1 year and 10 months of age, and attained complete cure after surgery. Keywords: Thyroid-stimulating hormone receptor, Autonomous adenoma, Thyroidectomy

Intensive analysis of the SMARCB1 gene in malignant rhabdoid tumors (MRT) revealed eight of 16 patients with constitutional genetic variants. Three patients had mosaicism of deletion/variant of the SMARCB1 gene, which conventional methods might overlook. The prevalence of cancer predisposition in MRT may thus be higher than previously reported.

Fluorescence-guided surgery with indocyanine green (ICG) for malignant hepatic tumors has been gaining more attention with technical advancements. Since hepatoblastomas (HBs) possess similar features to hepatocellular carcinoma, fluorescence-guided surgery can be used for HBs, as aggressive surgical resection, even for distant metastases of HBs, often contributes positively to R0 (complete) resection and subsequent patient survival. Despite a few caveats, fluorescence-guided surgery allows for the more sensitive identification of lesions that may go undetected by conventional imaging or be invisible macroscopically. This leads to precise resection of distant metastatic tumors as well as primary liver tumors.

Purpose: Treatment outcomes for hepatoblastoma have improved markedly in the contemporary treatment era, principally due to therapy intensification, with overall survival increasing from 35% in the 1970s to 90% at present. Unfortunately, these advancements are accompanied by an increased incidence of toxicities. A detailed analysis of age as a prognostic factor may support individualized risk-based therapy stratification.Methods: We evaluated 1605 patients with hepatoblastoma included in the CHIC database to assess the relationship between event-free survival (EFS) and age at diagnosis. Further analysis included the age distribution of additional risk factors and the interaction of age with other known prognostic factors.Results: Risk for an event increases progressively with increasing age at diagnosis. This pattern could not be attributed to the differential distribution of other known risk factors across age. Newborns and infants are not at increased risk of treatment failure. The interaction between age and other adverse risk factors demonstrates an attenuation of prognostic relevance with increasing age in the following categories: metastatic disease, AFP < 100 ng/mL, and tumor rupture.Conclusion: Risk for an event increased with advancing age at diagnosis. Increased age attenuates the prognostic influence of metastatic disease, low AFP, and tumor rupture. Age could be used to modify recommended chemotherapy intensity.

Anti-ganglioside GD2 antibodies mainly work through antibody-dependent cellular cytotoxicity (ADCC) and have demonstrated clinical benefit for children with neuroblastoma. However, high-risk neuroblastoma still has a high recurrence rate. For further improvement in patient outcomes, ways to maximize the cytotoxic effects of anti-GD2 therapies with minimal toxicity are required. Activated invariant natural killer T (iNKT) cells enhance both innate and type I acquired anti-tumor immunity by producing several kinds of cytokines. In this report, we investigated the feasibility of combination therapy using iNKT cells and an anti-GD2 antibody. Although some of the expanded iNKT cells expressed natural killer (NK) cell markers, including FcγR, iNKT cells were not directly associated with ADCC. When co-cultured with activated iNKT cells, granzyme A, granzyme B and interferon gamma (IFNγ) production from NK cells were upregulated, and the cytotoxicity of NK cells treated with anti-GD2 antibodies was increased. Not only cytokines produced by activated iNKT cells, but also NK-NKT cell contact or NK cell-dendritic cell contact contributed to the increase in NK cell cytotoxicity and further IFNγ production by iNKT cells and NK cells. In conclusion, iNKT cell-based immunotherapy could be an appropriate candidate for anti-GD2 antibody therapy for neuroblastoma.

Contemporary state-of-the-art management of cancer is increasingly defined by individualized treatment strategies. For very rare tumors, like hepatoblastoma, the development of biologic markers, and the identification of reliable prognostic risk factors for tailoring treatment, remains very challenging. The Children's Hepatic tumors International Collaboration (CHIC) is a novel international response to this challenge.Four multicenter trial groups in the world, who have performed prospective controlled studies of hepatoblastoma over the past two decades (COG; SIOPEL; GPOH; and JPLT), joined forces to form the CHIC consortium. With the support of the data management group CINECA, CHIC developed a centralized online platform where data from eight completed hepatoblastoma trials were merged to form a database of 1605 hepatoblastoma cases treated between 1988 and 2008. The resulting dataset is described and the relationships between selected patient and tumor characteristics, and risk for adverse disease outcome (event-free survival; EFS) are examined.Significantly increased risk for EFS-event was noted for advanced PRETEXT group, macrovascular venous or portal involvement, contiguous extrahepatic disease, primary tumor multifocality and tumor rupture at enrollment. Higher age (≥ 8 years), low AFP (100 ng/ml) and metastatic disease were associated with the worst outcome.We have identified novel prognostic factors for hepatoblastoma, as well as confirmed established factors, that will be used to develop a future common global risk stratification system. The mechanics of developing the globally accessible web-based portal, building and refining the database, and performing this first statistical analysis has laid the foundation for future collaborative efforts. This is an important step for refining of the risk based grouping and approach to future treatment stratification, thus we think our collaboration offers a template for others to follow in the study of rare tumors and diseases.

Esophageal duplication cyst is the second most common type of duplication cyst in the alimentary tract (10–15%). However, most of these cysts occur in the mediastinal part of the esophagus and cervical esophageal duplication cyst is extremely rare. Only approximately 20 pediatric cases have been reported in the English literature. We report the case of an infant who had suffered from prolonged wheezing since birth and was finally diagnosed with esophageal duplication cyst by ultrasonography and CT examination. The cyst had a common muscular layer with the normal esophagus and mucosal stripping was performed.

A 2-month-old boy who had undergone radical surgery for esophageal atresia at 10 h after birth started to present intermittent choking and coughing during suckling and sleep. Upper gastrointestinal series revealed recurrent tracheoesophageal fistula at the Th3 level. Enteral feeding via trans-jejunal tube was started and reoperation was performed at 10 months old, when he weighed 9.6 kg (+0.56SD). Thoracotomy was performed after inserting the guidewire into the fistula under both bronchoscopy and gastroscopy. The fistula was resected and both esophageal and tracheal ends were sutured. Part of the thymus was obtained and the free thymic fat pad (FTFP) was interposed between sutured sites along with the application of fibrin-glue to the affected area to prevent re-recurrence. Postoperative course was uneventful and computed tomography (CT) at 1 month following the operation demonstrated the residual FTFP. FTFP can be a feasible, useful, and effective option for interposition in recurrent TEF surgery, compared to conventional pedicled or free tissue.