Challenges for Safe Electrolytes Applied in Lithium-Ion Cells-A Review.

The aspect of safety in electronic devices has turned out to be a huge challenge for the world of science. Thus far, satisfactory power and energy densities, efficiency, and cell capacities have been achieved. Unfortunately, the explosiveness and thermal runaway of the cells prevents them from being used in demanding applications such as electric cars at higher temperatures. The main aim of this review is to highlight different electrolytes used in lithium-ion cells as well as the flammability aspect. In the paper, the authors present liquid inorganic electrolytes, composite polymer-ceramic electrolytes, ionic liquids (IL), polymeric ionic liquids, polymer electrolytes (solvent-free polymer electrolytes (SPEs), gel polymer electrolytes (GPEs), and composite polymer electrolytes (CPEs)), and different flame retardants used to prevent the thermal runaway and combustion of lithium-ion batteries (LIBs). Additionally, various flame tests used for electrolytes in LIBs have been adopted. Aside from a detailed description of the electrolytes consumed in LIBs. Last section in this work discusses hydrogen as a source of fuel cell operation and its practical application as a global trend that supports green chemistry.

Germinoma Mimicking Brain Inflammation: A Case Report.

The authors report a case of a germinoma of the brain in the child with symptoms restricted to central nervous system. Ten-year-old girl presented initially with sight deterioration, learning difficulties, abnormal behavior, polydipsia, and polyuria. Brain magnetic resonance examination revealed T2 hyperintensity of the corpus callosum, anterior commissure, and caudate nuclei. Brain biopsy revealed extensive macrophage infiltration. Given these results and positive antinuclear antibodies in the blood, immunosuppressive and immunomodulatory treatment was implemented but it was not effective. The patient developed progressive quadriparesis, sleep disturbances, and dementia. Second brain biopsy was performed and it revealed germinoma cells. Chemotherapy was administered, but the girl died due to disseminated intravascular coagulation syndrome. The reported case shows an unusual coexistence of germinoma with prominent inflammation in the brain and highlights the importance of brain biopsy in such complex cases.

Expression-based decision tree model reveals distinct microRNA expression pattern in pediatric neuronal and mixed neuronal-glial tumors.

BACKGROUND: The understanding of the molecular biology of pediatric neuronal and mixed neuronal-glial brain tumors is still insufficient due to low frequency and heterogeneity of those lesions which comprise several subtypes presenting neuronal and/or neuronal-glial differentiation. Important is that the most frequent ganglioglioma (GG) and dysembryoplastic neuroepithelial tumor (DNET) showed limited number of detectable molecular alterations. In such cases analyses of additional genomic mechanisms seem to be the most promising. The aim of the study was to evaluate microRNA (miRNA) profiles in GGs, DNETs and pilocytic asytrocytomas (PA) and test the hypothesis of plausible miRNA connection with histopathological subtypes of particular pediatric glial and mixed glioneronal tumors. METHODS: The study was designed as the two-stage analysis. Microarray testing was performed with the use of the miRCURY LNA microRNA Array technology in 51 cases. Validation set comprised 107 samples used during confirmation of the profiling results by qPCR bioinformatic analysis. RESULTS: Microarray data was compared between the groups using an analysis of variance with the Benjamini-Hochberg procedure used to estimate false discovery rates. After filtration 782 miRNAs were eligible for further analysis. Based on the results of 10 × 10-fold cross-validation J48 algorithm was identified as the most resilient to overfitting. Pairwise comparison showed the DNETs to be the most divergent with the largest number of miRNAs differing from either of the two comparative groups. Validation of array analysis was performed for miRNAs used in the classification model: miR-155-5p, miR-4754, miR-4530, miR-628-3p, let-7b-3p, miR-4758-3p, miRPlus-A1086 and miR-891a-5p. Model developed on their expression measured by qPCR showed weighted AUC of 0.97 (95% CI for all classes ranging from 0.91 to 1.00). A computational analysis was used to identify mRNA targets for final set of selected miRNAs using miRWalk database. Among genomic targets of selected molecules ZBTB20, LCOR, PFKFB2, SYNJ2BP and TPD52 genes were noted. CONCLUSIONS: Our data showed the existence of miRNAs which expression is specific for different histological types of tumors. miRNA expression analysis may be useful in in-depth molecular diagnostic process of the tumors and could elucidate their origins and molecular background.

Symptomatic Rathke cleft cyst in paediatric patients - clinical presentations, surgical treatment and postoperative outcomes - an analysis of 38 cases.

BACKGROUND: Rathke cleft cysts (RCC) are benign, epithelium-lined intrasellar and/or suprasellar cysts believed to originate from the remnants of the Rathke pouch. The aim of this study was to analyse the symptoms and surgical outcome of patients with the diagnosis of RCC verified in a histopathological examination of the postoperative material. METHODS: The study is a retrospective analysis of 38 cases of children who underwent a neurosurgical treatment due to RCC at the Children's Memorial Health Institute in Warsaw, Poland, between 1994 and 2015. RESULTS: At diagnosis, the mean age was 13 years and 8 months (6 years and 11 months-17 years and 10 months, sex ratio was 1:0.9 with a female prevalence). The most common symptoms were the following: headache (50%), hypothyroidism (50%), short stature and/or decreased growth velocity (47%), delayed puberty and menstrual abnormalities (37%), diabetes insipidus or polydipsia and polyuria (26%), adrenal dysfunction (26%), sleepiness and general weakness (13%) and visual disturbances (11%). Due to the gravity of symptoms and size of the lesion, all the patients underwent a surgical treatment. All but one were successful (one patient died due to postoperative neurosurgical complications). The most common postoperative complications were the following: adenohypopituitarism (67%) and diabetes insipidus (45%). CONCLUSIONS: RCC can present with serious symptoms that significantly deteriorate patients' quality of life. Despite a successful neurosurgical treatment in most of the analysed cases, patients required long-term pharmacological treatment.

Surgical treatment of neuronal-glial tumors of mesial-basal part of temporal lobe: Long term outcome and control of epilepsy in pediatric patients.

BACKGROUND: Neuronal-glial tumors (ganglioglioma and dysembryoplastic neuroepithelial tumor) are a frequent cause of focal, drug-resistant and epilepsy in children and young adults, that is amenable for surgical treatment. AIM OF PAPER: Assessment of late outcome of surgical treatment and degree of seizure control, as well as prognostic significance of selected clinical factors. MATERIAL AND METHOD: 52 Pediatric patients presenting with epilepsy, lesion of mesio-basal temporal lobe and histologically verified neuronal-glial tumor treated at our facility since 2000-2011. RESULTS: After the mean follow-up of 2.94 years, satisfactory treatment outcome (Engel classes I and II) was obtained in 92% of the patients (n=48). Poor outcome (Engel class III) was seen in 8% of patients (n=4). New neurological deficits appeared in 28% of the patients (n=20) but in most of them resolved over time. CONCLUSIONS: In patients with drug-resistant epilepsy and a lesion of mesial-basal part of temporal lobe suggestive of a glial-neuronal tumor, surgical treatment is strongly recommended, aiming at excision of tumor and elimination of seizures. Histological verification of the lesion is a pre-requisite for optimal treatment planning. In most patients, both treatment goals may be reached. Short duration of epilepsy prior to surgery and young age are favorable prognostic factors. Histological diagnosis of GG, co-existence of cortical dysplasia and location of tumor extending beyond mesial-basal temporal structures are associated with a higher risk of postoperative complications. These may out-weight expected benefits of surgery.

Airgun shot wound to the orbit with retention of pellet. Case report and review of the literature.

Shot wounds become a growing clinical concern in the civilian setting, due to increasing popularity of air guns among minors. We present a pediatric case of a shot wound to the orbit with sparing of the eyeball and retention of airgun pellet in the retrobulbar space. The pellet was removed 3 months after injury via lateral orbitotomy. Pathophysiology and ballistics of shot wounds are briefly reviewed and current views on the management strategy of shot wounds with retained projectile are discussed.

Contrast enhancement pattern predicts poor survival for patients with non-WNT/SHH medulloblastoma tumours.

Recent studies revealed the biological heterogeneity of medulloblastoma, with the existence of at least four groups which are associated with several clinical and morphological features. We investigated for further correlations between molecular types, location of tumours, their contrast enhancement pattern and survival of patients. Altogether 76 tumours were analyzed and molecular subtypes were identified by immunohistochemistry using representative antibodies, detection of chromosome 6 monosomy and CTNNB1 mutation. The site of the tumour was assessed on diagnosis using Magnetic Resonance images and intra-operative surgical reports. In addition, the gadolinium enhancement pattern was also investigated in pre-treatment tumours. Cerebellar hemispheric location was associated with SHH tumours (p < 0.001), as opposed to midline location being typical for WNT and non-WNT/SHH tumours. Remarkably, for patients with non-WNT/SHH tumours, the extensive gadolinium enhancement pattern (present in >75% of tumour volume) predicted worse OS and EFS than for those with none/weak or heterogeneous enhancement (>10-75% of tumour volume), (both p < 0.001). Our analysis indicates that distribution of the medulloblastoma tumours location is related to the biological characteristics of tumour. Importantly, the enhancement pattern of the tumour may be a clinically useful prognostic marker for patients with non-WNT/SHH medulloblastomas.

Angiocentric glioma: a rare intractable epilepsy-related tumour in children.

Angiocentric glioma is a low-grade tumour that occurs in children and young adults with a long-standing epilepsy. The typical histopathological features of this tumour is the presence of spindle-shaped cells, radially oriented around the cortical blood vessels. We present two teenage cases of the angiocentric variant of glioma: 1) a 15-year-old girl with a chronic and intractable partial epilepsy with cystic tumour located in the right temporal lobe and 2) a 14-year-old boy with intractable seizures and an extensive cortical lesion in the left parieto-occipital area. In both cases, the total tumours excision was performed. The histopathological findings revealed a characteristic angiocentric pattern that was composed of elongated cells arranging in pseudorosette-like structures around blood vessels. Moreover, schwannoma-like areas and subpial neoplastic infiltration with palisading of tumour cells at the brain surface were seen. The neoplastic cells displayed immunoreactivity for GFAP, S-100 protein and vimentin. A slight "dot-like" EMA staining, suggesting ependymal differentiation, was detected. The clinical and pathological picture allowed to establish the diagnosis of angiocentric gliomas. The patients were discharged home in a good condition and without seizures. During the 4-year follow-up, the tumour recurrence and seizures were not observed. The appropriate diagnosis of this peculiar type of usually low-grade glial tumour is important for adequate and successful treatment. The differential diagnosis requires the exclusion of other tumours with an angiocentric pattern, i.e. ependymoma, astroblastoma, which are associated with more aggressive biology.

Surgical treatment of subependymal giant cell astrocytoma in tuberous sclerosis complex patients.

BACKGROUND: Subependymal giant cell astrocytoma is a brain tumor associated with tuberous sclerosis complex. There are two treatment options for subependymal giant cell astrocytomas: surgery or mammalian target of rapamycin inhibitor. The analysis of outcome of subependymal giant cell astrocytoma surgery may help characterize the patients who may benefit from pharmacotherapy. METHODS: Sixty-four subependymal giant cell astrocytoma surgeries in 57 tuberous sclerosis complex patients with at least a 12-month follow-up were included in the study. The tumor size, age of the patients, mutation in the TSC1 or TSC2 gene, indication for the surgery, and postsurgical complications were analyzed. RESULTS: The mean age of patients at surgery was 9.7 years. Mean follow-up after surgery was 63.7 months. Thirty-seven (57.8%) tumors were symptomatic and 27 (42.2%) were asymptomatic. Patients with TSC2 mutations developed subependymal giant cell astrocytoma at a significantly younger age than individuals with TSC1 mutations. Four patients (6.2% of all surgeries) died after surgery. Surgery-related complications were reported in 0%, 46%, 83%, 81%, and 67% of patients with tumors <2 cm, between 2 and 3 cm, between 3 and 4 cm, >4 cm, and bilateral subependymal giant cell astrocytomas, respectively, and were most common in children younger than 3 years of age. The most common complications included hemiparesis, hydrocephalus, hematoma, and cognitive decline. CONCLUSIONS: Our study indicates that subependymal giant cell astrocytoma surgery is associated with significant risk in individuals with bilateral subependymal giant cell astrocytomas, tumors bigger than 2 cm, and in children younger than 3 years of age. Therefore, tuberous sclerosis complex patients should be thoroughly screened for subependymal giant cell astrocytoma growth, and early treatment should be considered in selected patients.

Upregulation of mitogen-activated protein kinase in ganglioglioma.

Ganglioglioma (GG) is a low-grade neoplasm, often associated with intractable epilepsy in pediatric patients. Available data suggest a relationship between GG and other glioneuronal lesions. So far, little is known about activation of kinases belonging to the mTor (mammalian target of rapamycin) pathway, although its upregulation is often found in brain tumors. Involvement of mTor kinase is responsible for excessive proliferation. In the current study we focused on the possible role of the Erk/Mapk (extracellular-signal-regulated kinase/mitogen-activated protein kinase) pathway in GG development. Eight GG tumors were resected from pediatric patients. Collected data reveal activation of proteins from the Erk pathway: Mek (extracellular regulated protein kinase kinase/mitogen-activated protein kinase kinase), Erk, Rsk1 (ribosomal S6 kinase 1), Rheb (Ras homolog enriched in brain) and Msk1 (mitogen- and stress-activated protein kinase 1), as detected by the western blot method. Moreover, activation of other proteins upstream of mTor - IGF-1R ß (insulin-like growth factor 1ß receptor), INR ß (insulin receptor ß), Akt/PKB (protein kinase B) - or downstream - 4E-BP1 (eukaryotic translation initiation factor 4E-binding protein 1) and rpS6 (ribosomal protein S6) - was also confirmed.

Giant cerebellar cavernous malformation in 4-month-old boy. Case report and review of the literature.

Cavernous malformations (CMs) are rare vascular lesions that affect 0.4-0.9% of the population. The diagnosis of CMs is simple in most typical cases although some lesions may present unusual imaging features: localization, signal intensity, or size. Extremely rare giant CMs can mimic neoplastic lesion because of their size. We report a case of giant cerebellar CM that is more than 6 cm in size, diagnosed in 4-month-old boy. We discuss magnetic resonance findings and histopatholo-gical features of this lesion.

Matrix metalloproteinase-9 (MMP-9) in human intractable epilepsy caused by focal cortical dysplasia.

Focal cortical dysplasia (FCD) is a developmental brain disorder characterized by localized abnormalities of cortical layering and neuronal morphology. It is associated with pharmacologically intractable forms of epilepsy in both children and adults. The mechanisms that underlie FCD-associated seizures and lead to the progression of the disease are unclear. Matrix metalloproteinases (MMPs) are enzymes that are able to influence neuronal function through extracellular proteolysis in various normal and pathological conditions. The results of experiments that have used rodent models showed that extracellular MMP-9 can play an important role in epileptogenesis. However, no studies have shown that MMP-9 is involved in the pathogenesis of human epilepsy. The aim of the present study was to determine whether MMP-9 plays a role in intractable epilepsy. Using an unbiased antibody microarray approach, we found that up regulation of MMP-9 is prominent and consistent in FCD tissue derived from epilepsy surgery, regardless of the patient's age. Additionally, an up regulation of MMP-1, -2, -8, -10, and -13 was found but was either less pronounced or limited only to adult cases. In the dysplastic cortex, immunohistochemistry revealed that the highest MMP-9 immuno reactivity occurred in the cytoplasm of abnormal neurons and balloon cells. The neuronal over expression of MMP-9 also occurred in sclerotic hippocampi that were excised together with the dysplastic cortex, but sclerotic hippocampi were free of dysplastic features. In both locations, MMP-9 was also found in reactive astrocytes, albeit to a lesser extent. At the subcellular level, increased MMP-9 immunoreactivity was prominently upregulated at synapses. Thus, although upregulation of the enzyme in FCD is not causally linked to the developmental malformation, it may be a result of ongoing abnormal synaptic plasticity. The present findings support the hypothesis of the pathogenic role of MMP-9 in human epilepsy and may stimulate discussions about whether MMPs could be novel therapeutic targets for intractable epilepsy.

Bacteria and Candida yeasts in inflammations of the oral mucosa in children with secondary immunodeficiency.

BACKGROUND: Oral microbial flora and a damaged oral mucosa may increase the risk of bacteriemia, fungemia and complications in immunocompromised patients. AIM OF THE STUDY: Assessment of presence: bacteria and Candida spp. in different oral lesions, and the incidence of bacteremia in the case of a damaged mucosa in transplant recipients and patients receiving anti-tumour chemotherapy. MATERIAL AND METHOD: Forty-five patients ­ 18 months to 18 years of life, were included (20 ­ organ recipients, 14­ anti-tumour chemotherapy, 11 ­ control group). Clinical, oral mucosa examination focused on the type, severity and site of lesions, and microbiology assessed the presence of bacteria and fungi in the material from lesions. Blood cultures were performed in ten immunocompromised patients with manifestations of systemic infection. The control material consisted of blood cultures made prior to the onset of oral lesions and after 4­6 weeks following their remission in a diagnosed bacteremia. The statistical analysis was performed. RESULTS: In the subjects with secondary immunodeficiency, among other coagulase-negative Staphylococcus (CoNS), Candidia spp. were more frequent. In cancer patients, mucositis was associated with Candida spp., Streptococcus spp. Organ recipients with stomatitis exhibited the presence of CoNS, Streptococcus viridians and other. Oral lesions in the control group contained Haemophilus parainfluenzae, Neisseria spp. and Staphylococcus aureus. In 30% of immunocompromised patients, oral lesions were accompanied by bacteremia. CONCLUSIONS: A correlation has been found between oral lesions and the presence of S. aureus in patients without secondary immunodeficiency, and of CoNS, Enterococcus spp., Candida spp. in immunocompromised patients.

Congenital brain tumors in a series of 56 patients.

INTRODUCTION: Central nervous system tumors diagnosed before the end of the first year of life differ from those found in older children and in adults. The differences include mode of clinical presentation, anatomical distribution, histopathological diagnoses, response to therapy, and outcome. MATERIALS AND METHODS: The material consists of 56 children (23 girls and 33 boys), aged at recognition 32 Hbd-12 months. We reviewed charts and MR exams according to age of the onset of symptoms, location of tumors, treatment, histopathology, and outcomes. Data of the outcome were analyzed using Kaplan-Meier plots and chi-square test. RESULTS: Eleven cases were recognized before 6 weeks of life, 24 before the age of 6 months, and 21 were diagnosed up to the end of 1 year of age. Thirty-eight tumors were located in the supratentorial compartment; 18 were infratentorial. Median age of tumors' recognition was 5.2 months; 4.3 months for supratentorial and 7.2 months for infratentorial tumors. We found 18 glial cell tumors (high and low grade), 15 embryonal tumors, and 12 choroid plexus tumors. CONCLUSIONS: The outcome of congenital CNS tumors depends on the size, location, time of diagnosis, histological type of the tumor, and therapeutic option. Neurosurgical procedures are necessary in most cases. Despite the notable advances in therapy, the outcome remains poor.

Subependymal giant cell astrocytomas with atypical histological features mimicking malignant gliomas.

Subependymal giant cell astrocytoma (SEGA) is a rare, benign brain tumour developing in patients with tuberous sclerosis complex (TSC). Typical histopathological findings of this neoplasm are solid sheets and perivascular pseudorosettes of large, gemistocytic, polygonal and occasionally ganglion-like cells within a fibrillated background, accompanied by spindle-shaped cells creating broad fascicles. Rich vascular stroma, and numerous calcifications are common. Mitoses, focal necrosis, and endothelial proliferation are rarely encountered. In this study we report 3 cases of SEGA out of 29 TSC patients, operated on in the Department of Neurosurgery, Children's Memorial Health Institute, from 1990 to 2011 and retrospectively reviewed. These 3 cases exhibited distinct anaplastic features that might mimic malignant glioma. Histologically, the tumours were composed of pleomorphic, gemistocytic, polygonal, ganglion-like or multinucleated cells arranged in sheets or forming perivascular pseudorosettes. Numerous foci of necrosis, microvascular proliferation and high mitotic activity with atypical mito-tic figures were documented. The Ki67 labelling index was about 15-20%. These tumours might be confused with high-grade gliomas and such a misleading diagnosis might result in aggressive radio- or chemotherapy. Despite the common statement that morphological features of anaplasia, i.e. pleomorphism, necrosis, microvascular proliferation and increased mitotic activity, are not of prognostic value, the tumour behaviour in our cases seems to be more aggressive and requires longer follow-up studies. We suggest recognizing such cases of subependymal giant cell astrocytoma as atypical SEGAs.

Cognitive and social functioning in children and adolescents after the removal of craniopharyngioma.

PURPOSE: The aim of this study is to assess cognitive, emotional and social functioning in children and adolescents after the removal of craniopharyngioma. METHODS: Twenty-seven children operated for craniopharyngioma and their parents participated in the study. Cognitive functions were assessed with WISC-R/WAIS-R-PL and Rey-Osterrieth Complex Figure Test. Parents completed Achenbach's Child Behaviour Checklist (CBCL) questionnaires on problems in functioning and psychopathological symptoms and took part in an interview on children coping in everyday life. RESULTS: Eighty-two percent of patients were diagnosed with an average level of intellectual functioning. No child received results indicating mental disability. In half of the children, effectiveness of visual memory was reduced, despite normal visual-spatial abilities. The results in the CBCL scale indicated more frequent presence of psychopathological symptoms-especially social problems, depression, anxiety and withdrawal. The most frequent problems in children's everyday functioning included inability to control emotions, difficulties in learning, unsatisfactory peer relationships, and unattractive appearance resulting from hormonal disorders (short height and obesity). One third of parents also reported problems with pathological appetite in their children. CONCLUSIONS: Despite normal intellectual abilities and relatively good physical condition, children after removal of craniopharyngioma experience many difficulties in everyday life regarding social relationships, emotion control and learning. The analogy between the above-mentioned symptoms and symptoms observed in patients after infantile damage in the frontal area leads to an observation that, apart from endocrine disorders, damage to the frontal lobe caused by the growth of tumour and operational intervention is of crucial importance to the further development of children with craniopharyngioma.

Ganglioglioma associated with alterations of NBN gene. A case report.

We report a case of a 13-year-old girl with a tumour of the right fronto-parietal region of the brain. The tumour consisted of two components: a well-differentiated astroglial component with Rosenthal fibres and a neoplastic neuronal component. The final histopathology established diagnosis of ganglioglioma WHO grade I. The patient was selected from a group of children with central nervous system (CNS) tumours screened for the most common molecular variants in the NBN gene (exons 5 and 6). Molecular analysis revealed the presence of c.511A>G (p.Ile171Val) substitution on one allele. This is the first patient with ganglioglioma and confirmed mutation in the NBN gene.

Neuronavigation-guided implantation of foramen ovale electrodes in a child.

The purpose of this paper is to present a novel technique of implantation of foramen ovale electrodes under neuronavigation guidance. The technique is simple, safe, and effective, greatly reducing the patient's trauma, the operating time, and the surgeon's stress.

Long-term functional outcome of surgical treatment of juvenile pilocytic astrocytoma of the cerebellum in children.

PURPOSE: Increasing incidence of pediatric brain tumors and improving survival rates encouraged us to assess long-term functional outcome of patients with cerebellar juvenile pilocytic astrocytoma (JPA). MATERIALS AND METHODS: Our study encompassed 105 children treated since 1980-2005 and consisted in analysis of mailed, custom-designed questionnaires. RESULTS: Mean follow-up time was 8.3 years. Sixty out of 104 patients presented permanent neurological deficits and 47/104 presented significant behavioral disorders. Eighty-nine children continued their education at primary, secondary or high school level. Most patients and their parents were satisfied with treatment outcome. Patients' and parents' notes were usually concordant. CONCLUSIONS: Long-term functional treatment outcome of cerebellar JPA is relatively favorable, in spite of permanent neurological deficits and emotional disorders in over half of the patients. Vermian tumors are associated with worse long-term functional outcome. Neurological deficits and emotional disorders do not preclude further education and independent functioning.

Papillary ependymoma with unique superficial cortical location: immunohistochemical and ultrastructural studies. A case report.

Ependymomas are relatively rare neoplasms of the central nervous system that typically develop along cerebral ventricles and central canal of spinal cord. Occasionally, the tumours of ependymal origin arise supratentorially in brain parenchyma as ectopic cortical mass without any connection to the ventricular system. Ependymomas are heterogeneous group of tumours including cellular, papillary, clear cell and tanacytic histology. The papillary ependymoma is an unusual variant of ependymoma characterized by distinct morphology resembling other papillary tumours and corresponding to WHO grade II malignancy. We present an unique case of ependymoma with distinctive papillary morphology at ectopic superficial cortical localization. The tumour occurred in eleven-years-old girl as a large, well-circumscribed mass in the left parietal lobe without continuity with the ventricular system. The patient presented with severe headache, vomiting and sudden-onset right hemiparesis. Histopathologically, the tumour revealed distinct papillary pattern with numerous pseudorosettes. Immunohistochemically, the neoplastic cells of both papillary structures and pseudorosettes were positive for glial fibrillary acidic protein and vimentin, whereas they were only slightly immunoreactive for epithelial membrane antigen and negative for cytokeratins. Ultrastructural findings revealed the presence of cilia usually located in the neoplastic cell bodies and intermediate glial-like filaments. The final diagnosis of papillary ependymoma at ectopic superficial localization was based on both, immunophenotypic profile and ultrastructural features that confirmed ependymal nature of neoplastic cells.