title: Ollier disease.
abstract: BACKGROUND
  Ollier disease is a rare, nonfamilial disorder characterized by multiple enchondromatosis with an asymmetric distribution and areas of dysplastic cartilage. Clinical manifestations usually start with local pain, bone swelling, and palpable bony masses, often associated with bone deformity. Intracranial enchondromas arise from the skull base because of its cartilage embryological derivation. Headache and cranial nerve palsy are the most prominent clinical findings. The only effective treatment is represented by surgery that allows to resect the tumors and to treat their complications, such as pathological fractures, growth defect, and neurological symptoms.
  
  
  METHODS
  We report on a 12-year-old boy affected with Ollier disease and operated on for a skull base enchondroma. The tumor was partially removed through a right pterional approach to the cavernous sinus. Serial postoperative magnetic resonance imaging showed an increasing residual tumor and the patient underwent radiation therapy.
  
  
  CONCLUSIONS
  Surgery remains the main therapy for intracranial enchondromas. Radiotherapy is required in case of sarcomatous evolution or when a gross total tumor resection is not feasible, as in the present case.
authors.affiliation: Paediatric Neurosurgical Unit, Catholic University of Rome, Rome, Italy. lucadangelo_80@hotmail.com
authors.forename: Luca
authors.initials: L
authors.lastname: D'Angelo
authors.forename: Luca
authors.initials: L
authors.lastname: Massimi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Narducci
authors.forename: Concezio
authors.initials: C
authors.lastname: Di Rocco