title: Computed tomography-guided resection of osteoid osteoma of the sacrum: a case report.
abstract: BACKGROUND
  Osteoid osteoma is a benign tumor that usually occurs in the long bones of young adults. Its symptoms can be diverse depending on the location of the tumor and especially difficult to diagnose when occurring in an atypical location. Osteoid osteoma arising in the sacrum is extremely rare, and here, we present a case that was treated successfully in a minimally invasive fashion under computed tomography guidance.
  
  
  METHODS
  A 25-year-old Asian man was referred to our institution due to persistent pain in the buttock after 12 months of conservative treatment. Computed tomography and magnetic resonance imaging scans revealed a ring-shaped radiolucency consistent with a nidus of osteoid osteoma in the sacrum. The lesion was subsequently resected under computed tomography guidance and the histological diagnosis was compatible with osteoid osteoma. His postoperative course was uneventful, and at two years after surgery our patient is symptom-free with no evidence of recurrence.
  
  
  CONCLUSIONS
  Computed tomography-guided resection of osteoid osteoma in the spinal column is feasible and accurate if there is adequate margin from vital organs. Although rare, it is important to always bear in mind the possibility of osteoid osteoma occurring in the sacrum when no other apparent lesion is detected.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Fukuda
authors.affiliation: Department of Orthopedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. msusa@z6.keio.jp.
authors.forename: Michiro
authors.initials: M
authors.lastname: Susa
authors.forename: Itsuo
authors.initials: I
authors.lastname: Watanabe
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Nishimoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Horiuchi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Hideo
authors.initials: H
authors.lastname: Morioka
mesh_terms: D000328:Adult; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010017:Osteoma, Osteoid / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D012447:Sacrum / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed