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

Abstract

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.