Integration of genomic analysis and transcript expression of ABCC8 and KCNJ11 in focal form of congenital hyperinsulinism.

Background: The focal form of CHI is caused by an autosomal recessive pathogenic variant affecting the paternal homologue of genes ABCC8 or KCNJ11 and a second somatic event specifically occurring in the affected islet of Langerhans. The approach of this study was to integrate the genetic changes occurring in pancreatic focal lesions of CHI at the genomic and transcriptional level. Research Design and Methods: Patients receiving therapeutic surgery and with proven ABCC8 or KCNJ11 pathogenic variants were selected and analyzed for loss of heterozygosity (LOH), changes in copy number and uniparental disomy (UPD) on the short am of chromosome 11 by molecular microarray analysis and methylation-specific MLPA. Gene expression was analyzed by RT-PCR and Massive Analysis of cDNA Ends (MACE). Results: Both genes, ABCC8 and KCNJ11, are located in proximity to the Beckwith-Wiedemann (BWS) imprinting control region on chromosome 11p15. Somatic paternal uniparental isodisomy (UPD) at chromosome 11p was identified as second genetic event in focal lesions resulting in LOH and monoallelic expression of the mutated ABCC8/KCNJ11 alleles. Of five patients with samples available for microarray analysis, the breakpoints of UPD on chromosome 11p were different. Samples of two patients were analyzed further for changes in gene expression. Profound downregulation of growth suppressing genes CDKN1 and H19 was detected in focal lesions whereas growth promoting gene ASCL2 and pancreatic transcription factors of the endocrine cell lineage were upregulated. Conclusions: Paternal UPD on the short arm of chromosome 11 appears to be the major second genetic event specifically within focal lesions of CHI but no common breakpoint for UDP can be delineated. We show for the first time upregulation of growth promoting ASCL2 (achaete-scute homolog 2) suggestive of a driving factor in postnatal focal expansion in addition to downregulation of growth suppressing genes CDKN1C and H19.

Decision-Making in the Pediatric Emergency Department-A Survey of Guidance Strategies among Residents.

(1) Introduction: Working in an emergency department requires fast and straightforward decisions. Therefore, decision guidance represents an essential tool for successful patient-centered care. Beyond the residents' own knowledge and experience, printed books have been the primary source of information in the past. The aim of this study was to discover which strategies current residents use the most and to identify alternative quick reference strategies in the digital age. (2) Materials and Methods: This study analyzed the responses of a short questionnaire directed at 41 residents in a single pediatric emergency department (32 pediatric and 9 pediatric surgery residents) over a period of one month. (3) Results: Thirty-three (80.5%) residents answered the entire questionnaire. Strikingly, responses indicated that printed books are still pivotal in guiding decision-making. In addition, the acquisition of information via computers or smartphones plays an increasing role. However, the opinion and council of the attending physician is still of great value to the residents and is not to be underestimated. Overall, most of the residents would prefer to have access to a specially designed smartphone application. (4) Conclusions: Certainty and validity are essential in decision-making in a pediatric emergency department. Although printed books and attending physicians are still considered as reliable sources of information, internet-based information plays an increasing role. In order to provide the best up-to-date and most recent information, a validated and consistently updated smartphone application could be a useful option.

Correlation of PET-MRI, Pathology, LOH, and Surgical Success in a Case of CHI With Atypical Large Pancreatic Focus.

Congenital hyperinsulinism (CHI) is a rare cause of severe hypoglycemia in newborns. In focal CHI, usually one activity peak in fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography-magnetic resonance imaging (PET-MRI) indicates one focal lesion and its resection results in cure of the child. We present the case of a 5-month-old girl with CHI. Mutational screening of genes involved in CHI revealed a heterozygous pathogenic variant in the ABCC8 gene, which was not detectable in the parents. 18F-DOPA PET-MRI revealed 2 distinct activity peaks nearby in the pancreatic body and neck. Surgical resection of the tissue areas representing both activity peaks resulted in long-lasting normoglycemia that was proven by a fasting test. Molecular analysis of tissue samples from various sites provided evidence that a single second genetic hit in a pancreatic precursor cell was responsible for the atypical extended pancreatic lesion. There was a close correlation in the resected areas of PET-MRI activity with focal histopathology and frequency of the mutant allele (loss of heterozygosity) in the tissue. Focal lesions can be very heterogenous. The resection of the most affected areas as indicated by imaging, histopathology, and genetics could result in complete cure.

Operative Volume of Newborn Surgery in German University Hospitals: High Volume Versus Low Volume Centers.

INTRODUCTION: Adequate patient volume is essential for the maintenance of quality, meaningful research, and training of the next generation of pediatric surgeons. The role of university hospitals is to fulfill these tasks at the highest possible level. Due to decentralization of pediatric surgical care during the last decades, there is a trend toward reduction of operative caseloads. The aim of this study was to assess the operative volume of the most relevant congenital malformations at German academic pediatric surgical institutions over the past years. METHODS: Nineteen chairpersons representing university-chairs in pediatric surgery in Germany submitted data on 10 index procedures regarding congenital malformations or neonatal abdominal emergencies over a 3-year period (2015 through 2017). All institutions were categorized according to the total number of respective cases into "high," "medium," and "low" volume centers by terciles. Some operative numbers were verified using data from health insurance companies, when available. Finally, the ratio of cumulative case load versus prevalence of the particular malformation was calculated for the study period. RESULTS: From 2015 through 2017, a total 2,162 newborns underwent surgery for congenital malformations and neonatal abdominal emergencies at German academic medical centers, representing 51% of all expected newborn cases nationwide. The median of cases per center within the study period was 101 (range 18-258). Four institutions (21%) were classified as "high volume" centers, four (21%) as "medium volume" centers, and 11 (58%) as "low volume" centers. The proportion of patients operated on in high-volume centers varied per disease category: esophageal atresia/tracheoesophageal fistula: 40%, duodenal atresia: 40%, small and large bowel atresia: 39%, anorectal malformations: 40%, congenital diaphragmatic hernia: 56%, gastroschisis: 39%, omphalocele: 41%, Hirschsprung disease: 45%, posterior urethral valves: 39%, and necrotizing enterocolitis (NEC)/focal intestinal perforation (FIP)/gastric perforation (GP): 45%. CONCLUSION: This study provides a national benchmark for neonatal surgery performed in German university hospitals. The rarity of these cases highlights the difficulties for individual pediatric surgeons to gain adequate clinical and surgical experience and research capabilities. Therefore, a discussion on the centralization of care for these rare entities is necessary.

Technical aspects of paediatric robotic pancreatic enucleation based on a case of an insulinoma.

BACKGROUND: Insulinomas are rare insulin-producing pancreatic neuroendocrine tumours leading to severe episodes of hypoglycaemia. Surgery is the predominant curative therapy. METHODS: We report here the first paediatric case of an insulinoma of the pancreatic body resected completely robotically under ultrasound guidance in a 10-year-old male with multiple endocrine neoplasia type 1. The port set-up was adapted for the narrowed dimensions of the paediatric peritoneal space. We comment on technical key steps for the organ-preserving procedure that was performed in close proximity to critical anatomic structures, with supporting video. Preoperative diagnostics, including endoscopic ultrasound, to determine surgical management are highlighted. RESULTS: Following an uneventful post-operative course, the boy was discharged on day 11 with normalised glucose-metabolism. A pseudocyst developing after 4 weeks was treated with endoscopic stenting. CONCLUSIONS: The applicability of a robotic surgical system in limited space conditions such as found in the paediatric abdominal cavity is demonstrated here for pancreatic surgery.

Pasireotide treatment for severe congenital hyperinsulinism due to a homozygous ABCC8 mutation.

ABCC8 and KCJN11 mutations cause the most severe diazoxide-resistant forms of congenital hyperinsulinism (CHI). Somatostatin analogues are considered as secondline treatment in diazoxide-unresponsive cases. Current treatment protocols include the first-generation somatostatin analogue octreotide, although pasireotide, a second-generation somatostatin analogue, might be more effective in reducing insulin secretion. Herein we report the first off-label use of pasireotide in a boy with a severe therapy-resistant form of CHI due to a homozygous ABCC8 mutation. After partial pancreatectomy, hyperinsulinism persisted; in an attempt to prevent further surgery, off-label treatment with pasireotide was initiated. Short-acting pasireotide treatment caused high blood glucose level shortly after injection. Long-acting pasireotide treatment resulted in more stable glycemic control. No side effects (e.g., central adrenal insufficiency) were noticed during a 2-month treatment period. Because of recurrent hypoglycemia despite a rather high carbohydrate intake, the boy underwent near-total pancreatectomy at the age of 11 months. In conclusion, pasireotide treatment slightly improved glycemic control without side effects in a boy with severe CHI. However, the effect of pasireotide was not sufficient to prevent near-total pancreatectomy in this case of severe CHI.

Possible New Strategies for the Treatment of Congenital Hyperinsulinism.

Objective: Congenital hyperinsulinism (CHI) is a rare disease characterized by persistent hypoglycemia as a result of inappropriate insulin secretion, which can lead to irreversible neurological defects in infants. Poor efficacy and strong adverse effects of the current medications impede successful treatment. The aim of the study was to investigate new approaches to silence ß-cells and thus attenuate insulin secretion. Research Design and Methods: In the scope of our research, we tested substances more selective and more potent than the gold standard diazoxide that also interact with neuroendocrine ATP-sensitive K+ (KATP) channels. Additionally, KATP channel-independent targets as Ca2+-activated K+ channels of intermediate conductance (KCa3.1) and L-type Ca2+ channels were investigated. Experiments were performed using human islet cell clusters isolated from tissue of CHI patients (histologically classified as pathological) and islet cell clusters obtained from C57BL/6N (WT) or SUR1 knockout (SUR1-/-) mice. The cytosolic Ca2+ concentration ([Ca2+]c) was used as a parameter for the pathway regulated by electrical activity and was determined by fura-2 fluorescence. The mitochondrial membrane potential (ΔΨ) was determined by rhodamine 123 fluorescence and single channel currents were measured by the patch-clamp technique. Results: The selective KATP channel opener NN414 (5 µM) diminished [Ca2+]c in isolated human CHI islet cell clusters and WT mouse islet cell clusters stimulated with 10 mM glucose. In islet cell clusters lacking functional KATP channels (SUR1-/-) the drug was without effect. VU0071063 (30 µM), another KATP channel opener considered to be selective, lowered [Ca2+]c in human CHI islet cell clusters. The compound was also effective in islet cell clusters from SUR1-/- mice, showing that [Ca2+]c is influenced by additional effects besides KATP channels. Contrasting to NN414, the drug depolarized ΔΨ in murine islet cell clusters pointing to severe interference with mitochondrial metabolism. An opener of KCa3.1 channels, DCEBIO (100 µM), significantly decreased [Ca2+]c in SUR1-/- and human CHI islet cell clusters. To target L-type Ca2+ channels we tested two already approved drugs, dextromethorphan (DXM) and simvastatin. DXM (100 µM) efficiently diminished [Ca2+]c in stimulated human CHI islet cell clusters as well as in stimulated SUR1-/- islet cell clusters. Similar effects on [Ca2+]c were observed in experiments with simvastatin (7.2 µM). Conclusions: NN414 seems to provide a good alternative to the currently used KATP channel opener diazoxide. Targeting KCa3.1 channels by channel openers or L-type Ca2+ channels by DXM or simvastatin might be valuable approaches for treatment of CHI caused by mutations of KATP channels not sensitive to KATP channel openers.

Management of tumor rupture and abdominal compartment syndrome in an infant with bilateral high risk stage 4 neuroblastoma: A case report.

RATIONALE: Tumor rupture and bleeding at initial presentation of infants with neuroblastoma (NBL) is a rare, but life threatening condition and challenge in pediatric oncology. Here, we report successful multidisciplinary management of an abdominal compartment syndrome as a result of tumor rupture and bleeding in an infant with bilateral high risk stage 4 NBL. PATIENT CONCERNS: The patient was admitted to a cooperating hospital with vomiting, failure to thrive and a large mass in the abdomen and was then referred to our center. DIAGNOSES: Stage 4 NBL with MYC-N amplification and 1p36 deletion was diagnosed in an 11 months old girl. Due to rapid and massive tumor growth she developed abdominal compression with renal failure, severe bleeding, and tumor lysis syndrome (TLS). INTERVENTIONS: Surgical decompression by enterostomy, local, and systemic bleeding control with platelets and coagulation factors, antiinfective and TLS therapy were effective in stabilizing the patient's condition. This allowed initiation of the multimodal antineoplastic treatment according to protocol NB 2004. OUTCOMES: Mechanical ventilation was stopped after 11 days, the abdominal wall was closed 3 months after the start of therapy, and treatment according to the protocol be started and successfully completed. LESSONS: Only the immediate, coordinated multidisciplinary intervention managed to overcome the life-threatening abdominal compartment syndrome and its associated problems, eventually enabling successful curative treatment.

Tolerability, response and outcome of high-risk neuroblastoma patients treated with long-term infusion of anti-GD2 antibody ch14.18/CHO.

Immunotherapy with short term infusion (STI) of monoclonal anti-GD2 antibody (mAb) ch14.18 (4 × 25 mg/m2/d; 8-20 h) in combination with cytokines and 13-cis retinoic acid (RA) prolonged survival in high-risk neuroblastoma (NB) patients. Here, we investigated long-term infusion (LTI) of ch14.18 produced in Chinese hamster ovary cells (ch14.18/CHO; 10 × 10 mg/m2; 24 h) in combination with subcutaneous (s.c.) interleukin-2 (IL-2) in a single center program and report clinical response, toxicity and survival. Fifty-three high-risk NB patients received up to 6 cycles of 100 mg/m2 ch14.18/CHO (d8-17) as LTI combined with 6 × 106 IU/m2 s.c. IL-2 (d1-5; 8-12) and 160 mg/m2 oral RA (d19-32). Pain toxicity was documented with validated pain scores and intravenous (i.v.) morphine usage. Response was assessed in 37/53 evaluable patients following International Neuroblastoma Risk Group criteria. Progression-free (PFS) and overall survival (OS) was analyzed by the Kaplan-Meier method and compared to a matched historical control group from the database of AIEOP, the "Italian Pediatric Ematology and Oncology Association". LTI of ch14.18/CHO showed acceptable toxicity profile indicated by low pain scores, reduced i.v. morphine usage and low frequency of Grade ≥3 adverse events that allowed outpatient treatment. We observed a best response rate of 40.5% (15/37; 5 CR, 10 PR), 4-year (4 y) PFS of 33.1% (observation 0.1- 4.9 y, mean: 2.2 y) and a 4 y OS of 47.7% (observation 0.27 - 5.20 y, mean: 3.6 y). Survival of the entire cohort (53/53) and the relapsed patients (29/53) was significantly improved compared to historical controls. LTI of ch14.18/CHO thus shows an acceptable toxicity profile, objective clinical responses and a strong signal of clinical efficacy in NB patients.

Clowns in Paediatric Surgery: Less Anxiety and More Oxytocin? A Pilot Study.

Background Hospital stays and medical interventions are accompanied by worries and anxiety in children and parents. Recent studies show that hospital clowns may reduce anxiety and enhance well-being. However, so far studies are based solely on subjective measures and clowns are usually not integrated in medical routine. With this pilot study, we aim to provide both psychological and physiological evidence of positive effects of clowns' interventions in hospitalized children. Patients/Method In a consecutive randomized intervention-control group design with 31 children aged 4 to 13 years, 17 patients were accompanied by a clown prior to surgery or during ward round (intervention group) and 14 were not (control group). Saliva samples for oxytocin measurement were taken from all patients before hospitalization (T1) and prior to surgery or after ward round (T2). Self- and parents-reports were obtained at T1, T2 as well as at time of discharge from hospital (T3) regarding children's anxiety (STAI), worries and well-being. Clowns evaluated their success in cheering up the child. Health professionals were asked for their acceptance of clowns in hospitals. Results Children in the intervention group had lower anxiety ratings and a higher oxytocin concentration at T2 as compared with T1; the control group showed no changes. Parents rated the well-being of their children higher if their child had clown's contact and were more willing to recommend the hospital. The staff judged the clowns as helpful for patients. Discussion Consistent psychological and physiological results suggest the positive impact of a clown's intervention in hospitalized children.

The LXR Ligand T0901317 Acutely Inhibits Insulin Secretion by Affecting Mitochondrial Metabolism.

The role of liver X receptor (LXR) in pancreatic ß-cell physiology and pathophysiology is still unclear. It has been postulated that chronic LXR activation in ß-cells induces lipotoxicity, a key step in the development of ß-cell dysfunction, which accompanies type 2 diabetes mellitus. In most of these studies, the LXR ligand T0901317 has been administered chronically in the micromolar range to study the significance of LXR activation. In the current study, we have evaluated acute effects of T0901317 on stimulus-secretion coupling of ß-cells. We found that 10 µM T0901317 completely suppressed oscillations of the cytosolic Ca2+ concentration induced by 15 mM glucose. Obviously, this effect was due to inhibition of mitochondrial metabolism. T0901317 markedly depolarized the mitochondrial membrane potential, thus inhibiting adenosine triphosphate (ATP) production and reducing the cytosolic ATP concentration. This led in turn to a huge increase in KATP current and hyperpolarization of the cell membrane potential. Eventually, T0901317 inhibited glucose-induced insulin secretion. These effects were rapid in on-set and not compatible with the activation of a nuclear receptor. In vivo, T0901317 acutely increased the blood glucose concentration after intraperitoneal application. In summary, these data clearly demonstrate that T0901317 exerts acute effects on stimulus-secretion coupling. This observation questions the chronic use of T0901317 and limits the interpretation of results obtained under these experimental conditions.

Surgery in Focal Congenital Hyperinsulinism (CHI) - The "Hyperinsulinism Germany International" Experience in 30 Children.

OBJECTIVES: Results of surgery for focal CHI in 30 children PATIENTS AND METHODS: All showed an ABCC8 or KCNJ11 mutation. After PET/CT in 29 children and PET/MRT in 1 case, frozen-section guided resection was performed, in left-sided cases by laparoscopy. Mean age at surgery was 11.7 months (2-49). RESULTS: In 28/30 children, the PET/CT or MRT correlated with histopathology. In two cases, a focal lesion was undectable; one of these was cured, one not. In total, 24 children showed lesions with sizes of 5-12 mm. All were cured instantly. In four children with huge lesions in the pancreatic head, pathological cells remained at the resection margins. One child was cured instantly, two children after a 2nd surgery, and one child was not cured, even after three surgeries. The overall cure rate was 93%. CONCLUSIONS: Imaging, surgical findings, histopathology and clinical outcome in surgery for focal CHI match in most, but not all cases.

Kidney protein profiling of Wilms' tumor patients by analysis of formalin-fixed paraffin-embedded tissue samples.

UNLABELLED: Wilms' tumor (nephroblastoma, WT) is the most frequent renal cancer in children. However, molecular details leading to WT have not been characterized sufficiently yet. Proteomic studies might provide new insights but are hampered by limited availability of fresh frozen tissue specimen. Therefore, we tested formalin-fixed paraffin-embedded (FFPE) tissue sections routinely collected for pathological inspection for their use in in-depth-proteomic analyses of WT samples in comparison to fresh frozen specimen. The overlap of the proteins identified was over 65%. Thus we used FFPE material from 7 patients for tandem mass spectrometry based comparison of the proteomes of WT and healthy renal tissues. We detected 262 proteins, which were differentially expressed in tumor compared to healthy renal tissue. The majority of these proteins displayed lower levels in the tumor tissue and only 30% higher levels. For selected candidates data were confirmed by immunohistochemical staining. Correlation analysis of blastemal proportions in WT and protein intensities revealed candidates for tumor stratification. CONCLUSION: This proof of principle proteomic study of FFPE tissue sections from WT patients demonstrates that these archived tissues constitute a valuable resource for larger in-depth proteomic studies to identify markers to follow chemotherapy efficiency or for stratification of tumor subtypes.

Long-term culture and functionality of pancreatic islets monitored using microelectrode arrays.

Extracellular recording of the glucose-induced electrical activity of mouse islets of Langerhans on microelectrode arrays (MEAs) is an innovative and powerful tool to address beta-cell (patho-)physiology. In a dual approach we tested whether this technique can detect concentration-dependent drug effects as well as characterize alterations in beta-cell activity during prolonged culture. First we established conditions that allow long-term investigation of beta-cell function by recording electrical activity. The results provide the first measurements of beta-cell membrane potential oscillations of individual murine islets during long-term culture. Oscillations were recorded for up to 34 days after islet isolation. Importantly, the glucose dependence of electrical activity did not change over a period of one month. Thus we can follow electrophysiological changes of individual islets induced by alterations in the beta-cell environment over weeks. Second, we used the MEA technique to assay beta-cell damage induced by oxidative stress and to evaluate appropriate protection mechanisms. Oxidative stress plays a key role in the development of type 2 diabetes mellitus (T2DM). Examination of the acute effects of H2O2 on electrical activity showed that the oxidant reduced the electrical activity in a concentration-dependent manner. The superoxide dismutase mimetic, tempol, protected against the detrimental effects of H2O2. In conclusion, we demonstrated that MEA recordings can be used to address disease-related mechanisms and protective interventions in beta-cells. In the future, this fundamental work should enable the monitoring of the electrical activity of islets of Langerhans under controlled ex vivo conditions including long-term exposure to oxidative stress, glucolipotoxicity, and other diabetes-inducing agents.

Clinical and genetic evaluation of patients with KATP channel mutations from the German registry for congenital hyperinsulinism.

Congenital hyperinsulinism (CHI) causes hypoglycemia due to irregular insulin secretion. In infants, a rapid diagnosis and appropriate management to avoid severe hypoglycemia is mandatory. CHI is a heterogeneous condition at the clinical and genetic level, and disease-causing genes have been identified in about half of the patients. The majority of mutations have been identified in the ABCC8 and KCNJ11 genes encoding subunits of the KATP channel responsible for two distinct histological forms. The diffuse form is caused by autosomal recessive or dominant inherited mutations, whereas the focal form is caused by a paternally transmitted recessive mutation and a second somatic event. We report on an unselected cohort of 136 unrelated patients from the German CHI registry. Mutations in either the ABCC8 or KCNJ11 gene were identified in 61 of these patients (45%). In total, 64 different mutations including 38 novel ones were detected in this cohort. We observed biparental (recessive) inheritance in 34% of mutation-positive patients, dominant inheritance in 11% and paternal transmission of a mutation associated with a focal CHI type in 38%. In addition, we observed inheritance patterns that do not exactly follow the classical recessive or dominant mode, further adding to the genetic complexity of this disease.

Spontaneous vesicoureteral reflux resolution in children: A ten-year single-centre experience.

BACKGROUND/AIM: To evaluate the spontaneous resolution rate in infants and young children with vesicoureteral reflux (VUR). PATIENTS AND METHODS: Paediatric patients with VUR treated in our hospital from January 2000 to December 2010 were retrospectively analyzed. Only patients with pretreatment and follow-up voiding cystourethrogram were included into the study. Treatment success was defined as complete VUR resolution. RESULTS: The resolution rate for infants less than 1 year of age was 38.6% (17 of 44 renal units). Renal units with mild-moderate VUR (I-III) had a resolution rate of 40% (12 of 30 renal units) compared to 35.7% (5 of 14 renal units) with severe grade (IV-V) VUR. The resolution rate for children over 1 year of age was 39,1% (9 of 23 renal units). Renal units with mild-moderate VUR (I-III) had a resolution rate of 42.9% (9 of 21 renal units) compared to 0% (0 of 2 renal units) with severe grade (IV-V) VUR. CONCLUSION: Infants less than 1 year of age with nonsymptomatic, mild, moderate or severe VUR have a spontaneous resolution rate of more than 35% and therefore should receive a primary conservative therapy. Children over 1 year of age with nonsymptomatic mild-moderate VUR (I-III) have a spontaneous resolution rate of about 40% and should receive primary conservative treatment as well.

Hepatitis in an infant treated with octreotide for congenital hyperinsulinism.

Congenital hyperinsulinism is characterized by hypoglycemia caused by several genetic disorders of inappropriate insulin secretion. Octreotide, an analogue of somatostatin, plays a major role in the pharmaceutical treatment of this condition. A 9-month-old infant treated with octreotide developed anicteric hepatitis with no other proven cause. After the discontinuation of this drug, the liver enzymes declined rapidly. Liver function tests should be followed in patients receiving octreotide.

Impact of magnetic resonance urography and ultrasonography on diagnosis and management of hydronephrosis and megaureter in paediatric patients.

BACKGROUND: (1) To evaluate the diagnostic value of magnetic resonance urography (MRU) in comparison with ultrasonography (US) to determine the extent of upper urinary tract dilation and (2) to evaluate the impact of MRU on therapy management. MATERIALS AND METHODS: From January 2005 to December 2010, paediatric patients with hydronephrosis or megaureter who underwent MRU in addition to standard work-up imaging were included. Data were retrospectively collected and analysed in comparison with the data obtained from results by US. RESULTS: Forty-five patients with upper urinary tract dilatation were included into the study. Twenty-six patients (58%) had a hydronephrosis and 19 patients (42%) presented with a megaureter. Diagnosis was established in all patients by multimodulary imaging work-up including micturating cysto-urethrography, MAG3 renography, US and MRU and could be confirmed in all patients who underwent surgery (n = 28). Hydronephrosis was detected in 26 of 26 patients by US (100% sensitivity) and in 25 of 26 patients (96%) by MRU (Not significant (n.s.)). Megaureter was detected in 17 of 19 patients (sensitivity 89%) by US and in 18 of 19 patients (sensitivity 95%) by MRU (n.s.). In all 45 patients, MRU had no impact on surgical or conservative management of hydronephrosis or megaureter. CONCLUSION: In our experience, MRU was not superior to US in detecting hydronephrosis or megaureter and had no impact on the surgical or conservative management of upper urinary tract dilation.

Mucoepidermoid carcinoma of the lung in a 6-year-old boy.

Primary malignant lung tumours, especially the mucoepidermoid cancer of the bronchus, are very uncommon in childhood. Obtaining the diagnosis might be difficult due to unspecific initial symptoms but early detection and treatment is crucial for a good long-term survival. Bronchoscopy is considered the "gold standard" for making the diagnosis. The recommended therapy for a mucoepidermoid lung cancer is sleeve lobectomy with favourable overall survival after complete resection. We report the case of a 6-year-old boy with a right-upper-lobe bronchus tumour. The histological examination revealed a low-grade mucoepidermoid carcinoma.

A rare case of an isolated triquetrum body fracture in a 14-year-old boy.

Isolated carpal fractures are uncommon injuries usually caused by a fall on the outstretched hand. The patient might present with non-specific clinical signs and X-ray diagnosis might be difficult due to bone overlay. An isolated triquetrum body fracture is an absolute rarity. The treatment is easy and the outcome excellent but if missed, degenerative changes with chronic pain and impaired movement might be the consequence.