Rosette-Forming Glioneuronal Tumor
Figure 1: (Left) This mildly complex, circumscribed T2-FLAIR hyperintense rosette-forming glioneuronal tumor fills and expands the fourth ventricle, contributing to hydrocephalus in this patient, but causes little edema. (Right) The tumor demonstrates a heterogeneous internal pattern of enhancement.
BASIC DESCRIPTION
- Uncommon, slow-growing, and benign tumor that usually arises in the posterior fossa
PATHOLOGY
- WHO grade I
- Composed of pseudorosette-forming neurocytes and astrocytes
- No malignant transformation
CLINICAL FEATURES
- Affects young adults (mean age, 30 years)
- Female gender predilection (2:1)
- Commonly presents with signs/symptoms of increased intracranial pressure secondary to obstructive hydrocephalus
- Headache, nausea, ataxia, vertigo
- Treatment: surgical resection
- Prognosis: recurrence uncommon after total resection; 90% 5-year survival rate
IMAGING FEATURES
- General
- Mixed solid-cystic tumor ± calcification, hemorrhage; may be solid
- Minimal peritumoral edema
- Majority arise in fourth ventricle or midline cerebellum
- Pineal, cerebellopontine angle cistern, or hemispheric locations are uncommon
- CT
- Solid-cystic midline posterior fossa mass
- MRI
- T1WI: hypointense to isointense
- T2WI: usually hyperintense with cystic or bubbly appearance; ±flow voids
- FLAIR: heterogeneously hyperintense
- T2*/GRE/SWI: black signal blooming in foci of calcification, hemorrhage
- T1WI+C: variable enhancement
IMAGING RECOMMENDATIONS
- MRI with contrast
For more information, please see the corresponding chapter in Radiopaedia.
Contributor: Rachel Seltman, MD
References
Hsu C, Kwan G, Lau Q, et al. Rosette-forming glioneuronal tumour: imaging features, histopathological correlation and a comprehensive review of literature. Br J Neurosurg 2012;26:668–673. doi.org/10.3109/02688697.2012.655808.
Schlamann A, von Bueren AO, Hagel C, et al. An individual patient data meta-analysis on characteristics and outcome of patients with papillary glioneuronal tumor, rosette glioneuronal tumor with neuropil-like islands and rosette forming glioneuronal tumor of the fourth ventricle. PLoS One 2014;9:e101211. doi.org/10.1371/journal.pone.0101211.
Osborn AG, Salzman KL, Jhaveri MD. Diagnostic Imaging (3rd ed). Elsevier, Philadelphia, PA; 2016.
Smith AB, Smirniotopoulos JG, Horkanyne-Szakaly I. From the radiologic pathology archives: intraventricular neoplasms: radiologic-pathologic correlation. Radiographics 2013;33:21–43. doi.org/10.1148/rg.331125192.
Zhang J, Babu R, McLendon RE, et al. A comprehensive analysis of 41 patients with rosette-forming glioneuronal tumors of the fourth ventricle. J Clin Neurosci 2013;20:335–341. doi.org/10.1016/j.jocn.2012.09.003.
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