title: Clinical case seminar: Fibroblast growth factor 23: a new clinical marker for oncogenic osteomalacia.
abstract: The phosphate-wasting condition, oncogenic osteomalacia, is problematic to diagnose and manage clinically due to difficulty in locating the causative tumor. Fibroblast growth factor 23 (FGF23) has recently been implicated in the pathogenesis of oncogenic osteomalacia. In this case the patient presented with clinical features typical of oncogenic osteomalacia. Removal of an angiolipoma from the thigh did not correct the clinical or biochemical abnormalities. Subsequent identification and removal of a benign giant cell tumor in the pubic ramus, however, did result in normalization of his symptoms and signs. Positive staining for FGF23 protein by immunohistochemistry was demonstrated in the giant cell tumor, but not in the angiolipoma. The serum concentration of FGF23 was elevated in preoperative serum, then normalized after removal of the giant cell tumor. Expression of both FGF23 mRNA and protein was demonstrated in the giant cell tumor tissue, and FGF23 mRNA expression and renal phosphate uptake inhibitory activity were also detected in cultured giant cell tumor cells. This case provides further evidence for the involvement of FGF23 in the pathogenesis of oncogenic osteomalacia and for the utility of serum FGF23 measurement and immunohistochemical detection of FGF23 in the diagnosis and clinical management of this condition.
authors.affiliation: Cancer Genetics, Kolling Institute of Medical Research, University of Sydney and Royal North Shore Hospital, St. Leonards, Sydney 2065, Australia. annen@med.usyd.edu.au
authors.forename: Anne E
authors.initials: AE
authors.lastname: Nelson
authors.forename: Roderick Clifton
authors.initials: RC
authors.lastname: Bligh
authors.forename: Michiko
authors.initials: M
authors.lastname: Mirams
authors.forename: Anthony
authors.initials: A
authors.lastname: Gill
authors.forename: Amy
authors.initials: A
authors.lastname: Au
authors.forename: Adele
authors.initials: A
authors.lastname: Clarkson
authors.forename: Harald
authors.initials: H
authors.lastname: Jüppner
authors.forename: Stephen
authors.initials: S
authors.lastname: Ruff
authors.forename: Paul
authors.initials: P
authors.lastname: Stalley
authors.forename: Richard A
authors.initials: RA
authors.lastname: Scolyer
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Robinson
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Mason
authors.forename: Phillip Clifton
authors.initials: PC
authors.lastname: Bligh
mesh_terms: D015415:Biomarkers; D015153:Blotting, Western; D001859:Bone Neoplasms / Q000150:complications / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D006393:Hemangiopericytoma / Q000150:complications / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D010018:Osteomalacia / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D015415:Biomarkers; C000717427:FGF23 protein, human; D010710:Phosphates; D012333:RNA, Messenger; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23