title: H3F3A mutation in giant cell tumour of the bone is detected by immunohistochemistry using a monoclonal antibody against the G34W mutated site of the histone H3.3 variant.
abstract: OBJECTIVE
  Giant cell tumour of the bone (GCTB) is a neoplasm predominantly of long bones characterized by the H3F3A mutation G34W. Conventional diagnosis is challenged by the tumour's giant cell-rich morphology, which overlaps with other giant cell-containing lesions of the bone. Recently, a monoclonal antibody specific for the H3F3A mutation has been generated. Our aim was to test this antibody on a cohort of giant cell-containing lesions.
  
  
  RESULTS
  We used the antibody for analysis of 22 H3F3A-mutated GCTB, including two patients with recurrences; for comparison we analysed a cohort of 36 H3F3A wild-type giant cell-rich lesions of the bone and soft tissue, containing one brown tumour, six aneurysmal bone cysts (ABC), six chondroblastomas, five non-ossifying-fibromas, two fibrous dysplasias, nine tenosynovial giant cell tumours, one giant cell-rich sarcoma and six osteosarcomas. Furthermore, among the 22 mutated cases, we included one GCTB with two recurrences and lung metastases; the patient was treated with the anti-receptor activator of nuclear factor κB (RANK) ligand denosumab. We show that all 22 H3F3A-mutated GCTB display strong nuclear H3.3 G34W staining in the neoplastic component, while the osteoclastic giant cells are negative. 36 H3F3A wild-type lesions are negative. The GCTB treated with denosumab revealed a reduction in the H3.3 G34W-positive tumour cells and a decrease in osteoclastic giant cells accompanied by matrix and osteoid formation.
  
  
  CONCLUSIONS
  We conclude that positive H3.3 G34W staining is a specific and sensitive method for detection of H3F3A-mutated GCTB. Denosumab treatment leads to a pathomorphosis of the lesion characterized by matrix and osteoid producing H3.3 G34W-negative stromal cells.
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Julian
authors.identifier: http://orcid.org/0000-0002-9263-6350
authors.initials: J
authors.lastname: Lüke
authors.affiliation: Department of Surgery, Ulm University, Ulm, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: von Baer
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Jordan
authors.initials: J
authors.lastname: Schreiber
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Lübbehüsen
authors.affiliation: Department of Radiology, Ulm University, Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Breining
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Kevin
authors.initials: K
authors.lastname: Mellert
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Marienfeld
authors.affiliation: Department of Surgery, Ulm University, Ulm, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schultheiss
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Möller
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Thomas F E
authors.initials: TFE
authors.lastname: Barth
mesh_terms: D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000235:genetics; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D018212:Giant Cell Tumor of Bone / Q000175:diagnosis* / Q000235:genetics; D006657:Histones / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008297:Male; D009154:Mutation; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; C000609950:H3-3A protein, human; D006657:Histones
keywords: G34W; H3F3A mutation; giant cell tumour of bone