title: Metastatic hemangiopericytoma to the cauda equina: a case report.
abstract: BACKGROUND
  Hemangiopericytoma is an aggressive tumor associated with high recurrence and metastasis. Metastases are usually delayed, long after diagnosis of the primary lesion. Metastatic hemangiopericytoma to the spinal cord is especially rare.
  
  
  OBJECTIVE
  To report a rare clinical presentation of a metastatic intradural, intramedullary hemangiopericytoma to the cauda equina from a cerebellar hemangiopericytoma.
  
  
  METHODS
  Case report with a review of the literature.
  
  
  METHODS
  Clinical history, physical findings, and magnetic resonance imaging studies of a patient with a metastatic intradural, intramedullary hemangiopericytoma to the cauda equina are reported.
  
  
  RESULTS
  A case report is presented of a female with an intradural, intramedullary lesion at the L4-S1 level, presenting initially with progressive pain and motor weakness affecting the left lower extremity. She had a history of a cerebellar hemangiopericytoma, which had been treated with total resection and radiotherapy 4 years earlier. This patient developed urinary urgency and frequency. Pathological analysis revealed a hemangiopericytoma, which had a similar character to a cerebellar lesion. After radiotherapy, the tumor was mostly diminished and her symptoms totally resolved.
  
  
  CONCLUSIONS
  Hemangiopericytomas have a strong tendency to both local recurrence and metastasis. Common metastatic sites are the skeletal system, lung, liver, and abdominal cavity. To the authors' knowledge, there have been no reports of spinal intradural, intramedullary metastasis of hemangiopericytoma.
authors.affiliation: Department of Neurosurgery, Tokyo Metropolitan Neurological Hospital, Tokyo 183-0042, Japan. taniura@sanmedia.or.jp
authors.forename: Seijiro
authors.initials: S
authors.lastname: Taniura
authors.forename: Makoto
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Toshio
authors.initials: T
authors.lastname: Mizutani
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D002528:Cerebellar Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D005260:Female; D006393:Hemangiopericytoma / Q000556:secondary* / Q000628:therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D010524:Peripheral Nervous System Neoplasms / Q000532:radiotherapy / Q000556:secondary*