rosette-forming glioneuronal tumor
A rare WHO grade I tumor characterized by perivascular rosettes and neurocytic rosettes, typically occurring in young adults.
Full Definition
Rosette-forming glioneuronal tumor (RGNT) is a rare, WHO grade I mixed glioneuronal tumor that typically occurs in the fourth ventricle and adjacent brain stem in children and young adults. The tumor is characterized by two distinct components: perivascular rosettes resembling those seen in ependymoma, and neurocytic rosettes similar to those in central neurocytoma. The perivascular component consists of astrocytic cells forming rosettes around blood vessels, while the neurocytic component shows small round cells with perinuclear halos forming true rosettes. Despite its complex histological appearance, RGNT has an excellent prognosis following surgical resection.
Usage
Usage note: Extremely rare tumor; combination of two distinct rosette types is pathognomonic.
In Context
- "The fourth ventricular tumor showed both perivascular rosettes and neurocytic rosettes characteristic of rosette-forming glioneuronal tumor." — Pediatric neuropathology report
- "RGNT was diagnosed based on the biphasic pattern of ependymal-like and neurocytoma-like components." — Pathology consultation