Rosette-forming Glioneuronal Tumors in the Posterior Third Ventricle.

tumor found almost exclusively within the fourth ventricle. These grade I tumors were first included in the World Health Organization (WHO) Classification for the central nervous system in 20071. Since then, approximately 49 cases have been published1,2. There are no reported cases of RGNT within the third ventricle, although this tumor has also been described in the pineal region, the tectum and within the aqueduct2. Supratentorial localization is quite rare, with only three published: one was found in the septum pellucidum3, another within the optic nerve in neurofibromatosis type 1 (NF1) patient1 and one in a patient with multiple RGNT in the lateral ventricle2. The authors report the first case series in the literature of RGNT occurring within the posterior third ventricle.