Rosette-forming glioneuronal tumor in the pineal gland and the third ventricle: a case with radiological and clinical implications.

A 39-year-old man presented with more than 20 years history of episodic headache and one year history of dizziness, impaired vision and memory disorders. Computed tomography and Magnetic resonance imaging revealed a cystic mass involving the pineal gland, tectum and the third ventricle and obstruction of the aqueduct. Interestingly, the fourth ventricle was not involved in this case. The pathological diagnosis was rosette forming glioneuronal tumor (RGNT). These lesions are considered low-grade tumors (WHO grade I). We describe here the fifth reported patient with a pineal gland RGNT and the eighth reported patient with a RGNT outside the fourth ventricle.