A child with intravascular fasciitis mimicking deep vein thrombosis: a case report.

BACKGROUND: Intravascular fasciitis (IF) is a benign, reactive, myofibroblastic proliferation that originates from the superficial or deep fascia of small / medium-sized arteries and veins. CASE REPORT: An 8-year-old male patient was admitted to a health center with the complaint of swelling in the inguinal region. Lower extremity venous Doppler ultrasonography showed deep vein thrombosis (DVT) of the femoral vein and anticoagulation with low-molecular weight heparin (LMWH) was initiated. The patient was referred to our center for follow-up. The D-dimer level was detected within normal limits. Doppler ultrasonography was repeated and showed an intraluminal expanding mass lesion with increasing vascularity, without distinct borders and LMWH was discontinued. This lesion at the sapheno-femoral junction was excised surgically and the histopathological examination revealed intravascular fasciitis. CONCLUSION: Clinicians should be aware that the clinical findings of IF may mimic sarcoma and thrombosis.

Pediatric paravertebral tumors: analysis of 96 patients.

PURPOSE: The most important complication of paravertebral tumors is cord compression (CC), which is an oncologic emergency. Early and appropriate intervention is important in terms of reducing morbidity and mortality. Here, we report our clinical experience with paravertebral tumors. METHODS: The files of patients who were followed up for benign/malignant paravertebral tumors between 1988 and 2022 were evaluated retrospectively. RESULTS: There were 96 patients with paravertebral tumors. The median age at diagnosis was 5 years (1 month-17 years). The male/female ratio was 1.13. The median time to diagnosis was 4 weeks (0-28 weeks). The most common presenting complaint was pain (62.5%). The diagnosis distribution was as follows: sympathetic nervous system (SNS) tumors (n: 38), soft tissue sarcomas (STS) (n: 23), Langerhans cell histiocytosis (LCH) (n: 12), central nervous system (CNS) tumors (n: 9), germ cell tumor (n: 6), lymphomas (n: 4), and benign tumors (n: 4). Sixty-five patients (67.7%) had CC, 40% of whom received chemotherapy as first-line treatment. Decompression surgery was performed in 58.5% of the patients. For patients with CC, 26 patients had advanced disease at admission. Serious neurologic sequelae were observed in seventeen (17.7%) patients. CONCLUSION: Pain and neurological findings in childhood are warning signs for paravertebral tumors and CC. A detailed neurologic examination and radiodiagnostic imaging should be performed, and a definitive diagnosis should be made quickly. Anticancer treatment should be planned multidisciplinary. Decompression surgery should be discussed for patients with severe neurological deficits. Childhood cancers are chemosensitive; if possible, treatment should be initiated with chemotherapy to avoid neurological sequelae.

Atypical Presentation and Course of ACTH-independent Cushing's Syndrome in Two Families.

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare genetic disease mainly associated with Carney complex (CNC), which is caused by germline mutations of the regulatory subunit type 1A (RIα) of the cAMP-dependent protein kinase (PRKAR1A) gene. We report three cases suffering from CNC with unique features in diagnosis and follow-up. All cases had obesity and a cushingoid appearance and exhibited laboratory characteristics of hypercortisolism. However biochemical and radiological examinations initially suggested Cushing's disease in one case . All of the cases were treated surgically; two of them underwent bilateral adrenalectomy at once, one of them had unilateral adrenalectomy at first but required contralateral adrenalectomy after nine months. Contrary to what is usually known regarding PPNAD, the adrenal glands of two cases (case 2 and 3) had a macronodular morphology. Genetic analyses revealed pathogenic variants in PRKAR1A (case 1: c.440+5 G>A, not reported in the literature; cases 2 and 3: c.349G>T, p.V117F). One case developed Hodgkin lymphoma five year after adrenalectomy, this association was not previously reported with CNC. The findings of these families provide important information for a better understanding of the genetic pathogenesis, diagnosis, and clinical management of CNC. Hodgkin lymphoma may be a component of CNC.

Unraveling the Mystery: Next Generation Sequencing Sheds Light on Neuroblastoma Pathogenesis and Targeted Therapies.

BACKGROUND: There is considerable interest in the molecular evaluation of solid tumors in pediatric cases. Although clinical trials are in progress for targeted therapies against neuroblastoma (NB), novel therapeutic strategies are needed for high-risk cases that are resistant to therapy. The aim of the present study was to document the specific gene mutations related to targeted therapy in relapsed or refractory NB patients by using next generation sequencing (NGS). METHODS: The study included 57 NB patients from amongst 1965 neuroblastic cases in Turkey who experienced a recurrence after multi-model therapy. The cases were diagnosed, risk-stratified, and treated according to the classification system from the International Neuroblastoma Risk Group. Single nucleotide variations in 60 genes were investigated using the Pillar Onco/Reveal Multicancer v4 panel and Pillar RNA fusion panel on the Illumina Miniseq platform. RESULTS: ERBB2 I655V was the most frequent mutation and was found in 39.65% of cases. Anaplastic Lymphoma Kinase (ALK) mutations (F1174L, R1275Q, and rare mutations in the tyrosine kinase domain) were detected in 29.3% of cases. Fusion mutations in NTRK1, NTRK3, ROS1, RET, FGFR3, ALK and BRAF were observed in 19.6% of cases. CONCLUSIONS: This study presents valuable mutation data for relapsed and refractory NB patients. The high frequency of the ERBB2 I655V mutation may allow further exploration of this mutation as a potential therapeutic target. Rare BRAF mutations may also provide opportunities for targeted therapy. The role of ABL1 mutations in NB should also be explored further.

The association of miR-204 and mir-483 5p expression with clinicopathological features of Wilms tumor: Could this provide foresight?

BACKGROUND: Wilms tumor is the most common cancer of the kidney that occurs during childhood, and histologically, it mimics renal embryogenesis. With the development and improvement of up-to-date treatment protocols, the survival rates of Wilms tumor have increased. However, metastases or local relapses are still observed in 15% of patients. The search for reliable biomarkers to identify at-risk patients is ongoing to predict the variability in treatment success. Currently, the evaluation of clinical, histopathological and genetic features are common diagnostic methods; however, epigenetic features can be examined with microRNA expression analyses and might allow us to comment on the behavior of the tumor and treatment response. METHODS: In this study, we aimed to evaluate the relationship between microRNA-204 and microRNA-483-5p expression with clinicopathological data and the effect on Wilms tumor survival. For this purpose, the expression levels of RNU6B, microRNA-204 and microRNA-483-5p were evaluated in tumor and normal tissue by qreal time-polymerase chain reaction. We also investigated the relationship between microRNA expression levels with the clinicopathological and histological features of Wilms tumor. RESULTS AND CONCLUSION: The results of our study indicate that the relative expression levels of microRNA-204 in Wilms tumor tissues were significantly lower than that in adjacent normal tissues. By contrast, tumor tissue had a higher microRNA-483-5p expression than the corresponding normal tissues. A statistically significant difference between microRNA-204 expression level with age and the presence of anaplasia was observed. The upregulation of microRNA-483-5p was found to have a significant correlation with patients after preoperative chemotherapy and complete tumor necrosis. Taken together, our data suggest that microRNA-204 could play a critical role as a tumor suppressor, whereas microRNA-483-5p acts as an oncogene in Wilms tumor progression. More importantly, microRNA-204 might be a novel predictive biomarker for anaplastic histology and could be useful for developing therapeutic interventions targeting this marker.

Profiling of Immunomodulatory Genes and Quantification of CD25+ Cells in Different Types of Early Pregnancy Loss.

INTRODUCTION: Maternal regulatory T (Treg) cells play a pivotal role in establishing general immune homeostasis in the decidua for maintenance of pregnancy. We aimed in this study to investigate the relationship between mRNA expression of immunomodulatory genes and CD25+ Treg cells with early pregnancy losses. METHODS: Our study included 3 groups of early pregnancy losses including sporadic spontaneous abortions, recurrent spontaneous abortions, sporadic spontaneous abortions post IVF treatment and the control group. We performed RT-PCR for analyzing mRNA expression levels of 6 immunomodulatory genes and CD25 immunohistochemistry for quantification of Treg cells. RESULTS: Only FOXP3, CD274 (PDL1), and TGFß1 mRNA expression levels were significantly decreased in the miscarriage groups in comparison to the control group, whereas there was no significant mRNA expression change of CD4, IL2RA, and IL10. We also found significantly lower number of CD25+ cells in the miscarriages. CONCLUSION: We conclude that decreased expression of FOXP3 and PD-L1 may play a significant role in the pathogenesis of spontaneous abortion cases whereas decreased expression of TGFß1 gene may be associated with the occurrence of early loss in IVF-treated pregnancies. Additional immunoprofiling of Treg cell population is needed to quantify Treg cells in early pregnancy losses.

Exploring the immunological basis of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome: immunohistochemical staining features of palatine tonsils.

OBJECTIVES: Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common periodic fever syndrome during early childhood period with regular febrile attacks of sterile upper airway inflammation. The cessation of attacks following tonsillectomy points to fundamental role of tonsil tissue on etiopathogenesis of disease, which is not clarified satisfactorily. The aim of this study is to explore the immunological basis of PFAPA by evaluating the cellular properties of tonsils, and microbial exposition such as Helicobacter pylori on tonsillectomy materials. METHODS: The paraffinized tonsil samples of 26 PFAPA and 29 control patients with obstructive upper airway disorder were compared in terms of immunohistochemical staining features including CD4, CD8, CD123, CD1a, CD20, and H. pylori. RESULTS: The median number of CD8+ cells was 1485 (1218-1287) in PFAPA while it was 1003 (852-1261.5) in control group and the difference was statistically significant (p=0.001). Similarly, CD4+ cell counts were statistically higher in PFAPA group than control (833.5 vs 622). The ratio of CD4/CD8 did not differ between two groups; also, there was no statistically difference in terms of the other immunohistochemical staining results, such as CD20, CD1a, CD123 and H. pylori. CONCLUSION: This is the largest number of pediatric tonsillar tissue study of PFAPA patients in current literature and we emphasized the triggering effects of CD8+ and CD4+ T-cells on PFAPA tonsils. KEY POINTS: • The cessation of attacks following tonsillectomy points to fundamental role of tonsil tissue on etiopathogenesis of disease, which is not clarified satisfactorily. • In current study, 92.3% of our patients did not experience any attacks following operation similarly with literature. • We observed the increased number of CD4+ and CD8+ T cell counts on PFAPA tonsils compared to control group and emphasized the active role of both CD4+ and CD8+ cells localized on PFAPA tonsils in immune dysregulation. • Some other cell types evaluated in this study such as CD19+ (B cells), CD1a (dendritic cells), and CD123 (IL-3 receptors, for pluripotent stem cells) and H. pylori did not differ in PFAPA patients compared to the control group.

Clues for the early loss of renal function in congenital hydronephrosis: Analysis of renal pelvis collagen ratio, diuresis renography and upper urinary tract morphology.

INTRODUCTION: Diagnosing real urinary obstruction and surgical decision making for the operative correction of urinary obstruction, are still problematic in congenital hydronephrosis (CH). Compliance of the renal pelvis is one of the important defense mechanisms of renal parenchyma against urinary obstruction. We observed early loss of function in some cases of CH with low and moderate anteroposterior diameter of the renal pelvis (APDRP). OBJECTIVE: To evaluate structural properties of the renal pelvic tissue of patients with CH and the relation of these structural properties with renal function and Anteroposterior diameter of the renal pelvis. STUDY DESIGN: Ureteropelvic junction (UPJ) excised during UPJ obstruction operations from 2013 to 2019 were evaluated histopathologically. The patients were divided into the two groups according to initial renal function, i.e. group with initial preoperative differential renal function (DRF) less than 35% and group with initial DRF greater than 35%. The percentage of collagen to whole tissue area were analyzed using image processing program. The relationship between DRF and tissue collagen ratio, SFU and APDRP was evaluated. RESULTS: There were 5 patients in the DRF <35% group and 16 patients in the DRF >35% group. However, APDRP's of the DRF <35% group were also significantly lower than the DRF >35% group. The collagen distribution in the muscle layer was more prominent in the DRF <35% group. Proportionally, percentage of collagen stained surface was significantly higher in DRF <35% group. DISCUSSION: There are numerous histopathological studies evaluating the cause of UPJ obstruction. Besides these studies that are oriented to etiology, there are many studies comparing the histopathological changes at UPJ with surgical outcome and prognosis. In the present study, we found that renal pelvis collagen ratio was significantly increased in patients with lower APDRP and with severe renal function loss. This increase in the collagen content in the renal pelvis have been shown to affect the compliance negatively and decrease APDRP, which leads to a faster loss of renal function. Thus, pelvic structural changes accompanying UPJ obstruction may aggravate urinary obstructive process. CONCLUSION: Increased renal pelvis collagen ratio negatively affects the expansion of the renal pelvis, which is one of the protective mechanisms of the renal parenchyma, and may be one of the triggering mechanisms of early loss of renal function.

Intraoperative cytological diagnosis of brain tumours: A preliminary study using a deep learning model.

BACKGROUND: Intraoperative pathological diagnosis of central nervous system (CNS) tumours is essential to planning patient management in neuro-oncology. Frozen section slides and cytological preparations provide architectural and cellular information that is analysed by pathologists to reach an intraoperative diagnosis. Progress in the fields of artificial intelligence and machine learning means that AI systems have significant potential for the provision of highly accurate real-time diagnosis in cytopathology. OBJECTIVE: To investigate the efficiency of machine-learning models in the intraoperative cytological diagnosis of CNS tumours. MATERIALS AND METHODS: We trained a deep neural network to classify biopsy material for intraoperative tissue diagnosis of four major brain lesions. Overall, 205 medical images were obtained from squash smear slides of histologically correlated cases, with 18 high-grade and 11 low-grade gliomas, 17 metastatic carcinomas, and 9 non-neoplastic pathological brain tissue samples. The neural network model was trained and evaluated using 5-fold cross-validation. RESULTS: The model achieved 95% and 97% diagnostic accuracy in the patch-level classification and patient-level classification tasks, respectively. CONCLUSIONS: We conclude that deep learning-based classification of cytological preparations may be a promising complementary method for the rapid and accurate intraoperative diagnosis of CNS tumours.

A challenging etiology of myopathy: The late-onset Pompe disease.

Pompe disease is a rare metabolic disorder that is characterized by the deficiency of the acid aglucosidase. As a result, glycogen accumulates in several tissues including motor neurons, skeletal, cardiac, and smooth muscles. The course of the disease varies according to the type of mutations, and the clinical phenotype can be affected by the enzyme levels. Late-onset Pompe disease (LOPD) is a challenging issue for clinicians as it has a milder phenotype with later onset of symptoms and slower disease progression. One of the most important differentials in the diagnosis of LOPD is inflammatory myositis as both diseases have some common clinical and laboratory features. Herein, we presented a 30-year-old female patient initially diagnosed as polymyositis and treated with immunosuppressive therapy without a benefit on her symptoms and later diagnosed as LOPD.

Relationship between placental autophagy and inflammasome activities with morbidity of extremely preterm infants.

BACKGROUND: The placenta is the major regulatory element of the in-utero environment, and alterations in placental cellular functions in infection, inflammation, and hypoxemia lead to adverse preterm birth outcomes. The importance of regulation of autophagy and inflammasome activities has been shown in the pathogenesis of morbidities in immature animal models. This study aimed to determine the relationship between placental autophagy and inflammasome activities with morbidity in extremely preterm infants. METHODS: Premature infants born between 24th to 29th gestational weeks were evaluated prospectively. Placental LC3B and NLRP3 immunostainings were performed to assess autophagy and inflammasome activities. Preterm morbidities including respiratory distress syndrome (RDS), patent ductus ateriosus: (PDA), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), periventricular leukomalacia (PVL), sepsis, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP) and mortality were evaluated. RESULTS: Fifty-nine infants with a mean gestational age of 26.9 ± 1.5 weeks were included. Anti-LC3B staining scores were moderate or intense positive in 75% of the placentas. Anti-LC3B activity was not associated with the existance of evaluated neonatal morbidities or mortality. Autophagy and inflammasome coexistence were demonstrated in 35 placentas (59.3%). Anti-NLRP3 staining score was moderate or intensely positive in 75% of the placentas. Infants with BPD had a lower rate of positive anti -NLRP3 staining than infants without BPD (42.9 vs 57.1%, p=0.048). Infants who had hemodynamic significant patent ductus arteriosus (hsPDA) and surgical- NEC showed significantly intense anti-NLRP3 staining compared to infants who did not (18.8% vs 0%, p= 0.027 and 33% vs 7.5%, p=0.048 respectively). CONCLUSIONS: The results showed that autophagy and inflammatory activities were present in varying amounts in the placenta of preterm infants. Association of decreased or increased rates of inflammasome activities with certain diseases such as BPD, hsPDA and surgical-NEC indicates the role of the intrauterin inflammatory process and the importance of critical balance in inflammation. Because of the complex pathophysiology of preterm morbidities, placental autophagy and inflammasome activities seem worthy of further investigation.

Effect of humic acid on oxidative stress and neuroprotection in hypoxic-ischemic brain injury: part 1.

BACKGROUND: Aimed to investigate in an animal model the efficacy of humic acid by showing its antioxidant and anti-apoptotic effect comparing with the histopathological and neurological outcomes for the hypoxic-ischemic brain injury. METHODS: 28 Wistar-Albino rats who were on the 7th postnatal day and weighting between 9 and 19 g randomly divided into four groups with developed HIE model under the gas anesthesia. 20 mg/kg and 10 mg/kg intraperitoneal HA were given to Group I and II respectively. Saline was given to Group III and the sham group was Group IV. The brain tissues were stained with cresyl-violet histochemistry for grading neuronal cell injury and caspase immunohistochemistry. RESULTS: The neuronal cell injury was statistically lower in all neuroanatomical lands in HA treatment groups. The degree of ischemia was significantly smaller in HA groups. Caspase-3 immunoreactivity was decreased in the HA groups compared with the saline group. When the groups were compared, there were no serious neuronal injury in Group I. CONCLUSIONS: This is the first study which investigates the role of HA in HIE model. HA reduces apoptosis and neuronal injury in cerebral tissue of the rats. This findings suggest that HA may be viable protective agent against HIE.

The immune landscape of solid pediatric tumors.

BACKGROUND: Large immunogenomic analyses have demonstrated the prognostic role of the functional orientation of the tumor microenvironment in adult solid tumors, this variable has been poorly explored in the pediatric counterpart. METHODS: We performed a systematic analysis of public RNAseq data (TARGET) for five pediatric tumor types (408 patients): Wilms tumor (WLM), neuroblastoma (NBL), osteosarcoma (OS), clear cell sarcoma of the kidney (CCSK) and rhabdoid tumor of the kidney (RT). We assessed the performance of the Immunologic Constant of Rejection (ICR), which captures an active Th1/cytotoxic response. We also performed gene set enrichment analysis (ssGSEA) and clustered more than 100 well characterized immune traits to define immune subtypes and compared their outcome. RESULTS: A higher ICR score was associated with better survival in OS and high risk NBL without MYCN amplification but with poorer survival in WLM. Clustering of immune traits revealed the same five principal modules previously described in adult tumors (TCGA). These modules divided pediatric patients into six immune subtypes (S1-S6) with distinct survival outcomes. The S2 cluster showed the best overall survival, characterized by low enrichment of the wound healing signature, high Th1, and low Th2 infiltration, while the reverse was observed in S4. Upregulation of the WNT/Beta-catenin pathway was associated with unfavorable outcomes and decreased T-cell infiltration in OS. CONCLUSIONS: We demonstrated that extracranial pediatric tumors could be classified according to their immune disposition, unveiling similarities with adults' tumors. Immunological parameters might be explored to refine diagnostic and prognostic biomarkers and to identify potential immune-responsive tumors.

Expression Profile of Selected Antitumor Immune Response Genes in Pediatric Classic Hodgkin Lymphoma.

Classic Hodgkin lymphoma (cHL) is one of the most common pediatric solid tumors and is responsible for cancer-related deaths in children. Therefore, to modulate the active antitumor T-cell immune response in cHL can be a treatment strategy. In the present study, we aimed to investigate the expression profiles of selected antitumor immune response genes in pediatric cHL and their relationships with clinical and prognostic parameters to determine their significance in precision medicine. Thirty-nine pediatric nodal cHL patients were enrolled in the study. We analyzed mRNA expression of selected immune response regulatory genes such as PD-L1, CSF2, CTLA4, CXCL5, IDO1, CXCL8, MIF, NOS2, PDCD1, PTGS2, and TGFß1 using real-time quantitative polymerase chain reaction. Only PD-L1 overexpression was statistically related to bulky disease, advanced tumor stage, and high-risk disease category and seen significantly in Epstein-Barr virus-negative pediatric cHL. No expression profiles were correlated with relapse or survival. We conclude that PD-L1 overexpression in pediatric cHL cases is a strong predictor of high-risk categorization. In addition to being a prognostic biomarker, PD-L1 blockade is also a druggable marker for the targeted therapy in Epstein-Barr virus-negative pediatric Hodgkin lymphoma.

PD-L1 and PD-L2 Mutations in Pediatric Hodgkin Lymphoma: Do They Have Any Prognostic Significance?

Background: Reed-Sternberg cells can escape from the immune system by enhancement of the expression of PD-L1 and PD-L2. Objectives: The aim of the present study was to investigate the significance PD-L1 and PD-L2 gene mutations in childhood Hodgkin Lymphoma's (HL). Methods: The study included 39 pediatric classical HL cases. PD-L1 and PD-L2 mutations were determined by Sanger sequencing. Clinicopathological parameters were obtained from patients' records. Results: Eight cases (20.5%) showed p.R260C mutations, and three (7.7%) p.R234L in the exome 5 of PD-L1 gene. None of the cases had PD-L2 mutations. p.R260C mutation exhibited a significant relationship with older age and nodular sclerosing (NS) histology and was associated with longer event free survival. Conclusions: Although PD-L1 mutational status did not show statistically significance with well-established prognostic factors, our preliminary data indicate that p.R260C mutation of PD-L1 gene may be associated with longer event free survival in older patients and NS histology in pediatric HL.

Gene-Specific DNA Methylation Profiles in Pediatric Medulloblastomas.

INTRODUCTION: Medulloblastoma is the most common pediatric central nervous tumor of high malignancy that has been classified into both histological subtypes and molecular subgroups by the 2016 World Health Organization classification. However, there is a still need to understand the genomic characteristics and predict the clinical course. The aim of the study is to investigate the significance of the methylation profiles in molecular subclassification and precision medicine of the disease. METHODS: The study enrolled 47 pediatric medulloblastoma patients. DNA methylation levels of KLF4, SPINT2, RASSF1A, EZH2, ZIC2, and PTCH1 genes were analyzed using methylation-specific pyrosequencing. The significance of the statistical relationship between methylation profiles and clinicopathological parameters including molecular subgroups and histological subtypes, the status of metastasis, and event-free survival were analyzed. RESULTS: DNA methylation analysis demonstrated that KLF4, PTCH1, and ZIC2 hypermethylation were associated with the SHH-activated subgroup, whereas both SPINT2 and RASSF1A hypermethylation were associated with metastatic disease. EZH2 gene was not methylated in any of the samples. CONCLUSION: We think that customized DNA methylation profiling may be a useful tool in the molecular subclassification of pediatric medulloblastoma and a potential technical approach in precision medicine.

The Significance of Histopathologic Assessment in Bone Marrow Disease in Neuroblastoma.

OBJECTIVE: Neuroblastoma (NB) is the most common extracranial solid tumor in children and is responsible for 12% of cancer-related deaths. The status of metastatic disease in the bone marrow (BM) is a predictor of poor outcome. The purpose of this study was to investigate the predictive significance of histopathological examination of BM in NB. MATERIAL AND METHOD: The study included 61 cases with archival bone marrow biopsy tissues. The cases were evaluated regarding the percentage of metastatic tissue and its differentiation. Primary tumor slides were also reviewed to perform the Shimada classification based on the differentiation status and mitosis-karyorrhexis index. The patients' age, gender, NMYC amplification, clinical risk group, and disease outcome were also noted. RESULTS: Of the 61 cases, 17 had BM involvement. Of those, eight cases (47.1%) were refractory NB showing disease relapse. Based on BM examination, five cases (29.4%) were categorized as complete response, seven (41.2%) as progressive disease, three (17.6%) as minimal disease, and two (11.8%) as stable disease. The progressive disease category was significantly related with refractory disease and NMYC amplification along with the high-risk category (p =0.002 and p= 0.003 respectively). Undifferentiated histology and presence of more than 20% of tumor tissue in the BM biopsy at diagnosis were significantly associated with the progressive disease category (p=0.01 and p < 0.001, respectively). CONCLUSION: We conclude that evaluating the percentage of metastatic tumor tissue and tumor differentiation in BM biopsies is of clinical importance in the management of neuroblastoma patients.

Quantitative Analysis of Serum Zinc Levels in Primary Brain Tumor Patients.

Although the close relationships between most of the trace elements and tumor formation mechanisms are very well-defined, studies on some elements such as zinc are still ongoing. When examining studies on brain tumors, it was observed that studies investigating the role played by serum zinc levels on tumor etiology and prognosis have gained momentum. In this study, we investigate the relationship between different brain tumor types and serum zinc levels by quantitatively analyzing serum zinc levels in patients with primary brain tumors. In this study, we measured serum zinc levels of 33 brain tumor patients as well as 35 healthy individuals serving as a control group. Metal concentrations were measured using atomic absorption spectrophotometry. Serum zinc levels were lower in patients with primary brain tumors compared to control group (p < 0.05). Additionally, patients' serum zinc levels were significantly different according to their brain tumor types and also according to their age (p < 0.05). Our findings suggest that brain tumor patients' serum zinc levels may play a role in tumor etiology, typology, and prognosis.

Methylation Profiling of Specific Genes in Ependymomas.

OBJECTIVE: Ependymomas are neuroepithelial tumors of the central nervous system with heterogeneous biology and clinical course. The aim of the present study is to investigate the relationship between the methylation status and clinicopathological parameters in ependymomas. MATERIAL AND METHOD: DNA methylation status of CDKN2A, RASSF1A, KLF4 and ZIC2 genes were quantitatively analyzed with pyrosequencing in 44 ependymoma tumor tissues. The relationship of methylation profiles with tumor subtype, histological grade and patient age was statistically analyzed. RESULTS: DNA methylation analyses for CDKN2A revealed no difference in methylation levels. Of the 31 included samples for optimal ZIC2 methylation analysis, 10 were hypermethylated (32.3%) and this change was significantly found in the adult spinal ependymomas (p=0.01). KLF4 hypermethylation was observed in 6 of the overall included 35 samples (17.1%); however, there was no statistically significant relation of the methylation status with tumor subtype, histological grade or age group. RASSF1A hypermethylation was observed in overall 40 included samples with varying methylation levels. Higher levels of hypermethylation were significantly related to the grade 3 histology (p=0.01) and spinal ependymomas (p=0.006). The pediatric cases with grade 3 ependymomas and ependymomas of adulthood showed significantly increased RASSF1A hypermethylation levels (p < 0.001 and p=0.001, respectively). CONCLUSION: DNA methylation changes are likely to have biological importance in ependymomas. Both ZIC2 and RASSF1A methylation status may be useful parameters in the subclassification of these tumors.

Dinutuximab beta plus conventional chemotherapy for relapsed/refractory high-risk neuroblastoma: A single-center experience.

Background: Relapsed/refractory high-risk neuroblastoma has a dismal prognosis. Anti-GD2-mediated chemo-immunotherapy has a notable anti-tumor activity in patients with relapsed/refractory high-risk neuroblastoma. The purpose of this study was to analyze the efficacy and safety of the combination of immunotherapy with dinutuximab beta (DB) and chemotherapy in patients with relapsed/refractory high-risk neuroblastoma. Methods: All patients received the Turkish Pediatric Oncology Group NB 2009 national protocol for HR-NB treatment at the time of diagnosis. Salvage treatments were administered after progression or relapse. The patients who could not achieve remission in primary or metastatic sites were included in the study. The most common chemotherapy scheme was irinotecan and temozolomide. DB was administered intravenously for 10 days through continuous infusion with 10 mg/m2 per day. The patients received 2 to 14 successive cycles with duration of 28 days each. Disease assessment was performed after cycles 2, 4, and 6 and every 2 to 3 cycles thereafter. Results: Between January 2020 and March 2022, nineteen patients received a total of 125 cycles of DB and chemotherapy. Objective responses were achieved in 12/19 (63%) patients, including complete remission in 6/19 and partial response in 6/19. Stable disease was observed in two patients. The remaining five patients developed bone/bone marrow and soft tissue progression after 2-4 cycles of treatment. The most common Grade ≥3 toxicities were leukopenia, thrombocytopenia, hypertransaminasemia, fever, rash/itching and capillary leak syndrome, respectively. Conclusion: Our study results suggest that DB-based chemo-immunotherapy seems to be suitable with encouraging response rates in patients with relapsed/refractory high-risk neuroblastoma.