Whole-exome sequencing reveals genetic variants that may play a role in neurocytomas.

OBJECTIVES: Neurocytomas (NCs) are rare intracranial tumors that can often be surgically resected. However, disease course is unpredictable in many patients and medical therapies are lacking. We have used whole exome sequencing to explore the molecular etiology for neurocytoma and assist in target identification to develop novel therapeutic interventions. METHODS: We used whole exome sequencing (WES) to compare the molecular landscape of 21 primary & recurrent NCs to five normal cerebellar control samples. WES data was analyzed using the Qiagen Clinical Insight program, variants of interest (VOI) were interrogated using ConSurf, ScoreCons, & Ingenuity Pathway Analysis Software to predict their potential functional effects, and Copy number variations (CNVs) in the genes of interest were analyzed by Genewiz (Azenta Life Sciences). RESULTS: Of 40 VOI involving thirty-six genes, 7 were pathogenic, 17 likely-pathogenic, and 16 of uncertain-significance. Of seven pathogenic NC associated variants, Glucosylceramidase beta 1 [GBA1 c.703T > C (p.S235P)] was mutated in 5/21 (24%), Coagulation factor VIII [F8 c.3637dupA (p.I1213fs*28)] in 4/21 (19%), Phenylalanine hydroxylase [PAH c.975C > A (p.Y325*)] in 3/21 (14%), and Fanconi anemia complementation group C [FANCC c.1162G > T (p.G388*)], Chromodomain helicase DNA binding protein 7 [CHD7 c.2839C > T (p.R947*)], Myosin VIIA [MYO7A c.940G > T (p.E314*)] and Dynein axonemal heavy chain 11 [DNAH11 c.3544C > T (p.R1182*)] in 2/21 (9.5%) NCs respectively. CNVs were noted in 85% of these latter 7 genes. Interestingly, a Carboxy-terminal domain RNA polymerase II polypeptide A small phosphatase 2 [CTDSP2 c.472G > A (p.E158K)] of uncertain significance was also found in > 70% of NC cases. INTERPRETATION: The variants of interest we identified in the NCs regulate a variety of neurological processes including cilia motility, cell metabolism, immune responses, and DNA damage repair and provide novel insights into the molecular pathogenesis of these extremely rare tumors.

Long-term outcomes of central neurocytoma - an institutional experience.

INTRODUCTION: Central Neurocytoma (CN) is a rare, WHO grade 2 brain tumor that predominantly affects young adults. Gross total resection (GTR) is often curative for CNs, but the optimal treatment paradigm including incorporation of RT, following subtotal resection (STR) and for scarcer pediatric cases has yet to be established. METHODS: Patients between 2001 and 2021 with a pathologic diagnosis of CN were reviewed. Demographic, treatment, and tumor characteristics were recorded. Recurrence free survival (RFS) and overall survival (OS) were calculated according to the Kaplan Meier-method. Post-RT tumor volumetric regression analysis was performed. RESULTS: Seventeen adults (≥ 18 years old) and 5 children (< 18 years old) met the criteria for data analysis (n = 22). With a median follow-up of 6.9 years, there was no tumor-related mortality. Patients who received STR and/or had atypical tumors (using a cut-off of Ki-67 > 4%) experienced decreased RFS compared to those who received GTR and/or were without atypical tumors. RFS at 5 years for typical CNs was 67% compared to 22% for atypical CNs. Every pediatric tumor was atypical and 3/5 recurred within 5 years. Salvage RT following tumor recurrence led to no further recurrences within the timeframe of continued follow-up; volumetric analysis for 3 recurrent tumors revealed an approximately 80% reduction in tumor size. CONCLUSION: We provide encouraging evidence that CNs treated with GTR or with RT after tumor recurrence demonstrate good long-term tumor control.

Gamma Knife radiosurgery for central neurocytoma: a quantitative systematic review and metanalysis.

Central neurocytomas (CN) are rare tumors within the central nervous system. Originating from the septum pellucidum and subependymal cells, they are typically found in the third and lateral ventricles. For this reason, they may lead to hydrocephalus and increased intracranial pressure. CNs are generally benign lesions that exhibit locally aggressive behavior and a high recurrence rate. Complete surgical resection is the preferred treatment; however, due to their anatomical location, this is often not feasible. Based on these findings, Gamma Knife radiosurgery (GKRS) has been introduced for managing both residual and recurrent tumors and as an initial therapy in selected cases. This study aimed to systematically review the available knowledge regarding GKRS for CN. A systematic investigation of the scientific literature was undertaken through an exhaustive search across prominent databases, including PubMed, Web of Science, and Google Scholar, by employing precise MeSH terms such as "Central neurocytoma," "Radiosurgery," "Gamma Knife," and "Stereotactic Radiosurgery." A comprehensive quantitative systematic review and meta-analysis were meticulously conducted, focusing on cases of CN treated with GKRS for a thorough evaluation of outcomes and efficacy. Seventeen articles, including 289 patients, met the inclusion criteria. Random effects meta-analysis estimates for disease control and local tumor control were 90% (95% CI 87-93%; I2 = 0%, p < 0.74) and 94% (95% CI 92-97%; I2 = 0%, p < 0.98), respectively. When considering only studies with at least 5 years of follow-up, progression-free survival was 89% (95% CI 85-94%; I2 = 0.03%, p < 0.74). The mean clinical control rate was 96%. This systematic review and meta-analysis confirmed the safety and efficacy of GKRS in managing CN.

How I do it? Resection of left ventricular central neurocytoma via trans-sulcal approach.

BACKGROUND: The management of lateral ventricle tumors requires a balance between maximizing safe resection and preserving neurological function. METHOD: The authors present a successful case of a left lateral ventricular central neurocytoma resection. The trans-superior frontal sulcus approach was employed, providing a safe corridor while minimizing damage to the surrounding neuroanatomy. The use of an endoscope further facilitated the procedure, enabling the confirmation of complete tumor removal and the preservation of deep venous drainage and periventricular structures. CONCLUSION: This case highlights the utility of the trans-sulcal approach and the benefits of endoscopic assistance in the management of lateral ventricle tumors.

Consensus guidelines for the management of primary supra-tentorial intraventricular tumour for low- and middle-income countries.

Almost any primary or metastatic brain tumour can manifest in intraventricular (IV) locations. These tumours may either originate within the ventricular system or extend into the IV space through growth. Such neoplasms represent a broad spectrum, with supratentorial IV tumours forming a heterogeneous group. This group includes primary ependymal tumours, central neurocytomas, choroid plexus tumours, and notably, meningiomas, as well as a variety of non-neoplastic, benign, glial, and metastatic lesions that can secondarily invade the IV compartment. Often presenting with nonspecific symptoms, these tumours can lead to delayed medical attention. The diversity in potential diagnoses, combined with their deep and complex locations, poses significant management challenges. This paper aims to delineate optimal management strategies, underscoring the importance of multidisciplinary care, especially in settings with limited resources, to effectively navigate the complexities associated with treating intraventricular brain tumours.

Epigenetic Alteration of H3K27me3 as a Possible Oncogenic Mechanism of Central Neurocytoma.

Central neurocytoma (CN) is a low-grade neuronal tumor that mainly arises from the lateral ventricle (LV). This tumor remains poorly understood in the sense that no driver gene aberrations have been identified thus far. We investigated immunomarkers in fetal and adult brains and 45 supratentorial periventricular tumors to characterize the biomarkers, cell of origin, and tumorigenesis of CN. All CNs occurred in the LV. A minority involved the third ventricle, but none involved the fourth ventricle. As expected, next-generation sequencing performed using a brain-tumor-targeted gene panel in 7 CNs and whole exome sequencing in 5 CNs showed no driver mutations. Immunohistochemically, CNs were robustly positive for FGFR3 (100%), SSTR2 (92%), TTF-1 (Nkx2.1) (88%), GLUT-1 (84%), and L1CAM (76%), in addition to the well-known markers of CN, synaptophysin (100%) and NeuN (96%). TTF-1 was also positive in subependymal giant cell astrocytomas (100%, 5/5) and the pituicyte tumor family, including pituicytoma and spindle cell oncocytoma (100%, 5/5). Interestingly, 1 case of LV subependymoma (20%, 1/5) was positive for TTF-1, but all LV ependymomas were negative (0/5 positive). Because TTF-1-positive cells were detected in the medial ganglionic eminence around the foramen of Monro of the fetal brain and in the subventricular zone of the LV of the adult brain, CN may arise from subventricular TTF-1-positive cells undergoing neuronal differentiation. H3K27me3 loss was observed in all CNs and one case (20%) of LV subependymoma, suggesting that chromatin remodeling complexes or epigenetic alterations may be involved in the tumorigenesis of all CNs and some ST-subependymomas. Further studies are required to determine the exact tumorigenic mechanism of CN.

Machine learning-based multiparametric magnetic resonance imaging radiomics model for distinguishing central neurocytoma from glioma of lateral ventricle.

OBJECTIVES: To develop a machine learning-based radiomics model based on multiparametric magnetic resonance imaging (MRI) for preoperative discrimination between central neurocytomas (CNs) and gliomas of lateral ventricles. METHODS: A total of 132 patients from two medical centers were enrolled in this retrospective study. Patients from the first medical center were divided into a training cohort (n = 74) and an internal validation cohort (n = 30). Patients from the second medical center were used as the external validation cohort (n = 28). Features were extracted from contrast-enhanced T1-weighted and T2-weighted images. A support vector machine was used for radiomics model investigation. Performance was evaluated using the sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). The model's performance was also compared with those of three radiologists. RESULTS: The radiomics model achieved an AUC of 0.986 in the training cohort, 0.933 in the internal validation cohort, and 0.903 in the external validation cohort. In the three cohorts, the AUC values were 0.657, 0.786, and 0.708 for radiologist 1; 0.838, 0.799, and 0.790 for radiologist 2; and 0.827, 0.871, and 0.862 for radiologist 3. When assisted by the radiomics model, two radiologists improved their performance in the training cohort (p < 0.05) but not in the internal or external validation cohorts. CONCLUSIONS: The machine learning radiomics model based on multiparametric MRI showed better performance for distinguishing CNs from lateral ventricular gliomas than did experienced radiologists, and it showed the potential to improve radiologist performance. KEY POINTS: • The machine learning radiomics model shows excellent performance in distinguishing CNs from gliomas. • The radiomics model outweighs two experienced radiologists (area under the receiver operating characteristic curve, 0.90 vs 0.79 and 0.86, respectively). • The radiomics model has the potential to enhance radiologist performance.

Central neurocytomas in children: Clinicopathologic features and long-term surgical outcomes.

PURPOSE: Pediatric central neurocytomas (PCNs) is an extremely rare entity, and very few reports have exclusively focused on the clinicopathologic features and surgical outcomes of PCNs. METHODS: This study was undertaken to elucidate the clinical and pathological characteristics and long-term surgical outcomes of PCNs. RESULTS: Fourteen consecutive patients with pathologically verified PCNs were identified, including 9 girls and 5 boys, with a mean age of 15.2 ± 3.9 years (range 3-18 years). Children tended to present with symptoms of increased intracranial pressure (ICP) (p = 0.003), an acute clinical course (p = 0.044), and a shorter duration of symptoms (p = 0.019) than their adult counterparts. Surgery was performed under the guidance of a neuronavigation system and intraoperative ultrasound; gross total resection (GTR) was achieved in 12 patients (85.7%), and subtotal resection (STR) was achieved in two patients (14.3%). One child received adjuvant radiotherapy (RT) owing to the atypical features of the lesion. During a mean follow-up of 90.2 ± 37.0 months (range 42-156 months), one patient (7.1%) with atypical features experienced lesion relapse 2 years after surgery and received RT, and the symptoms of all children were relieved. CONCLUSION: Surgery can benefit children with CNs and ensure relatively long-term progression-free survival. RT can be administered to patients with residual or relapsed lesions.

Pediatric atypical extraventricular neurocytoma: Clinical features and survival outcomes.

BACKGROUND: Extraventricular neurocytoma (EVN) in children is an extremely rare encountered tumor. Little information is available about the treatment and prognosis of this rare disease in children. This study was undertaken to elucidate the clinical-radiological characteristics and treatment outcomes of pediatric patients with atypical EVN. METHODS: A retrospective review of patients' demographic features, treatment modalities, and outcomes in our institution from January 2011 to December 2019 was conducted. RESULTS: Seven consecutive children harboring atypical EVN in our center were included, with a male predominance (n = 5, 71.4%) and a mean age of 11.8 ± 4.9 years (range: 2-18 years). The lesions mainly involved the frontal (n = 4, 57.1%) and temporal lobes (n = 4, 57.1%). Gross total resection (GTR) was achieved in 6 patients (85.7%), and subtotal resection (STR) was achieved in the remaining patient (14.3%). All lesions demonstrated a high Ki-67 index (≧5%) and atypical features pathologically. Five patients (71.4%) received radiotherapy and/or chemotherapy after surgery. During follow-up, 5 patients (71.4%) experienced lesion progression, and 2 (14.3%) of them died. The median progression-free survival was 48 months. CONCLUSIONS: The prognosis of pediatric patients with atypical EVN was dismal after aggressive treatment. Most tumors progressed, and this progression was positively correlated with the Ki-67 index. Surgical excision is the main treatment modality for atypical EVN, and radiation/chemotherapy should also be introduced after surgery.

Central neurocytomas: research trends, most cited papers, and scientometrics analysis to date.

Central neurocytoma is the most common primary intraventricular tumor in adults being classified by the World Health Organization (WHO) as a benign grade II tumor with a good prognosis. Given the recent advances with regard to this tumor, a bibliometric analysis was due to study the future direction of research for neurocytomas. A comprehensive Elsevier's Scopus database search was performed to capture all published and indexed studies to date relevant to neurocytoma. A discrete set of validated bibliometric parameters were extracted and analyzed on R v4.1.3. A total of 1002 documents were included in our analysis covering a period between 1910 and 2021 (111 years). Around 98.5% of the documents were multi-author publications with a collaboration index (CI) of 4.21. Acta Neuropathologica, The American Journal of Surgical Pathology, and Cancer were the journals to include the highest number of top ten cited articles (2 out of 10 most cited articles, 20%). Switzerland (4 out of 10, 40%) accounted for the country to have the highest number of top 10 most cited articles with the USA (5588 out of 16,395 citations, 34.1%) having the greatest number of citations. Lastly, our analysis reported an annual growth rate of 6.9% for the number of papers produced by year. This is the first bibliometric analysis to study the top 10 most cited articles with regard to neurocytomas. A shift from histopathologic and clinical symptoms towards the treatment and management of the tumor was observed in our analysis.

Tumors of Choroid Plexus and Other Ventricular Tumors.

Tumors arising inside the ventricular system are rare but represent a difficult diagnostic and therapeutic challenge. They usually are diagnosed when reaching a big volume and tend to affect young children. There is a wide broad of differential diagnoses with significant variability in anatomical aspects and tumor type. Differential diagnosis in tumor type includes choroid plexus tumors (papillomas and carcinomas), ependymomas, subependymomas, subependymal giant cell astrocytomas (SEGAs), central neurocytomas, meningiomas, and metastases. Choroid plexus tumors, ependymomas of the posterior fossa, and SEGAs are more likely to appear in childhood, whereas subependymomas, central neurocytomas, intraventricular meningiomas, and metastases are more frequent in adults. This chapter is predominantly focused on choroid plexus tumors and radiological and histological differential diagnosis. Treatment is discussed in the light of the modern acquisition in genetics and epigenetics of brain tumors.

Comparison of surgery with or without adjuvant radiotherapy in treating central neurocytoma: a single-center retrospective real-world study.

PURPOSE: To investigate the efficacy and safety of adjuvant radiotherapy (RT) in patients with central neurocytoma (CN). METHODS: The study included 68 patients with CN retrospectively, was further divided into surgery + RT group (31 patients) and surgery alone group (37 patients). Progression-free survival (PFS), overall survival (OS), and adverse reactions (AEs) were compared between the two groups. RESULTS: The median follow-up duration was 82.2 (interquartile range, 64.7-104.5) months. Patients in the surgery + RT group tended to have longer PFS than those in the surgery alone group (5-year PFS rate: 92.7% vs. 86.3%; P = 0.074). There was no significant difference in OS between the two groups (5-year OS rate: 96.8% vs. 94.3%; P = 0.639). Subgroup analysis revealed a significant improvement in PFS in patients receiving RT after surgery in patients who underwent subtotal resection (STR) (P = 0.045). In the overall population, univariate multivariate analysis revealed that gross total resection (GTR) (P = 0.002), tumor location in the unilateral ventricle (P = 0.008), and MIB-1 (Ki-67) labeling index (LI) < 5% (P = 0.009) were favorable independent prognostic factors for PFS. Whereas tumor location in the unilateral ventricle (P = 0.043) was a favorable independent prognostic factor for OS. Moreover, RT patients experienced AEs (Grade 1-2, well-tolerated). CONCLUSION: Adjuvant RT in the treatment of CNs showed satisfactory safety, and postoperative RT could improve PFS in STR patients. Furthermore, GTR, tumor development in the unilateral ventricle, and MIB-1 LI < 5% were found to be favorable factors affecting the prognosis of CNs.

The role of methylation profiling in histologically diagnosed neurocytoma: a case series.

PURPOSE: To highlight the clinical, neuroradiographic, neuropathologic, and molecular features of histologically identified neurocytoma in a pediatric cohort and highlight the evolving use methylation profiling in providing diagnostic clarity in difficult to diagnosis pediatric brain tumors. METHODS: Five consecutive children (ages 9-13, 2 girls 3 boys) were histologically diagnosed with neurocytoma at Rady Children's Hospital San Diego from 2012 to 2018. Clinical and molecular features were analyzed with regards to treatment course and outcome. RESULTS: Presenting symptoms included seizures (n = 2), syncope (n = 1), headache (n = 2), visual disturbances (n = 2) and emesis (n = 2). Tumor location included intraventricular (n = 2), intraventricular with parenchymal spread (n = 1), and extraventricular (n = 2). Magnetic resonance imaging demonstrated reduced diffusivity (2/5), signal abnormality on susceptibility-weighted sequences (3/5), and varying degrees of contrast enhancement (4/5). All patients underwent surgical resection alone. Recurrence occurred in four children that were treated with surgery (4/4), adjuvant radiation (2/4), and chemoradiation (1/4). Neuropathologic features included positivity for GFAP (4/5), synaptophysin (4/5), NSE (2/2), NeuN (4/4), and variable Ki-67 (< 1% to 15%). Next generation sequencing (3/5) and microarray (3/5) collectively were abnormal in four of five tumors. Methylation profiling was successfully performed on four of five samples which led to modification of diagnosis in two patients and the others were either unclassifiable or confirmatory with the histologic diagnosis. Mean time to follow up was 77 months (range 44-112 months). Mean progression free survival and overall survival were 24 months (range 6 to 52 months) and 100% respectively. CONCLUSION: Neurocytomas are a rare clinical entity that warrants further investigation into molecular and pathologic prognosticating features. Methylation profiling may aid in differentiation of neurocytoma from other difficult to diagnose tumors who share similar histologic features.

Recurrent cerebellar liponeurocytoma with anaplastic features at initial presentation: A case report.

BACKGROUND: Cerebellar liponeurocytoma is a rare entity with fewer than 100 reported cases and series in the available literature to date. Although the cerebellum remains the typical primary site, the entity has been shown to demonstrate increased aggressiveness and malignant progression with multiple recurrences. CASE DESCRIPTION: We present a unique case in a 64-year-old gentleman of a cerebellar liponeurocytoma with multiple recurrences and progressive anaplasia. The tumor showed anaplastic features at first presentation and recurred in a more aggressive fashion in a short 2-year period despite surgical debulking and post-operative radiotherapy. It re-recurred within 6 months with subsequent re-debulking without further radiotherapy. At latest follow-up almost 3 years since surgical management of the patient's second recurrence, the patient remains well with minimal neurological impairment and no radiological signs of recurrence. CONCLUSION: Cerebellar liponeurocytoma may present with increasingly atypical histological features that may warrant more aggressive post-operative treatment to prevent disease recurrence and clinical deterioration. This may include a more aggressive surgical resection margin and consideration of adjuvant radiotherapy in all cases.

Cerebellar liponeurocytoma in an elderly patient: DNA methylation profiling as a helpful diagnostic tool.

AIM: Cerebellar liponeurocytoma is a rare primary cerebellar neoplasm that mostly occurs in adults, however, it is rare in the elderly. MATERIALS AND METHODS: We report, in a 79-year-old female, a recurrent vermian cerebellar mass that was previously diagnosed as primary cerebellar tumor with neuroendocrine differentiation. The recurrent lesion showed anaplastic features and lipidization. RESULTS: DNA methylation profiling was performed for the recurrent tumor, which showed a high score match for cerebellar liponeurocytoma. CONCLUSION: This report confirms the usefulness of DNA methylation profiling for the diagnosis of challenging CNS tumors.

A rare case of atypical spinal neurocytoma with EGFR mutation in a 12-year-old boy.

Spinal neurocytoma (SN), although frequently reportedly as tumors of the central nervous system (CNS), are a distinct class of tumors, which can achieve a better prognosis following subtotal or gross total tumor resection. Nonetheless, even with the premise of successful treatment after tumor resection, poor prognosis after treatment due to the SN high proliferation index (typically known as atypical SN) have been reported. Over the past two decades, atypical SN was only reported in four pediatric cases, amidst the lingering controversy surrounding its postoperative adjuvant therapy. Thus, herein, we report a unique case of atypical SN with epidermal growth factor receptor (EGFR) amplification mutation in a 12-year-old boy. We, however, also highlighted the significance of radiotherapy and target therapy for patients with SN.

Extraventricular neurocytomas: a systematic review of the literature in the pediatric population.

Extraventricular neurocytomas (EVNs) are rare neuroepithelial neoplasms of the central nervous system that were first described in 1997. Most studies in patients with EVNs have incorporated mixed age groups. The tumor's clinical behavior specifically in children has not been explored in depth, while a detailed statistical analysis has never been performed in this age group. Hence, we performed a systematic review to address possible prognostic factors and the appropriate management in children with EVNs. Relevant studies were identified by searching the MEDLINE and SCOPUS databases. We included studies concerning patients 18 years of age or younger who were histologically diagnosed with EVNs. A total of 52 studies with 79 patients were included. The mean age of the patients was ~ 10 years with a male predilection (~ 2:1). Most of these tumors were located in the frontal (49%) lobe. We observed that gross total resection of the tumor was significantly lower in cases of atypical EVNs (p < 0.05). Additionally, atypical EVNs were associated with worse overall survival compared to typical EVNs (p = 0.05). Children 4 years of age or under had a worst outcome (p = 0.001). The patient's sex and the extent of the tumor's resection did not appear to affect the prognosis in a statistically significant manner. Contrary to the results of previous studies, the use of adjuvant radiotherapy or chemotherapy for the treatment of EVNs was not associated with better outcomes in the pediatric population. Thus, a less aggressive management of children with EVNs compared to the adult population is suggested.

Gamma Knife radiosurgery for the treatment of central neurocytoma: a single-institution experience of 25 patients.

Central neurocytomas (CNs) are extremely rare tumors that account for 0.1-0.5% of all intracranial neoplasms. Recently, Gamma Knife radiosurgery (GKRS) has become a treatment option in patients with CN. We aimed to evaluate the efficacy and safety of GKRS in 25 CN patients and review the results along with relevant literature. GKRS patient database was searched, and 25 patients who underwent GKRS for CN between 2009 and 2018, were evaluated retrospectively. The study cohort included 15 female and ten male patients with a median age of 32 years (range, 5-60). The most common presenting symptom was headache (88%). The neurological examination was unremarkable in all patients, except for one patient with decreased vision. Twenty patients (80%) had a history of surgical resection. Most of the tumors (92%) were located in the ventricles, and the median tumor volume was 4.8 cm3 (range, 0.8-28.1). The median marginal dose was 14 Gy (range, 12-15) to a median isodose of 50% (range, 40-50). Following a median follow-up of 80 months (range, 36-138), local tumor control was achieved in 100% of patients. Distant recurrence was observed in one patient (4%). No adverse radiation effect was observed. Regarding non-specific post-GKRS symptoms, one patient experienced a prolonged headache, and one epileptic patient experienced a brief partial seizure. In our patient cohort, GKRS yielded favorable local tumor control (100%) during a median follow-up of 6.6 years. Our series demonstrates that GKRS is an effective and safe treatment option for patients with primary or residual CNs.

Organic bipolar disorder secondary to central neurocytoma resection: a case report.

entral neurocytoma is a neuroepithelial tumor described by Hassoun in 1982, predominantly located in the midline at the level of the septum pellucidum, or in the lateral ventricles wall1. They represent approximately 50% of intraventricular lesions in adults, and they are in total 0.25-0.5% of intracranial tumors.

[Central neurocytomas: long-term treatment outcomes]. / Tsentral'nye neirotsitomy golovnogo mozga: otdalennye rezul'taty lecheniya.

Central neurocytoma is a rare benign brain tumor. These tumors may be giant and accompanied by compression of ventricular system and surrounding structures. Modern treatment of brain neurocytoma includes extended resection and restoration of normal CSF circulation. Surgical treatment does not often lead to total resection of these tumors. Redo resection was preferred in patients with tumor progression for a long time. In the last decade, various authors report stereotactic irradiation for continued tumor growth to ensure local growth control. This study was aimed at evaluation of postoperative outcomes in patients with brain neurocytomas, as well as treatment of tumor progression in long-term period. OBJECTIVE: To analyze recurrence-free survival in patients with brain neurocytomas, risk factors of recurrence-free survival, effectiveness of various treatments for tumor progression and delayed complications. MATERIAL AND METHODS: Long-term postoperative follow-up data of patients with brain neurocytomas are reported in the manuscript. We analyzed recurrence-free survival and risk factors of recurrence-free survival, treatment outcomes in patients with progression of brain neurocytomas, long-term complications and their prevention. RESULTS: Follow-up included 84 out of 115 patients with brain neurocytoma after surgical treatment in 2008-2017. Follow-up period ranged from 2 to 10 years (mean 6 years) after resection. Most patients had regression of neurological symptoms after surgery. Continued tumor growth within 12-96 months after surgery occurred in 26 (30.19%) out of 84 patients (19 cases after partial resection and 7 cases after total resection according to MRI data). Two-year recurrence-free survival was 94%, 5-year survival - 83%. Risk factors of continued tumor growth were resection quality and Ki-67 index. Redo resection was performed in 7 cases. Eleven patients underwent stereotactic irradiation for tumor progression. Indications for stereotactic irradiation of central neurocytoma are MR data on continued growth of lateral ventricle tumor without signs of ICH and CSF flow impairment. There were no cases of hemorrhage inside the residual tumor and CSF flow impairment in early postoperative period after redo resection. In all cases (n=11), stereotactic irradiation (mean follow-up 2.5 years) ensured satisfactory control of tumor growth with reduction of the neoplasm in 4 cases and no tumor growth in 7 cases. CONCLUSION: Resection of central neurocytoma ensures long-term recurrence-free period. The main causes of tumor recurrence are partial resection and high proliferative activity (Ki-67 index over 5%). Redo resection is advisable for tumor progression followed by CSF flow impairment. In case of continued growth of neurocytoma without signs of intracranial hypertension, stereotactic irradiation with various fractionation modes ensures effective and safe control of tumor growth.