title: Brainstem oligodendroglial tumors in children: two case reports and review of literatures.
abstract: OBJECTIVE
  There is little information on pediatric oligodendroglial tumor located in the brainstem because of its rarity.
  
  
  METHODS
  Here, we present two pediatric cases of pontine oligodendroglial tumors with radiological findings atypical for diffuse intrinsic pontine glioma.
  
  
  RESULTS
  The first patient was an 8-year-old boy. Brain magnetic resonance imaging (MRI) demonstrated diffuse high-intensity changes in the pons, left middle cerebellar peduncle, and part of the left cerebellar hemisphere on T2-weighted and fluid-attenuated inversion recovery images, with an enhanced spot lesion in the left cerebellar hemisphere. The pathological diagnosis was anaplastic oligodendroglioma, and we identified a mutation in histone H3.3 in the tumor specimen. He succumbed to massive disseminated relapse 7 months from diagnosis despite local radiation therapy. The second patient, a 2-year-old girl, was diagnosed with oligoastrocytoma. Brain MRI revealed a large mass in her rostral pons extended to the fourth ventricle with obstructive hydrocephalus. The tumor recurred with intracranial dissemination 56 months post-surgery.
  
  
  CONCLUSIONS
  Pediatric brainstem oligodendroglial tumors can include histone H3.3-mutated tumors and have a tendency to disseminate throughout the neuroaxis at the time of relapse.
authors.affiliation: Division of Pediatric Neuro-Oncology, Department of Neuro-Oncology/Neurosurgery, Saitama Medical University International Medical Center, Yamane 1397-1, Hidaka-shi, Saitama-ken, 350-1298, Japan, kohfukuoka@gmail.com.
authors.forename: Kohei
authors.initials: K
authors.lastname: Fukuoka
authors.forename: Takaaki
authors.initials: T
authors.lastname: Yanagisawa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Tomonari
authors.initials: T
authors.lastname: Suzuki
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Shirahata
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Adachi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Mishima
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Fujimaki
authors.forename: Masao
authors.initials: M
authors.lastname: Matsutani
authors.forename: Satoru
authors.initials: S
authors.lastname: Wada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sasaki
authors.forename: Ryo
authors.initials: R
authors.lastname: Nishikawa
mesh_terms: D020295:Brain Stem Neoplasms / Q000235:genetics* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D006657:Histones / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009154:Mutation / Q000235:genetics*; D009837:Oligodendroglioma / Q000235:genetics* / Q000473:pathology
chemical_list: D006657:Histones