OBJECTIVES:Posttransplant lymphoproliferative disorder is a consequential complication following solid-organ transplant, particularly associated with the Epstein-Barr virus. We studied a single center's cases of pediatric posttransplant lymphoproliferative disorder for a 7-year period and focused on incidence rates, anatomic sites involved, and correlation with clinical outcomes. We explored clinical features and treatment outcomes in patients with pediatric posttransplant lymphoproliferative disorder, with emphasis on patient survival and associated clinical ramifications. MATERIALS AND METHODS:This was a retrospective analysis of medical records from pediatric solid-organ transplant recipients (liver or kidney) at Baskent University Ankara Hospital Organ Transplantation Center between January 1, 2017, and January 1, 2024, approved by the Institutional Review Board (KA24/63). We identified cases based on pathology-confirmed persistent lymphadenopathy or tumorous lesions. Patient categorization distinguished between malignant and benign groups. Early posttransplant lymphoproliferative disorder was defined within the initial year after transplant. Epstein?Barr virus association was determined through in situ hybridization, and patient characteristics were reviewed comprehensively. RESULTS:In 7 years, 10 pediatric patients (9 liver transplants, 1 kidney transplant) were diagnosed with posttransplant lymphoproliferative disorder, with an incidence of 8.7% for pediatric liver transplants. Mean age at diagnosis was 46.4 months, and mean time from transplant to diagnosis was 21.2 months. The most common complaints at diagnosis included fever, lymphadenopathy, hepatosplenomegaly, dyspnea, and diarrhea. Treatment modalities included rituximab, immunosuppression reduction, intravenous immunoglobulin therapy, and chemotherapy (NHL Berlin-Frankfurt-Münster 90 protocols). All patients achieved remission (mean follow-up, 22.9 mo). CONCLUSIONS:Early diagnosis of posttransplant lymphoproliferative disorder is important, and rituximab with immunosuppression reduction is effective to achieve complete remission, particularly in early polymorphic cases. Despite challenges, all patients achieved remission, signaling improved outcomes in pediatric posttransplant lymphoproliferative disorder. Active monitoring of Epstein?Barr virus infection may further reduce posttransplant lymphoproliferative disorder complications in pediatric solid-organ transplant; hence, early diagnosis is crucial.

Aim Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare autoimmune disorder. Approximately half of the cases are associated with neuroblastoma in children. This study's aim is to review management of our cases with OMAS-associated neuroblastoma for treatment approach as well as long-term follow-up.Methods Age at onset of symptoms and tumor diagnosis, tumor location, histopathology, stage, chemotherapy, OMAS protocol, surgery, and follow-up period were evaluated retrospectively in six patients between 2007 and 2022.Results Mean age of onset of OMAS findings was 13.5 months and mean age at tumor diagnosis was 15.1 months. Tumor was located at thorax in three patients and surrenal in others. Four patients underwent primary surgery. Histopathological diagnosis was ganglioneuroblastoma in three, neuroblastoma in two, and undifferentiated neuroblastoma in one. One patient was considered as stage 1 and rest of them as stage 2. Chemotherapy was provided in five cases. The OMAS protocol was applied to five patients. Our protocol is intravenous immunoglobulin (IVIG) 1 g/kg/d for 2 consecutive days once a month and dexamethasone for 5 days (20 mg/m (2) /d for 1-2 days, 10 mg/m (2) /d for 3-4 days, and 5 mg/m (2) /d for the fifth day) once a month, alternatively by 2-week intervals. Patients were followed up for a mean of 8.1 years. Neuropsychiatric sequelae were detected in two patients.Conclusion In tumor-related cases, alternating use of corticosteroid and IVIG for suppression of autoimmunity as the OMAS protocol, total excision of the tumor as soon as possible, and chemotherapeutics in selected patients seem to be related to resolution of acute problems, long-term sequelae, and severity.

Purpose Medulloblastoma is one of the brain tumors with increased life expectancy due to improvements in treatment approaches. Besides the promising results, various undesirable effects can be encountered. This study’s aim is to review long-term follow-up outcomes of our cases with medulloblastoma. Methods Age at diagnosis, histological type of medulloblastoma, resection extension, chemotherapy and radiotherapy schemes, follow-up duration, and endocrinological, neuropsychiatric, cardiological, auditory, and visual examination results were evaluated in 20 patients diagnosed between 2007 and 2018 and followed 5 years and more. Results Twenty of 53 patients were included to the study. Eleven (55%) were male. Mean age at diagnosis was 6.95 years; mean age at the time of the study was 14 years. Mean follow-up time was 8.95 years. In terms of surgery, 14 (70%) were gross total, 1 (5%) was near total, and 2 (10%) were subtotal resection. In histopathological examination, 14 (70%) were classical medulloblastoma, 4 (20%) were desmoplastic medulloblastoma, and 1 (5%) was anaplastic medulloblastoma. With regard to endocrinological evaluation, 15 (75%) patients had hypothyroidism, 5 (25%) had growth hormone deficiency, 7 (35%) had clinical growth hormone deficiency, and 5 (25%) had sex hormone disorders. In neuropsychiatric examination, 11 (55%) patients had neurological sequelae, 18 (90%) patients had psychiatric issues, and 14 (70%) patients had two or more neuropsychiatric problems simultaneously. One (5%) patient had mitral valve insufficiency. Twelve patients (60%) had hearing loss. According to visual examination, 6 (30%) patients had refraction problem, 4 (20%) had cataract, and 1 (5%) had dry eye. Conclusion Careful monitoring of long-term side effects is important for improving the quality of life of medulloblastoma patients. Besides endocrinological and other somatic sequelae of the disease and treatment, increased neuropsychiatric problems showed us that only cure is not the issue while treating childhood medulloblastoma.

AIM: To reevaluate the medulloblastoma cases according to histomorphological and molecular features, and to investigate the relationship between the prognostic factors of the new WHO classification by applying Beta-catenin, YAP1, GAP1, p53, and INI1 antibodies immunohistochemically. MATERIAL and METHODS: This study includes 41 patients who have been diagnosed with medulloblastoma between 2007-2019 in pathology department. Immunohistochemically, p53, beta-catenin, YAP1, GAP1, and INI1 immune markers were applied, and the relationship between the results and the prognostic parameters was evaluated statistically. RESULTS: When 41 patients were classified into WHO medulloblastoma histological subtype groups according to histomorphological features, 22 (53.7%) patients were classified as classical type, 11 (26.8%) patients as desmoplastic nodular type, and 8 (19.5%) patients as large cell/anaplastic type medulloblastoma. According to their molecular characteristics, 14 (34.1%) patients were in the Non-WNT/SHH group, 5 (12.2%) patients were SHH mutant, 17 (41.5%) patients were SHH wild, and 5 (12.2%) patients were in the WNT active group. There was no statistically significant correlation between age, gender, tumor size, recurrence, Ki67 proliferation index with molecular types and histopathological types. CONCLUSION: In our study, metastasis at the time of diagnosis, histological large cell anaplastic type, immunohistochemical p53 positivity, molecular SHH mutant type were the statistically significant indicators of worse prognosis and shorter survival time.

Patient: Female, 6-month-old Final Diagnosis: Hyperinsulinemic hypoglycemia with abdominal teratoma Symptoms: Hypoglycemia Medication: — Clinical Procedure: Surgery removal Specialty: Endocrinology and Metabolic Objective: Unusual clinical course Background: Pediatric intraabdominal pancreatic teratomas have been rarely reported. This is the first case of severe hyper-insulinemic hypoglycemia in a 6-month-old infant secondary to an intraabdominal teratoma. The hypoglycemia resolved after surgical removal. Case Rreport: A 6-month-old infant was seen in a pediatric emergency department with complaints of lethargy and abnormal eye movements. She was diagnosed with hyperinsulinemic hypoglycemia and started on diazoxide. A CT and MRI of the abdomen revealed a 165×77×72 mm cyst with a 51×45×30 mm solid structure connecting to the wall of the cyst by a stalk, raising suspicion of a fetus in fetu. The mass had no connection to her pancreas. Following total excision of the intraabdominal mass, her hypoglycemia resolved. Histopathological examination showed immature fetal pancreatic tissue consistent with a mature teratoma. Whole exon sequencing of the infant’s peripheral blood showed a negative mutation of ABCC8 and presence of heterozygous variations of HNF1β and IRS1 genes. Conclusions: This is the first case report of an infant with severe hyperinsulinemic hypoglycemia secondary to a pancreatic teratoma. The heterozygous variations of HNF1β and IRS1 genes likely played a role in the embryogenesis, causing a pancreatic teratoma and hyperinsulinemic hypoglycemia.

Background/aim COVID-19 has become the biggest health problem of this century. It has been hypothesized that immunity against hepatitis A virus (HAV) may provide protection from COVID- 19. Materials and methods As of 10June 2020, the infection had spread to 213 countries, with 7.3 million people infected and 413,733 dead. This data was combined with the World Health Organization susceptibility classification on the worldwide prevalence of HAV, and the relationship between HAV susceptibility and COVID-19 mortality were analyzed. Results When the data from 213 countries were analyzed, it was found that there was a significant increasing trend in COVID-19 mortality rates by HAV susceptibility (P <0.001). Using a cut-off of 200/million population, the mortality risk associated with living in a more susceptible country (medium/high) was 27.8 times higher (95% CI for OR: 3.6–213.2) Conclusion The results of this study showed that, despite confounding factors in different countries, hepatitis A susceptibility of the population may have been correlated with COVID-19 mortality. This observation needs to be confirmed by further studies.

Currently, our world is facing the 2019 Novel Coronavirus (COVID-19) outbreak and tremendous efforts are made for developing drugs to treat and vaccines to prevent the disease. At present, there is no specific antiviral drug or vaccine for COVID-19. The pathogenic infectivity of the virus requires the S1 subunit of the spike (S) protein to bind the host cell receptor, angiontensin converting enzyme (ACE2). While the binding to host cell receptor is the first step of infection, the entrance of the virus into the cell needs the cleavage of S1-S2 subunits to expose S2 for fusion to cell membrane via host proteases including cathepsins, cell surface transmembrane protease/serine (TMPRSS) proteases, furin, trypsin and factor Xa. Previous in vitro studies have shown that factor Xa inhibition can decrease viral infectivity. We suppose that host cell proteases including furin (as expressed highly in lungs), factor Xa and cathepsin are possible targets to decrease viral burden, therefore unfractioned heparin and low molecular weight heparin-LMWH (specifically dalteparin and tinzaparin for their anti inflammatory action) can be potential inhibitors of multiple endoproteases involved in virus infectivity. Our hypothesis needs to be tested in in vitro and clinical studies, however as we are in an urgent situation as the burden of SARS-CoV2 is increasing all around the world, we recommend the usage of unfractioned heparin or LMWH in intensive care unit (ICU) and non-ICU hospitalized patients with the risk-benefit judgement of the clinician. Whether our hypothesis is clinically applicable and successful in decreasing viral infection will be evaluated for further studies.

Introduction We evaluated our 16 years of experience of pediatric PTLD cases who were liver transplanted in Başkent University Hospital between 2001-2017 years. Materials and Methods We reviewed the clinical and laboratory data of 8 patients who were diagnosed as PTLD out of 236 pediatric patients who were liver transplanted in Başkent University Hospital between 2001-2017 years. Pretransplant EBV statuses of 172 patients were also recorded. Results The total PTLD incidence was 3.4%. The incidence of PTLD was 10% in pretransplant EBV IgG negative patients, while it was 0.8% in pretransplant EBV seropositive patients. Mean age of the patients at liver transplant was 2.71±3.21 years; four patients were under 1 year of age at the time of transplant. PTLD was diagnosed 21.81±18.1 months after transplant. The primary site of involvement was variable among patients: peripheral and mediastinal lymph nodes, stomach-intestinal, transplanted graft, bone marrow, and nasopharynx. Eosinophil count varied greatly among patients, with mean values of 524.62±679. Food allergy prevalence was higher than the non-PTLD patients (23/236; 10% versus 3/8; 37.5%) The lymphoproliferative disease was of B cell origin in 6 of the patients. One patient died due to neutropenic sepsis during chemotherapy, while seven patients are being followed up in full remission for 7.75±4 years. Conclusion PTLD is a life-threatening complication of solid organ transplantation with a heterogenous clinic. Food allergy had a close association with PTLD. Close follow-up of patients who had risk factors and early diagnosis with appropriate treatment may lead to good outcome.

BACKGROUND/AIMSWe evaluated our 16-year single-center experience of pediatric post-transplant lymphoproliferative disorder (PTLD) cases who underwent liver transplantation between 2001 and 2017.MATERIALS AND METHODSOf the 236 pediatric patients who underwent liver transplantation between 2001 and 2017, the clinical and laboratory data of eight patients diagnosed with PTLD were reviewed. The pre-transplant Epstein-Barr virus (EBV) status of 172 patients was also recorded.RESULTSThe total incidence of PTLD was 3.4%. The incidence of PTLD was 10% in pre-transplant EBV immunoglobulin G (IgG)-seronegative patients and 0.8% in pre-transplant EBV IgG-seropositive patients. The mean age of the patients at liver transplantation was 2.71±3.21 years, and four patients were aged below 1 year at the time of transplantation. PTLD was diagnosed at 21.81±18.1 months after transplantation. The primary site of involvement was variable among patients: peripheral and mediastinal lymph nodes, stomach and intestine, transplanted graft, bone marrow, and nasopharynx. The eosinophil count varied greatly among patients, with a mean value of 524.62±679/mm3. Three patients had a food allergy and were administered an elimination diet at the time of PTLD diagnosis. Six patients had PTLD of B-cell origin. One patient died due to neutropenic sepsis during chemotherapy, whereas seven patients were followed up in full remission for 7.75±4 years.CONCLUSIONPTLD is a life-threatening complication of solid-organ transplantation with a heterogeneous clinical spectrum. Food allergy had a close association with PTLD. A close follow-up of patients with risk factors and an early diagnosis with appropriate treatment may lead to a better outcome.