Papillary glioneuronal tumor of the fourth ventricle: case report and review of the literature.

Rosette-forming glioneuronal tumour (RGNT) of the fourth ventricle is a relatively new entity recently described. Neuronal and mixed neuronal-glial tumours have been incorporated in the same category in the WHO Classification of Nervous System Tumours. This category comprises heterogeneous neoplasms composed of neuronal and glial cells with various grades of differentiation. We present a case of papillary glioneuronal tumor occurring in a 44-year-old man with an unusual hemorrhagic onset. The clinical, morphological and immunohistochemical features are discussed and the published literature is reviewed.