title: Rosette-forming glioneuronal tumor of the fourth ventricle in an elderly patient.
abstract: Rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) is a rare condition, which previously has been described predominantly in middle-aged patients. There is limited experience with this kind of tumor in the elderly. Clinical, neuroimaging, and histological features of an example in a 70-year-old male who presented initially with vertigo are detailed and compared with published cases. Neuroimaging studies demonstrated a 4-cm cystic lesion in posterior fossa containing a 1-cm contrast-enhancing nodule on its lateral margin. The lesion was confined to the fourth ventricle and initially thought to be a hemangioblastoma until angiography clarified the minimal tumor vascularization. Gross total resection was achieved. Pathological examination showed a rosette-forming low grade tumor with a cell proliferation rate of 2% being consistent with RGNT. The postoperative course was uneventful and clinical symptoms resolved completely. There was no tumor recurrence after 2 years follow-up. We confirm that the rare and only recently characterized tumor entity of RGNT can also be found in elderly patients; furthermore, it can be associated with a benign course. The main differential diagnosis of RGNT resulting from CNS-imaging modalities in elderly patients are pilocytic astrocytoma and hemangioblastoma of the posterior fossa, which after metastasis are the most common primary adult intra-axial posterior fossa tumors. Therefore, a subtle preoperative radiological diagnosis is warranted and surgery should be performed by experienced hands to avoid neurological deterioration.
authors.affiliation: Department of Neurosurgery, Carl Gustav Carus University Hospital, Fetscherstr. 74, 01307 Dresden, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Podlesek
authors.forename: K
authors.initials: K
authors.lastname: Geiger
authors.forename: D J
authors.initials: DJ
authors.lastname: Hendry
authors.forename: G
authors.initials: G
authors.lastname: Schackert
authors.forename: D
authors.initials: D
authors.lastname: Krex
mesh_terms: D000368:Aged; D002551:Cerebral Ventricle Neoplasms / Q000473:pathology* / Q000601:surgery; D020546:Fourth Ventricle / Q000473:pathology*; D018303:Ganglioglioma / Q000473:pathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male