Pediatric Central Neurocytoma

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.

Imaging of supratentorial intraventricular masses in children: a pictorial review-part 2

PURPOSE

This article is the second in a two-part series aimed at exploring the spectrum of supratentorial intraventricular masses in children. In particular, this part delves into masses originating from cells of the ventricular lining, those within the septum pellucidum, and brain parenchyma cells extending into the ventricles. The aim of this series is to offer a comprehensive understanding of these supratentorial intraventricular masses, encompassing their primary clinical findings and histological definitions.

METHODS

We conducted a review and analysis of relevant epidemiological data, the current genetics/molecular classifications as per the fifth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (WHO CNS5), and imaging findings. Each supratentorial intraventricular mass was individually evaluated, with a detailed discussion on its clinical and histological features.

RESULTS

This article covers a range of supratentorial intraventricular masses observed in children. These include colloid cysts, subependymal giant cell astrocytomas, ependymomas, gangliogliomas, myxoid glioneuronal tumors, central neurocytomas, high-grade gliomas, pilocytic astrocytomas, cavernous malformations, and other embryonal tumors. Each mass type is characterized both clinically and histologically, offering an in-depth review of their individual imaging characteristics.

CONCLUSION

The WHO CNS5 introduces notable changes, emphasizing the vital importance of molecular diagnostics in classifying pediatric central nervous system tumors. These foundational shifts have significant potential to impact management strategies and, as a result, the outcomes of intraventricular masses in children.

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 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.

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.

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.

Complete resection of hypervascularised extraventricular neurocytoma after preoperative embolisation

A 13-year-old female arrived at the Emergency Department with a two-week history of headache, and bilateral papilloedema on examination. The initial study with CT and MRI showed a large multicystic left frontal mass with calcification surrounded by peripheral oedema, subacute intralesional bleeding and association of multiple large vessels. She was initially operated on in another centre where a subacute haematoma was found, evacuating to multiple vessels and arteriolised veins. Despite the earlier neuroimaging findings, arteriovenous malformation (AVM) was suspected, so she was referred to our centre for further treatment. We performed angiography, MR angiography and MRI with advanced sequences, diagnosing a highly vascularised intra-axial tumour which was embolised. The patient was then definitively operated on, with the resulting finding of extraventricular neurocytoma (EVN). EVN are extremely rare lesions, not previously described in the literature as hypervascularised lesions, which in our case required prior angiography and embolisation for proper diagnosis and adequate management.