title: [Meningioma of the olfactory groove: review of a series of 27 cases].
abstract: OBJECTIVE
  To describe our experience with olfactory groove meningiomas, analysing their clinical and radiological form of presentation and their surgical treatment.
  
  
  METHODS
  The clinical records of 27 patients diagnosed of olfactory groove meningioma, extracted from the series of meningiomas operated on in our department since 1973, were retrospectively reviewed. Demographical data, the clinical presentation and duration of the symptoms before diagnosis were collected. Several radiological characteristics were also reviewed such as the tumour size, associated brain edema, type of contrast enhancement, presence of endostosis and invasion of the cranial base. The surgical resection grade, the histological type and the presence of recurrences in the follow-up were also analysed.
  
  
  RESULTS
  The average age at presentation was 59 years. Average duration of symptoms prior to diagnosis was 39 months. The most frequent symptom at presentation was higher function impairment (52%), The average maximum tumoral diameter was 6.2 cm. 61% of the patients presented moderate or severe brain edema, which was quite frequently bilateral (74%). Radiological endostosis was present in 37% of the cases, but there were no signs of bone invasion in any case. The approach used was the basal frontal, uni or bilateral. In all cases the grade of resection was Simpson II. The majority of the cases presented a typical histology. Over 80% of the cases presented a good recovery at discharge. None of the patients presented with a tumoral recurrence after an average radiological follow-up of 74 months.
  
  
  CONCLUSIONS
  The olfactory groove is an infrequent location for intracranial meningiomas, accounting for only 4.5% of all meningiomas in our experience. These tumours reach a big size due to the delay in diagnosis. Drilling of the cranial base does not seem necessary for preventing tumoral recurrence.
authors.affiliation: Servicio de Neurocirugía, Hospital 12 de Octubre, Madrid.
authors.forename: A
authors.initials: A
authors.lastname: Lagares
authors.forename: R D
authors.initials: RD
authors.lastname: Lobato
authors.forename: S
authors.initials: S
authors.lastname: Castro
authors.forename: R
authors.initials: R
authors.lastname: Alday
authors.forename: A
authors.initials: A
authors.lastname: De la Lama
authors.forename: J F
authors.initials: JF
authors.lastname: Alén
authors.forename: P
authors.initials: P
authors.lastname: González
mesh_terms: D000328:Adult; D000368:Aged; D005004:Ethmoid Bone; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008579:Meningioma / Q000175:diagnosis* / Q000601:surgery; D008875:Middle Aged; D012189:Retrospective Studies; D012888:Skull Neoplasms / Q000175:diagnosis* / Q000601:surgery