A Rare Tumor in a Rare Location: Radiology and Pathology Findings With a Literature Review on Intraventricular Gliosarcoma.

Gliosarcoma (GS) is an extraordinarily rare variant of glioblastoma, which is differentiated by its distinct biphasic histopathological morphology consisting of both glial and mesenchymal elements. Although GS has a predilection for the cortical hemispheres, rare occurrences of intraventricular gliosarcoma (IVGS) have been documented in the literature. In this report, we present a 68-year-old female patient with a primary IVGS arising from the frontal horn of the left ventricle with corresponding left ventricular entrapment. The clinical course as well as associated tumor features as observed on computed tomography (CT), magnetic resonance imaging (MRI), and immunohistochemical studies are presented along with a relevant review of the current literature.

Lethal Pediatric Cerebral Vasculitis Triggered by Severe Acute Respiratory Syndrome Coronavirus 2.

BACKGROUND: We report the clinical, radiological, laboratory, and neuropathological findings in support of the first diagnosis of lethal, small-vessel cerebral vasculitis triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a pediatric patient. PATIENT DESCRIPTION: A previously healthy, eight-year-old Hispanic girl presented with subacute left-sided weakness two weeks after a mild febrile illness. SARS-CoV-2 nasopharyngeal swab was positive. Magnetic resonance imaging revealed an enhancing right frontal lobe lesion with significant vasogenic edema. Two brain biopsies of the lesion showed perivascular and intraluminal lymphohistiocytic inflammatory infiltrate consistent with vasculitis. Despite extensive treatment with immunomodulatory therapies targeting primary angiitis of the central nervous system, she experienced neurological decline and died 93 days after presentation. SARS-CoV-2 testing revealed positive serum IgG and positive cerebrospinal fluid IgM. Comprehensive infectious, rheumatologic, hematologic/oncologic, and genetic evaluation did not identify an alternative etiology. Postmortem brain autopsy remained consistent with vasculitis. CONCLUSION: This is the first pediatric presentation to suggest that SARS-CoV-2 can lead to a fatal, postinfectious, inflammatory small-vessel cerebral vasculitis. Our patient uniquely included supportive cerebrospinal fluid and postmortem tissue analysis. While most children recover from the neurological complications of SARS-CoV-2, we emphasize the potential mortality in a child with no risk factors for severe disease.

Ablation of polyamine catabolic enzymes provokes Purkinje cell damage, neuroinflammation, and severe ataxia.

BACKGROUND: Polyamine catabolism plays a key role in maintaining intracellular polyamine pools, yet its physiological significance is largely unexplored. Here, we report that the disruption of polyamine catabolism leads to severe cerebellar damage and ataxia, demonstrating the fundamental role of polyamine catabolism in the maintenance of cerebellar function and integrity. METHODS: Mice with simultaneous deletion of the two principal polyamine catabolic enzymes, spermine oxidase and spermidine/spermine N1-acetyltransferase (Smox/Sat1-dKO), were generated by the crossbreeding of Smox-KO (Smox-/-) and Sat1-KO (Sat1-/-) animals. Development and progression of tissue injury was monitored using imaging, behavioral, and molecular analyses. RESULTS: Smox/Sat1-dKO mice are normal at birth, but develop progressive cerebellar damage and ataxia. The cerebellar injury in Smox/Sat1-dKO mice is associated with Purkinje cell loss and gliosis, leading to neuroinflammation and white matter demyelination during the latter stages of the injury. The onset of tissue damage in Smox/Sat1-dKO mice is not solely dependent on changes in polyamine levels as cerebellar injury was highly selective. RNA-seq analysis and confirmatory studies revealed clear decreases in the expression of Purkinje cell-associated proteins and significant increases in the expression of transglutaminases and markers of neurodegenerative microgliosis and astrocytosis. Further, the α-Synuclein expression, aggregation, and polyamination levels were significantly increased in the cerebellum of Smox/Sat1-dKO mice. Finally, there were clear roles of transglutaminase-2 (TGM2) in the cerebellar pathologies manifest in Smox/Sat1-dKO mice, as pharmacological inhibition of transglutaminases reduced the severity of ataxia and cerebellar injury in Smox/Sat1-dKO mice. CONCLUSIONS: These results indicate that the disruption of polyamine catabolism, via coordinated alterations in tissue polyamine levels, elevated transglutaminase activity and increased expression, polyamination, and aggregation of α-Synuclein, leads to severe cerebellar damage and ataxia. These studies indicate that polyamine catabolism is necessary to Purkinje cell survival, and for sustaining the functional integrity of the cerebellum.

Conformal Radiation Therapy for Pediatric Ependymoma, Chemotherapy for Incompletely Resected Ependymoma, and Observation for Completely Resected, Supratentorial Ependymoma.

PURPOSE: The Children's Oncology Group trial ACNS0121 estimated event-free survival (EFS) and overall survival for children with intracranial ependymoma treated with surgery, radiation therapy, and-selectively-with chemotherapy. Treatment was administered according to tumor location, histologic grade, and extent of resection. The impacts of histologic grade, focal copy number gain on chromosome 1q, and DNA methylation profiles were studied for those undergoing surgery and immediate postoperative conformal radiation therapy (CRT). METHODS: ACNS0121 included 356 newly diagnosed patients (ages 1 to 21 years). Patients with classic supratentorial ependymoma were observed after gross total resection (GTR). Those undergoing subtotal resection received chemotherapy, second surgery, and CRT. The remaining patients received immediate postoperative CRT after near-total resection or GTR. CRT was administered with a 1.0-cm clinical target volume margin. The cumulative total dose was 59.4 Gy, except for patients who underwent GTR and were younger than age 18 months (who received 54 Gy). Patients were enrolled between October 2003 and September 2007 and were observed for 5 years. Supratentorial tumors were evaluated for RELA fusion; infratentorial tumors, for chromosome 1q gain. Classification of posterior fossa groups A and B was made by methylation profiles. RESULTS: The 5-year EFS rates were 61.4% (95% CI, 34.5% to 89.6%), 37.2% (95% CI, 24.8% to 49.6%), and 68.5% (95% CI, 62.8% to 74.2%) for observation, subtotal resection, and near-total resection/GTR groups given immediate postoperative CRT, respectively. The 5-year EFS rates differed significantly by tumor grade (P = .0044) but not by age, location, RELA fusion status, or posterior fossa A/posterior fossa B grouping. EFS was higher for patients with infratentorial tumors without 1q gain than with 1q gain (82.8% [95% CI, 74.4% to 91.2%] v 47.4% [95% CI, 26.0% to 68.8%]; P = .0013). CONCLUSION: The EFS for patients with ependymoma younger than 3 years of age who received immediate postoperative CRT and for older patients is similar. Irradiation should remain the mainstay of care for most subtypes.

Extending the Neuroanatomic Territory of Diffuse Midline Glioma, K27M Mutant: Pineal Region Origin.

Diffuse midline glioma, H3-K27M mutant (DMG-K27M) is a newly described, molecularly distinct infiltrative glioma that almost exclusively arises in midline CNS structures, including the brain stem, especially the pons, as well as the thalamus and spinal cord with rare examples seen in the cerebellum, third ventricle, and hypothalamus. To our knowledge, only 1 case of a molecularly confirmed DMG-K27M arising in the pineal region has been previously reported. We present the second occurrence of a tissue-confirmed DMG-K27M of the pineal region, which, to our knowledge, is the first case reported in a child and the first case with documented preoperative MRI. This case, in addition to a prior report described in an adult, defines the lower end of a broad age range of DMG-K27M onset (12-65 years) and establishes the pineal gland as a bona fide site of origin for this newly codified midline glioma.

New Classification for Central Nervous System Tumors: Implications for Diagnosis and Therapy.

The 2016 World Health Organization Classification of Tumors of the Central Nervous System (WHO 2016) represents a noteworthy divergence from prior classification schemas. This new classification introduced the concept of "integrated diagnoses" based on a marriage of both phenotypic (microscopic) and genotypic parameters, with the intended goals of improving diagnostic accuracy and patient management. The result is a major restructuring in many of the brain tumor categories, with the codification of multiple new tumor entities and subgroups. It is therefore imperative that pathologists, clinicians, and neuro-oncology researchers alike rapidly become familiar with this new classification schema. Many of the diagnostic updates set forth in the WHO 2016 have impacted brain tumor types that commonly arise in the pediatric age group, particularly within the diffuse glioma, ependymoma, and embryonal tumor categories. This review gives a brief overview of (1) the WHO 2016 as it relates to pediatric central nervous system (CNS) tumors, with an emphasis on molecular diagnostic tools used in the clinical arena, (2) ongoing and developing approaches to the molecular and genomic classification of pediatric CNS tumors, and (3) the impact of this new classification schema on clinical trials in pediatric neuro-oncology.

All things rhabdoid and SMARC: An enigmatic exploration with Dr. Louis P. Dehner.

Over the past several decades, our understanding of malignant rhabdoid tumors (MRT) and the central nervous system equivalent atypical teratoid/rhabdoid tumor (ATRT) has undergone considerable refinement, particularly in terms of genetic characterization. MRT (both renal and extra-renal) and ATRT share phenotypic similarities and a common genetic signature, that being inactivating alterations of the SWI/SNF complex component SMARCB1 (or rarely SMARCA4). Unfortunately, a wide array of tumors bears significantly overlapping phenotypic characteristics to MRT/ATRT, posing a formidable diagnostic challenge. Likewise, the list of tumors bearing SMARC-related alterations has grown at a dizzying pace, and the original assumption that SMARCB1 alterations were unique to MRT/ATRT has been essentially negated. It should come as no surprise that Dr. Louis P. Dehner, no stranger to enigmatic lesions, participated significantly in this pathologic controversy, and the circuitous journey of entity discovery and clarification. This review aims to (1) summarize our current knowledge of MRT and ATRT with an emphasis on genetic characterization, (2) present insight into so-called "composite rhabdoid tumors" (CRTs), and (3) and provide an updated account of others tumors bearing SMARC alterations.

Pilomatrixoma Presenting as a Rapidly Expanding Mass of the Infant Nasion.

Objective: Pilomatrixomas are benign neoplasms originating from the cells of hair follicles. They typically present as a slowly enlarging, solitary mass on hair-bearing areas of the head and neck. While a common childhood lesion, pilomatrixomas are unusual in infancy. Our objective is to present an atypical pilomatrixoma located on the midline nasion of an 11-month-old as such a lesion and its management has not been previously described. Methods: Despite preoperative diagnostic imaging, including computed tomography and magnetic resonance imaging, the diagnosis was not made until examination by pathology after complete surgical excision. We also completed a thorough review of the literature pertaining to pilomatrixomas, which is presented in a concise fashion. Results: Our patient's clinical presentation did not correlate with traditional descriptions in the literature, skewing preoperative diagnosis. However, surgical management was ultimately appropriate and effective. To date, the patient has not demonstrated evidence of recurrence. Conclusion: We believe that this is the first such reported presentation of a pilomatrixoma. Given its incidence, we encourage readers to consider this diagnosis when evaluating similar pediatric skin lesions of the head and neck. Complete surgical excision is the definitive treatment.

MDA-9/syntenin is a key regulator of glioma pathogenesis.

BACKGROUND: The extraordinary invasiveness of human glioblastoma multiforme (GBM) contributes to treatment failure and the grim prognosis of patients diagnosed with this tumor. Consequently, it is imperative to define further the cellular mechanisms that control GBM invasion and identify promising novel therapeutic targets. Melanoma differentiation associated gene-9 (MDA-9/syntenin) is a highly conserved PDZ domain-containing scaffolding protein that promotes invasion and metastasis in vitro and in vivo in human melanoma models. To determine whether MDA-9/syntenin is a relevant target in GBM, we investigated its expression in tumor samples and involvement in GBM invasion and angiogenesis. MATERIALS: We assessed MDA-9/syntenin levels in available databases, patient tumor samples, and human-derived cell lines. Through gain-of-function and loss-of-function studies, we analyzed changes in invasion, angiogenesis, and signaling in vitro. We used orthotopic xenografts with GBM6 cells to demonstrate the role of MDA-9/syntenin in GBM pathogenesis in vivo. RESULTS: MDA-9/syntenin expression in high-grade astrocytomas is significantly higher than normal tissue counterparts. Forced overexpression of MDA-9/syntenin enhanced Matrigel invasion, while knockdown inhibited invasion, migration, and anchorage-independent growth in soft agar. Moreover, overexpression of MDA-9/syntenin increased activation of c-Src, p38 mitogen-activated protein kinase, and nuclear factor kappa-B, leading to elevated expression of matrix metalloproteinase 2 and secretion of interleukin-8 with corresponding changes observed upon knockdown. GBM6 cells that stably express small hairpin RNA for MDA-9/syntenin formed smaller tumors and had a less invasive phenotype in vivo. CONCLUSIONS: Our findings indicate that MDA-9/syntenin is a novel and important mediator of invasion in GBM and a key regulator of pathogenesis, and we identify it as a potential target for anti-invasive treatment in human astrocytoma.

Giant cell reparative granuloma of the pediatric cranium: case report and review of the literature.

PURPOSE: Giant cell reparative granulomas are rare bone tumors. Although benign, these tumors are locally destructive and can be highly vascular. They seldom occur in the cranial vault. We describe a multidisciplinary approach to a case of giant cell reparative granuloma of the cranium in a 3-year-old patient. CASE REPORT: A 3-year-old girl female referred to the pediatric neurosurgery department for evaluation of a retro-auricular mass. She had a history of recurrent otitis media with two subsequent courses of antibiotics without resolution. CT imaging revealed an expansive lesion located in the right mastoid region. Open surgical biopsy revealed a hemorrhagic tumor consistent with a giant cell reparative granuloma. Angiography identified a hypervascular tumor blush that was supplied by the occipital artery. Preoperative transcatheter embolization was performed followed by a multidisciplinary surgical resection and reconstruction. Blood loss was minimal, and the patient recovered well after surgery. CONCLUSION: Preoperative endovascular embolization and a multidisciplinary intraoperative approach with primary resection and cranial vault reconstruction is an effective approach to hypervascular giant cell reparative granulomas.

Desmoplastic fibroma of the pediatric cranium: case report and review of the literature.

PURPOSE: Desmoplastic fibromas are primary bone tumors that seldom occur in the cranial bones. Furthermore, reports of desmoplastic fibromas of the skull in children are exceedingly rare. Although desmoplastic fibromas are histologically benign, they are locally aggressive and have a propensity to reoccur. Their radiographic appearance may mimic other more common central nervous system and bone neoplasms. There are only 19 reported cases of desmoplastic fibroma of the cranium in the literature, and only seven occurred in the pediatric age group. We present a case report of an 11-year-old female patient with a desmoplastic fibroma of the parieto-occipital region and review the literature. CASE REPORT: An 11-year-old female presented to the craniofacial clinic complaining of intermittent pain and a soft mass in the occipital region. There was a distant history of trauma to the region that did not require medical intervention. Computed tomography imaging revealed a lytic bone lesion overlying the sagittal sinus in the parieto-occipital region. Surgical resection with wide margins and immediate autologous reconstruction was performed. Pathological analysis revealed a desmoplastic fibroma. At 4 months of follow-up, no recurrence has been noted. CONCLUSION: Desmoplastic fibroma of the cranium is rare. Complete surgical resection with careful follow-up is the treatment of choice.

Intradiploic dermoid cyst of the lateral frontotemporal skull: case report and review of the literature.

BACKGROUND: Intradiploic dermoid cysts represent 0.04-0.7% of cranial tumors. Fewer than 20 cases of dermoid cysts occurring in the lateral frontotemporal region with a sinus tract and bony involvement are described, only 7 with intracranial extension. We present the first report of such a lesion arising within the lateral coronal suture. As the literature on this topic grows, the matter of preoperative imaging for soft tissue and bony lesions of the lateral frontotemporal region is evolving, and this report offers a preliminary set of criteria for when imaging is a necessity. CASE REPORT: A 2-year-old male presented with a bony lesion in the right frontotemporal region. Since birth the lesion had grown commensurately with the patient. Examination revealed an immobile hard mass overlying the right coronal suture with no discernable abnormality. Computed tomography demonstrated a cystic lesion without evidence of intracranial extension. Intraoperatively, the exophytic lesion was fully enclosed by bony matrix, interrupting the coronal suture as it approached the pterion. Following resection, pathology revealed an intradiploic dermoid cyst. CONCLUSION: Intradiploic dermoid cysts occurring within patent cranial sutures away from the midline are rarely described lesions. Complete surgical resection with careful follow-up is the treatment of choice.

Clinical verification of the performance of the pathwork tissue of origin test: utility and limitations.

Gene expression-based assays have been introduced into the clinical arena to assist in the diagnosis of poorly differentiated or undifferentiated tumors. The US Food and Drug Administration has cleared the microarray-based Pathwork Tissue of Origin (TOO) Test (Pathwork Diagnostics, Sunnyvale, CA) for the molecular characterization of such challenging specimens. We aimed at verifying the analytic and clinical performance of this test on 43 poorly differentiated and undifferentiated tumor samples, including 6 off-panel cases and 7 cancers of unknown primary (CUP). Our results showed 97% (95% confidence interval, 80.4%-99.8%) agreement between the Pathwork TOO Test result and the complete diagnosis, which included clinical correlations and immunohistochemical staining, after the original diagnosis. We concluded that for off-panel and CUP samples, the tissue type and the cell type may be confounded by the Pathwork TOO Test and that careful clinicopathologic assessment is needed when interpreting results from this helpful ancillary tool for pathologists.

Metallofullerene-based nanoplatform for brain tumor brachytherapy and longitudinal imaging in a murine orthotopic xenograft model.

PURPOSE: To demonstrate in an orthotopic xenograft brain tumor model that a functionalized metallofullerene (f-Gd3N@C80) can enable longitudinal tumor imaging and, when radiolabeled with lutetium 177 (¹77Lu) and tetraazacyclododecane tetraacetic acid (DOTA) (¹77Lu-DOTA-f-Gd3N@C80), provide an anchor to deliver effective brachytherapy. MATERIALS AND METHODS: All experiments involving the use of mice were carried out in accordance with protocols approved by the institutional animal care and use committee. Human glioblastoma U87MG cells were implanted by using stereotactic procedures into the brains of 37 female athymic nude-Foxn1nu mice and allowed to develop into a tumor for 8 days. T1- and T2-weighted magnetic resonance (MR) imaging was performed in five mice. Biodistribution studies were performed in 12 mice at four time points over 7 days to evaluate gadolinium content. Survival studies involved 20 mice that received infusion of a nanoplatform by means of convection-enhanced delivery (CED) 8 days after tumor implantation. Mice in survival studies were divided into two groups: one comprised untreated mice that received f-Gd3N@CC80 alone and the other comprised mice treated with brachytherapy that received 1.11 MBq of ¹77Lu-DOTA-f-Gd3N@CC80. Survival data were evaluated by using Kaplan-Meier statistical methods. RESULTS: MR imaging showed extended tumor retention (25.6% ± 1.2 of the infused dose at 52 days, confirmed with biodistribution studies) of the f-Gd3N@CC80 nanoplatform, which enabled longitudinal imaging. Successful coupling of ¹77Lu to the f-Gd3N@CC80 surface was achieved by using a bifunctional macrocyclic chelator. The extended tumor retention allowed for effective brachytherapy, as indicated by extended survival time (> 2.5 times that of the untreated group) and histologic signs of radiation-induced tumor damage. CONCLUSION: The authors have developed a multimodal nanoplatform and have demonstrated longitudinal tumor imaging, prolonged intratumoral probe retention, biodistribution, and extended survival in an orthotopic xenograft brain tumor model.

Intracranial aneurysms in klippel-trenaunay/weber syndromes: case report.

OBJECTIVE: We present a comprehensive review of intracranial aneurysms in Klippel-Trenaunay and Klippel-Trenaunay-Weber syndromes (KTS/KTWS), and examine factors influencing the risks of surgery vs conservative management. CLINICAL PRESENTATION: A 58-year-old physician with KTS affecting the right extremities presented with left hemispheric cerebellar stroke and was discovered to harbor four intracranial aneurysms of the posterior circulation: fusiform mid and distal BA (2.6 x 2 x 2 cm), fusiform right proximal P1 (2 x 1.3 x 1.3 cm), fusiform right distal P1 (2.8 x 2.7 x 2 cm), and saccular left distal posterior inferior cerebellar artery (2.5 x 2.5 x 2.5 cm). Ten years later he had an infarct in the paramedian distribution of the basilar artery and a right internal capsule stroke. Two months later, he developed hydrocephalus, ultimately presenting in status epilepticus 4 months later secondary to ongoing aneurysm expansion and mass effect. INTERVENTION: Systemic anticoagulation for acute thrombosis with possible distal arterioarterial embolization from giant P1 aneurysms. Ventriculoperitoneal shunting for hydrocephalus. The patient died within 9 days after admission and 10 years after the initial discovery of aneurysms. CONCLUSION: Strict control of modifiable risk factors compromising vascular integrity and periodic neuroimaging are warranted in KTS/KTWS patients. KTS/KTWS patients are hypercoagulable, and may be predisposed to aneurysm thrombosis with increased risk for distal arterial microembolization. Stroke-related morbidity secondary to distal arterioarterial aneurysm thrombus embolization and acute aneurysm thrombosis may be decreased with systemic anticoagulation in this patient population. KTS/KTWS patients have significantly higher rates of DVT and PE than the general population, and should be classified in the high-risk category for venous thromboembolism prophylaxis. Both endovascular and open cerebrovascular techniques have been used successfully in KTS/KTWS patients with intracranial aneurysms.

Astrocyte elevated gene-1: a novel target for human glioma therapy.

Malignant gliomas including glioblastoma multiforme (GBM) and anaplastic astrocytomas are the most common primary brain tumors. Despite multimodal treatment including surgery, chemotherapy, and radiation, median survival for patients with GBMs is only 12 to 15 months. Identifying molecules critical for glioma progression is crucial for devising effective targeted therapy. In the present study, we investigated the potential contribution of astrocyte elevated gene-1 (AEG-1) in gliomagenesis and explored the possibility of AEG-1 as a therapeutic target for malignant glioma. We analyzed the expression levels of AEG-1 in 9 normal brain tissues and 98 brain tumor patient samples by Western blot analysis and immunohistochemistry. AEG-1 expression was significantly elevated in >90% of diverse human brain tumor samples including GBMs and astrocytic tumors, and also in human glioma cell lines compared with normal brain tissues and normal astrocytes. Knockdown of AEG-1 by small interfering RNA inhibited cell viability, cloning efficiency, and invasive ability of U87 human glioma cells and 9L rat gliosarcoma cells. We also found that matrix metalloproteases (MMP-2 and MMP-9) are involved in AEG-1-mediated invasion of glioma cells. In an orthotopic nude mouse brain tumor model using primary human GBM12 tumor cells, AEG-1 small interfering RNA significantly suppressed glioma cell growth in vivo. Taken together, these provocative results indicate that AEG-1 may play a crucial role in the pathogenesis of glioma and that AEG-1 could represent a viable potential target for malignant glioma therapy.

Aggressive pediatric meningioma with soft tissue and lymph node metastases: a case report.

Metastatic meningioma is extremely rare, occurring in an estimated 0.1% of cases. We report a case of pediatric meningioma metastatic to cervical soft tissue and lymph nodes. An 8-year-old boy presented with headaches, dizziness, and involuntary eye flickering. Magnetic resonance imaging (MRI) revealed a 7.5-cm parasagittal, dural-based mass with venous sinus encasement. Therapeutic embolization was followed by bilateral craniotomy, achieving subtotal resection. Histopathologic examination revealed an atypical meningioma with regions of hypercellularity, small cell morphology, sheeting architecture, increased mitoses, and brain invasion. Surveillance MRI studies showed growth of residual tumor and enlarging cervical soft tissue masses with posterior triangle lymphadenopathy. Radiation and surgical resection were employed for the intracranial tumor burden; resection of the soft tissue masses revealed metastatic meningioma, with soft tissue infiltration and metastasis to 8 lymph nodes. This case demonstrates the aggressive biologic potential of pediatric meningiomas, with potential for distant spread via cerebrospinal fluid leakage and lymphatic invasion.