title: Osteosarcoma presenting as hemorrhagic cerebellar metastasis.
abstract: OBJECTIVE
  Osteosarcoma is the most common malignant bone tumor in children and adolescents. Brain metastasis from osteosarcoma was once uncommon; however, with the advent of chemotherapeutic agents and improved imaging modalities, it has become a more common and recognized finding. Brain metastases are, rarely, the initial presenting symptom, but instead are a late and preterminal event in the disease process. When osteosarcomas manifest in the central nervous system, they tend to occur in the gray-white junction in the anterior circulation akin to other metastatic lesions in the brain.
  
  
  METHODS
  The authors report a case of a 16-year-old boy who presented with acute neurological deterioration due to a posterior fossa hemorrhage and was subsequently found to have a primary site localizing to the metaphysis of the right femur with florid metastatic disease.
  
  
  CONCLUSIONS
  This is the first case reported in the literature in which an osteosarcoma initially presented as cerebral metastasis in the form of a posterior fossa hemorrhage with a rapidly deteriorating course.
authors.affiliation: Department of Neurosurgery, Primary Children's Medical Center, University of Utah, 100 N. Mario Capecchi Drive, Salt Lake, Utah 84113, USA. jay.riva-cambrin@hsc.utah.edu
authors.forename: Toba N
authors.initials: TN
authors.lastname: Niazi
authors.forename: Craig
authors.initials: C
authors.lastname: Forester
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Afify
authors.forename: Jay
authors.initials: J
authors.lastname: Riva-Cambrin
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000175:diagnosis / Q000556:secondary*; D002531:Cerebellum / Q000473:pathology*; D017809:Fatal Outcome; D005269:Femur / Q000473:pathology; D006801:Humans; D020300:Intracranial Hemorrhages / Q000175:diagnosis / Q000473:pathology*; D008297:Male; D012516:Osteosarcoma / Q000175:diagnosis* / Q000556:secondary*