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.

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.

The role of single fraction Gamma Knife radiosurgery for intraventricular central neurocytomas and the utility of F-18 fluroethyltyrosine: two case reports.

BACKGROUND: Primary treatment of central neurocytomas is surgical resection. Gamma Knife surgery is considered a valuable therapeutic option in case of residual (after subtotal resection) or recurrent central neurocytomas. Here, we focused on the role of F-18 fluroethyltyrosine as a marker to document tumor progression after initial resection, in the context of an atypical central neurocytoma. We also describe MIB-1's role in evaluating therapeutic decision-making. CASE PRESENTATION: Two patients with central neurocytomas were treated by Gamma Knife surgery in our center. The first case (31-year-old Caucasian male) had atypical central neurocytoma. Four and a half years after surgical resection, magnetic resonance imaging and F-18 fluroethyltyrosine documented clear progression of residual central neurocytoma, further treated by Gamma Knife surgery (18 Gy at 50%, target volume 1.4 cc, and prescription isodose volume 1.8 cc). The initial post-Gamma Knife surgery clinical course was uneventful, with progressive volumetric reduction of residual tumor up to 4.5 years, when out-of-field recurrence was suspected and confirmed by local F-18 fluroethyltyrosine hyperactivity. Second single-fraction Gamma Knife surgery was performed (18 Gy at 50%, target volume 0.49 cc, prescription isodose volume 0.72 cc). The second (32-year-old Caucasian female) had previous subtotal resection and typical central neurocytoma. Seven years later, she had residual tumor progression. Single-fraction Gamma Knife surgery was performed (16 Gy at 50% isodose line, target volume 1.7 cc, and prescription isodose volume 2.5 cc). Last follow-up showed tumor volume reduction. Follow-up magnetic resonance imaging showed important volumetric reduction of both treated lesions. CONCLUSIONS: In atypical central neurocytomas, F-18 fluroethyltyrosine could be used as postoperative examination to detect small tumor remnants, follow-up evaluation following the Gamma Knife surgery or, in select cases, following surgical resection. The role of MIB-1 is important in therapeutic decision-making, as tumors with MIB-1 exceeding 2% are characterized by more aggressive clinical course. Single-fraction Gamma Knife surgery remains a valuable therapeutic option for postoperative residual atypical central neurocytomas and central neurocytoma recurrences.

MR Finding of Extraventricular Neurocytoma.

OBJECTIVE: To determine the MR (magnetic resonance), pathologic, and clinical findings of extraventricular neurocytoma (EVN). STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Department of Radiology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China, from January 2020 to March 2022. METHODOLOGY: The MR radiological and pathological data of 11 patients with EVNs proved by histopathology after surgery were analysed retrospectively. Above-mentioned features were studied. RESULTS: There were 5 men and 6 women, ages ranging from 16 to 56 years. Seven cases (63.6%) were located in the cerebral hemisphere, three cases (27.3%) in the cerebellar hemisphere, and one case in cervical cord. Ten cases (91.0%) were cystic-solid, and one case was predominantly solid with small cystic components. Six cases (54.5%) had mild peritumoural ooedema. The signal was isointense (8/11, 72.7%) or hypointense (3/11, 27.3%) on T1WI, and isointense (1/11, 9.1%) or hyperintense (10/11, 90.9%) on T2WI; all cases showed hyperintense on FLAIR and restricted diffusion on DWI. Haemorrhage was found in two cases (18.2%) and flow-void was found in one case (9.1%). All the tumours demonstrated contrast enhancement. CONCLUSION: An accurate diagnosis of EVN is difficult to be made preoperatively. It should be considered when a solid-cystic tumour with the solid part showing isointense on T1WI, hyperintense on FLAIR with mild to moderate enhancement especially restricted diffusion on DWI sequence in patients aged 20-30. When the radiologic manifestations are atypical, more aggressive treatment should be chosen. KEY WORDS: Neurocytoma, Extraventricular, Clinical, Imaging characteristics, MRI.

Extraventricular neurocytoma at the sellar region: Report of 8 cases and literature review.

BACKGROUND: Extraventricular neurocytoma at the sellar region (EVNSR) is an exceedingly rare tumor. Given the paucity of specificity and its peculiar nature, our study aimed to characterize the clinical, imaging, and pathological features, including treatment and clinical outcomes of this tumor. METHOD: Eight patients with pathologically confirmed EVNSR at Beijing Tiantan Hospital from 2012 to 2020 were retrospectively analyzed. Additionally, 7 cases from the prior detailed literature were also retrieved. FINDINGS: Among the 8 patients from Beijing Tiantan Hospital, 2 males and 6 females with an average age of 45.3 (range, 8-61). Vision impairment and headache were the most common complaints at presentation. Preoperative diagnoses were pituitary adenoma (n = 6), meningioma (n = 1), and oligodendroglioma (n = 1). Treatment included subtotal tumor resection (n = 3), partial resection (n = 5), adjuvant therapy covered radiotherapy (n = 2), and gamma knife surgery (n = 3). The clinical outcomes of these 8 cases were stable (n = 5), survival after progression (n = 1), and death after recurrence (n = 2). CONCLUSIONS: EVNSRs are extremely rare tumors, and most have benign prognoses after appropriate treatment. Due to the unique location, total removal of the tumor is challenging; And adjuvant radiation therapy for eligible patients is recommended. Regular imaging review is also advised. Future studies with more patients are needed to elucidate the biological nature of EVNSRs.

Metabolic, immunohistochemical, and genetic profiling of a cerebellar liponeurocytoma with spinal dissemination: a case report and review of the literature.

Cerebellar liponeurocytoma (cLNC), categorized as a World Health Organization grade II tumor, is a rare neoplasm characterized by advanced neuronal/neurocytic differentiation and focal lipid accumulation in neuroepithelial tumor cells. However, the expression and genetic profiling of cLNC have been poorly studied. A 44-year-old woman with a three-year history of cerebellar ataxia and numbness in lower extremities underwent radiological examination revealing multiple contrast-enhancing tumors at the floor of the fourth ventricle and in the lower vermis, and spinal dissemination. The high uptake of 11 C-methionine in positron emission tomography (Met-PET) supported the preoperative cLNC diagnosis. Subtotal removal of the tumor around the obex and inferior vermis was performed. Histologically, the tumor was composed of small, uniform cells with round nuclei in a sheet-like fashion. Tumor cells were diffusely reactive for the neuronal markers synaptophysin and neurofilament. Vacuolate cells with a displacement of nuclei suggested the accumulation of lipid, which was further supported by immunohistochemical staining of S-100. These findings confirmed the diagnosis of cLNC. Next-generation sequencing of tumoral DNA detected a splice site mutation in the ATRX gene. Further reports of cLNC cases with detailed expression and genetic profiles are essential for precise diagnosis and clarifying the oncogenic pathway in cLNC.

[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.

Lateral ventricular liponeurocytoma: Review of literature and case illustration.

BACKGROUND: Liponeurocytoma is an uncommon tumor of the central nervous system. It is very rare for this tumor to originate within the lateral ventricle. In the context of the rarity of this tumor entity, this review article aims to summarize the clinical, radiological, and pathological features of lateral ventricular liponeurocytoma to facilitate its diagnosis and management. METHODS: Here, we conduct a systematic literature review using the Pubmed, Scopus, and Cochrane Library database for all cases of lateral ventricular liponeurocytoma. A case illustration complements this review. RESULTS: The described cases from 1997 onward include 14 cases that have been published in full papers in the English literature. Six additional cases are reported in short English abstracts in full non-English papers, and one case was described in a central neurocytoma report. There is a definite male predominance of 70% (14 male) and a mean age of 37 years (range 24-62). Heterogenous enhancement and signals in magnetic resonant images (MRI) are the radiological characteristics. In all reported cases, the presence of lipocytes and fat vacuoles is considered the paramount histopathological feature. Total surgical resection was achieved in 80% (12 out of 15) of the cases. Only two cases (including ours) received radiation therapy. Recurrence was seen in two patients during follow-up that was treated by radiation therapy in one and surgery in the other. The proliferation index is mostly below 5% in all cases, with the Ki-67 range between<1% to 10%. CONCLUSIONS: Lateral ventricular liponeurocytoma has been treated effectively by surgical resection in a limited number of cases. The decision for radiation therapy is based on a high proliferation index and tumor recurrence.

The importance of staged surgery for giant atypical central neurocytoma.

The aim of this article is to discuss the importance of staged surgeries when approaching atypical central neurocytoma in children. Also, we show the preoperative embolization of the lesion as a maneuver to reduce the intraoperative bleeding. Central neurocytomas represent less than 0.5% of all intracranial tumors, and atypical central neurocytomas usually have unfavorable outcome, with high recurrence rate. The intraventricular location is frequent, with a predilection for the lateral ventricles. When completely resected, these lesions have a good prognosis. We report a case of a 12-year old male patient that presented with a history of headache for about 6 months, which worsened for 1 week prior to admission. Magnetic resonance imaging (MRI) brain showed a massive lesion occupying both lateral ventricles. He underwent a microsurgical treatment of a highly vascularized lesion, but the perioperative bleeding required interruption of the surgery. Thus, a preoperative embolization was able to occlude most arterial feeders and allowed subtotal resection in a second surgery. The patient had complete neurological recovery despite immediate post-operative deficits, and the histopathology was suggestive of atypical neurocytoma. Two-stage surgery with preoperative adjuvant embolization is a feasible strategy for treatment of large central neurocytomas in children.

Transcortical Approach to Deep-Seated Intraventricular and Intra-axial Tumors Using a Tubular Retractor System: A Technical Note and Review of the Literature.

BACKGROUND: Retraction of white matter overlying a brain lesion can be difficult without causing significant trauma especially when using traditional methods of bladed retractors. These conventional retractors can produce regions of focal pressure resulting in contusions and areas of infarct. METHODS: In this article, we present a retrospective case series of six patients with deep-seated intraventricular and intra-axial tumors that were approached using a ViewSite Brain Access System (tubular retractor). The authors describe a unique method of creating a pathway using a dilated glove. We shall also review the relevant literature that reports this type of surgery. Cases included three cases with third ventricular colloid cysts, one case of a third ventricular arachnoid cyst, one case with a lateral ventricular neurocytoma, and a case with a deeply seated intra-axial metastatic tumor. RESULTS: Gross total resection was achieved in five cases with small residual in the central neurocytoma operation, with no documented neurological deficit in any case. One case had persistent memory problems and one case had continuing decline from the metastatic disease. CONCLUSION: The introduction of tubular-shaped retractor systems has offered the advantage of reducing retraction pressures and distributing any remaining force in a more even and larger distributed area, thus reducing the risk of previous associated morbidity while also permitting great visualization of the target lesion.

Differential Diagnosis of Central Neurocytoma: Two Cases.

Central neurocytoma are rare primary brain tumors of the young and middle-aged adult, typically located in the lateral ventricles. Diagnosis has historically been difficult due to histomorphologic similarities to oligodendroglioma and ependymal tumors and remains a challenge even today. We present two cases of intraventricular central neurocytoma in which careful consideration of the clinical and radiological findings led to reevaluation of the preliminary histological interpretation, highlighting the importance of a meticulous differential diagnosis.

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.

Atypical central neurocytoma with leptomeningeal dissemination: a case report.

BACKGROUND: Central neurocytomas represent 0.25-0.5% of all intracranial tumors in adults. Leptomeningeal spread is uncommon, and the exact incidence of meningeal spread is unknown due to sparse literature. We present the clinical course and management outcome of a case of atypical central neurocytoma with leptomeningeal spread. CASE PRESENTATION: A young gentleman, who initially presented with memory loss, was found to have a right intra-axial periventricular mass on imaging. He underwent subtotal resection, and operative histopathology suggested a periventricular atypical neurocytoma. In view of subtotal resection, adjuvant focal radiation therapy was recommended, but he developed headache and blurring of vision 10 days postoperatively. Contrast enhanced craniospinal magnetic resonance imaging (MRI) showed residual primary tumor as well as diffuse leptomeningeal spread. Cerebrospinal fluid cytology also showed malignant cells. After tumor board discussion, craniospinal axis irradiation was advised and delivered. He remained disease-free for 10 months after radiation therapy, but then developed local and spinal recurrence, and offered salvage chemotherapy. His general condition deteriorated following chemotherapy with disease progression, and he was subsequently advised best supportive care. CONCLUSION: Leptomeningeal dissemination in atypical neurocytomas portends an aggressive course and adverse prognosis; management decisions may need tailoring as per individual presentation.

Atypical extraventricular neurocytoma: A case report.

Atypical extraventricular neurocytoma (EVN) is a rare condition characterized by diffuse tumor cell hyperplasia, increased neovascularization, increased necrosis, and aggressive characteristics. A case of a 25-year old man who presented with atypical EVN in his left parietal - occipital flaps is reported. Magnetic resonance imaging (MRI) revealed a well-defined globular mass with heterogeneous signals in the left parietal lobe, and mild perilesional edema. After left parietal craniotomy and tumor excision, pathologic examination of the resected tissue revealed that the lesion was localized mainly in the white matter and imbued with tumor cells possessing round hyperchromatic nuclei with perinuclear halos and increased microvascular proliferation. The patient underwent radiotherapy at 21st postoperative day. Over the past 26 months, the patient has been regularly followed up, and so far no neurologic deficits have been observed. The latest MRI showed that the tumor bed was stable with slight peritumoral edema. The results of clinical, histopathological and immunohistochemical examinations indicate that atypical EVN is a rare neoplasm with unique radiographic and pathologic characteristics. It possesses more aggressive properties than typical EVN.

Imaging of extraventricular neurocytoma: a systematic literature review.

OBJECTIVE: Extraventricular neurocytoma (EVN) was firstly described in 1997. The current literature regarding imaging of EVN is limited to sporadic case reports and case series. EVN is still poorly considered in the differential diagnosis by neuroradiologists, thus diagnosis remains challenging. In this systematic review, we summarize and discuss computed tomography (CT) and magnetic resonance imaging (MRI) features of EVN cases described in the literature, in order to provide useful informations to neuroradiologists. To the best of our knowledge, this is the most extensive review about imaging of EVN. MATERIALS AND METHODS: A systematic review of the literature about imaging of EVN cases was done. Only case reports or case series in which imaging (CT and/or MRI) features were deeply described were included in the revision. Eligibility of studies was assessed independently by two authors and any disagreements resolved by discussion. RESULTS: Our search strategy revealed 224 articles. After implementation of inclusion and exclusion criteria, 35 studies were considered, and a total of 79 cases of EVN were analyzed. CONCLUSION: EVN has not specific characteristics, with a large and variable imaging spectrum. Usually it appears as a large tumor, with diameters superior to 40 mm, frequently involving the frontal lobe. CT density and MRI signal intensity typically mirror the presence of cystic, solid, or calcified elements; contrast enhancement is visible in 87% of cases. Today, diagnosis of EVN with only imaging techniques is not univocal; neuroradiologists can only suspect this type of lesion, while the definitive diagnosis remains histological.

Diffuse Leptomeningeal Glioneuronal Tumor: A Unique Leptomeningeal Tumor Entity.

BACKGROUND: Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a recent addition to the World Health Organization classification schema of brain tumors, under the heading of neuronal and mixed neuronal-glial tumors. DLGNTs have a classic imaging appearance. However, it has often been misdiagnosed owing to its rarity, its resemblance to granulomatous/leptomeningeal etiologies, and the clinical presentation. CASE DESCRIPTION: We have described the case of a 3-year-old girl who had presented with complaints of nonprojectile vomiting and altered sensorium that had been initially diagnosed and treated as a case of tubercular meningitis at a peripheral health facility. However, the nonresponse to antitubercular medication necessitated a repeat magnetic resonance imaging evaluation at our institute, which had revealed the classic imaging appearance of DLGNT. The diagnosis was further established by meningeal biopsy and the histopathological evaluation findings. CONCLUSION: We have described the classic imaging appearance of this rare brain tumor. Radiologists and clinicians should be aware of this entity to avoid misdiagnosis and a delay in management.

Application of diffusion-weighted imaging combined with apparent diffusion coefficient in differential diagnosis between central neurocytoma and ependymoma.

PURPOSE: Differential diagnosis between central neurocytoma and ependymoma is very important for making preoperative scheme. We explored the application of diffusion-weighted imaging (DWI) combined with apparent diffusion coefficient (ADC) in differential diagnosis between both. METHODS: The data of preoperative MR plain and contrast-enhanced scan, DWI and ADC values of neoplastic solid parts from 18 cases with central neurocytoma and 19 cases with lateral ventricular ependymoma, were retrospectively analyzed. Mann-Whitney test was used for the comparison of ADC values between central neurocytoma and ependymoma. The application of ADC values in the differential diagnosis between central neurocytoma and ependymoma was evaluated by ROC curve. RESULTS: The lesions showed hyperintensity-dominant mixed signal intensity on DWI and mean ADC was (0.65 ± 0.13) × 10-3 mm2/s in the 18 cases with central neurocytoma. In the 19 cases with ependymoma, 13 had hyperintensity-dominant mixed signal intensity on DWI and 6 had hypointensity-dominant mixed signal intensity on DWI, and mean ADC was (1.20 ± 0.23) × 10-3 mm2/s. The mean ADC value was significantly higher in the 19 cases with ependymoma than in the 18 cases with central neurocytoma (P < 0.001). The ADC of 0.87 × 10-3 mm2/s might be used as a threshold for differential diagnosis between central neurocytoma and ependymoma with an area under ROC curve of 0.98 ± 0.02 and a 95% confidence interval of 0.95-1.00. Its sensitivity, specificity, and accuracy were 90%, 100%, and 90%, respectively. CONCLUSION: There is a certain overlap in MRI imaging features between central neurocytoma and ependymoma. DWI combined with ADC value can improve peoperative diagnostic accuracy.