title: Denosumab: a potential new and innovative treatment option for aneurysmal bone cysts.
abstract: BACKGROUND
  Aneurysmal bone cysts (ABCs) are expansive and destructive lesions positive for osteoclast markers, resembling benign giant cell tumors (GCTs). Treatment options include surgical resection, curettage and cavity filling, embolization, injection of fibrosing agents, or radiotherapy. Particularly in children and adolescents with spinal ABCs, these options may be unsatisfactory, and innovative forms of treatment are needed. Denosumab is a human monoclonal antibody that inhibits osteoclast function by blocking the cytokine receptor activator of the nuclear factor-kappa B ligand. Satisfactory results with denosumab in treating GCTs and immunohistochemical similarities suggest that it may also have positive effects on ABCs.
  
  
  RESULTS
  This report is the first description of the therapeutic use of denosumab in two patients with spinal ABCs. Two boys (aged 8 and 11) had recurrent ABCs at C5 after surgery with intralesional tumor resection. Treatment options were discussed by the interdisciplinary tumor board. Arterial embolization was attempted, but failed due to an absence of appropriate afferent arteries. After the families had received extensive information and provided written consent, denosumab therapy was initiated as an individualized treatment, despite the absence as yet of scientific evidence. After the start of denosumab therapy, both patients recovered from pain and neurologic symptoms significantly and are now in a healthy condition with no severe side effects. Magnetic resonance imaging check-ups after 2 or 4 months of denosumab treatment, respectively, showed tumor regression in both patients.
  
  
  CONCLUSIONS
  Longer follow-up and clinical studies are warranted to establish the value of denosumab in the treatment of ABCs.
authors: Department of Orthopedics and Tumor Orthopedics, Münster University Hospital, Albert-Schweitzer-Campus 1, 48149, Münster, Germany. tobias.lange@ukmuenster.de
authors: Tobias
authors: T
authors: Lange
authors: Christoph
authors: C
authors: Stehling
authors: Birgit
authors: B
authors: Fröhlich
authors: Mark
authors: M
authors: Klingenhöfer
authors: Philip
authors: P
authors: Kunkel
authors: Reinhard
authors: R
authors: Schneppenheim
authors: Gabriele
authors: G
authors: Escherich
authors: Georg
authors: G
authors: Gosheger
authors: Jendrik
authors: J
authors: Hardes
authors: Heribert
authors: H
authors: Jürgens
authors: Tobias L
authors: TL
authors: Schulte
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D017824:Bone Cysts, Aneurysmal / Q000188:drug therapy* / Q000473:pathology; D002648:Child; D000069448:Denosumab; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013122:Spinal Diseases / Q000188:drug therapy* / Q000473:pathology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000069448:Denosumab