Background/aims: Congenital hyperinsulinism (CHI) is a heterogeneous disease most frequently caused by KATP-channel (ABCC8 and KCNJ11) mutations, with neonatal or later onset, variable severity, and with focal or diffuse pancreatic involvement as the two major histological types. CHI confers a high risk of neurological impairment, however sparsely studied in larger patient series. We assessed the neurodevelopmental outcome in children with CHI at follow-up in a mixed international cohort. Methods: In two hyperinsulinism expert centers, 75 CHI patients were included (Russian, n= 33, referred non-Scandinavian, treated in Denmark n=27, Scandinavian, n=15). Hospital files were reviewed. At follow-up, neurodevelopmental impairment was defined as Bayley-III or Movement ABC-2 score 5 days; OR 4.0 (1.0-16.6), trend p=0.05. In multivariate analysis (n=31) for early predictors with exclusion of brain MRI, treatment delay from first symptom to expert center >5 days conferred a significantly increased risk of neurodevelopment impairment, adjusted OR (aOR) 15.6 (1.6-146.7), p=0.016, while lowest blood glucose ≤1 mmol/L had a trend towards increased risk, aOR 3.5 (1.1-14.3), p=0.058. No associations for early vs. late disease onset, KATP-channel mutations, disease severity, focal vs. diffuse disease, or age at follow-up were seen in uni- or multivariate analysis. Conclusion: Not only very low blood glucose, but also insufficient treatment as expressed by delay until expert center hospitalization increased the risk of neurodevelopmental impairment. This novel finding calls for improvements in spread of knowledge about CHI among health care personnel and rapid contact with an expert CHI center on suspicion of CHI.

Purpose Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F–fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3-octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI. Methods PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV_max) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard. Results Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85–1); specificity of 0.96 (0.82–0.99). The optimal 18F-DOPA PET SUV_max ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV_max cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93–1) for 18F-DOPA PET vs. 0.71 (0.43–0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively. Conclusion 18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged.

Background: Insulinomas are very rare in childhood with sparse knowledge on the clinical aspects and the presence of Multiple Endocrine Neoplasia type 1 (MEN1).Methods: We conducted a retrospective review of patients diagnosed with insulinoma between 1995 and 2021, presenting to one referral centre in Russia. Clinical, biochemical, genetic, imaging and histological data were collected. In addition, follow-up and family data were obtained.Results: A total of twenty-two children aged 5 to 16 years were identified. The median (range) gap between the first hypoglycaemia symptoms and diagnosis was 10 (1–46) months. Twelve children (55%) were misdiagnosed to have epilepsy and were treated with anticonvulsants before hypoglycemia was revealed. Contrast enhanced MRI and/or CT were accurate to localize the lesion in 82% (n=18). Five patients (23%) had multiple pancreatic lesions. All children underwent surgical treatment. The median (range) diameter of removed tumors was 1.5 (0.3-6) cm. Histopathological studies confirmed the presence of insulinoma in all cases. Immunohistochemical studies revealed G2 differentiation grade in 10 out of 17 cases. Two patients were diagnosed with metastatic insulinoma. One of them had metastases at the time of insulinoma diagnosis, while the other was diagnosed with liver metastases eight years after the surgery. Eight children (36%) were found to carry MEN1 mutations, inherited n=5, de novo n=1, no data, n=2. Children with MEN1 had significantly higher number of pancreatic tumors compared to sporadic cases. All of them developed additional MEN1 symptoms during the following 2-13 years. In the five patients with inherited MEN1, seven family members had hitherto undiscovered MEN1 manifestations.Conclusions: In this large cohort of children with rare pediatric insulinomas, MEN1 syndrome and G2 tumors were frequent, as well as hitherto undiscovered MEN1 manifestations in family members. Our data emphasize the need of genetic testing in all children with insulinoma and their relatives, even in the absence of any other features, as well as the importance of a prolonged follow-up observation.

Background: Idiopathic postprandial hyperinsulinaemic hypoglycaemia (PPHH) has rarely been reported in the paediatric age. The objective of this study was to describe the clinical characteristics, diagnosis and management in a group of children with PPHH.Methods: Six children (three females) with a mean follow-up of 3.5±3.0 years at a single tertiary paediatric hospital. All had 24-h blood glucose monitoring, diagnostic fast and prolonged oral glucose tolerance test (OGTT). Follow-up included: 24-h blood glucose monitoring or continuous glucose monitoring system, prolonged OGTT and/or mixed meal (MM) test.Results: Age at diagnosis ranged from 5.4 to 15.7 years and auxology parameters were within normal range in all subjects. All the children had a normal fasting tolerance for age. Prolonged OGTT demonstrated symptomatic hypoglycaemia after 120 min in all the patients with simultaneous detectable serum insulin concentration. Acarbose was tried in three patients, having a positive effect on glycaemic and symptom control, but due to side effects, only two patients continued acarbose in the long run. Diazoxide proved to be beneficial in one patient. The rest of the patients were managed with frequent feeds but despite this, prolonged OGTT/MM demonstrated on-going PPHH.Conclusions: Prolonged OGTT is necessary to diagnose PPHH in children. Acarbose is beneficial in children with PPHH, although not well tolerated. Patients managed exclusively on frequent feeds demonstrated persistent hypoglycaemia on OGTT. The underlying cause of the PPHH in these patients remains unknown.

BACKGROUND: Congenital hyperinsulinism (CHI) is a severe disease with a high risk of complications including neurological deficit. Persistent hypoglycemia in patients with focal form of CHI can not be managed with medical treatment in 96.4% of cases, what subsequently leads to surgical treatment. Currently, there is a lack of information regarding patients with focal form of CHI. This study is aimed at finding better approaches for diagnosis and treatment of patients with focal form of CHI. AIMS: To study clinical, genetic and PET/CT findings of the focal form of CHI in Russian group of patients. MATERIALS AND METHODS: The observational research included all patients with a histologically confirmed focal form of CHI, who were admitted to Endocrinology Research Centre during the period from January 2008 to January 2019. A statistical analysis of clinical data, genotype, and positron emission tomography (PET) with 18F-dihydroxyphenylalanine (18F-DOPA) was performed. The median follow-up was 18 months. RESULTS: The study included 31 patients with focal CHI (14 boys, 45.2%). All patients had a neonatal presentation of the disease and demanded high levels of continuous glucose infusion to maintain euglycemia. The difference between the age of hypoglycemia presentation and the age of diagnosis ranged from 1 day to 3.9 months. In all cases, diazoxide was found to be ineffective. However, in 9 patients, it was possible to withdraw continuous glucose infusion and maintain euglycemia using octreotide in the preoperative period. A molecular genetic study allowed us to detect diverse pathogenic variants in ABCC8 and KCNJ11 genes in 30 patients. According to PET data with 18F-DOPA, the pancreatic index (PI) varied widely from 1.16 to 3.59. After partial resection of the pancreatic region with insulin hypersecretion, all patients showed complete recovery. CONCLUSIONS: The focal form of CHI is a severe condition with high prevalence of neurological complications. For preoperative diagnosis of the morphological form of the disease, it is necessary to conduct genetic analysis and radionuclide studies. Solely evaluation of mathematical parameters in 18F-DOPA PET without taking into account the visual data and the results of genetic analysis does not allow establishing the robust diagnosis. Timely diagnosis, identification of risk factors, and prevention of complications of persistent hypoglycemia are important tasks for clinicians.

A 26-year-old female with the classic major and minor components of autoimmune polyglandular syndrome type 1 was diagnosed as having pure red cell aplasia. Treatment with 1.5 g/d mycofenolate mofetil for 3 months failed to restore erythroid production. Treatment with cyclosporine A produced a good partial response but led to renal toxicity and was therefore substituted with cyclophosphamide, which had a good partial effect and lasted for 18 months. The relapse of anemia was not observed during the 6-month follow-up period after the cessation of treatment.