Choroid Plexus Papilloma Research Articles

A Rare Case of Endolymphatic Sac Tumour: Clinical, Radiological, Pathological and Immunohistochemical Findings with Review of Literature.

Endolymphatic sac tumour (ELST) is a rare low grade malignant epithelial tumour of the petrous temporal bone, thought to arise from papillary epithelium of the endolymphatic sac. They may occur sporadically or in association with Von-Hippel Lindau disease. ELST is extremely rare neoplasm with benign histopathological appearance and clinically destructive behaviour. Because of the rarity of this tumour, it can easily be confused with other tumours such as paraganglioma, middle ear adenoma, metastatic carcinomas or choroid plexus papilloma. We report here a rare case of ELST with review of literature and discuss the differentiating features of ELST from its mimickers, showing a papillary configuration.

CTNI-69. PRECISION NEURO-ONCOLOGY TREATMENT GUIDED BY NEXT GENERATION SEQUENCING (NGS)-BASED COMPREHENSIVE GENOMIC PROFILING: REAL WORLD EXPERIENCE IN HONG KONG

Abstract BACKGROUND The development of next generation sequencing (NGS) based comprehensive genomic profiling (CGP) has enabled identification of druggable somatic mutations in brain tumours. This cohort reviewed the efficacy of CGP-guided precision treatment in a tertiary neuro-oncology centre. METHODOLOGY From May 2017 to May 2020, CGP were arranged for 43 patients. All patients had exhausted conventional treatments or received CGP for clinical trial screening. Targeted deep NGS was used to assess the mutational status, single nucleotide variant, small insertions and deletions and copy number variant of 440 cancer-related genes. RESULTS The diagnoses of the 43 patients were GBM (n=23), high grade glioma (n=11), brain metastases (n=4), chordoma (n=3), atypical choroid plexus papilloma (n=1) and meningioma (n=1). In most of the patients (42/43, 97.7%), CGP identified at least one druggable targets with a median of 3. Based on the CGP, 27 patients received precision treatment (62.7%). Among these, 14 were GBM and 6 were other high grade glioma. Treatment given included PARP inhibitors, immunotherapy, multi-kinase inhibitor, selective CDK4/6 inhibitor and mTOR inhibitor. Clinical benefit was achieved in 20 patients out of 27 (74%), including 2 complete response (7.4%), 9 partial response (33.3%) and 9 stable disease (33.3%). The median progression free survival (PFS) were 183 days [95% confident intervals (CI): 81–302 days]. For GBM/high grade glioma patients, median PFS was 125 days [95% CI: 52–215] and six-month PFS was 32.7%. Treatment toxicity was mild except two patients developed grade 3 complications and one grade 5 complication (fatal neutropenic fever). For the 16 patients who did not receive precision treatment, one had no druggable target identified, nine were still stable on standard therapies, 6 were too weak when CGP was available. CONCLUSION CGP guided precision treatment for selected, advanced neuro-oncological patients yielded modest clinical efficacy and satisfactory safety profile in real world setting.

Intracranial Hemorrhage

Intracranial Hemorrhage

Pediatric atypical choroid plexus papilloma: Clinical features and diagnosis

ObjectiveAtypical choroid plexus papilloma (aCPP) is a newly introduced subtype of choroid plexus tumors (CPTs) defined by the World Health Organization (WHO) in 2007 and is characterized by intermediate characteristics between choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC). Currently, the available data describing the clinical features of aCPP in children are limited. MethodsWe performed a retrospective review of 24 pediatric patients with CPTs in our institute and focused on the clinical, radiological and histopathological features of 9 patients with aCPP. ResultsThe median age of aCPP patients was 12 (3−144) months, which was younger than the age of CPP patients (36 (5−132) months, P < 0.05). Of the 9 aCPPs, there were 4 cases of giant masses in the cerebral hemisphere, which was significantly higher than that in CPPs (44.4 % vs 0.0 %, P < 0.05). According to MRI analysis, cysts and necrosis (66.7 % vs 16.7 %, P < 0.05), peritumoral edema (55.6 % vs 8.3 %, P < 0.05) and blurred borders (55.6 % vs 8.3 %, P < 0.05) were more common in aCPPs than in CPPs. T1WI isointense signals were mainly observed in aCPPs and CPPs (aCPP66.7 % vs CPP58.3 %, P >0.05), while T2WI slightly low signals were more common in CPPs (CPP41.7 % vs aCPP0%, P < 0.05); moreover, the tumor volume of aCPPs was significantly larger than that of CPPs (aCPP78.3 cm3 vs 8.4 cm3, P < 0.05). For the DWI sequence scans, isointense signals were more common in aCPPs (aCPP77.8 %>CPP25.0 %, P < 0.05), while slightly low signals were more common in CPPs (CPP58.3 %>aCPP0%, P < 0.05). Both aCPPs and CPPs mainly showed homogeneously strong enhancement (aCPP66.7 % vs CPP91.7 %, P > 0.05). Interestingly, 1 aCPP showed annular enhancement. For the pathological and immunohistochemical studies, the Ki67 proliferation index was significantly higher in aCPPs than in CPPs (13 % vs 6%, P < 0.05), and the S-100(+)/Vim(+)/Syn(+) positive rate was higher in aCPPs (58.3 % vs 11.1 %, P < 0.05). ConclusionsaCPP shows some distinctive clinical features compared with CPP, such as younger age, larger tumor size, more frequent necrosis and peritumoral edema, blurred borders, slightly low signals on T2WI and isointense signals on DWI, and a higher S-100(+)/Vim(+)/Syn(+) positive rate, which may provide more valuable evidence for differential diagnosis and clinical decisions surrounding aCPP.

Fourth ventricle tumors in children: complications and influence of surgical approach.

The goal of this study was to characterize the complications and morbidity related to the surgical management of pediatric fourth ventricle tumors. All patients referred to the authors' institution with posterior fossa tumors from 2002 to 2018 inclusive were screened to include only true fourth ventricle tumors. Preoperative imaging and clinical notes were reviewed to extract data on presenting symptoms; surgical episodes, techniques, and adjuncts; tumor histology; and postoperative complications. Three hundred fifty-four children with posterior fossa tumors were treated during the study period; of these, 185 tumors were in the fourth ventricle, and 167 fourth ventricle tumors with full data sets were included in this analysis. One hundred patients were male (mean age ± SD, 5.98 ± 4.12 years). The most common presenting symptom was vomiting (63.5%). The most common tumor types, in order, were medulloblastoma (94 cases) > pilocytic astrocytoma (30 cases) > ependymoma (30 cases) > choroid plexus neoplasms (5 cases) > atypical teratoid/rhabdoid tumor (4 cases), with 4 miscellaneous lesions. Of the 67.1% of patients who presented with hydrocephalus, 45.5% had an external ventricular drain inserted (66.7% of these prior to tumor surgery, 56.9% frontal); these patients were more likely to undergo ventriculoperitoneal shunt (VPS) placement at a later date (p = 0.00673). Twenty-two had an endoscopic third ventriculostomy, of whom 8 later underwent VPS placement. Overall, 19.7% of patients had a VPS sited during treatment.Across the whole series, the transvermian approach was more frequent than the telovelar approach (64.1% vs 33.0%); however, the telovelar approach was significantly more common in the latter half of the series (p < 0.001). Gross-total resection was achieved in 70.7%. The most common postoperative deficit was cerebellar mutism syndrome (CMS; 28.7%), followed by new weakness (24.0%), cranial neuropathy (18.0%), and new gait abnormality/ataxia (12.6%). Use of intraoperative ultrasonography significantly reduced the incidence of CMS (p = 0.0365). There was no significant difference in the rate of CMS between telovelar or transvermian approaches (p = 0.745), and multivariate logistic regression modeling did not reveal any statistically significant relationships between CMS and surgical approach. Surgical management of pediatric fourth ventricle tumors continues to evolve, and resection is increasingly performed through the telovelar route. CMS is enduringly the major postoperative complication in this patient population.

Posterior fossa tumors in children, Histopathology &amp;extent of excision as prognostic factors

The Posterior fossa is the commonest site of primary intracranial tumors in children, for the last two decades the over-all survival and 5-years progression-free survival of children with posterior fossa tumors (PFT) like Medulloblastoma&amp; Ependymomas has been doubled due to the improvement in the diagnostic tools and the advances in the surgical techniques approaching total or near total resection. The aim of the study is to find the relation of histopathology and the extent of excision with mortality and survival. A total of twenty eight cases with Histologically (26 cases) and two cases radiologically (CT-scan and MRI) confirmed pediatric posterior fossa tumors treated in Erbil Teaching Hospital between ,Jan.2013 and Dec.2015 were included in the study As a result the twenty-eight pediatric patients were included in the study, mean age was (8 years),16 boys and 12 girls, mean follow-up period was 14 months,11 cases had Medulloblastoma (39%), 5 cases had Ependymoma (18%), 9 cases had Astrocytoma(32%) , 2 cases had Brainstem mass (7%) and one case had Choroid plexus papilloma (4%).Tumor resection was performed in 26 patients, Twenty cases had total resection (77%), and six Pts .had subtotal resection (23%), two cases without surgery During the follow-up period out of the 20 cases that had total resection nineteen are still alive(95%) and only one died (5%),six cases that had Subtotal resection; four of them are dead (67%) and only two cases are still alive(33%). Two cases that had no surgery both of them are dead (100%).Eleven cases of Medulloblastoma 8 of them had gross total resection and three of them had subtotal resection, 9 of them still alive (82%) and two are dead (18%). Nine Pts of Astrocytoma, 8 of them had total resection and one subtotal; eight of them are still .(alive (89%) and only one died (11%Five pts with Ependymoma, three had total resection and two had subtotal resection, three are still alive (60%) and two dead (40%). Two cases of Brainstem mass not operated and both are dead, One case of Choroid papilloma totally resected &amp; still alive. In conclusion treatment of posterior fossa tumors in children with surgery yields long survival rates, children with gross total resection or a near total resection had better outcome. Histopathology subtypes of the tumors were associated with a favorable outcome for Astrocytoma which has less mortality and better survival rate than others

The radiotherapy utilization rate in pediatric tumors: An analysis of 13,305 patients

PurposeAlthough the radiotherapy utilization rate (RUR) is determined for most adult cancers, it is seldom reported in childhood tumors, particularly in low- and middle-income countries (LMIC) where the majority of pediatric cancer patients reside. This study aims to investigate the real-life RUR for pediatric tumors in a large LMIC center. Materials and methodsThe electronic files of patients treated at a single institution during 2010–2017 were reviewed and the RUR was defined as the percentage of patients who received at least one radiotherapy (RT) course from the total number of patients. ResultsA total of 4390 out of 13,305 pediatric cancer patients received at least one RT course with a RUR of 33%. The curative, salvage, and palliative RURs were 27.8%, 2%, and 5.7%, respectively. There was a considerable variation in the RUR between various tumors, ranging from 0% in choroid plexus papilloma and other rare tumors to 100% in intracranial germinoma. Moreover, the RUR varied among different stages within each tumor type. Overall, 753 patients received 920 palliative RT courses (range 1–9) at a median dose of 30 Gy. The most commonly irradiated metastatic sites were the bone (34%) and the brain (9.8%). ConclusionThis is the first analysis to provide valuable insights into the RUR for childhood tumors. Together with population-based pediatric cancer registries, this will help decipher pediatric RT needs and deficits. Additionally, the underutilization of palliative RT calls for multidisciplinary palliative care provision for pediatric cancer patients.

Torticollis as a Rare Presentation of Cerebellopontine Angle Choroid Plexus Papilloma in Children

Background and Importance: The rare intracranial neoplasms are Choroid Plexus Papillomas (CPPs), especially in the cerebellopontine angle. The main location of choroid plexus papillomas in adults and children are 4th ventricle and lateral ventricles, respectively. Case Presentation: We report on a little girl with a cerebellopontine angle CPP who presented with symptoms of torticollis. Assessment of Magnetic Resonance Imaging showed a mass in the right cerebellopontine angle, next to the brain stem. The tumor was completely resected using the right retrosigmoid approach method. A pathological examination determine a typical CPP that this being should be considered an extremely rare cause of a lesion in the posterior fossa. Conclusion: CPP is usually presented in the atrium of the lateral ventricle in children; however, we reported a rare case in the cerebellopontine angle.

Incidental Findings on Brain Magnetic Resonance Imaging (MRI) in Pediatric Endocrine Patients

Objective: To explore incidental findings on brain magnetic resonance imaging (MRI) studies of pediatric patients referred due to endocrine disorders.Methods: A retrospective, observational study conducted in a tertiary referral center. The neuroimaging database of 17,445 brain MRI studies of 11,011 pediatric patients were searched for cases with endocrine referrals and without medical history of malignancy, genetic syndromes, and/or neurologic comorbidities. This database was linked to the pediatric neurosurgical database. Clinical data were retrieved from medical files.Results: In total, 524 patients (50.2% males, mean age 8.5±3.5 years) were referred to brain MRI due to growth disturbances (n = 313), pubertal disorders (n = 183), prolactin hypersecretion (n = 18), central diabetes insipidus (n = 8), and obesity (n = 1). Incidental findings were found in 128 (24.4%) cases. Chiari type 1 malformation was more prevalent in patients with growth disturbances (P<.001). Small pituitary cysts were observed in 20 (3.8%) patients, and pineal cysts in 25 (4.8%) patients, mostly girls (68%, P<.001). White matter lesions were diagnosed in 30 (5.7%) patients, none with clinical evidence of neurologic disease. Brain asymmetry without clinical significance and developmental venous anomalies were observed in 14 (2.7%) and 8 (1.5%) patients, respectively. Twelve patients were diagnosed with intracranial tumors, and 5 required surgical intervention for a histopathologic diagnosis of juvenile pilocytic astrocytoma (n = 3), choroid plexus papilloma (n = 1), or inconclusive (n = 1). The rest were managed conservatively.Conclusion: Incidental findings on brain MRIs of pediatric patients referred by endocrinologists are common and raise dilemmas. The spectrum ranges from structural disruptions to tumors. Decision-making is individualized and patient-centered.

Midline Posterior Fossa Tumors in Young Adults: Evolution of Thought and Practice

Objective: The aim of our study was to evaluate the surgical outcome of posterior fossa lesions and to find out the relation between surgical skill and post-operative outcome and to determine how evolution in surgical skill dictates post-operative outcome.&#x0D; Material &amp; Methods: This was a retrospective analysis of 207 patients with midline posterior fossa lesions over a period of 10 years from Jan 2009 till December 2018. The degree of surgical outcome was assessed by degree of surgical resection, Post-operative neurological deficits and complications, Stay in ICU and duration in hospital.&#x0D; Results: 207 Midline posterior fossa tumors were operated. Headache was leading symptom in patients followed by vomiting and balance problem. Medulloblastoma was a most common pathology in 133, Ependymoma 32, Astrocytoma in 28 Choroid Plexus Papilloma in 3, dermoid cyst 3,arachnoid cyst 4 and Hemangioblastoma in 4 patients. Gross Total resection was possible in 110 patients. Post operatively gag reflex was impaired in 36 and facial palsy in 5 patients. Chest infection was the most common complication in 84 patients, followed by wound infection, CSF Leak and Meningitis. Mortality was 11.59% as 24 patients died within one month, while 28.5% patients stayed in ICU.&#x0D; Conclusion: Post-operative mortality and morbidity is relatively high among post fossa tumors. Improvement in surgical skills better instruments revealed better outcome over a period of 10 years due to better understanding of microsurgical anatomy and utilization of modern therapeutic strategies for resection.

Pediatric choroid plexus papilloma arising from the cerebellopontine angle: systematic review with illustrative case.

Choroid plexus tumors are uncommon intraventricular tumors that develop from the choroid plexus of the central nervous system. Choroid plexus papillomas arising from the cerebellopontine angle have been reported to almost exclusively occur in adults and are rarely found in children. We report a systematic review conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines of SCOPUS and PubMed databases for case reports and case series of choroid plexus papillomas arising in the cerebellopontine angle in the pediatric population and discuss clinical presentation, imaging features, management options, and outcomes. We also report a case managed at our center. Ten cases of pediatric choroid plexus papillomas arising in the cerebellopontine angle were identified from the systematic review in addition to the case reported here, resulting in a total of eleven cases. The patients' median age was 8years with a slight female sex predilection (1.2:1). Patients most commonly presented with headache, cerebellar signs, and cranial nerve palsies with median duration of symptoms at 4months. All patients underwent surgical treatment with majority achieving gross total excision. No deaths were reported at median follow-up of 12months. Complete neurologic recovery was attained in seven cases while partial recovery was seen in two cases. Choroid plexus papillomas found in the cerebellopontine angle in the pediatric population are extremely rare but they should be considered in the differential diagnosis. Complete surgical resection is the mainstay of treatment with excellent outcomes achievable in majority of patients.

Foramen magnum papilloma case report and review of the literature

Atypical choroid plexus papillomas are rare in adults, especially in an extraventricular location. We present a case of a 42-year-old male patient suffering from a foramen magnum choroid plexus papilloma, which resembled meningioma in an initial evaluation, who developed dizziness, hearing loss, and gait disturbance. The patient was treated with suboccipital craniotomy and the tumor was partially removal. We describe the technique and postoperative complications. We also review other published cases of atypical choroid plexus papillomas of the posterior fossa in adults. Keywords: Papilloma; foramen magnum; suboccipital craniotomy; posterior fossa

Intraventricular choroid plexus tumors: clinical characteristics and impact of current management on survival

Choroid plexus tumors (CPTs) represent one of the most common intraventricular tumors. Although most are benign, they often reach considerable sizes before clinical manifestation, challenging their surgical management. We aim to describe the clinical characteristics and the impact of current management on the survival of patients harboring intraventricular CPT. The National Cancer Database (NCDB) was queried to identify biopsy-proven intraventricular CPT patients (2004-2015). Demographic and patterns of care were described, the log-rank method was used to independently analyze survival according to age, WHO grade and extent of resection (EOR). Multivariate analysis was performed to investigate the impact of prognostic factors on overall survival (OS). A total of 439 CPT patients with known WHO grade were included. WHO grade I tumors were more frequent in adults, while WHO grade III tumors were more common in pediatric population. Most CPTs were benign, with a median tumor size of 3-4cm. Mean tumor size in pediatric population was greater than in adult population (4.39cm vs. 2.7cm; p < 0.01). Frequency was similar between males and females (51.7% vs. 48.3%; p > 0.0.5). Five- and ten-year OS among all patients was 87% and 84%, respectively. EOR was not associated with survival for any WHO grade. On multivariable analysis, only patient age (p = 0.022), WHO grade (p = 0.003) and medical comorbidity scores (p = 0.002) were independently associated with OS after diagnosis. Patients with CPTs present at different stages of life, with sizable tumor burden and distinct WHO grade prevalence. Considering their favorable survival, efforts to improve tumor control should be meticulously weighed against the long-term risk associated with surgery, radiation, and chemotherapy.

Transcallosal Interforniceal Approach for a Large Choroid Plexus Tumor in a 4-Month-Old Boy: 2-Dimensional Operative Video.

Tumors in the third ventricle constitute a challenge for the neurosurgeon, regardless of the chosen approach. The additional risk of severe blood loss in the pediatric population, specially for choroid plexus tumors, which are the most common ventricular tumors in children, adds a significant challenge in these cases. Therefore, a careful selection of the approach in addition to surgical technique is crucial for a favorable outcome. In this video, we discuss the approach selected for the treatment of a large choroid plexus tumor in a 4-mo-old male and highlight the surgical technique chosen for this case, a transcallosal interforniceal approach.1 Appropriate consent for the video authorization and the procedure was obtained from the parent of the patient. Images in video from Rhoton AL Jr, The Cerebrum, Neurosurgery, 2007, 61, suppl_1, SHC-37-SHC-119, by permission of the Congress of Neurological Surgeons.

The Smallest Choroid Plexus Papilloma at the youngest age of presentation ever reported

The Smallest Choroid Plexus Papilloma at the youngest age of presentation ever reported

Polar Infection of Echovirus-30 Causes Differential Barrier Affection and Gene Regulation at the Blood-Cerebrospinal Fluid Barrier.

Echovirus-30 (E-30) is responsible for the extensive global outbreaks of meningitis in children. To gain access to the central nervous system, E-30 first has to cross the epithelial blood–cerebrospinal fluid barrier. Several meningitis causing bacteria preferentially infect human choroid plexus papilloma (HIBCPP) cells in a polar fashion from the basolateral cell side. Here, we investigated the polar infection of HIBCPP cells with E-30. Both apical and basolateral infections caused a significant decrease in the transepithelial electrical resistance of HIBCPP cells. However, to reach the same impact on the barrier properties, the multiplicity of infection of the apical side had to be higher than that of the basolateral infection. Furthermore, the number of infected cells at respective time-points after basolateral infection was significantly higher compared to apical infection. Cytotoxic effects of E-30 on HIBCPP cells during basolateral infection were observed following prolonged infection and appeared more drastically compared to the apical infection. Gene expression profiles determined by massive analysis of cDNA ends revealed distinct regulation of specific genes depending on the side of HIBCPP cells’ infection. Altogether, our data highlights the polar effects of E-30 infection in a human in vitro model of the blood–cerebrospinal fluid barrier leading to central nervous system inflammation.

Abstract LB-221: Aggresome-based classification is a promising prognostic marker for pediatric choroid plexus tumors

Abstract Protein misfolding and aggregation result in proteotoxic stress, and underlie the pathogenesis of many diseases. To overcome proteotoxicity, cells compartmentalize misfolded and aggregated proteins in different inclusion bodies. Aggresome is a paranuclear inclusion body that functions as a storage compartment for misfolded proteins. Our previous work revealed the presence of aggresomes in pediatric choroid plexus tumors (CPT). CPTs are rare neoplasms comprised of three pathological subgroups; choroid plexus carcinoma (CPC), a grade III tumor, atypical choroid plexus papilloma (ACPP), a grade II tumor, and choroid plexus papilloma (CPP), a grade I tumor. In the current study, we aimed to investigate the prognostic value of aggresomes-positivity and if it could be used to improve the disease subclassification. Forty two pediatric CPT tumor samples were stratified into two molecular subgroups; Cluster “A", and “B”, using Illumina Infinium Methylation EPIC BeadChip array. Kaplan Meier analysis showed that “cluster B” is associated with significantly shorter overall survival (OS) and event free survival (EFS) with P= 0.008 and P =0.007 respectively. Aggresomes were detected in 64.2% of samples using immunohistochemistry and they were distributed among different pathological and molecular subgroups. The presence of aggresomes significantly correlated with patient outcome in both OS (P = 0.057) and EFS (P = 0.051). The survival-based cutoff determination was performed using various percentages of aggresomes; ranging from 10% to 50%. Aggresome presence maintained significance at all cutoffs, yet the 25% cutoff had the highest impact in OS and EFS (P = 0.001). Moreover, the classification based on the 25% cutoff concurred with the methylation signature of low-risk “A” and high-risk “B” clusters. Hence, the detection of aggresomes in CPTs provides a new prognostic marker supporting histopathological tumor classification. Citation Format: Nada Amer, Hala Taha, Dina Hesham, Noura Mahmoud, Moatasem Elayadi, Amal Mossab, Ayda Youssef, Mohamed Elbeltagy, Mohamed Saad Zaghloul, Ahmad Abdel Azziz, Shahenda El-Naggar. Aggresome-based classification is a promising prognostic marker for pediatric choroid plexus tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-221.

Abstract LB-173: DNA methylation analysis reveals epigenetic regulation of neural differentiation in AT/RTs

Abstract DNA methylation has proven to be powerful for brain tumor characterization and diagnostic classification. To obtain information about the oncogenic role of DNA methylation, we analyzed medulloblastoma, choroid plexus, and atypical teratoid/rhabdoid tumors (AT/RTs) with public data from 450K-methylation arrays (N=584) and gene-expression arrays (N=110). In addition, two AT/RTs, five choroid plexus tumors and three medulloblastomas were analyzed by using reduced representation bisulfite sequencing, exome sequencing, and RNA-sequencing of matched samples. Only few somatic alterations in addition to SMARCB1 deletion were present in our AT/RTs. DNA methylation analysis generated 2325-5739 and 17175-25187 differentially methylated regions (DMRs) between tumor types in 450K array and RRBS sequencing data, respectively. AT/RTs harbored generally higher DNA methylation levels than the other tumor types. Next, DNA methylation differences were integrated with gene expression data. Surprisingly, only eight genes showed cancer-specific association between differential DNA methylation and an opposite expression change at promoter or linked enhancer in both public and in-house data. There were 44 cancer-specific genes with expression-methylation association when DNA methylation analysis was extended to genomic neighborhoods. To gain information about changes in epigenetic regulation between tumor types, we studied which previously experimentally validated transcription factor (TF) binding sites are enriched in cancer specific DMRs. Several TFs known to promote neural development, such as NEUROG2 and NEUROD1, were enriched in regions hypermethylated in AT/RT, whereas TFs, such as SMAD2, involved in the inhibition of neural development were associated with regions hypermethylated in medulloblastoma. This suggests that DNA methylation is regulating especially the target sites for neural regulators in AT/RT tumors, thus inhibiting neural development. Expression differences did not explain the predicted decreased activity of most of these neural TFs. Low number of genes with cancer-specific expression and methylation change is at least partly explained by the different gene expression patterns in medulloblastomas and choroid plexus tumors, thus providing different references for comparison. Also differences in the measurement techniques contribute to this. Taken together, these results suggest that DNA methylation has a role as an epigenetic regulator for the oncogenesis of AT/RTs. Citation Format: Kirsi Johanna Granberg, Joonas Tuominen, Kristiina Nordfors, Meeri Pekkarinen, Ville Kytölä, Sergei Häyrynen, Ebrahim Afyounian, Olli Lohi, Pauli Helen, Juha Kesseli, Joonas Haapasalo, Hannu Haapasalo, Matti Nykter. DNA methylation analysis reveals epigenetic regulation of neural differentiation in AT/RTs [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-173.

An extremely rare case of choroid plexus carcinoma in the third ventricle of an infant – Case report and review of the literature

BackgroundChoroid plexus tumors are rare intraventricular tumors. Most of these tumors are benign choroid plexus papillomas. Choroid plexus carcinoma is the most malignant choroid plexus tumor and constitutes a small percentage of these tumors. The most common location of these tumors is the lateral ventricle and fourth ventricle in pediatric and adult patients respectively. Rare locations such as the third ventricle are reported in the literature with 55 reports of choroid plexus papilloma and just 3 cases of carcinoma located in the third ventricle. Case descriptionWe present an extremely rare case of choroid plexus carcinoma of the third ventricle in a 9 months old boy which was resected successfully through transcortical-transforaminal approach along with a review of literature available around different aspects of these tumors. ConclusionChoroid plexus carcinomas even in rare locations such as the third ventricle can be effectively resected through the transcortical-transforaminal approach, although post-operative subdural effusion can be a potential complication.

Localization of ZIP14 and ZIP8 in HIBCPP Cells.

The blood–cerebrospinal fluid barrier (BCB) is important in maintaining brain manganese (Mn) homeostasis. This barrier consists of a single layer of epithelial cells, connected by tight junctions, that restrict the passage of nutrients to only allow molecules to be carried through the membrane by a transporter. These epithelial cells are polarized with asymmetrical blood-facing and cerebrospinal fluid-facing sides. Here, we have established a polarized model of a human choroid plexus papilloma cell line, HIBCPP. For the first time, Mn importers ZIP14 and ZIP8 were identified in HIBCPP cells and were found to be enriched at the basolateral and apical sides of the cell monolayer, respectively. The localization of each ZIP protein adds to the understanding of Mn transport across the HIBCPP BCB model to help understand the mechanism of Mn homeostasis within the brain.