title: Effect of denosumab on recurrent giant cell reparative granuloma of the lumbar spine.
abstract: METHODS
  A case of recurrent giant cell reparative granuloma (GCRG) of the lumbar spine successfully treated with denosumab is reported; a fully human monoclonal antibody against the receptor activator of nuclear factor kappa B (RANK) ligand (RANKL).
  
  
  OBJECTIVE
  To report the first case of recurrent GCRG of the lumbar spine treated with denosumab.
  
  
  BACKGROUND
  GCRG is a non-neoplastic osteofibrous lesion usually found in the maxilla and mandible but rarely in the spine. It is clinically distinct from giant cell tumor of bone (GCTB), although common histological characteristics such as the proliferation of spindle-shaped stromal cells and multinucleated giant cells are shared. Denosumab has recently been reported to be effective for unresectable GCTB; however, there is only one report of its effect on GCRG. Moreover, the effect of denosumab on GCRG of the spine is unknown.
  
  
  METHODS
  The clinical course, radiological features, pathology, and treatment outcome of a patient with recurrent GCRG of the lumbar spine treated with denosumab are documented.
  
  
  RESULTS
  Denosumab treatment was used for this patient with unresectable recurrent GCRG of the lumbar spine. Follow-up lumbar radiography showed significant bone formations in the tumor lesion after 3 months of treatment. On follow-up computerized tomography scans of the L2 and L3 vertebral lesions, the replacement of osoteolytic lesions by the formation of cortical-like bone tissue was clearly identified.
  
  
  CONCLUSIONS
  We report the first case of recurrent GCRG of the spine successfully treated with denosumab. Treatment with denosumab induced significant bone formation in the unresectable lumbar lesion with stable clinical improvement during the 12-month follow-up period without apparent complications. Denosumab shows promise as a new alternative treatment option for osteoclastic giant cell-rich tumors, such as GCRG, especially for unresectable lesions of the spine.
  
  
  METHODS
  4.
authors.affiliation: From the Departments of *Orthopaedic Surgery and †Spinal Surgery and Medical Engineering, Mie University Graduate School of Medicine, Mie, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Akeda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kasai
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Sakakibara
authors.forename: Akihiko
authors.initials: A
authors.lastname: Matsumine
authors.forename: Norihiko
authors.initials: N
authors.lastname: Takegami
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamada
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sudo
mesh_terms: D000368:Aged; D001706:Biopsy; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D000069448:Denosumab / Q000627:therapeutic use*; D005260:Female; D006101:Granuloma, Giant Cell / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D012008:Recurrence; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D000069448:Denosumab