title: Tumor-induced osteomalacia with normal systemic fibroblast growth factor-23 level.
abstract: A 38-year-old man presenting with long bone/rib fractures was diagnosed with tumor-induced osteomalacia (TIO) caused by a giant cell tumor in the right foot with normal systemic fibroblast growth factor-23 (FGF23) levels. Multiple imaging modalities done initially and one year later were unable to localize the tumor. New-onset foot pain discovered a right foot mass with resolution of metabolic abnormalities post-surgery. Sampling from both femoral veins showed an elevated FGF23 value on the right side. This case is unique in that the patient had a normal systemic FGF23 level even with severe clinical manifestations of TIO.
authors: Division of Endocrinology , John Stroger Hospital of Cook County , Chicago, IL 60612 , USA ; Rush University Medical Center , Chicago, IL 60612 , USA.
authors: Ambika
authors: A
authors: Amblee
authors: Elkhart Clinic , Elkhart, IN 46514 , USA.
authors: Juanito
authors: J
authors: Uy
authors: Department of Pathology , John Stroger Hospital of Cook County , Chicago, IL 60612 , USA.
authors: Carmencita
authors: C
authors: Senseng
authors: Rush University Medical Center , Chicago, IL 60612 , USA ; Division of Nephrology , John Stroger Hospital of Cook County , Chicago, IL 60612 , USA.
authors: Peter
authors: P
authors: Hart
keywords: FGF23; TIO; hyperphosphaturia; hypophostatemia; osteomalacia