A comprehensive analysis of 41 patients with rosette-forming glioneuronal tumors of the fourth ventricle.

The rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a recently described, rare, and distinct tumor of the glioneuronal family. The presentation, natural history, and treatment response of these tumors has been unclear as there are no significant series of a sizeable population with long-term follow-up. We report a comprehensive analysis of 41 patients with RGNT to provide the most current understanding of this rare tumor. Treatment of these patients has consisted of resection via the transvermian and telovelar approaches, with one patient requiring radiotherapy due to tumor recurrence. Various unique imaging characteristics may allow for the preoperative identification of these tumors. Resection via the telovelar approach should be considered for symptomatic tumors and those that pose a risk of obstructive hydrocephalus. Due to their benign nature and low propensity for recurrence, subtotal resection may be appropriate for those that are adherent to the brainstem. Radiotherapy may be considered for patients with tumor recurrence.