title: Chondroblastoma of the apex portion of petrousal bone.
abstract: BACKGROUND
  Skull chondroblastoma is extremely rare. We described in this study the first case of petrousal bone apex chondroblastoma.
  
  
  METHODS
  The tumor occurred in a 12-year-old girl and was revealed by left hypoacusis, vertigo, and walking instability. Computerized tomography scan depicted well-demarcated and osteolytic lesion of the left petrousal bone just before the internal acoustic meatus. The tumor was operated on by a subtemporal approach with a subtotal resection. Lesion recurred and was operated a second time by a combined approach subtemporal and translabyrinthine. This treatment was completed by radiotherapy. We used a combination of photon therapy and proton therapy. Outcome was good and free of recurrence 36 months after the second operation.
  
  
  CONCLUSIONS
  Proton therapy can be particularly useful for skull base tumors frequently radioresistant and near very important structures. This case is the first one of a successful treatment by proton therapy for chondroblastoma recurrence.
authors.affiliation: Department of Neurosurgery, Gui de Chauliac Hospital, 2 av Emile Bertin Sans, 34000, Montpellier, France. g-dran@chu-montpellier.fr
authors.forename: Grégory
authors.initials: G
authors.lastname: Dran
authors.forename: Eric
authors.initials: E
authors.lastname: Niesar
authors.forename: Fanny
authors.initials: F
authors.lastname: Vandenbos
authors.forename: Georges
authors.initials: G
authors.lastname: Noel
authors.forename: Philippe
authors.initials: P
authors.lastname: Paquis
authors.forename: Michel
authors.initials: M
authors.lastname: Lonjon
mesh_terms: D001859:Bone Neoplasms / Q000473:pathology*; D049109:Cell Proliferation; D002648:Child; D002804:Chondroblastoma / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D010579:Petrous Bone / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods