title: Giant presacral schwannoma presenting with constipation: a case report.
abstract: BACKGROUND
  Schwannoma, otherwise known as a neurilemmoma, is a tumor arising from peripheral nerve sheaths. Although commonly noted in association with the eighth cranial nerve as intracranial acoustic neuroma, cases of schwannoma arising in other locations have been reported in the literature. These tumors usually cause symptoms as a result of their mass effect and, since they are benign, encapsulated and non-invasive tumors, complete surgical excision is considered curative.
  
  
  METHODS
  We report the case of a 46-year-old Sri Lankan man who presented to our facility with recent onset of difficulty evacuating his bowels. He was noted to have a giant presacral schwannoma on magnetic resonance imaging scan. The mass was surgically excised with improvement of our patient's symptoms. A subsequent histopathological examination confirmed the presence of a benign schwannoma.
  
  
  CONCLUSIONS
  Although schwannomas commonly occur in the extremities, a rare case of occurrence in the pelvis is reported here. Due to the limited space in the pelvis, the local mass effect may be the presenting feature of such a lesion and surgical excision is curative.
authors.affiliation: General Surgical Unit, National Hospital, Colombo, Sri Lanka. LS-lasithamfc@gmail.com.
authors.forename: Lasitha
authors.initials: L
authors.lastname: Samarakoon
authors.forename: Amila
authors.initials: A
authors.lastname: Weerasekera
authors.forename: Rukman
authors.initials: R
authors.lastname: Sanjeewa
authors.forename: Sarath
authors.initials: S
authors.lastname: Kollure