title: Finding of IDH1 R132H mutation in histologically non-neoplastic glial tissue changes surgical strategies, a case report.
abstract: BACKGROUND
  In 2016, the WHO classification of diffuse astrocytoma began to include isocitrate dehydrogenase (IDH) mutation in addition to histology.
  
  
  RESULTS
  We here demonstrate a case where a 14-year-old boy presented with a parietal tumor with no histological evidence of neoplasia but with an IDH1 mutation. Due to the IDH1 R132H mutation, the patient was diagnosed with diffuse astrocytoma WHO grade II and underwent successful gross total resection of this near-eloquently located tumor.
  
  
  CONCLUSIONS
  This case exemplifies how inclusion of immunohistochemistry in tumor classification alters surgical strategy and might improve accuracy and time to diagnosis.
authors.affiliation: Department of Neurosurgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100, København Ø, Denmark. csoend@gmail.com.
authors.forename: Christian Baastrup
authors.initials: CB
authors.lastname: Søndergaard
authors.affiliation: Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100, København Ø, Denmark.
authors.forename: David
authors.initials: D
authors.lastname: Scheie
authors.affiliation: Department of Pediatrics, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Astrid Marie
authors.initials: AM
authors.lastname: Sehested
authors.affiliation: Department of Neurosurgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Jane
authors.initials: J
authors.lastname: Skjøth-Rasmussen
mesh_terms: D000293:Adolescent; D001254:Astrocytoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D008297:Male; D009154:Mutation / Q000235:genetics*
chemical_list: D007521:Isocitrate Dehydrogenase
keywords: Diffuse astrocytoma; IDH1 R132H mutation; Isocitrate dehydrogenase