CNS & pituitary tumors
Gliomas, glioneuronal tumors, and neuronal tumors
Neuronal and mixed neuronal-glial tumors
Rosette forming glioneuronal tumor
Author: Eman Abdelzaher, M.D., Ph.D.
Last author update: 1 July 2014
Last staff update: 14 April 2022
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Rosette forming glioneuronal tumor [title]
Table of Contents
Definition / general | Sites | Clinical features | Radiology description | Radiology images | Prognosis | Case reports | Treatment | Microscopic (histologic) description | Cytology description | Immunohistochemistry & special stains | Electron microscopy description | Differential diagnosisCite this page: Abdelzaher E. Rosette forming glioneuronal tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumorRGNT.html. Accessed March 30th, 2023.
Definition / general
- Rare, slow growing, mixed glioneuronal neoplasm with predilection to 4th ventricle region
- Initially described in 1995 as infratentorial DNT by Kuchelmeister et al. (Acta Neuropathol 1995;89:385)
- In 2002, established as a distinct disease entity by Komori et al. (Am J Surg Pathol 2002;26:582)
- Considered a novel, distinct grade I entity in WHO classification (2007) (Acta Neuropathol 2007;114:97)
Sites
- Typically arises in midline and primarily involves the cerebellum (vermis) with involvement of the 4th ventricle or aqueduct
- May show parenchymal extension
- Recently reported in spine, chiasmal - optic and pineal regions (Hum Pathol 2009;40:898, Neurosurgery 2009;64:E771, Quant Imaging Med Surg 2012;2:227)
Clinical features
- Affects children and young adults (mean age 33 years, range 12 - 59 years)
- Slight female predilection
- Presents with headache, ataxia
Radiology description
- Relatively circumscribed, solid or cystic
- Contrast enhancement: at least focal
- ± Calcifications, ± minimal edema
Radiology images
Images hosted on other servers:
Various images
Posterior fossa mass
Hyperintense tumor of midbrain
Suprasellar mass with intratumoral hemorrhage
Mass centered in pineal region
Well defined lesion in pineal gland
Prognosis
- Favorable clinical outcome
- Favorable prognosis in terms of survival but location may complicate surgical removal with a significant risk of neurologic injury
Case reports
- 15 year old girl with tumor of fourth ventricle (Neurol Med Chir (Tokyo) 2010;50:224)
- 16 year old girl with rosette forming glioneuronal tumor pineal region case (J Neurooncol 2011;102:477)
- 16 year old girl and 17 year old boy with rosette forming glioneuronal tumors (Neurol India 2011;59:276)
- 39 year old man with tumor in pineal gland and third ventricle (Quant Imaging Med Surg 2012;2:227)
Treatment
- Gross total surgical resection
Microscopic (histologic) description
- Relatively well defined tumor parenchyma interface
- Characterized by biphasic neurocytic and glial components
- Neurocytic component consists of uniform neurocytes that form neurocytic rosettes or perivascular pseudorosettes
- Neurocytic elements may lie unanchored in microcystic mucinous areas
- Ganglion cells may be present
- Glial component is usually identical to pilocytic astrocytoma with Rosenthal fibers and eosinophilic granular bodies (EGB)
- May show oligodendroglia-like cells that form microcysts or aggregate in sheets
- Mitoses, necrosis are absent and atypia is minimal
- Also stromal alterations indicative of chronicity and degeneration, vascular sclerosis, dense collagenization, microcalcifications, hemosiderin deposits, focal infarction
- Blood vessels are thin walled, ectatic or hyalinized, with glomeruloid microvascular proliferation
Cytology description
- Uniform nuclei, rosettes
Immunohistochemistry & special stains
- Neuronal component: synaptophysin+, NSE+, MAP2+
- Glial component: GFAP+, S100+
- Oligodendroglia-like cells: synaptophysin-, GFAP-, variable S100
- Low Ki67 proliferation index: < 3%
Electron microscopy description
- Neuronal component: microtubules and occasional dense core granules and synapses
- Glial component: dense bundles of glial filaments
Differential diagnosis
- Cerebellar liponeurocytoma:
- Lipidized cells
- Dysembryoplastic neuroepithelial tumor (DNET):
- Supratentorial
- Ependymoma:
- Perivascular pseudorosettes are GFAP+, synaptophysin-
- Oligodendroglioma:
- Rare in posterior fossa, diffusely infiltrative, no neurocytic component
- Papillary glioneuronal tumor:
- Lacks neurocytic rosettes, usually supratentorial
- Pilocytic astrocytoma:
- No neurocytic component
