title: [Old schwannoma: a rare type of schwannoma].
abstract: OBJECTIVE
  We report one case of retroperitoneal schwannoma with unfrequent histological characteristics evaluating its clinical significance and therapeutic options.
  
  
  METHODS
  We report the case of a benign retroperitoneal schwannoma as an incidental MRI finding in a 70 year-old female patient with symptoms of lumbosciatic pain for 6 months. We perform a bibliographic review.
  
  
  RESULTS
  After surgical excision the diagnosis was retroperitoneal old schwannoma. No additional treatment was given. There is no evidence of recurrence on follow-up. The histological changes apparent in the cases of old schwannoma have been interpreted as degenerative, indicating a long evolution, which has motivated its denomination as old. Some cases have been diagnosed as malignant.
  
  
  CONCLUSIONS
  The old schwannoma is a rare variety of the benign common schwannoma. Microscopically its shows areas of hypocellular tissue and pleomorphic nuclei suggestive of malignancy. Therapeutic management is similar to other benign retroperitoneal processes, surgical excision and follow-up.
authors.affiliation: Servicio de Urología, Hospital San Jorge, Huesca, España. agrasa@telefonica.net
authors.forename: Ana María
authors.initials: AM
authors.lastname: Grasa Arnal
authors.forename: Jorge
authors.initials: J
authors.lastname: Abad Roger
authors.forename: Araceli
authors.initials: A
authors.lastname: Bono Ariño
authors.forename: Jesús Javier
authors.initials: JJ
authors.lastname: Vera Alvarez
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: Sanz Vélez
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D009442:Neurilemmoma / Q000473:pathology*; D012186:Retroperitoneal Neoplasms / Q000473:pathology*