Thalamic rosette-forming a glioneuronal tumor in an elderly patient: Case report and literature review

Rosette-Forming Glioneuronal Tumor Mimicking Foramen Monro Colloid Cyst: Case Presentation and Systematic Literature Review

BACKGROUND

Rosette-forming glioneuronal tumors (RGNTs) are rare indolent and benign tumors, typically associated with the fourth ventricle. Cases in the third ventricle are less common, especially those involving only the anterior part.

METHODS

A literature review using "rosette-forming glioneuronal tumor" on PubMed yielded 176 articles from 2002 to 2024. Articles excluding third ventricle RGNTs were omitted, with titles and abstracts screened for relevance. We also present our case of an anterior third ventricle RGNT, tracking from initial presentation to follow-up.

RESULTS

Our patient, a 62-year-old woman, experienced 3 months of recurrent Hakim Triad symptoms-gait instability, urinary incontinence, and cognitive issues. Magnetic resonance imaging revealed a 1.0 × 0.7 cm mass, hypointense on T1-weighted imaging and heterogeneous on T2-weighted imaging, initially suspected as a colloid cyst. Given its high colloid cyst risk score, surgery was performed, but histopathology confirmed an RGNT diagnosis. To date, this is the first case of exclusive anterior third ventricle RGNT microsurgery reported, with 26 months of recurrence-free follow-up. Our literature review identified 20 articles detailing 23 cases of third ventricle RGNT, with only 7 achieving gross total resection, while most underwent biopsy and ventriculostomy.

CONCLUSIONS

RGNTs in the anterior third ventricle may resemble other tumor types, requiring careful monitoring. This case is significant due to the patient's clinical presentation, imaging, and extended recurrence-free follow-up.

Clinicopathological analysis of rosette-forming glioneuronal tumors

BACKGROUND

This study aimed to investigate the clinicopathological characteristics, diagnostic indicators, and critical factors for the differential diagnosis of rosette-forming glioneuronal tumor (RGNT).

PATIENTS AND METHODS

This retrospective study included six surgically treated RGNT cases. We analyzed and summarized their clinical manifestations, radiological features, histological morphology, immunophenotype, and molecular genetic changes, supplemented with a literature review.

RESULTS

The patients comprised four males and two females with a mean age of 35 years. The tumors were located in the cerebellum (two cases); the fourth ventricle, quadrigeminal cistern, and third ventricle (one case each); and the fourth ventricle and brainstem (one case). Clinical manifestations included headaches in four cases, left eyelid ptosis in one case, and one asymptomatic case only identified during physical examination. Microscopically, the tumor cells were uniform in size and were marked by rosette-like or pseudorosette-like structures around the neuropil and blood vessels. Immunohistochemistry revealed biphasic patterns. The central neuropil components of the rosette-like structures around the neuropil and the pseudorosette structures of the perivascular regions expressed Syn, while the cells surrounding the rosettes expressed Olig2 and not GFAP. GFAP and S-100 were expressed in the glial components but not in the rosette or pseudorosette regions. The Ki-67 proliferation index was typically low. Molecular genetic analysis showed that the main molecular changes involved FGFR1 mutation accompanied by PIK3R1 mutation. None of the patients received chemoradiotherapy postoperatively. Follow-up durations varied between 4 and 23 months with no recorded recurrence or metastasis.

CONCLUSION

RGNT is a comparatively rare mixed glioneuronal tumor that occurs in the midline structures. Its morphology shows certain overlaps with other low-grade neuroepithelial tumors. Identifying the rosettes around the neuropil is critical for morphological diagnosis, and the molecular identification of FGFR1 mutations accompanied by PIK3R1 mutations can facilitate diagnosis.

A Rare Lesion in the Anterior Region of the Third Ventricle: Rosette-Forming Glioneuronal Tumor

Rosette-forming glioneuronal tumor (RGNT) is a rare and indolent mixed glioneuronal tumor involving primarily the fourth ventricular region and occurring predominantly in young adults. We present a case of a 44-year-old woman presented with progressive headaches, vomiting, and a sudden decreasing level of consciousness. The magnetic resonance imaging showed a regular lesion within the anterior portion of the third ventricle and the patient underwent an endoscopic approach to remove the tumor that was exclusively within the anterior portion of the third ventricle. Histopathology showed an RGNT that was totally removed. We also report some unusual complications that are described in the literature and are related to ventricular endoscopy such as seizures and hydroelectrolyte disorders. With two years of follow-up, the patient had no complaints and no tumor progression was observed.

Efficacy of endoscopic management of primary central nervous system lymphoma: a multicentric study and literature review

INTRODUCTION

To date, confined intra-ventricular localization of primary central nervous system lymphoma (PCNSL) has been usually managed with open surgical resection and/or stereotactic biopsy; nonetheless, the endoscopic approach to such localization can provide many advantages over standard microsurgery and/or stereotactic biopsy. Here we present our experience in managing such a rare pathology through the endoscopic approach.

METHOD

In order to gather more information about such a rare pathology, a retrospective multicentric study on a prospectively built database has been performed during a 5 year period. Ten different European centers have been involved.

RESULTS

A total of 60 patients, 25 women and 35 men, have been enrolled in the study. The mean age was 65.3 years. The mean lesion size was 40.3 mm. Among all selected patients, 40 (66.6%) had superficial lesions within the ventricle, whereas the remaining 20 (33.4%) had lesions involving/extending to deeper structures. All surgical procedures were uneventful and ETV was deemed necessary only in 20/60 cases.

CONCLUSION

In our experience, endoscopic management of intraventricular PCNSL is an effective option. It should be considered after a careful examination of neurological and immunological status, alternative options for diagnostic sampling, location of the lesion, and presence or absence of hydrocephalus. Endoscopic management could be considered as a safe and minimally invasive option to obtain: (a) a biopsy sample of the lesion for further diagnostic workup, (b) CSF diversion through third ventriculostomy or VP shunt for the management of hydrocephalus, and (c) insertion of ventricular access devices for long term medical management and whenever necessary as a rescue option for ventricular tap.

Rosette-Forming Glioneuronal Tumor of the Fourth Ventricle: A Case of Relapse Treated with Proton Beam Therapy

Rosette-forming glioneuronal tumors (RGNTs) are rare, grade I, central nervous system (CNS) tumors typically localized to the fourth ventricle. We describe a 9-year-old girl with dizziness and occipital headache. A magnetic resonance imaging (MRI) revealed a large hypodense posterior fossa mass lesion in relation to the vermis, with cystic component. Surgical resection of the tumor was performed. A RGNT diagnosis was made at the histopathological examination. During follow-up, the patient experienced a first relapse, which was again surgically removed. Eight months after, MRI documented a second recurrence at the local level. She was a candidate for the proton beam therapy (PBT) program. Three years after the end of PBT, the patient had no evidence of disease recurrence. This report underlines that, although RGNTs are commonly associated with an indolent course, they may have the potential for aggressive behavior, suggesting the need for treatment in addition to surgery. Controversy exists in the literature regarding effective management of RGNTs. Chemotherapy and radiation are used as adjuvant therapy, but their efficacy management has not been adequately described in the literature. This is the first case report published in which PBT was proposed for adjuvant therapy in place of chemotherapy in RGNT relapse.

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.

Adult Brain Tumors and Pseudotumors: Interesting (Bizarre) Cases

Some brain tumors results are interesting due to their rarity at presentation and overwhelming imaging characteristics, posing a diagnostic challenge in the eyes of any experienced neuroradiologist. This article focuses on the most important features regarding epidemiology, location, clinical presentation, histopathology, and imaging findings of cases considered "bizarre." A review of the most recent literature dealing with these unusual tumors and pseudotumors is presented, highlighting key points related to the diagnosis, treatments, outcomes, and differential diagnosis.