title: A rare anterior sacral osteochondroma presenting as sciatica in an adult: a case report and review of the literature.
abstract: BACKGROUND
  Osteochondroma is the most common primary benign bone tumor and is usually located in the metaphyses of long bones and rarely in the spine or anterior sacrum. To the best of our knowledge, en bloc excision of a solitary osteochondroma of the anterior sacrum in an adult patient has not been previously reported in a peer-reviewed journal.
  
  
  OBJECTIVE
  The purposes of this study were to document the first report of an osteochondroma of the anterior sacrum along with the clinical course and operative management and review the literature on solitary osteochondroma of the sacrum.
  
  
  METHODS
  The study setting is an academic institution. This is a case report and review of the literature.
  
  
  METHODS
  The patient is an adult female.
  
  
  METHODS
  The outcome measure is the visual analog score for pain.
  
  
  METHODS
  A 54-year-old woman presented with 9/10 disabling low back and radicular pain in the left lower extremity. Radiologic studies showed a pedunculated mass occurring from the anterior sacrum thought to be causing nerve root compression. The patient received en bloc excision of the mass through an abdominal retroperitoneal approach. We also conducted a literature review of solitary sacral osteochondroma in peer-reviewed journals.
  
  
  RESULTS
  Histologic studies confirmed the mass to be an osteochondroma without pathologic signs of malignant transformation. The patient complained of dysesthesia in the left leg after surgery, which progressively improved completely over 8 months after the operation. At the 2-year follow-up, there was no evidence of local recurrence and she was pain free. A literature review revealed one previous case of en block resection of a solitary osteochondroma, but it involved the posterior sacrum.
  
  
  CONCLUSIONS
  Solitary osteochondroma can rarely present in the sacrum as low back pain and sciatica. In general, when osteochondroma causes pain in an adult, we should think that some structure is impinged or that it could have initiated a malignant transformation, so en bloc excision should be used to remove the tumor and histologic studies performed to assess for malignant transformation. Battered nerve root syndrome may take up to 8 months to resolve.
authors.affiliation: The Spine Service, Department of Orthopaedic Surgery, University of Pennsylvania Medical School, Philadelphia, PA 19104, USA. kingsleychin@iMISsurgery.com
authors.forename: Kingsley R
authors.initials: KR
authors.lastname: Chin
authors.forename: Jaehon M
authors.initials: JM
authors.lastname: Kim
mesh_terms: D005260:Female; D006801:Humans; D008875:Middle Aged; D015831:Osteochondroma / Q000150:complications / Q000175:diagnosis*; D012447:Sacrum; D012585:Sciatica / Q000209:etiology*; D013125:Spinal Neoplasms