Rosette-forming glioneuronal tumor of the fourth ventricle.

Introduction & Komori et al. (2002) were the fi rst authors to recognize the existence of a new brain tumor entity, rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle. The authors described 11 cases of this distinctive tumor of the posterior fossa [6] . A few further RGNT cases were published in the following 5 years [1, 2, 4, 5, 8, 10] , eventually leading to the inclusion of RGNT in the 4 th edition of the WHO brain tumor classifi cation as a benign primary brain tumor classifi ed as WHO grade 1 [7, 9] . We describe here the clinical and neuroradiological features of a further patient with RGNT of the fourth ventricle. Our report may contribute to establishing the natural history of these tumors and identifying the best course of treatment.