title: [Tumor-induced osteomalacia caused by a late-revealing phosphaturic mesenchymal tumor].
abstract: BACKGROUND
  Osteomalacia is associated with diffuse pain and multiple fractures and therefore, diagnosis and treatment of this condition are necessary. Clinicians should be aware of an uncommon mechanism of osteomalacia where hypophosphataemia is secondary to renal phosphaturia because of the production by a mesenchymal phosphaturic tumor of FGF-23. This tumor should be localized and removed to cure this tumor-induced osteomalacia.
  
  
  METHODS
  A 70-year-old female patient was admitted to explore diffuse pain caused by multiple fractures secondary to osteomalacia. Despite vitamin D supplementation, she remained profoundly hypophosphoremic with major renal phosphaturia. A tumor-induced mechanism was suspected because of high level of FGF-23. It took more than three years of investigation to spot the causal phosphaturic mesenchymal tumor despite annual repetition of indium-labelled scintigraphy and PET-scan. The resection of the tumor, located between two phalanges of the right foot, cured the patient with sustained normal rate of serum level of phosphorus after two years.
  
  
  CONCLUSIONS
  Tumor-induced osteomalacia is a diagnostic challenge because the localization of the tumor may be a long process. Patients should be monitored clinically and imaging studies repeated until a diagnosis is made and the causal tumor removed.
authors.affiliation: Service de médecine interne et rhumatologie, groupe hospitalier diaconesses Croix-Saint-Simon, 125, rue d'Avron, 75020 Paris, France. Electronic address: thibchazal@gmail.com.
authors.forename: T
authors.initials: T
authors.lastname: Chazal
authors.affiliation: Service de médecine interne et rhumatologie, groupe hospitalier diaconesses Croix-Saint-Simon, 125, rue d'Avron, 75020 Paris, France.
authors.forename: V
authors.initials: V
authors.lastname: Khanine
authors.affiliation: Service de médecine interne et rhumatologie, groupe hospitalier diaconesses Croix-Saint-Simon, 125, rue d'Avron, 75020 Paris, France.
authors.forename: O
authors.initials: O
authors.lastname: Lidove
authors.affiliation: Service de médecine interne et rhumatologie, groupe hospitalier diaconesses Croix-Saint-Simon, 125, rue d'Avron, 75020 Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Godot
authors.affiliation: Service de médecine interne et rhumatologie, groupe hospitalier diaconesses Croix-Saint-Simon, 125, rue d'Avron, 75020 Paris, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Ziza
mesh_terms: D000368:Aged; D057210:Delayed Diagnosis; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005528:Foot; D006801:Humans; D017674:Hypophosphatemia / Q000150:complications; D007015:Hypophosphatemia, Familial / Q000175:diagnosis / Q000209:etiology*; D008637:Mesenchymoma / Q000150:complications* / Q000175:diagnosis; D009372:Neoplasms, Connective Tissue / Q000175:diagnosis / Q000209:etiology*; D010018:Osteomalacia; D010257:Paraneoplastic Syndromes; D012983:Soft Tissue Neoplasms / Q000150:complications* / Q000175:diagnosis
keywords: Diabète phosphaté; FGF-23; Osteomalacia; Ostéomalacie; Renal phosphaturia; Tumeur mésenchymateuse phosphaturique; Tumor-induced osteomalacia