title: Immunohistochemical detection of the receptor activator of nuclear factor Kappa B ligand and c-fos in giant cell granuloma.
abstract: BACKGROUND
  Giant cell granuloma (GCG) is an intraosseous giant cell fibroblastic lesion that predominantly affects the jaw bones in children and adults. Despite its frequent local progression and destructive effect, it is traditionally considered reparative or reactive in nature. The receptor activator of nuclear factor Kappa B ligand (RANKL), a member of the tumor necrosis factor family and the transcription factor c-fos play a major role in osteoclast proliferation and differentiation. In this study, we examined the expression of RANKL and c-fos in lesional tissues from seven patients with GCG.
  
  
  METHODS
  Automated immunohistochemical staining was performed on formalin-fixed paraffin-embedded sections from 7 cases, using antibodies against RANKL, c-fos and p53.
  
  
  RESULTS
  All tissues showed nuclear staining for c-fos and cytoplasmic staining for RANKL. The staining was strong, diffuse and observed in both mononuclear lesional cells and giant cells. No staining was observed with p53.
  
  
  CONCLUSIONS
  Expression of RANKL and c-fos in this lesion, similar to what has been reported in giant cell tumors of bone, suggests a similar pathogenesis and hence a potential response to anti-RANKL inhibitors. A larger study is needed to confirm these findings and define the relationship of this lesion to other giant cell-rich bone lesions.
authors.affiliation: Department of Pathology, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: Atif A
authors.initials: AA
authors.lastname: Ahmed
authors.affiliation: Department of Pathology, School of Dentistry, University of Missouri, Kansas City, Missouri, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Dunlap
keywords: C-fos; giant cell granuloma; receptor activator of nuclear factor Kappa B ligand