Primary intra-osseous malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare tumors either associated with neurofibromatosis type 1 (NF1) or arise spontaneously from a peripheral nerve or nerve sheath-associated cells. We report a case of primary MPNST involving the proximal tibia in a 53-year-old gentleman who presented with pain and swelling near the right knee joint. These tumors pose a distinct challenge to the clinician from diagnosis to management. Immunohistochemistry is pivotal in making the appropriate diagnosis. Radical resection remains the mainstay of treatment, while currently the role of adjuvant therapies has not been clearly established.

BACKGROUND:Changing vascular integrity with aging may be a crucial factor presuming Arterio-Venous fistula (AVF) maturation. Present study compared outcome of AVF maturation and associated factors responsible between adult and elderly population. METHODOLOGY:In this prospective observational study, CKD 4/5 patients of age ⩾18 years in whom AVF was planned were included. All were divided as adult (18-59 years) and elderly (⩾60 years) groups. Various clinical, biochemical, and radiological parameters including doppler assisted vascular mapping were recorded. AVF was created by side to side anastomosis. Clinical and doppler assessment like blood flow and wall shear stress (WSS) were done at 4th, 6th, and 12th weeks. Radiological maturation of AVF was defined as combination of blood flow of ⩾500 mL/min and vessel diameter of 5 mm. At 12 weeks, maturation of both group and association of biochemical factors with primary AVF failure were compared. RESULTS:A total of 120 patients (60 in each age group) were included. Overall AVF maturation rate was 75% (n = 90). Among elderly 70% (n = 42) and adult 80% (n = 48); p < 0.02. Early clinical and radiological maturation were seen in adult as compared to elderly (p = 0.022). Hyperphosphatemia, and higher c-reactive protein (CRP) levels were associated with AVF primary failure (p = 0.033) and (p = 0.005) respectively which are more in elderly group. Elderly patients had more arterial calcification (p = 0.034). Radio cephalic AVF (RCAVF) was common in both group, adult (85%) and elderly (76.5%), however elderly have more brachiocephalic AVF (BCAVF) (14.8% vs 23.3%). Blood flow, fistula diameter, and WSS had significant differences between the matured and non-matured groups (p < 0.001) in both adult and elderly. CONCLUSION:Higher serum phosphate level, CRP, arterial calcification, and higher WSS were likely cause of reduced AVF maturation rate in elderly. Meticulous clinical, biochemical, and radiological evaluation, site of AVF creation selection are essential to reduce AVF failure rate.

BACKGROUND:This study compares the outcomes of tunneled catheters (TCs) and non-tunneled catheters (NTCs) in incident hemodialysis patients undergoing early arteriovenous fistula (AVF) creation. METHODS:Adult incident ESKD patients were randomized in two catheter groups (TC and NTC) for hemodialysis initiation and were followed for 12 weeks from March 2021 in a 3-year study period. Catheter salvage was attempted in both the groups until AVF maturation in cases of catheter-related bloodstream infection (CRBSI) or mechanical dysfunction. Catheter insertion and removal dates, infection episodes, and mechanical dysfunction events were recorded. CRBSI rates, dysfunction rates, and catheter survival were compared. RESULTS:A total of 133 patients were randomized into TC (65) and NTC (68) groups. Seventy-six patients developed symptoms of CRBSI, of whom eight patients required catheter removal (TC: 2, NTC: 6). CRBSI episodes per 1000 catheter days were 15.14 for TCs and 16.85 for NTCs, but mechanical dysfunction rates were 0.96 and 1.68, respectively. By 6 weeks, one catheter was removed in the TC group (AVF maturation), and eight in the NTC group were removed (four due to AVF maturation, three due to CRBSI, and one due to mechanical dysfunction). Kaplan-Meier analysis showed significantly longer catheter survival for TCs compared to NTCs (66.9 vs. 57.9 days, p = 0.001). CONCLUSION:CRBSI rates and catheter patency were comparable between TCs and NTCs at 6 weeks, but TCs demonstrated better survival beyond this period. When early AVF creation is ensured, NTCs may serve as a viable short-term vascular access option, particularly in resource-limited settings.

Abstract Background and Aims For long term hemodialysis, tunnel catheters are preferred over non –tunneled as vascular access. High cost and expertise in its catheterization are major limitations. It is unclear about the advantage of low cost non- tunneled catheter preference over costly tunnel catheters as short term access while awaiting AVF maturation. Method All consented incident End Stage Kidney Disease (ESKD) patients requiring hemodialysis from March’ 2021 to October’ 2023 were included. Less than 18 years of age, opting for peritoneal dialysis and patients initiating hemodialysis with AVF or AV Graft were excluded from the study. Subjects were randomized in two catheter groups (Tunneled and Non-tunneled). Under aseptic precautions, all catheters were inserted by ultrasound and C-arm guided following standard protocol. Mechanical, infective and catheter survival outcomes were recorded during dialysis initiation, at 2nd, 6th and 12th weeks. Blood culture samples were sent for those patients who were having fever with chills during dialysis. If the blood culture comes out to be positive for organism, all were treated for one week intravenous antibiotic depending upon the sensitivity or as per standard protocol. Catheter salvage in both the groups was tried till 6 weeks or till AVF maturation. If in any case, AVF is not matured, we continued dialysis with the same catheter. New catheter was inserted if patient do not respond antibiotics after one week of therapy, mechanical complications or due to inadequate flow. Adequacy of the dialysis and overall outcome of patients were monitored in both the groups of catheter. All demography data and survival analysis were analyzed. Results A total 133 patients were randomized into Tunneled-65 (48.87%) and non-tunneled-68 (51.12%). Average patient's age of tunneled and non-tunneled was 45.15 ± 15.89 and 40.39 ± 12.21 respectively. A total of 50 (37.3%) were males in tunneled and 54 (40.3%) males in non tunneled groups. A total 65 (54.2%) patients were complained fever with chills during dialysis, of them 31 (25.8%) in tunneled and 34 (28.3%) in non-tunneled group. Among the CRBSI group a total 3 catheters were removed in non-tunneled group whereas all patients in tunneled group were responded to antibiotic. There were total of 24 (18.2%) infections were reported and labelled as CRBSI. Of them 9 (6.7%) in tunneled and 15 (11.2%) in non-tunneled. Most common organism was Klebsiella and Coagulase negative Staphylococcus (Cons) in both the groups. There was only one mechanical complication in case of non- tunneled catheter. The estimated days for catheter survival is 66 for tunneled and 57 for non tunneled (p-0.001). However, in case of non tunneled catheter, 15 cases were reported in which two times catheter were inserted. A total of 14 (10.5%) patients were lost to follow up 8 (6%) in tunneled and 6 (4.5%) in non- tunneled. A total of 9 (5.8%) patients died, 5 (3.8%) in tunneled and 4 (3%) in non- tunneled within 12 weeks. Conclusion Although tunneled catheter showed longer catheter survival period, low cost and easy cannulation procedure in non-tunneled hemodialysis catheter is a better viable option for all incident ESKD patients while waiting for AVF maturation.

BACKGROUND:Primary malignant tumors of the spine are rare and most commonly occur in lumbar and thoracic vertebrae. We report a rare case of retroperitoneal chondrosarcoma of L3 that was managed with sagittal en bloc spondylectomy following chemoradiation. CASE DESCRIPTION:A 26-year-old woman was evaluated for abdominal pain with contrast-enhanced computed tomography of the abdomen and pelvis, which revealed a soft tissue retroperitoneal mass arising from L3. She underwent laparotomy and biopsy, which revealed chondrosarcoma, and she received chemoradiation over a period of 28 weeks 6 days. After repeat imaging, she underwent single-stage combined approach sagittal en bloc spondylectomy of retroperitoneal chondrosarcoma of L3 with right nephrectomy and spine reconstruction. At 3-year follow-up, there was no evidence of recurrence on contrast-enhanced computed tomography of the abdomen and pelvis. She demonstrated no gait abnormality or spinal deformity. CONCLUSIONS:Sagittal en bloc spondylectomy is a preferred surgical approach for eccentrically placed spinal tumors that offers better oncological and functional outcomes.

Osteosarcoma is a matrix-producing neoplasm. Most patients are treated with neoadjuvant chemotherapy (NACT. Various parameters are available for response assessment which include radiological and histological criteria. Data on clinical responses such as pain response and size assessment is meagre. In this study, we aimed to analyze if clinical assessment used for response evaluation can predict prognosis in patients receiving neoadjuvant chemotherapy for extremity osteosarcoma. All patients diagnosed with osteosarcoma and who underwent treatment with curative intent between January 2000 and December 2018 were identified. Patients who had progression were identified and whether clinical progression impacted overall survival (OS) and disease-free survival (DFS) was analyzed. Forty-three patients who had progression on NACT were identified. When compared to patients who did not have clinical progression, more patients in the clinical progression group had large tumors (p = 0.025), the majority underwent amputation (p = <0.001), and most were poor responders to chemotherapy (p = 0.011). Clinical progression on NACT predicted poor OS and DFS on univariate analysis but not on multivariate analysis. Although patients with clinical progression had poor oncological outcomes, it was not a statistically significant factor affecting oncological outcomes. The role of continuing the same chemotherapy regimen in the adjuvant setting in this subset of patients is doubtful. Large multicentric studies are needed to know the prognostic impact of clinical progression during NACT on oncological outcomes.

To the Editor: Intracerebral schwannomas are very rare, and account for less than 1% of all intracranial neoplasms.1 The first case of an intracerebral schwannoma was described by Gibson et al. in 1966.2 We present the first case of intracerebral schwannoma in a pediatric patient who was later discovered as having underlying schwannomatosis. A 14-year-old female presented to our hospital with a history of unprovoked, new-onset seizure. Review of systems revealed a history of gradually worsening paresthesia in the right lower extremity, and intermittent blurred vision for 6 months prior to presentation. The vital signs on presentation were normal, and the physical exam was significant for decreased sensation and strength in the right lower extremity, and a circumduction gait. Laboratory evaluation including complete blood count, iron studies, urinalysis, urine drug screen, coagulation profile, and C-reactive protein were all unremarkable. Magnetic resonance imaging of brain with and without contrast showed an enhancing mass on the left upper parietal lobe measuring 2.0 × 1.7 × 2.0 cm with vasogenic edema, and midline shift of 3 mm (Figure 1) The differentials included glioma, lymphoma, andmetastasis. Based on recommendations by pediatric neurosurgery, the patient was given a dose of dexamethasone for vasogenic edema and started on Keppra for seizure prophylaxis. She underwent a gross total resection of the mass. Following surgery, Keppra prophylaxis and dexamethasone wean were continued. The surgical pathology confirmed the diagnosis of schwannoma, as shown in Figure 2. Further molecular testing showed a germline sequence variation (a heterozygous gene variant) in LZTR1 gene, which is known to be associated with schwannomatosis. She continues to follow-up with neurology, neurosurgery, and oncology, and her surveillance scans for the first year post resection have not shown any recurrence. She has had a complete resolution of neurological symptoms and has no neurodevelopmental sequalae on follow-up. Schwannomas are nerve sheath tumors, which comprise around 5%–8% of primary intracranial neoplasms.3 Around 80%–90% of theses schwannomas are seen in association with the eighth cranial nerve and noted at the cerebellopontine angle.3 Less than 1% of schwannomas are intracerebral and unrelated to cranial nerves, with only 150 cases reported in literature thus far; leading to a lot of speculation on the histogenesis of these rare tumors.4 Various theories have been proposed to explain the origin of intracerebral schwannomas. Menkü et al. proposed developmental, and nondevelopmental theories of histogenesis.5 According to the developmental theory, a distorted embryogenesis forms the source of aberrant foci of Schwann cells in the brain parenchyma. These foci may originate from transformation of developed mesenchymal pial cells into Schwann cells, differentiation of multipotential mesenchymal elements into Schwann cells, ectopicmigration of neural crest cells forming foci of Schwann cells, or misplacedmyelinated nerve fibers.4–7 The nondevelopmental theory suggests that these Schwann cells arise from the perivascular nerve plexus noted around arterioles in the brain parenchyma.4–7 Intracerebral schwannomas are primarily supratentorial, typically found in the frontotemporal lobe, while subtentorial schwannomas accounts for less than 33% of the total intracerebral schwannomas.8 The clinical manifestations depend on the size and location of the tumor. The supratentorial tumors usually present with seizures, and those that are greater than 5 cm in size can present with signs of raised intracranial pressure.9 The diagnosis is almost never made preoperatively. On neuroimaging, the differential diagnosis includes meningioma (most common mimicker), gliomas, and dysembryoplastic neuroepithelial tumors.10 The combination of histological analysis and immunohistochemical reactivity findings is needed to make a definite diagnosis of intracerebral schwanommas.4 Strong staining reaction with S-100 and lack of immunoreactivity with epithelial membrane antigen (EMA; positivity is a characteristic feature of meningiomas), and negative glial fibrillary acidic protein (GFAP) stains confirm the diagnosis of schwannoma.6,10 Intracerebral schwannomas are mostly benign lesions, and total resection is usually curative, with a low recurrence rate of around 5.3% following complete resection. All the recurrences are related to rare malignant intracerebral schwannomas.4 Individuals with schwannomatosis most commonly present between the second and fourth decade of life and have a predisposition to developmultiple schwannomas, and less frequentlymeningiomas.11 The diagnosis of schwannomatosis is established based on clinical criteria or combined molecular and clinical criteria.11,12 Combined criteria include identification of a heterozygous germline pathogenic variant in SMARCB1or LZTR1 in an individual with a pathologically confirmed schwannoma or meningioma.11 Treatment includes comprehensive, multimodal approach to pain management; referral to mental health professionals for associated anxiety or depression; surgical resection of schwannomas presenting with uncontrolled localized pain and/or neurologic deficit.11,12

Mixed extragonadal teratoma with malignant nephroblastoma (TWN) is an exceptionally rare and complex combination of solid tumors which has been referred to as “teratoid Wilms tumor,” “teratoid nephroblastoma,” or “teratoma with nephroblastoma.” Here we report a seven-year-old male who presented with a large retroperitoneal mass outside of the right kidney with lung metastases and diagnosed with a malignant mixed germ cell tumor with mature teratoma and extensive malignant nephroblastoma. Our case report highlights the controversial pathogenesis of this rare tumor and describes the variety of treatment regimens delivered for this type of tumor. In this case report, we described a young child with metastatic TWN who was successfully treated with multimodal approach based on Wilms tumor management including surgery, chemotherapy, and radiation.

Surgery remains mainstay modality of treatment of STS of extremity. In majority of patients, primary closure is possible following surgical resection of the tumor. Primary closure of wound may not be feasible in tumors with large area of skin involvement and sometimes following a whoops procedure. We analyzed postoperative complications and oncological outcomes in patients who underwent free flap reconstruction. Thirty-seven patients who required a free flap for reconstruction of the defect following resection of the STS were included in the study. There were 26 men and 11 women with a mean age of 40 years. Seventy-three percent tumors were in lower limb; 62

Since the advent of COVID-19 in 2019, the virus has affected all age groups and has a very wide clinical spectrum, ranging from asymptomatic infection to serious life-threatening complications including multi-organ dysfunction syndrome in children. The virus tends to affect all organ systems including the hematological system. There are many contradictory views on the effect of the COVID-19 pandemic on the incidence of hematological malignancies. Some studies have shown an increased incidence of acute lymphoblastic leukemia (ALL) after COVID-19 infection supporting the Greaves two-hit hypothesis of leukemogenesis, while others have shown a decline in the incidence of ALL postulated to be due to widespread lockdown and decreased exposure to environmental pathogens. We report the cases of three children who were diagnosed with acute lymphoblastic leukemia shortly after the initial diagnosis of multisystem inflammatory syndrome in children (MIS-C) or COVID related transient erythroblastopenia of childhood.

Recurrent parosteal sarcomas with vascular involvement are rare and present unique challenges in their diagnosis and management. We report the case of a 21-year-old woman with parosteal osteosarcoma of the left distal femur, encasing the popliteal vessels. En bloc transarticular resection of the distal femur and popliteal vessels was performed, followed by reconstruction using a modular prosthesis and a saphenous vein autograft for both the artery and vein. On the 1st postoperative day, the patient developed an arterial thrombus requiring reintervention with a jump polytetrafluoroethylene (PTFE) graft. Histopathology confirmed parosteal osteosarcoma. After a disease-free survival of 41 months, the patient experienced local recurrence involving the PTFE graft, leading to graft compression, erosion, and subsequent thrombosis. Despite these complications, limb salvage was possible due to adequate collateral blood supply. This case highlights the feasibility of limb salvage surgery in select cases of parosteal osteosarcoma with vascular involvement.

Primitive neuroectodermal tumors of the central nervous system, or CNS neuroblastoma, are rare neoplasms in children. Recently, methylation profiling enabled the discovery of four distinct entities of these tumors. The current treatment paradigm involves surgical resection followed by chemotherapy and radiation. However, upfront surgical resection carries high surgical morbidity in this patient population due to their young age, tumor vascularity, and often deep location in the brain. We report a case of CNS neuroblastoma that can be successfully treated with neoadjuvant chemotherapy followed by minimally invasive laser interstitial thermal therapy and radiation. The patient has complete treatment with no evidence of recurrence at one year follow-up. This case illustrates a potential paradigm shift in the treatment of these rare tumors can be treated using minimally invasive surgical approach to achieve a favorable outcome.

Reconstruction of distal tibial defects pose a difficult challenge because the bone is subcutaneous and close to the tendons and neurovascular bundles. Distally based pedicled fibula with retrograde flow can be used for the reconstruction of distal tibial defects. This is based on the communicating branch of the peroneal artery to the posterior tibial artery. We present three cases of distal tibia primary tumours which were resected and reconstructed using recycled autograft plus distally based pedicled fibula and ankle arthrodesis. This pedicled retrograde fibula flap is a novel technique for the reconstruction of distal tibial defects after oncological resections. It provides a vascularized graft without the need for microvascular surgery and without violating the normal limb. Meticulous dissection of and preservation of the communicating branches between the peroneal artery and the posterior tibial artery with confirmation of retrograde flow before dividing the proximal peroneal pedicle is sine quo non for the success of this graft. This flap overcomes the drawback of the limited arc of rotation and limited reach of proximal pedicle-based flap for distal tibial reconstruction. Long-term functional outcomes, limb shortening associated with this flap, and its effect on functional outcomes remain to be ascertained.

Mixed phenotype leukemia (MPAL) is a rare type of acute leukemia with blasts that co-express antigens of more than one lineage on the same cell or that have separate populations of blasts of different lineages. Here, we report a five-year-old male with inguinal lymphadenopathy diagnosed with MPAL-T/Myeloid MPAL-T/M. The clone demonstrated lineage and immunophenotypically distinct blast populations in the bone marrow and lymph nodes. Bone marrow cytogenetic studies confirmed a rare PICALM::MLLT10 gene fusion. Patients with this fusion gene have been found to have high risk features and poor survival rates in several small case series. Our case report highlights an unusual presentation in medullary and extramedullary sites, within a pediatric patient. At the time of submission of this case report, the patient has shown good response to chemotherapy and continues to be in remission.

Introduction: Nonmaturation of arteriovenous fistula (AVF) is a common obstacle due to neointimal hyperplasia (NIH). The present study evaluated the clinical and histopathological factors predicting AVF nonmaturation. Methodology: This prospective observational study was conducted over 18 months in 100 patients. AVF site venous tissue samples of 55 4/5 chronic kidney disease stages patients were collected. Histopathological analysis was done to detect four immunohistochemistry (IHC) markers, namely cluster of differentiation (CD68), CD31, α-SMA, and Ki67. IIntimal composition, hyperplasia, and calcification were also assessed. Fistulae were followed up at the 2nd, 6th, and 12th weeks and classified into mature and nonmature groups at 12 weeks based on clinical and Doppler examination. A comparison between the two groups was done and an association of radiological, histopathological, and IHC parameters of nonmature AVF was also carried out. Results: Among 55 patients, 35 (63.6%) had mature AVF and 26 (47%) had preexisting NIH. Preexisting NIH had no significant association with maturation (odds ratio: 0.44). Subjects without preexisting NIH had a significantly higher luminal diameter in 2nd week (P ≤ 0.05). There was a significant increase in blood flow both between the 2nd and 6th and between the 6th and 12th week (P < 0.05). Of the four IHC markers, three markers viz., CD68 (ρ = 0.525), CD31 (ρ = 0.420), and α-smooth muscle actin (ρ = 0.718) correlated significantly (P < 0.05) with the NIH. The mean AVF diameter and blood flow in the matured arm were more than that in the nonmatured arm at all the follow-ups (P < 0.09). Conclusion: The presence of CD68, CD31, and α-smooth muscle actin in the venous tissue suggests preexisting NIH which postoperative luminal diameter and blood flow may have long-term consequences in AVF functioning.

BACKGROUND:The physiology and pathology of AVF maturation depends on the vessels characteristics and its ability to remodel. Outcome of AVF using flow mediated dilatation (FMD), AVF blood flow and diameter has been studied.METHODOLOGY:Present observational study included single stage AVF (both Radiocephalic and Brachiocephalic) in consecutive CKD five patients (n = 158) prospectively over 1 year. Demographic and Doppler ultrasound parameters of upper limb (for vessel diameter and FMD) at baseline were recorded. Blood flow, diameter and depth of AVF were studied at 2, 6 and 12 weeks and their association with clinical maturation (usage of fistula with two needles for 75% of dialysis sessions during 15 day period) was studied (n = 129, after excluding lost to followup and expired patients; accordingly cohort was divided in matured (M) or non-matured (NM) groups. Clinical and radiological parameters between both groups were compared; receiver operator curve (ROC) and correlation of Doppler parameters were analysed.RESULTS:Of 129 AVF, 67.4% were matured and 32.5% non-matured. Mean age was 40 years with male predominance75% in both the groups. The mean arterial diameter for distal (NM = 1.96 ± 0.58 and M = 2.02 ± 0.41) and proximal AVF (NM = 3.37 ± 0.82 and M = 3.36 ± 0.75) was not statistically different in both the groups. The matured fistula group had a mean FMD of 11.67 ± 4.09 as against FMD value of 9.365 ± 3.55 in the failed fistula group (p value 0.01). For maturation prediction, sensitivity and specificity of blood flow at 2 weeks were 86.2% and 59.5% and at 6 weeks 96.6% and 64.3%, respectively. In multivariate analysis predictors for AVF maturation were FMD (adjusted odds ratio (AOR) = 1.15) and blood flow (AOR = 1.67).CONCLUSION:Second and Sixth week AVF blood flow was found to be predicting AVF maturation. Higher baseline FMD correlated with the AVF maturation, but not with vessel diameter.

Introduction Primary intraosseous synovial sarcoma (PISS) is a rare cancer of the bone, with few reported cases across literature. Data from our institute reveals seven indigenous cases. This study aims to evaluate these PISS diagnoses, and to further investigate any histopathological findings and prognostic factors associated with patient survival.Materials and Methods Data from patients diagnosed with PISS at the institute were obtained from January 1995 to December 2016, in the form of a retrospective study. Patient demographics, pathology locations, histological findings, surgical margins, and treatment modalities were audited as variables that can impact patient survival.Results This research identified seven cases which fulfilled the diagnostic criteria and were subsequently classified as PISS of the bone. There were five men and two women among the cases, with ages ranging from 16 to 46 years, with a mean of 29.6 years. The study found that the lower limb was the most affected site in PISS, followed by the pelvis. Limb salvage was performed in six patients and one patient underwent amputation. Of these patients, six received adjuvant chemotherapy and four received adjuvant radiation as per institution guidelines. The study found that the 5-year disease-free and overall survival rate was 80 and 61%, respectively.Conclusion PISS is a rare malignancy with limited cases in literature, and hence, there is no evidence for a standardized management protocol. The survival rates were similar between soft tissue and intraosseous synovial sarcoma among the case series.

Abstract Diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype (pHGG) was newly introduced in the 2021 WHO CNS5. pHGG is further divided into distinct methylation subtypes (MYCN, A/B, RTK1, RTK2). Compared to adult-type diffuse gliomas, relatively little is known about pHGG, especially in the adult population and we therefore aimed to more fully understand the clinicopathological spectrum of pHGG. Our cohort of methylation-profiling-confirmed pHGGs (n=299) included pediatric (n=211) and adult (n=88) populations (age range=0-79 years). The mean age was highest in the A/B subtypes (27.7 years) and lowest in the MYCN subtype (13.5 years). Median survival (18 months for the entire cohort), MGMT promoter methylation status, and history of prior radiation did not differ between the pediatric and adult populations. MGMT promoter methylation was highest in RTK1C (51%) and lowest in subtype A (0%). All those with history of prior radiation (n=37) were classified as RTK1, with subclass distribution differing between patients with history of prior radiation (RTK1A=7.3%, RTK1B=41.8%, RTK1C=50.9%) versus those without (RTK1A=41.8%, RTK1B=21.5%, RTK1C=36.7%). Interestingly, the genomic somatic copy number alteration (SCNA) load did not differ for RTK1 based on prior radiation history status. However, adult pHGG did harbor a higher SCNA load than pediatric pHGG (p< 0.01). The higher SCNA load was driven by genomic copy number losses rather than amplifications, including adult pHGG harboring more CDKN2A/B and RB1 deletions. Amplifications of MET, CDK4, PDGFRA, MYC, and KIT were present across all subtypes, but were enriched in RTK1. MYCN amplification was enriched in the MYCN subtype. EGFR, MDM4, and CDK6 amplifications did not have subtype predilection. Overall, while the pediatric and adult pHGG have similar outcomes, there are differences in their genomic structures, most notably in adult pHGG harboring a higher SCNA load. Overall, pHGG represent a biologically diverse set of clinically aggressive tumors that warrant further intensive study.