title: Giant cystic sacral schwannoma mimicking tarlov cyst: a case report.
abstract: To present a rare case of a giant schwannoma of the sacrum mimicking a Tarlov cyst.
  
  
  
  A 58-year-old woman had a 1-year history of low back pain. MRI revealed a large cystic mass in the sacral canal with bony erosion. Radiological diagnosis of Tarlov cyst was made.
  
  
  
  The patient underwent surgical treatment for the lesion, which revealed a solid mass. Histopathological examination of the tumor confirmed the diagnosis of schwannoma. The postoperative course was uneventful and the patient has had significant improvement in her pain 1 month postoperatively.
  
  
  
  Giant cystic schwannoma of the sacrum is a very rare diagnosis overlooked by practitioners for more common cystic etiologies, but its treatment is significantly different. Care should be taken to include this diagnosis in a differential for a cystic sacral mass.
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, 19104, USA. mattiah12@gmail.com.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Attiah
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, 19104, USA.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Syre
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, 19104, USA.
authors.forename: John
authors.initials: J
authors.lastname: Pierce
authors.affiliation: Department of Pathology, University of Pennsylvania, Philadelphia, USA.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Belyaeva
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, 19104, USA.
authors.forename: William C
authors.initials: WC
authors.lastname: Welch
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009442:Neurilemmoma / Q000000981:diagnostic imaging / Q000473:pathology*; D012447:Sacrum / Q000473:pathology; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D052958:Tarlov Cysts / Q000000981:diagnostic imaging*
keywords: Giant Schwannoma; Sacral; Tarlov cyst