title: Tumor(s) induced osteomalacia--a curious case of double trouble.
abstract: BACKGROUND
  We report a case of tumor-induced osteomalacia with evidence of synchronous multifocal fibroblast growth factor 23 (FGF23) production.
  
  
  OBJECTIVE
  The aim is to present a case of tumor-induced osteomalacia and to highlight the fact that incomplete removal of multifocal FGF23-producing tumors, which are not entirely picked up by functional imaging, could be the cause of treatment failure.
  
  
  METHODS
  The patient was treated in the Department of Endocrinology of a tertiary care center in India.
  
  
  METHODS
  We report the case of a 42-year-old male with tumor-induced osteomalacia.
  
  
  METHODS
  We treated the tumor-induced osteomalacia with staged surgery of the two tumors. The 18F-fluorodeoxyglucose (FDG)-avid lesion (considered the sole culprit lesion after functional imaging) was resected first, followed by the non-FDG-avid lesion. The sequential removal of both tumors resulted in complete cure.
  
  
  RESULTS
  The patient had hypophosphatemia and hyperphosphaturia. C-Terminal FGF23 level was elevated. Positron emission tomography-computed tomography showed two lesions-an FDG-avid lesion in the right leg, and a non-avid lesion in the left thigh. After removal of the FDG-avid lesion, the hypophosphatemia persisted, and the FGF23 level showed only modest reduction. The patient had complete clinical and biochemical resolution only after removal of the second non-FDG-avid tumor.
  
  
  CONCLUSIONS
  We present the case of a tumor-induced osteomalacia whose biochemical parameters did not improve after removal of the FDG-avid tumor initially. The possibility of multifocal FGF23 production was considered, and the second, non-FDG-avid lesion was resected, which resulted in complete cure. Thorough clinical examination and meticulous follow-up with documentation of the biochemical resolution are necessary for management of all patients with this rare disorder.
authors.affiliation: Departments of Endocrinology (J.S., K.B., S.K., A.K.D.), Orthopedics (D.K.P.), Nuclear Medicine (D.H.), and Pathology (B.B.), Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry 605006, India.
authors.forename: Jayaprakash
authors.initials: J
authors.lastname: Sahoo
authors.forename: Karthik
authors.initials: K
authors.lastname: Balachandran
authors.forename: Sadishkumar
authors.initials: S
authors.lastname: Kamalanathan
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Das
authors.forename: Dilip Kumar
authors.initials: DK
authors.lastname: Patro
authors.forename: Dhanapathi
authors.initials: D
authors.lastname: Halanaik
authors.forename: Bhawana
authors.initials: B
authors.lastname: Badhe
mesh_terms: D000328:Adult; D000089703:Fibroblast Growth Factor-23; D006801:Humans; D017674:Hypophosphatemia / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D007015:Hypophosphatemia, Familial / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D007194:India; D008297:Male; D008875:Middle Aged; D009372:Neoplasms, Connective Tissue / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D010018:Osteomalacia; D010257:Paraneoplastic Syndromes