title: Presacral schwannoma with purely cystic form.
abstract: METHODS
  Case report.
  
  
  OBJECTIVE
  To point out that presacral schwannoma can display markedly cystic degeneration.
  
  
  BACKGROUND
  Benign schwannoma sometimes displays degenerative changes, such as cyst formation, calcification, hemorrhage, and hyalinization. Usually these degenerations are partially seen in the tumors.
  
  
  METHODS
  Medical history, physical findings, imaging features, and histologic findings were reviewed in a case with a large presacral schwannoma.
  
  
  RESULTS
  A 62-year-old woman presented with an 18-month history of right sciatic pain. Magnetic resonance images detected a large cystic, presacral tumor. Initially the tumor was misdiagnosed as a cystic ovarian tumor. Preoperative diagnostic workup led to the diagnosis of cystic schwannoma. Intralesional curettage achieved good pain relief.
  
  
  CONCLUSIONS
  This tumor was unusual in its totally cystic appearance and resemblance to a cystic ovarian tumor or anterior sacral meningocele. Preoperative diagnosis is important to prevent major neurologic deficit at surgery.
authors.affiliation: Department of Orthopedic Surgery, Niigata University School of Medicine, Japan. aogose@med.niigata-u.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Ogose
authors.forename: T
authors.initials: T
authors.lastname: Hotta
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: R
authors.initials: R
authors.lastname: Takano
authors.forename: T
authors.initials: T
authors.lastname: Higuchi
mesh_terms: D003560:Cysts / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008588:Meningocele / Q000175:diagnosis; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology* / Q000601:surgery; D010051:Ovarian Neoplasms / Q000175:diagnosis; D012186:Retroperitoneal Neoplasms / Q000473:pathology* / Q000601:surgery; D012187:Retroperitoneal Space / Q000473:pathology* / Q000601:surgery; D012447:Sacrum / Q000473:pathology* / Q000601:surgery