Supratentorial CNS-PNETs in children; a Swedish population-based study with molecular re-evaluation and long-term follow-up.

BACKGROUND: Molecular analyses have shown that tumours diagnosed as supratentorial primitive neuro-ectodermal tumours of the central nervous system (CNS-PNETs) in the past represent a heterogenous group of rare childhood tumours including high-grade gliomas (HGG), ependymomas, atypical teratoid/rhabdoid tumours (AT/RT), CNS neuroblastoma with forkhead box R2 (FOXR2) activation and embryonal tumour with multi-layered rosettes (ETMR). All these tumour types are rare and long-term clinical follow-up data are sparse. We retrospectively re-evaluated all children (0-18 years old) diagnosed with a CNS-PNET in Sweden during 1984-2015 and collected clinical data. METHODS: In total, 88 supratentorial CNS-PNETs were identified in the Swedish Childhood Cancer Registry and from these formalin-fixed paraffin-embedded tumour material was available for 71 patients. These tumours were histopathologically re-evaluated and, in addition, analysed using genome-wide DNA methylation profiling and classified by the MNP brain tumour classifier. RESULTS: The most frequent tumour types, after histopathological re-evaluation, were HGG (35%) followed by AT/RT (11%), CNS NB-FOXR2 (10%) and ETMR (8%). DNA methylation profiling could further divide the tumours into specific subtypes and with a high accuracy classify these rare embryonal tumours. The 5 and 10-year overall survival (OS) for the whole CNS-PNET cohort was 45% ± 12% and 42% ± 12%, respectively. However, the different groups of tumour types identified after re-evaluation displayed very variable survival patterns, with a poor outcome for HGG and ETMR patients with 5-year OS 20% ± 16% and 33% ± 35%, respectively. On the contrary, high PFS and OS was observed for patients with CNS NB-FOXR2 (5-year 100% for both). Survival rates remained stable even after 15-years of follow-up. CONCLUSIONS: Our findings demonstrate, in a national based setting, the molecular heterogeneity of these tumours and show that DNA methylation profiling of these tumours provides an indispensable tool in distinguishing these rare tumours. Long-term follow-up data confirms previous findings with a favourable outcome for CNS NB-FOXR2 tumours and poor chances of survival for ETMR and HGG.

Sclerosing Aortic and Coronary Arteritis Due to IgG4-Related Disease.

We present the case of a 55-year-old woman admitted for a coronary artery bypass operation because of three-vessel coronary artery disease based on angiographic findings and clinical symptoms. Unexpected intraoperative findings with diffuse tissue thickening of the ascending aorta and coronary arteries indicated an alternate pathogenesis rather than coronary artery atherosclerosis. Histopathologic findings and clinical evaluation could confirm IgG4-related disease (IgG4-RD). IgG4-RD is a newly recognized fibroinflammatory condition that can present in a variety of organs and is characterized by common histopathologic features. Low disease awareness among clinicians makes this condition underdiagnosed.

Stem cell cultures derived from pediatric brain tumors accurately model the originating tumors.

Brain tumors are the leading cause of cancer-related death in children but high-grade gliomas in children and adolescents have remained a relatively under-investigated disease despite this. A better understanding of the cellular and molecular pathogenesis of the diseases is required in order to improve the outcome for these children. In vitro-cultured primary tumor cells from patients are indispensable tools for this purpose by enabling functional analyses and development of new therapies. However, relevant well-characterized in vitro cultures from pediatric gliomas cultured under serum-free conditions have been lacking. We have therefore established patient-derived in vitro cultures and performed thorough characterization of the cells using large-scale analyses of DNA methylation, copy-number alterations and investigated their stability during prolonged time in culture. We show that the cells were stable during prolonged culture in serum-free stem cell media without apparent alterations in morphology or growth rate. The cells were proliferative, positive for stem cell markers, able to respond to differentiation cues and initiated tumors in zebrafish and mice suggesting that the cells are cancer stem cells or progenitor cells. The cells accurately mirrored the tumor they were derived from in terms of methylation pattern, copy number alterations and DNA mutations. These unique primary in vitro cultures can thus be used as a relevant and robust model system for functional studies on pediatric brain tumors.

MethPed: a DNA methylation classifier tool for the identification of pediatric brain tumor subtypes.

BACKGROUND: Classification of pediatric tumors into biologically defined subtypes is challenging, and multifaceted approaches are needed. For this aim, we developed a diagnostic classifier based on DNA methylation profiles. RESULTS: Methylation data generated by the Illumina Infinium HumanMethylation 450 BeadChip arrays were downloaded from the Gene Expression Omnibus (n = 472). Using the data, we built MethPed, which is a multiclass random forest algorithm, based on DNA methylation profiles from nine subgroups of pediatric brain tumors. DNA from 18 regional samples was used to validate MethPed. MethPed was additionally applied to a set of 28 publically available tumors with the heterogeneous diagnosis PNET. MethPed could successfully separate individual histology tumor types at a very high accuracy (κ = 0.98). Analysis of a regional cohort demonstrated the clinical benefit of MethPed, as confirmation of diagnosis of tumors with clear histology but also identified possible differential diagnoses in tumors with complicated and mixed type morphology. CONCLUSIONS: We demonstrate the utility of methylation profiling of pediatric brain tumors and offer MethPed as an easy-to-use toolbox that allows researchers and clinical diagnosticians to test single samples as well as large cohorts for subclass prediction of pediatric brain tumors. This will immediately aid clinical practice and importantly increase our molecular knowledge of these tumors for further therapeutic development.

Increase of sodium channels (nav 1.8 and nav 1.9) in rat dorsal root ganglion neurons exposed to autologous nucleus pulposus.

PURPOSE: It has been assumed that nucleus pulposus-induced activation of the dorsal root ganglion (DRG) may be related to an activation of sodium channels in the DRG neurons. In this study we assessed the expression of Nav 1.8 and Nav 1.9 following disc puncture. METHOD: Thirty female Sprague-Dawley rats were used. The L4/L5 disc was punctured by a needle (n=12) and compared to a sham group without disc puncture (n=12) and a naive group (n=6). At day 1 and 7, sections of the left L4 DRG were immunostained with anti-Nav 1.8 and Nav 1.9 antibodies. RESULT: At day 1 after surgery, both Nav 1.8-IR neurons and Nav 1.9-IR neurons were significantly increased in the disc puncture group compared to the sham and naive groups (p<0.05), but not at day 7. CONCLUSION: The findings in the present study demonstrate a neuronal mechanism that may be of importance in the pathophysiology of sciatic pain in disc herniation.

Epilepsy surgery in children with accompanying impairments.

The aim of this study was to assess seizure outcome 2 years after epilepsy surgery in a consecutive series of paediatric patients, with special focus on children with learning disabilities and other neuroimpairments in addition to the epilepsy. Outcome 2 years after surgery was assessed in 110 of 125 children operated upon for drug resistant epilepsy in Gothenburg 1987-2006. More than half of the children had learning disabilities, 43% motor impairments and 30% a neuropsychiatric diagnosis. Fifty-six per cent of those with an IQ < 70 became seizure-free or had a >75% reduction in seizure frequency, and two thirds if the operation was a resection. The corresponding figure in those with more than 100 seizures per month was 15 out of 31, and another seven had a 50-75% reduction in seizure frequency. The message is that learning disability, motor impairment and psychiatric morbidity should not be contraindications for paediatric epilepsy surgery. More than half of the children with learning disabilities had a worthwhile seizure outcome, with even better results after resective surgery. Children with drug resistant epilepsy and additional severe neurological impairments should have the benefit of referral to a tertiary centre for evaluation for epilepsy surgery.

Haemangiopericytoma presenting with acute intracerebral haemorrhage--a case report and literature review.

BACKGROUND: Intracranial haemangiopericytoma (HPC), a rare malignant tumour, should be distinguished from meningioma and solitary fibrous tumour, which have been considered as separate entities since 1993, according to histopathology and clinical characteristics. METHODS: A PUBMED search for "Intracranial Haemangiopericytoma" yielded 176 articles, where 26 were of particular interest for this review article. CASE REPORT: Our patient, a 27-year-old man with HPC of grade III according to WHO, presents with an acute intracerebral haematoma, which is extremely rare. RESULTS: Surgery (total resection) is the primary treatment. Long-term close clinical and radiological follow-up is crucial due to the high rate of recurrence and tendency for development of metastasis. DISCUSSION: The effects of postoperative radiotherapy need further investigation. Besides neurosurgery, radiotherapy should always be considered in both patients with these highly malignant tumours (WHO grade III) and in patients with partial resection or inoperable cases (WHO grade II).

Successful epilepsy surgery in a patient with neurosarcoidosis.

This case concerns a patient with generalized neurosarcoidosis and pharmacoresistant focal epilepsy. Although immunosuppressive therapy resulted in remission of the neurosarcoidosis, seizures continued and were shown to originate from the right temporal lobe (TL). The patient underwent a right anterior temporal lobe resection (TLR) and obtained >90% reduction of seizure frequency.

Juvenile galactosialidosis with attacks of neuropathic pain and absence of sialyloligosacchariduria.

Galactosialidosis (MIM 256540) is an autosomal recessive lysosomal storage disease caused by a defect of the protective protein/cathepsin A. Increased amounts of urinary sialic acid-rich oligosaccharides are considered to be an essential diagnostic marker of the disease. We here report a patient with atypical clinical features who consistently has excreted normal amounts of sialyloligosaccharides in the urine. The boy started to have attacks of neuropathic pain associated with hyperesthesia around 1(1/2) years of age. From 4 years of age when his vision was first tested, the patient developed progressive visual loss and at the age of 10 years, macular cherry-red spots were found. At this age, he also had a mild learning disability and clinical examination showed mild facial coarsening, increased lumbar lordosis and pyramidal signs in the legs. In conclusion, the clinical and laboratory features of this patient show that galactosialidosis may be considered in patients even in the absence of oligosacchariduria and that galactosialidosis should be regarded as a differential diagnosis in patients with neuropathic pain.

Human neuroblasts migrate to the olfactory bulb via a lateral ventricular extension.

The rostral migratory stream (RMS) is the main pathway by which newly born subventricular zone cells reach the olfactory bulb (OB) in rodents. However, the RMS in the adult human brain has been elusive. We demonstrate the presence of a human RMS, which is unexpectedly organized around a lateral ventricular extension reaching the OB, and illustrate the neuroblasts in it. The RMS ensheathing the lateral olfactory ventricular extension, as seen by magnetic resonance imaging, cell-specific markers, and electron microscopy, contains progenitor cells with migratory characteristics and cells that incorporate 5-bromo-2'-deoxyuridine and become mature neurons in the OB.

Neocortical neurogenesis in humans is restricted to development.

Stem cells generate neurons in discrete regions in the postnatal mammalian brain. However, the extent of neurogenesis in the adult human brain has been difficult to establish. We have taken advantage of the integration of (14)C, generated by nuclear bomb tests during the Cold War, in DNA to establish the age of neurons in the major areas of the human cerebral neocortex. Together with the analysis of the neocortex from patients who received BrdU, which integrates in the DNA of dividing cells, our results demonstrate that, whereas nonneuronal cells turn over, neurons in the human cerebral neocortex are not generated in adulthood at detectable levels but are generated perinatally.

Stereological study of neovascularization in temporal arteritis.

OBJECTIVE: As giant cell arteritis (GCA) progresses, newly formed microvessels are one of the main sites of leukocyte-endothelial cell interaction. Our aim was to stereologically map the distribution of microvessels in the temporal arterial wall and to assess their relationship to the degree of inflammation in GCA. METHODS: Inflamed temporal arteries from 21 patients who fulfilled the American College of Rheumatology criteria for GCA were analyzed. Paraffin sections, stained with an antibody directed at vascular endothelium, were analyzed stereologically. The degree of inflammation and the surface of microvascular endothelium per volume (microm2/microm3) were assessed in 4 different layers of the arterial wall. RESULTS: The degree of inflammation and of vascularization was greatest in the adventitia, smaller in the media, and smallest in the intima. A significant positive relationship was observed between the degree of inflammation and the degree of vascularization in the media and in the outer and inner layers of the intima. In 8 biopsies, the microvessels formed a prominent plexus in the intima without apparent connection with microvessels in the adventitia/media, and there were no signs of endothelial budding from the arterial lumen. CONCLUSION: Our results confirm that inflammation is a major determinant in neovascularization in GCA. Some new microvessels are formed by the budding of the adventitial vasa vasorum. The presence of intimal microvascular networks without apparent connection with microvessels in the media might indicate additional influence on neovascularization.

Giant cell arteritis: strategies in diagnosis and treatment.

PURPOSE OF REVIEW: This review summarizes current diagnostic assessments and therapeutic strategies in giant cell arteritis. Giant cell arteritis or temporal arteritis is a chronic vasculitis of large and medium-size vessels. Concurrent symptoms of proximal muscular ache and morning stiffness, polymyalgia rheumatica, are commonly seen. Recent investigations support the contention that polymyalgia rheumatica and temporal arteritis are two different expressions of the same underlying vasculitic disorder. RECENT FINDINGS: The symptomatology of giant cell arteritis is quite varying. Recently a frequent occurrence of audiovestibular manifestations was demonstrated, which should be actively searched for in the clinical investigation. Although color Doppler ultrasound, MRI, and positron emission tomography have illustrated the widespread nature of giant cell arteritis, none of these techniques may currently replace temporal artery biopsy. Biopsy of the superficial temporal artery is a safe and simple procedure, and remains the gold standard for the diagnosis of giant cell arteritis. The importance of long biopsies and meticulous histologic examination using sub-serial sectioning is emphasized. Numerous recent publications confirm the low diagnostic yield of a second, contralateral biopsy. Corticosteroids remain the cornerstone in the treatment of giant cell arteritis. Although steroid treatment promptly eliminates symptoms of systemic inflammation, its effect on inflammatory morphology is delayed. Consequently, there is a need for new therapeutic strategies. The potential role of aspirin has recently been implicated.

Evaluation of nerve cell distribution in cerebral cortex--a proposal for a new method applied to patients with epilepsy.

Microdysgenesis is a microscopic malformation of cortical development (MCD) associated with epilepsy, but its significance in epileptogenesis is debated. This is partly since the histopathological aberrations associated with microdysgenesis can also be found in normal brains. We here report a method for objective analysis of one criterion for microdysgenesis, irregular cortical nerve cell distribution. Tissue from the lateral temporal lobe from two epilepsy patients was compared with tissue from two post-mortem controls. An expansion/shrinkage factor was calculated to determine the change in tissue size during cutting and mounting. Neurons were identified and the positions of their nucleoli were marked and stored. The spatial distribution of neurons was analysed using distance to nearest neighbouring neuron and Voronoi tessellation. Specimens from the epilepsy patients expanded markedly during mounting compared with controls. Epilepsy specimens had shorter mean distances to nearest neighbour than controls and smaller Voronoi tessellation areas than controls. Both measurements suggest more densely packed neurons in epilepsy specimens. This pilot study describes a new objective method for identification of cortical neurons and their spatial distribution. Voronoi tessellation and distance to nearest neighbouring neuron might provide robust methods for objective analysis of cortical nerve cell distribution. The yield of such comparisons might be improved if each cortical layer is analysed separately.

Environmental influences on functional outcome after a cortical infarct in the rat.

The effect of postoperative housing conditions on functional outcome and brain-derived neurotrophic factor (BDNF) gene expression was evaluated 1 month after a distal ligation of the right middle cerebral artery (MCA) in spontaneously hypertensive rats. Two days postoperatively the rats were randomized into four groups; individually housed with no equipment (deprived group), individually housed with free access to a connected running wheel (running group), housed together in a large cage with no equipment (social group) or in the same size of cage furnished with bars, chains and various things to manipulate (enriched group). The enriched rats had significantly higher scores when crossing a rotating horizontal rod than deprived and running rats. The social group performed significantly better than the deprived group. The BDNF gene expression in the ipsi- and contralateral cortex, thalamus, hippocampus and cerebellum did not significantly differ between the groups. The weight of the adrenal glands was significantly increased in running rats suggesting that postischemic running may be stressful. We conclude that the beneficial effect of postischemic environmental enrichment is likely to be a combination of social and various physical activities, and that BDNF gene expression 1 month after a cortical infarct did not correlate with functional outcome.

Temporal Lobe Resections in Children with Epilepsy: Neuropsychiatric Status in Relation to Neuropathology and Seizure Outcome.

The purpose of this work was to relate clinical neuropsychiatric findings to histopathological diagnoses and seizure outcome in a retrospective study of 16 children undergoing temporal lobe resections due to medically intractable epilepsy. These children constitute a heterogeneous group in which neuropsychiatric symptoms were common. The results of this study indicate a correlation between malformations of cortical development, less chance of seizure freedom, and neuropsychiatric problems in children with pharmacoresistant temporal lobe epilepsy. It is important to include neuropsychiatric assessments pre- and postoperatively and to inform parents that symptoms of autism spectrum disorders may or may not be improved after epilepsy surgery.