title: Rosette-forming glioneuronal tumor: a pineal region case with IDH1 and IDH2 mutation analyses and literature review of 43 cases.
abstract: Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a mixed glio-neuronal neoplasm recently codified by the World Health Organization WHO Classification of Central Nervous System (CNS) Tumors (2007). To date, 43 cases have been described in the literature; most occurring in the fourth ventricle region. We report the fourth case involving the pineal region in a 16-year-old female with signs of increased intracranial pressure (ICP). A stereotactic biopsy of the mass was followed by a debulking procedure. Both specimens revealed classic RGNT histology. The patient had stable scans 7 months post-resection. The clinical, radiological and histopathologic features of the previously described 43 cases are reviewed along with our illustrative case. Mean age of patients was 30 ± 12.8 years with 1.9:1 female to male ratio. The most common presenting signs related to increased ICP and posterior fossa involvement, including: headache (62.8%), ataxia (39.5%) and vomiting and vertigo (both 16.3%). This tumor usually presents with cystic changes (54.5%) with focal enhancement (60.9%) and hydrocephalus (43.2%). Microcalcifications and satellite lesions were common radiographic observations. All reported cases had the classic biphasic pattern. Rosenthal fibers and eosinophilic granular bodies are each present in approximately two thirds of cases. Ki-67 labeling index is consistently low (mean (%): 1.8 ± 0.75 SD). The isocitrate dehydrogenase 1 or 2 mutation found in low grade diffuse gliomas is not identified in this RGNT case. Reported outcome is nearly uniformly excellent after complete or subtotal resection. A solitary report of recurrence after 10 years and the limited experience with this entity suggest that long term follow up is advisable.
authors.affiliation: Department of Pathology and Laboratory Medicine, Section of Neuropathology, University of California, Los Angeles, Los Angeles, CA, USA. OSolis@mednet.ucla.edu
authors.forename: Orestes E
authors.initials: OE
authors.lastname: Solis
authors.forename: Rupal I
authors.initials: RI
authors.lastname: Mehta
authors.forename: Albert
authors.initials: A
authors.lastname: Lai
authors.forename: Rashi I
authors.initials: RI
authors.lastname: Mehta
authors.forename: Lama O
authors.initials: LO
authors.lastname: Farchoukh
authors.forename: Richard M
authors.initials: RM
authors.lastname: Green
authors.forename: Jerry C
authors.initials: JC
authors.lastname: Cheng
authors.forename: Sathima
authors.initials: S
authors.lastname: Natarajan
authors.forename: Harry V
authors.initials: HV
authors.lastname: Vinters
authors.forename: Timothy
authors.initials: T
authors.lastname: Cloughesy
authors.forename: William H
authors.initials: WH
authors.lastname: Yong
mesh_terms: D000293:Adolescent; D000328:Adult; D002551:Cerebral Ventricle Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D004252:DNA Mutational Analysis; D005260:Female; D020546:Fourth Ventricle / Q000473:pathology*; D018303:Ganglioglioma / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D006801:Humans; D066298:In Vitro Techniques; D019586:Intracranial Hypertension / Q000209:etiology; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D008279:Magnetic Resonance Imaging; D008297:Male; D009154:Mutation / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010870:Pineal Gland / Q000473:pathology; D039781:PubMed / Q000706:statistics & numerical data; D012397:Rosette Formation; D055815:Young Adult
chemical_list: D009419:Nerve Tissue Proteins; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human