title: Non-optic glioma in adults and children with neurofibromatosis 1.
abstract: Non-optic gliomas occur in 5% of children with NF1, but little is known about these tumours in adults. We aimed to investigate progression, spontaneous regression and the natural history of non-optic gliomas in adults and compare these findings to the results found in children.
  
  
  
  One thousand seven hundred twenty-two brain MRI scans of 562 unselected individuals with NF1 were collected at the NF outpatient department of the University Hospital Hamburg-Eppendorf between 2003 and 2015. The number of scans per patient ranged from one to 12; patients were followed for a median of 3.7 years. We identified 24 patients (4.3%) with non-optic gliomas. Median age at first scan with glioma was 21.2 years, much higher than in previous publications. Only seven of the 24 non-optic glioma patients were symptomatic. Five of 24 patients had multiple non-optic gliomas. Four individuals developed a new tumour, and 4 cases showed progression. The risk of new tumour development was 0.19% (95% confidence interval 0.06% to 0.52%) per patient year of follow-up for patients over 10 years. The rate of progressing non-optic gliomas per patient year of follow-up in the first 5 years after tumour diagnosis was 4.7% (95% confidence interval 1.5% to 12%).
  
  
  
  Non-optic gliomas are twice as common in an unselected cohort of NF1 patients as previously reported. This is likely due to increased frequency of diagnosis of asymptomatic tumours when routine MRIs are performed and a higher prevalence in older individuals.
authors.affiliation: Department of Medical Genetics, University of British Columbia, Vancouver, Canada. lsellmer@cfri.ca.
authors.forename: Laura
authors.initials: L
authors.lastname: Sellmer
authors.affiliation: Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Said
authors.initials: S
authors.lastname: Farschtschi
authors.affiliation: Diagnostic and Therapeutic Neuroradiology, University of British Columbia, Vancouver, Canada.
authors.forename: Marco
authors.initials: M
authors.lastname: Marangoni
authors.affiliation: Diagnostic and Therapeutic Neuroradiology, University of British Columbia, Vancouver, Canada.
authors.forename: Manraj K S
authors.initials: MK
authors.lastname: Heran
authors.affiliation: Department of Medical Genetics, University of British Columbia, Vancouver, Canada.
authors.forename: Patricia
authors.initials: P
authors.lastname: Birch
authors.affiliation: Department of Radiology, MRI Institute Altona, Hamburg, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Wenzel
authors.affiliation: Department of Medical Genetics, University of British Columbia, Vancouver, Canada.
authors.forename: Jan M
authors.initials: JM
authors.lastname: Friedman
authors.affiliation: Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Victor-Felix
authors.initials: VF
authors.lastname: Mautner
mesh_terms: D000293:Adolescent; D000328:Adult; D016543:Central Nervous System Neoplasms / Q000150:complications*; D002648:Child; D005260:Female; D005910:Glioma / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017253:Neurofibromatoses / Q000150:complications*; D055815:Young Adult
keywords: Adults; Children; Cohort study; Glioma; Neurofibromatosis 1; Prospective