Rosette-forming glioneuronal tumor of the fourth ventricle with neurocytoma component

Treatment of Pineal Region Rosette-Forming Glioneuronal Tumors (RGNT)

Simple Summary

The WHO classification of tumors of the central nervous system described for the first time the extremely rare entity of rosette-forming glioneuronal tumors (RGNT, CNS WHO grade 1) in 2007. Due to the rarity of this entity in the pineal region, no specific therapy guidelines currently exist. With our large cohort of patients treated at a single center (from August 2018–June 2021) and with the already described cases in the literature, we would like to highlight possible therapy and follow-up concepts. After the main symptoms of headache or generalized epileptic seizure, cystic lesions adjacent to the pineal gland and the third ventricle were diagnosed in imaging. None of the patients underwent additional chemotherapy or radiotherapy after gross total (GTR)/subtotal resection or endoscopic biopsy. In cases where surgical resection seems feasible with a reasonable surgical risk, we advocate GTR. Long-term MRI follow-up is essential to detect a slow tumor progression.

Abstract

Background: Rosette-forming glioneuronal tumor (RGNT) is an extremely rare entity described for the first time in the WHO classification of tumors of the central nervous system in 2007. Predominantly, single case reports of RGNT in the pineal region have been published, and specific therapy concepts are pending. Methods: The study group comprised all patients with the RGNT (CNS WHO grade 1) in the pineal region that underwent microsurgical tumor removal in our center (August 2018–June 2021). Surgical strategy, histological findings, and clinical outcome are presented, and the results are evaluated and compared to published case reports. Results: Four male patients aged under 50 years (range between 20 and 48 years) and one female patient, 51 years old, were included in this study. Chronic headaches and generalized epileptic seizures were the main symptoms. Supra-cerebellar infratentorial gross total tumor resection (GTR) was performed in two cases, two patients underwent subtotal tumor resection, and an endoscopic biopsy was performed in case five. Conclusion: In cases where surgical resection seems feasible with a reasonable surgical risk, we advocate GTR. Regular and long-term MRI follow-up is essential to detect a slow tumor progression. The role of additional chemotherapy or radiotherapy remains unclear.

Rosette-Forming Glioneuronal Tumor in the Pineal Region: A Series of 6 Cases and Literature Review

Resected lesions from the pineal region are rare specimens encountered by surgical pathologists, and their heterogeneity can pose significant diagnostic challenges. Here, we reviewed 221 pineal region lesions resected at New York-Presbyterian Hospital/Columbia University Irving Medical Center from 1994 to 2019 and found the most common entities to be pineal parenchymal tumors (25.3%), glial neoplasms (18.6%), and germ cell tumors (17.6%) in this predominantly adult cohort of patients. Six cases of a rare midline entity usually found exclusively in the fourth ventricle, the rosette-forming glioneuronal tumor, were identified. These tumors exhibit biphasic morphology, with a component resembling pilocytic astrocytoma admixed with variable numbers of small cells forming compact rosettes and perivascular pseudorosettes. Targeted sequencing revealed a 100% co-occurrence of novel and previously described genetic alterations in the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) signaling pathways, suggesting a synergistic role in tumor formation. The most common recurrent mutation, PIK3CA H1047R, was identified in tumor cells forming rosettes and perivascular pseudorosettes. A review of the literature revealed 16 additional cases of rosette-forming glioneuronal tumors in the pineal region. Although rare, this distinctive low-grade tumor warrants consideration in the differential diagnosis of pineal region lesions.

Pediatric rosette-forming glioneuronal tumor of the septum pellucidum

Rosette-forming glioneuronal tumor (RGNT) is a rare tumor entity which has been reported mainly occurring in the fourth ventricle. It has been described as a benign lesion with limited extension into surrounding structures, including the cerebellar vermis, midbrain, and cerebral aqueduct. More recently, few cases involving also other midline structures have been documented as well. Here, we report about diagnosis and treatment of RGNT in the septum pellucidum in a pediatric patient which has not been described previously. A 7-year-old boy had a 3-week history of headache. Magnetic resonance imaging showed a solid mass in the septum pellucidum accompanied by hydrocephalus. The tumor was resected via a transcortical approach. Histological examination revealed the typical findings of a RGNT. At 2-year follow-up, there was no tumor recurrence, and clinical outcome was unremarkable. RGNT has to be considered in the differential diagnosis of pediatric midline tumors also outside of the fourth ventricle. Surgical resection is the first-line therapy which may result in beneficial outcome in the long term. The role of adjuvant therapy needs further definition since due to the rarity of this tumor entity, available data is very limited.

Rosette-forming Glioneuronal Tumor in the Optic Pathway of a Child

Rosette-forming glioneuronal tumor is a rare World Health Organization grade I neoplasm, primarily involving the posterior fossa. Most cases have been reported in young adults. Although maximal surgical resection is advocated, a precise treatment modality is yet to be established. We describe an unusual presentation of rosette-forming glioneuronal tumor occurring in the optic pathway in a child. As the site of the tumor was not amenable to resection, he underwent radiotherapy and is currently well on follow-up.

Rosette-forming glioneuronal tumor: an illustrative case and a systematic review

Background

Rosette-forming glioneuronal tumors (RGNTs) are rare, low-grade, primary CNS tumors first described in 2002 by Komori et al. RGNTs were initially characterized as a World Health Organization (WHO) grade I tumors typically localized to the fourth ventricle. Although commonly associated with an indolent course, RGNTs have the potential for aggressive behavior.

Methods

A comprehensive search of PubMed and Web of Science was performed through November 2019 using the search term “rosette-forming glioneuronal tumor.” Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. English, full-text case reports and series with histopathological confirmation were included. Patient demographics, presentations, MRI features, tumor location, treatment, and follow-up of all 130 cases were extracted.

Results

A 19-year-old man with a history of epilepsy and autism presented with acute hydrocephalus. MRI scans from 2013 to 2016 demonstrated unchanged abnormal areas of cortex in the left temporal lobe with extension into the deep gray-white matter. On presentation to our clinic in 2019, the lesion demonstrated significant progression. The patient’s tumor was identified as RGNT, WHO grade I. One hundred thirty patients were identified across 80 studies.

Conclusion

RGNT has potential to transform from an indolent tumor to a tumor with more aggressive behavior. The results of our systematic review provide insight into the natural history and treatment outcomes of these rare tumors.

Surgical treatment of a rare rosette-forming glioneuronal tumor in the pineal region

BACKGROUND

Rosette-forming glioneuronal tumors (RGNTs) in the pineal region are rare. RGNTs have been described in the fourth ventricle, but rarely reported in other brain regions. Here, we report the radiological findings, surgical treatment, and short-term outcome of an RGNT found in the pineal region.

CASE DESCRIPTION

We present a case of a 22-year-old medical student with a 4-month history of headaches and diplopia. A previous magnetic resonance imaging scan revealed a mass in the pineal region, with heterogeneous contrast enhancement and hydrocephalus. Three months prior, an endoscopic biopsy and third ventriculocisternostomy were performed elsewhere; the diagnosis was neurocytoma Grade I, and radiotherapy was planned. The patient presented at our hospital for a second opinion, and we suggested surgical treatment. A near-total resection was performed in sitting position using a supracerebellar infratentorial microsurgical approach. The tumor was very soft and not well vascularized. Diplopia was initially worsened after the tumor was removed and relieved completely after 2 weeks. An 8-week follow-up examination revealed that the patient was free of symptoms. Histological analysis confirmed it was an RGNT.

CONCLUSION

Maximal safe resection in pineal region RGNTs is a feasible and recommended treatment option.

Central Neurocytoma: Rare Presentation in Fourth Ventricle and Review of Literature

Central neurocytomas are rare tumors, typically found in the third ventricle. We present the unusual case of a fourth ventricular central neurocytoma in a 70-year-old female presenting with imbalance and headaches, with an enhancing fourth ventricular mass on imaging. We examine the details of her clinical presentation, imaging characteristics, histopathologic analysis, and postoperative course. We performed a critical literature review of fourth ventricular central neurocytoma, identifying 6 previously reported cases. In contrast to our patient, the majority of these cases were in young males. The 2 females with fourth ventricular neurocytoma developed it at a much later age (mean 63.5 years) than their male counterparts (mean 22.8 years; P = 0.005). Despite being a rare cause for a fourth ventricular lesion, given the appropriate clinical context and radiographic findings, this should remain part of the differential diagnosis.

Histopathological, molecular, clinical and radiological characterization of rosette-forming glioneuronal tumor in the central nervous system

Objective

A rosette-forming glioneuronal tumor (RGNT) is a rare entity originally described in the fourth ventricle. Recently, RGNTs occurring in extraventricular sites and those with malignant behaviors have been reported. The purpose of this study was to analyze the clinicoradiological and histopathological features, therapeutic strategies, and outcomes of RGNTs.

Methods

We enrolled 38 patients diagnosed with RGNTs pathologically between August 2009 and June 2016. CT and MRI, including diffusion-weighted imaging and spectroscopy, were performed. The surgical treatment and histopathological and molecular features were assessed. Additionally, we searched the relevant literatures and performed a pooled analysis of individual patient data. The potential risk factors of prognosis were analyzed.

Results

Our case series included 22 male and 16 female patients, with a mean age of 25.9 years. RGNTs involved the fourth ventricle (26.3%), cerebella (34.2%), supratentorial ventricular system (13.2%), spinal cord (10.5%), temporal lobe (10.5%), thalamus (7.9%), brain stem (7.9%), frontal lobe (5.3%), pineal region (5.3%), suprasellar region (2.6%), and basal ganglia (2.6%). Statistical analyses showed that pediatric age, purely solid appearance of the tumor, and inadequate resection (only partial removal or biopsy) were risk factors associated with progression events. Patients with subtotal resection appeared to do as well as those with gross total resection.

Conclusions

RGNTs can occur nearly anywhere in the CNS, at both supratentorial and infratentorial sites. Maximal safe surgical resection should be emphasized for treatment; whilst aggressive resection with the goal of complete resection may be unnecessary.

Rosette-Forming Glioneuronal Tumor of the Fourth Ventricle in Children: Case Report and Literature Review

BACKGROUND

Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a rare World Health Organization (WHO) grade I neoplasm. Gross total resection (GTR) is the treatment of choice, and there is no firm evidence supporting other treatment options when GTR is not feasible.

CASE DESCRIPTION

We report a 6-year-old boy who, following an initial subtotal resection of a fourth ventricular RGNT, received an individualized chemotherapy protocol with vincristine, etoposide, and carboplatin for 3 cycles. The tumor was stable for 2 years after the completion of chemotherapy but then began to progress, at which point GTR was successfully performed. In addition, we completed a comprehensive literature review of RGNT cases. To date, a total of 104 cases have been reported, 33 of which are pediatric cases. Recurrence has been reported in only 7 cases of all ages (4 in the pediatric population). Radiotherapy has been used in several cases, but adjuvant chemotherapy has been reported only once following a recurrence.

CONCLUSIONS

We report a case of chemotherapy administration as a first-line treatment for a subtotally resected RGNT. Chemotherapy may be considered as an adjuvant therapy option for RGNT when GTR cannot be achieved. Furthermore, increased incidence of recurrence in the pediatric population may suggest that the tumor biology of RGNT in children differs from that in adults.

Rosette-forming glioneuronal tumor outside the fourth ventricle: a case-based update

INTRODUCTION

Rosette-forming glioneuronal tumors (RGNTs) that do not involve the fourth ventricle are rare. RGNTs were originally thought to be exclusively localized into the fourth ventricle but were found in various anatomical localizations.

MATERIAL AND METHODS

We review the literature and found 32 cases of this particular RGNT. The outcome was excellent with no mortality reported after surgical treatment. Only two patients had received adjuvant therapy for progression. We added one case of a RGNT located in the cerebellar hemisphere.

CASE AND CONCLUSION

She underwent a subtotal removal with no evidence of progression after. This WHO grade I tumor with a specific biphasic histopathology is of a good oncological outcome after surgical treatment. A long follow-up is needed as recurrence or metastatic progressions exist.

Rosette-forming glioneuronal tumor originating in the hypothalamus

Rosette-forming glioneuronal tumors (RGNT) of the fourth ventricle are slow-growing tumors that primarily involve the fourth ventricular region. We here report the first patient, an 8-year-old girl, with an RGNT originating in the hypothalamus and manifesting with precocious puberty. After partial removal, the remaining tumor showed rapid enlargement, and the pathologic diagnosis at the second surgery revealed histopathologic features similar to those found in the initial samples, including biphasic patterns of neurocytic rosettes and GFAP-stained astrocytic components. These tumor cells had mildly atypical nuclei; however, mitotic figures and necrosis were absent. Eosinophilic granular bodies and a glomeruloid vasculature were found, but Rosenthal fibers were absent. The Ki-67 proliferative index was 3.5 % (vs 1.1 % at the initial surgery). No recurrence was recorded during the 3-year period after the proton radiotherapy.